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Introducción al modelado y simulación del electrodo transparente con CNTs
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Nanotecnología para 
Energías en Latinoamérica 
 
 
 
 
 
 
editado por 
Eva M. Barea 
Universitat Jaume I, España 
 
 
 
 
 
 
 
 
 
SEFIN 
Society for Nanomolecular Photovoltaics 
Castelló 
 
 
Please use the following format to cite material from this book: 
Author, “Title of Abstract”, in Nanotecnología para Energías en Latinoamérica, edited by E. 
Barea (SEFIN, Castelló, 2012), page numbers. 
 
 
ISBN: 978-84-940189-9-2 
 
Published by: 
 
Society for Nanomolecular Photovoltaics (SEFIN) 
Avda. Sos Baynat s/n 
Universitat Jaume I 
12071 Castelló (Spain) 
http://www.nanoge.org 
 
Copyright ©2012, Society for Nanomolecular Photovoltaics (SEFIN) 
 
The papers published in this volume reflect the work and thoughts of the authors and are 
published here in as submitted. The publisher is not responsible for the validity of the 
information. 
All the information contained on this book is subject to copyright. No part of this 
publication may be reproduced, distributed, transmitted or transformed, in any form or by any 
means, electronic or mechanical, photocopying or recording without the written permission of 
the publisher. This book has been published with the consent of each author, also being 
protected by intellectual property rights belonging to them. 
The Authors may reuse figures, tables, artwork, illustrations, text, and data from the 
published paper, in subsequent scholarly publications of which they are an Author, for 
teaching or training purposes, in presentations at conferences and seminars, and for posting 
on the Author’s personal website, university networks, or primary employer’s institutional 
websites. Abstracting and non-profit use of this material is permitted with a credit to a source. 
 
 
 
http://www.nanoge.org/
Nanotecnología para Energías en Latinoamérica 
978-84-940189-9-2 © SEFIN 2012 
 
 
Soporte 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Nanotecnología para Energías en Latinoamérica 
978-84-940189-9-2 © SEFIN 2012 
 
Contenido 
 
Presentación 7 
Introducción 8 
 
Capítulo 1: Visión general de la nanotecnología 
 
1.1. Juan Bisquert* 
Materiales para producción y almacenamiento de energía limpia. 
10 
1.2. Edgar González,* Victor Puntes 
New nanomaterials for clean energy production. 
12 
1.3. Eddy Herrera,* Edgar González 
Latin America in the energy challenge: renewable energy, emerging energy, 
emerging technologies and sustainability. 
13 
 
 
Capítulo 2: Fotovoltaica. Células solares 
 
2.1. Eva M. Barea,* Luis Otero, Juan Bisquert 
Present and future for dye sensitized solar cell. 
15 
2.2. Elena Vigil,* Sixto Giménez, Francisco Fabregat-Santiago, Pau Rodenas, Roberto 
Trevisan, Bernardo González, Deni Fernández 
Nanostructured CuxO-TiO2 three dimensional interface fabricated on mesoporous 
TiO2. 
17 
2.3. Luis Otero,* Miguel Gervaldo, Javier Durantini, Marisa Santo, Lorena Macor, 
Gabriela Marzari, Luciana Fernandez, Edgardo Durantini, Daniel Heredia, Fernando 
Fungo, Ken-Tsung Wong, Eva Barea, Juan Bisquert, Thomas Dittrich 
Development of supramolecular dyes with application in optoelectronics. 
19 
2.4. Marina Rincón,* Mauricio Solis, Julio Cesar Calva, German Alvarado 
Materiales unidimensionales de baja toxicidad para aplicaciones fotovoltaicas. 
21 
2.5. Helena Pardo* 
Synthesis, characterization and simulation of TiO2 and related nanostructures for 
dye sensitized solar cells. 
23 
2.6. Edward Steven Oliveros,* Mario Andres Chavarria, Faruk Fonthal Rico 
Electrical characterization and temperature-dependent of porous silicon/p-Si 
heterojunction. 
25 
2.7. Caio Bonilha,* João Benedetti, Ana Nogueira, Agnaldo Gonçalves 
Transparent conducting oxide-free dye-sensitized solar cells based solely on flexible 
foils. 
27 
2.8. Lorena Macor,* Javier Durantini, Miguel Gervaldo, Luis Otero, Eva Barea, Juan 
Bisquert 
Algunos desarrollo en Latinoamerica sobre celdas solares de sensibilización 
espectral.
 
30 
2.9. Jairo Plaza Castillo,* Alfonso Torres Jácome 
Activación rápida de obleas de Si <100> tipo n con películas SOD de boro. 
33 
2.10. Caterin Salas Redondo,* Jose Luis Villa Ramirez 
Estado del arte del modelado y simulación del electrodo transparente con CNTs en 
celdas solares orgánicas. 
37 
2.11. Jesús Baldenebro-López, Daniel Glossman Mitnik* 
Computational molecular nanoscience study of the properties of copper complexes 
for dye-sensitized solar cells. 
42 
 
Nanotecnología para Energías en Latinoamérica 
978-84-940189-9-2 © SEFIN 2012 
 
2.12. Caterin Salas Redondo,* Jose Luis Villa RamirezIntroducción al modelado y simulación del electrodo transparente con CNTs en 
celdas solares orgánicas. 
44 
2.13. Faruk Fonthal Rico,* Clara Eugenia Goyes, Marialena De los Rios, Liliana Tirado, 
Gerardo Fonthal 
Electrical and optical characterization of photosensitive porous silicon devices. 
47 
 
 
Capítulo 3: Aspectos de Nanoenergía 
 
3.1. Rubén J. Camargo, H. Lizcano-Valbuena, Diego F. Triviño-Bolaños* 
Construcción y evaluación de un módulo de tres miniceldas pasivas de etanol directo. 
50 
 
3.2. Helmer Acevedo Gamboa* 
The use of Enviroxtm (a nanotechnology additive) in a single cylinder engine fueled 
with diesel fuel of 500 ppm of sulphur and 7% of palm oil biodiesel at high altitudes 
(2650 MASL). 
52 
3.3. Susana Silva,* Johann F. Osma 
Impermeabilización de cuero y fibras textiles con nanocompuestos para la reducción 
de gastos energéticos. 
59 
 
3.4. Alberto Albis,* Ever Ortiz, Ismael Piñeres, Andrés Suárez
 
Estudio de termogravimetría acoplada a espectroscopía de masas de la 
descomposición térmica de la cáscara de Copoazú (Theobroma grandiflorum). 
61 
 
 
Capítulo 4: Conductores Iónicos 
4.1. Rubén A. Vargas,* Jesús Evelio Diosa, Diego Peña-Lara, Manuel N. Chacón, 
Esperanza Torijano 
Development of nanocomposite electrolytes for advanced energy conversion and 
storage devices. 
65 
4.2. Marisa A. Frechero, Mirko Rocci, Rainer Schmidt, Mario R. Diaz-Guillen, Oscar J. 
Dura, Alberto Rivera-Calzada, Jacobo Santamaria, Carlos León* 
Efectos de interfase sobre la conductividad iónica en materiales de aplicación en 
pilas de combustible. 
67 
4.3. Alexander Cortes* 
Efecto de la orientación cristalina del SrTiO3 sobre las propiedades dielectricas. 
70 
4.4. Julián Andrés Ángel Jiménez* 
Implemetacion de un clorimetro AC de alta resolución a bajas temperaturas. 
72 
4.5. Julián Andrés Ángel Jiménez,* Maria Elena Fernández López, Ruben Antonio Vargas 
Estudio del calor especifico en la membrana polimerica basada en PVA+ 
H3PO2/NAFION® entre 4 y 360 K. 
74 
4.6. Maria Elena Fernández López,* Julian Eduardo Castillo, Felipe Bedoya, Jesus Evelio 
Diosa, Rubén Antonio Vargas 
Mechanical and DC-ionic conductivity properties of a reinforced PEM based on 
PVAL+H3PO2/ZRO2. 
76 
4.7. Felipe Bedoya, Rubén Antonio Vargas, Maria Elena Fernández López* 
Thermomechanical characterization of polymeric ionic conductor membranes based 
on PVOH-H3PO2-ZrO2. 
79 
4.8. Fabián Jurado,* Juan Romero, Carlos Vargas 
Estabilidad vibracional y conductividad del composito complejo (PVAOH+xTiO2). 
81 
 
 
Nanotecnología para Energías en Latinoamérica 
978-84-940189-9-2 © SEFIN 2012 
 
4.9. Angélica Mazuera,* David Barbosa, Ruben Vargas 
Estudio del comportamiento térmico y eléctrico en nanocompositas poliméricas 
basadas en óxidos de nióbio micrométrico con poli(alcohol de vinilo), con 
composición (1-x)[PVOH + H3PO2+H2O]-x(Nb2O5). 
83 
4.10. David Barbosa,* Angelica Mazuera, Ruben Vargas, Jesus Diosa 
Estudio del comportamiento térmico y eléctrico del sistema (1-x) KHSO4-xKH2PO4. 
85 
4.11. Hernando Correa Gallego,* Jorge David Castaño Yepes, Edgar Arturo Gomez 
Gonzalez, Rubén Antonio Vargas Zapata 
Modelo cuántico de conducción super-iónica para el yoduro de plata (AgI) en sus 
fases α y β. 
87 
4.12. Jorge David Castaño Yepes,* Hernando Correa Gallego, Edgar Arturo Gomez 
Gonzalez 
Quantum model for superionic state of silver iodide (AgI). 
89 
 
 
 
 
 
 
 
 
 
 
 
 
 
Nanotecnología para Energías en Latinoamérica 
978-84-940189-9-2 © SEFIN 2012 
 
Presentación 
 
Este volumen tiene como finalidad plasmar el estado del arte de algunos aspectos de la 
Nanotecnología para energía en Latinoamérica y España. Se realiza dentro de las actividades 
de la Red Cyted, del Programa Iberoamericano de Ciencia y Tecnología para el desarrollo, 
proyecto “Materiales y Dispositivos de Nanoescala para Conversión y Almacenamiento de 
Energía” liderado por el catedrático Juan Bisquert, de la Universitat Jaume I de Castelló, 
España, con el fin de desarrollar investigación básica y aplicada en diversas áreas de 
nanotecnología para las energías limpias. 
El libro incluye contribuciones presentadas en la Conferencia Internacional Nanoenergía, 
que se celebró en Cartagena de Indias (Colombia) los días 10 y 11 de septiembre 2012, con el 
fin de promover y difundir las actividades de investigación sobre los Nanomateriales, 
Nanoenergía y Energías Renovables en Latinoamerica y áreas geográficas relacionadas. El libro 
también incluye otras contribuciones, todas ellas revisadas por el Comité organizador formado 
por 
 
Eva M. Barea (Presidenta) Universitat Jaume I, España 
Juan Bisquert, Universitat Jaume I, España 
Edgar González, Pontificia Universidad Javeriana, Colombia 
Rubén A. Vargas, Universidad del Valle, Colombia 
 
Este volumen sirve por tanto de punto de encuentro para científicos significados de ambas 
partes del océano Atlántico con objeto de presentar sus últimas contribuciones científicas y 
dar una visión del estado del arte de la “Nanoenergía”, en un momento en que este campo 
científico y tecnológico experimenta un extraordinario desarrollo en todo el mundo. 
 
Eva M. Barea 
Editora 
 
 
 
 
 
 
 
 
 
 
 
 
 
Nanotecnología para Energías en Latinoamérica 
978-84-940189-9-2 © SEFIN 2012 
 
Introducción 
 
Los sistemas de producción y distribución de energía en nuestra sociedad están formados 
por una compleja y entrelazada red de actores relacionados con los recursos, fuentes y 
tecnologías, procesos de extracción, minería, transporte, almacenamiento, conversión, 
distribución, comercialización, operación y mantenimiento, etc. Como la mayoría de los 
recursos energéticos no están distribuidos de forma equitativa, el acceso a los servicios 
energéticos se convierte cada vez más en un acuciante problema. 
En los últimos años se toman cada vez más medidas encaminadas a una mayor utilización 
de fuentes energéticas de origen renovable, la potenciación del ahorro energético y la 
diversificación, la mejora de los sistemas de combustión tradicional, la reconsideración de la 
energía nuclear y la búsqueda de nuevos portadores energéticos. Sin embargo, los problemas 
derivados del suministro energético podrían convertirse en factores limitantes del desarrollo, y 
por tanto del bienestar, debido a la posible disminución del acceso a los combustibles 
tradicionales, el encarecimiento de sus precios y al impacto ambiental de los combustibles 
fósiles. 
Cubrir las necesidades de crecimiento energético de los países considerados desarrollados, 
y posibilitar al resto las mismas o parecidas opciones, en algunos casos las mínimas necesarias, 
para conseguir un desarrollo sostenible implica necesariamente la potenciación de la I+D+I. 
El desarrollo de las capacidades potenciales de la región Latinoamericana se lleva a cabo en 
el proyecto “Materiales y Dispositivos de Nanoescala para Conversión y Almacenamiento de 
Energía” dentro de las actividades de la Red Cyted, donde se dan cita un gran número de 
científicos de Latinoamérica y España que con su trabajo y sus conocimientos en energías 
limpias y nanotecnología pretenden contribuir a dar solución a los problemas 
medioambientales y socioeconómicos. Este proyecto en nanotecnología es de gran 
importancia, ya que la nanotecnología es una ciencia multidisciplinaria donde trabajan 
coordinadamente especialistas en materiales con ingenieros mecánicos y electrónicos y 
también con investigadores médicos, biólogos, físicos y químicos. Una ciencia que une toda 
investigación nanoescalar y la necesidad de compartir saberes sobre métodos y técnicas, y 
combinarlos con conocimientos sobre las interacciones atómicas y moleculares para abarcar 
desde las interacciones básicas que forman materiales y nanoestructuras a las aplicaciones 
prácticas. 
Este libro está estructurado en cuatro grandes bloques. En el primer capítulo se da una 
visióngeneral de la nanotecnología, donde se describen particularmente las clases de 
materiales más interesantes para la producción y almacenamiento de energía limpia. Además 
en ese capítulo se da una visión general del estado del arte las energías renovables y las 
tecnologías emergentes en Latinoamérica. A continuación se abarcan los temas energéticos 
más relevantes actualmente, como son la Fotovoltaica con las células solares, comenzando por 
la visión general del tema para después profundizar en los diferentes tipos de dispositivos 
fotovoltaicos que se están estudiando y perfeccionando en la actualidad, como son las células 
solares de colorante, de silicio y células orgánicas. El tercer capítulo trata sobre aspectos de la 
nanotecnología que se aplican a diversos aspectos de la sociedad, como son la producción de 
combustible a partir de luz solar, las pilas de combustible, y estudios fundamentales aplicables 
a la industria textil y a la industria alimentaria. Y para terminar, en el cuarto capítulo, se trata el 
tema del uso de los conductores iónicos y superiónicos en dispositivos como pilas de 
combustible, como candidato a la producción de energía distribuida y de forma no 
contaminante. 
 
Nanotecnología para Energías en Latinoamérica 9 
 
978-84-940189-9-2 © SEFIN 2012 
 
 
 
 
 
 
 
 
 
 
 
 
Capítulo 1 
1. Visión general de la nanotecnología 
 
 
 
Nanotecnología para Energías en Latinoamérica 10 
 
978-84-940189-9-2 © SEFIN 2012 
 
1.1. Materiales para producción y almacenamiento de energía limpia 
Juan Bisquert* 
Universitat Jaume I, Avda Sos Baynat, Castello, 12071, Spain 
 
El desarrollo de nuevos materiales y sistemas de producción y ahorro energético persiguen 
el objetivo de garantizar una transición adecuada a un futuro sostenible y fiable, basado en el 
uso de energías limpias, accesibles localmente y seguras. Muchos de los dispositivos 
emergentes desarrollados para la producción de energía renovable se basan en 
nanoestructuras y combinaciones híbridas de materiales orgánicos y inorgánicos. Estas áreas 
estratégicas de ciencia y tecnología de frontera, requieren un gran esfuerzo de investigación y 
también de la existencia de entornos multidisciplinares adecuados para inspirar y formar 
futuros científicos y líderes para la ciencia de la conversión de energía limpia. La iniciativa de la 
Red Nanoenergía (www.nanoenergia.org ) con el soporte de CYTED persigue fomentar estas 
actividades en el ámbito de Latinoamérica. 
La velocidad media de consumo de energía en el mundo en 2007 fue de 16.2 teravatios 
(TW, un TW es igual a 1012 vatios, o 1012 joules/s). La energía global se doblará a mitad de 
siglo y triplicará en 2100. El rápido aumento de la población humana y el desarrollo económico 
global, crean una fuerte demanda de energía, mientras que las fuentes de combustible fósil de 
las que depende el suministro actual, se agotan. Además del contraste entre la oferta y la 
demanda, el consumo de combustible fósil también crea importantes problemas 
medioambientales como el calentamiento global que produce cambios del clima, polución del 
aire, y destrucción de la biodiversidad. 
Para mantener un desarrollo global sostenible, es necesario explorar con fuerza energías 
renovables con mínimos efectos medioambientales. Las características deseables son que sea 
abundante, barata, medioambientalmente limpia, particularmente, sin producir aumento del 
carbono atmosférico, y ampliamente disponible en la Tierra. Entre las energías renovables 
naturales que incluyen la luz solar, el viento, geotérmica, mareas oceánicas, y biomasa, la 
energía solar es la opción más atractiva. 
La luz solar es la principal fuente de energía libre de carbono para el futuro. El contenido de 
energía de la irradiación diaria excede todas las otras fuentes renovables combinadas, y 
excede miles de veces la energía necesaria para mantener una sociedad tecnológicamente 
avanzada. Actualmente existen dispositivos capaces de convertir la energía solar en 
electricidad. Las células solares han experimentado un enorme desarrollo en la última década, 
motivadas por la reconocida necesidad de expandir las energías renovables. Sin embargo 
existen enormes desafíos. 
Aunque todos los aspectos de la viabilidad de la energía solar han sido suficientemente 
demostrados, el imperativo científico consiste en desarrollar nuevos materiales, reacciones y 
procesos, que permitan que la energía solar sea suficientemente barata para penetrar en los 
mercados de energía globales. Desarrollos que empezaron en la década de los 1990, están 
alcanzando su madurez actualmente. Las células solares de colorante y las células orgánicas 
han centrado enormes esfuerzos de investigación en nanotecnologías para energía limpia. Las 
células solares de titanio nanoestructurado sensibilizado con colorante [1, 2] son células 
fotoelectroquímicas que han demostrado su estabilidad en los últimos años, aunque su 
rendimiento de conversión de luz solar a electricidad se mantiene alrededor del 11%. Las 
células solares orgánicas compuesta por una mezcla de materiales orgánicos con carácter 
dador y aceptador de electrones, han incrementado su rendimiento notablemente en los 
últimos años [3]. Sin embargo, la facilidad de procesado de los materiales orgánicos también 
provoca problemas a la hora de controlar la morfología de los dispositivos y sus interfaces [4]. 
Nanotecnología para Energías en Latinoamérica 11 
 
978-84-940189-9-2 © SEFIN 2012 
 
Para contrarrestar el carácter intermitente de la energía solar y eólica, son necesarios 
sistemas masivos de almacenamiento de energía. Hacen falta pues medios baratos de 
almacenar la energía solar para que esta se convierta en una fuente primaria de suministro. 
Recientemente ha experimentado un gran auge la idea de convertir la luz solar directamente 
en combustible, usando semiconductores que realizan la fotodescomposición del agua para 
formar hidrógeno [5]. El extraordinario desarrollo de los sistemas de almacenamiento en 
baterías de litio propone el escalado de estos sistemas para su uso en transporte y en 
acumuladores caseros. Particularmente la batería de litio-aire presenta una enorme densidad 
teórica de energía, aunque su realización requiere resolver diversos aspectos técnicos [6]. 
 
Referencias 
[1] O' Regan, B.; Grätzel, M. A low-cost high-efficiency solar cell based on dye-sensitized colloidal TiO2 films. 
Nature, 1991, 353,737-740. 
[2] Hagfeldt, A. et al. Dye-Sensitized Solar Cells. Chemical Reviews, 2010, 110, 6595-6663. 
[3] He, F.; Yu, L. How Far Can Polymer Solar Cells Go? In Need of a Synergistic Approach. The Journal of 
Physical Chemistry Letters, 2011, 2, 3102-3113. 
[4] Bisquert, J. Effects of Morphology on the Functionality of Organic Electronic Devices. The Journal of 
Physical Chemistry Letters, 2012, 3, 1515-1516). 
[5] Walter, M.G. et al. Solar Water Splitting Cells. Chemical Reviews, 2010, 110, 6446-6473. 
[6] Jake, C. et al. A Critical Review of Li/Air Batteries. Journal of The Electrochemical Society, 2011, 159, R1-
R30. 
 
 
 
Nanotecnología para Energías en Latinoamérica 12 
 
978-84-940189-9-2 © SEFIN 2012 
 
1.2. New nanomaterials for clean energy production 
Edgar Gonzalez,*,a Victor Puntesb 
a, Instituto Geofísico, Facultad de Ingeniería, Pontificia Universidad Javeriana, Cr 7 No 42-27 P7, Bogota, 110231, CO 
b, Institut Català de Nanotecnologia, Campus UAB, 08193, Bellaterra, SP 
 
Nanoscience and nanotechnology offer an alternative with the relation to the challenge 
imposed in the energy sector by the need to improve efficiency in processes and systems for 
conversion, production and storage of energy. The progress that has been achieved so far in 
the production of new nanostructured materials, as well as cost reduction and ease synthetic 
methods, open a transit route to a substantial improvement in the processes of production of 
cleanenergy (eg proton exchange membrane fuel cells PEMFC). 
The limited stability of catalytic materials used usually in PEMFC has been one of the 
relevant issues to the industrial scale production of this type of electrochemical devices. 
However, the activities on PEMFC research and development has steadily increased due to its 
low operating temperature, good performance, compact size, modular architecture, zero 
emission and response to transients among other attractive characteristics. Platinum is the 
most widely used catalyst in PEMFC, this material is dispersed in particles supported on 
carbon. In operating cycles of the electrode, loss of effective area of platinum occurs, due to 
platinum growth, migration, contamination (e.g. carbon monoxide) and corrosion of the 
carbon support (1). This stability problem threats seriously the durability of the electrodes and 
performance of the cell. Fuel cell systems will have to be cost-competitive with conventional 
energy sources. This requirement is compromised by the cost of platinum, aspect that has 
motivated the research of new supports (e.g. carbon nanotubes) (2), low-platinum (3) and 
platinum-free catalysts (e.g. carbon-iron-cobalt catalyst) (4), although there are still many 
unsolved problems which have not yet allowed the practical use of these novel materials. As is 
well known, composition, size, shape and structure are key factors in determining the physical 
and chemical properties of a material at the nanoscale. With recent advances in the 
management of reaction and diffusion processes at the nanoscale as synthetic tools, a new 
generation of nanomaterials has been achieved with simultaneous control of these four 
factors (5-6). 
The generation of these new materials offers interesting possibilities for solving the 
problems in PEMFC, specifically limiting kinetics of oxygen reduction at the cathode and the 
limited activity and poisoning of the catalyst on the electrodes. In this work, results from new 
methods for catalytic nanomaterials production, with control on the shape (nanotubes, 
nanocages, nanoboxes, etc), size and composition (alloys M1M2, M1@M2, core@shell with 
M1, M2= Pd, Ag, Au etc), are presented. The characterization and phenomenological study of 
some of these catalysts show that is possible to promote a high efficiency and reduction in the 
degradation and poisoning of electrodes in PEMFC. These advances can contribute to 
strengthening the competitive development of fuel cells, an essential step to address the 
energy challenge. 
 
References 
[1] Zhang, J.; Sasaki, K.; Sutter, E.; Adzic,R. Stabilization of Platinum Oxygen-Reduction Electrocatalysts Using 
 Gold Clusters.Science, 2007, 315, 220. 
[2] Zhang, W. et al. Carbon Nanotube Architectures as Catalyst Supports for Proton Exchange Membrane Fuel 
Cells. Energy and Env. Science, 2010, 3, 1286. 
[3] Strasser, P. et al. Lattice-strain control of the activity in dealloyed core-shell fuel cell catalysts. Nature 
Chemistry, 2010, 2, 454. 
[4] Wu, G.; More, K.; Johnston, C.; Zelanay, P. High-performance Electrocatalyst for Oxygen Reduction Derived 
from Polyaniline, Iron, and Cobalt. Science, 2011, 332, 443. 
[5] Parak, W. Complex Colloidal Assembly. Science, 2011, 334, 1359. 
[6] González, E.; Arbiol, J.; Puntes, V. Carving at the Nanoscale: Sequential Galvanic Exchange and Kirkendall 
Growth at Room Temperature. Science, 2011, 334, 1377. 
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1.3. Latin America in the energy challenge: renewable energy, emerging technologies 
and sustainability 
Eddy Herrera,*,a Edgar Gonzálezb 
a, Pontificia Universidad Javeriana. Departamento Matemáticas Facultad Ciencias, Carrera 7 No 42-27 Piso 7 Bogota, 1000, CO 
b, 4Instituto Geofísico, Facultad de Ingeniería.Pontificia Universidad Javeriana and Centro de Ciencia y Tecnología Nanoescalar, 
Carrera 7 No 42-27 Piso 7 Bogota, 1000, CO 
 
According to theInternational Energy Agency, the interest of the different Latin American 
countries, about renewable energy in the last decade, due in great part to the efforts of these, 
to diversify its generation of energy and reduce dependence of expensive fossil fuels. 
The International Energy Agency, estimates that in Latin America renewable energies 
correspond to 29% of total primary energy. Hydropower contributes considered renewable by 
62%, while the biofuels by 36% of total renewable. These measurements, show significant 
potential for Green Energy in the region, which should be evaluated in terms of sustainability 
and use of new technologies, and thus be able to meet the growing requirements on energy 
demand, which would be estimated by above 50% for the next two decades. 
Although inLatin America the availability of autonomous renewable energy resource is 
significant; yet to be effectively solved the problems related to efficiency and cost in energy 
conversion into criteria of sustainability and social impact. Moreover, changes of an exogenous 
energy demand and international programs to combat climate change impose drastic 
restructuring in the dynamics involved with I&D+i, which could meet this challenge 
momentous for the future of the region. Although this, the energy policy agendathat involves 
issues related to safety, efficient use, diversification of sources principally those related with 
renewable energies, the costs associated with these, equity, and social benefit, which has not 
yet reached the maturity necessary to promote a scenario that supports the crisis for the next 
years. 
The difficultiesof a political nature financial, technical and organizational among other 
questions, specifically the limited infrastructure for scientific and technological development, 
are an obstacle, since these restrict better use of wealth in renewable energy resources of 
most countries in the region. 
All of the aboveshows, the importance to assess the role of Latin America from renewable 
energy, in aspects such as research, development and innovation on these emerging 
technologies, achievements, constraints, cooperation projects and projections for the short 
and medium term. 
That's whythis work, presents a description, diagnosis, and analysis of current state in Latin 
America, about renewable energy and the impact of emerging technologies within the context 
of sustainability. This analysis will infer about the potential in Latin America with respect to 
renewable energy and the impact of emerging technologies within the context of sustainability 
for the improvement and implementation of new strategies, for production, conversion, and 
energy storage. 
Finally, this paper analyzes the water resource and its sustainable use in energy production, 
particularly in Colombia, due to the fact countries such as Colombia, represent a significant 
portion of total renewable energy in the region. 
 
References 
[1] Betancour, L. Las Energías Rnovables Marco Jurídico en Colombia. Revista Perpectiva, 2009. 
[2] Cadena, I. et al. Regulación para Incentivar las Energias Alternas y la Generación Distribuidad en Colombia. 
Revista Ingenería, 2008, No 28. 
[3] Meisen, P; Krumpler, S. El potencial de América Latina con Referencia a la Energía Renovable. Global 
Energy Institute, 2009. 
[4] Huacuz, M.; Dr. Jorge Overview of Renewable Energy Sources in Latin America, 2003, 
http://www.iea.org/work/2003/budapest/mexico.pdf. 
 
Nanotecnología para Energías en Latinoamérica 14 
 
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Capítulo 2 
2. Fotovoltaica. Células solares. 
 
 
 
 
Nanotecnología para Energías en Latinoamérica 15 
 
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2.1. Present and future for dye sensitized solar cell 
Eva M. Barea,*,a Luis Oterob, Juan Bisquerta 
a, Photovoltaic and Optoelectronic Devices Group, Universitat Jaume I, Av. Vicent Sos Baynat s/n, Castello, 12071, ES 
b,Departamento de Química, Universidad nacional de Río Cuarto, Agencia postal Nro. 3, X5804BYA Río Cuarto, Córdoba, AR 
 
Nanocrystalline semiconductor-based dye-sensitized solar cells (DSC) have attracted 
significant attention as a low cost alternative to conventional solid-state photovoltaic devices.1 
The most successful dye sensitizers employed so far in these cells are polypyridyl-type 
ruthenium complexes2,3 yielding overall AM 1.5 solar to electric power conversion efficiencies 
(PCE) up to 11.7%4. Further improvements are still necessary and new materials as well as 
novel device fabrications need to be thoroughly explored. Several efforts are focused on 
improving the overall efficiency of DSCs, such as the exploration of new dyes to extend the 
solar irradiation absorption to the infrared and near infrared regions,5-7 materials for 
counterelectrodes to improve charge extraction,8 new redox mediators that can get higher 
open circuit potential9 and new semiconductor materials. Also, composite metal oxides with 
different bandgaps10 have been widely studied, as well as porous structures ordered in a 
perpendicular fashion to the conducting substrate in order to improve the electron collection 
and transport.11,12-14 
Despite great improvements in the process of DSC fabrication there are several points to be 
optimized, like new materials for counterelectrodes,15 new redox media that can get higher 
open circuit potential,16 like the well known redox cobalt and new semiconductors materials, 
different from titania, or mixtures of materials, like for example those involving the use of 
graphene.18,19 
Different kinds of counterelectrodes have been studied for DSCs: platinum, graphite, 
activated carbon, carbon black, single-wall carbon nanotubes, PEDOT, polypyrrole, and 
polyaniline.19 In general, the best performances were obtained for platinized electrodes. But 
PEDOT is especially interesting due to its high stability, electrical conductivity and catalytic 
capability.20 
 
Figure 1. Scheme of a working electrode on DSC based on titania and graphene. 
 
Related with the use of graphene in the working electrode there are several papers using 
nanoribbons, nanotubes, layers and nanoparticles17 that increase the DSC efficiency 
conversion, but the mechanism and the role that nanoparticles of grapheme plays in it, is still 
unknown. 
 
Nanotecnología para Energías en Latinoamérica 16 
 
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It is clear that the use of new material is focuses to improve the performance of the devices 
but at the same time new studies are required to understand the new mechanism involved in 
the operation of the device and find the reasons why is possible to improve the efficiency of 
the dye solar cells. Based on large experience on DSC characterization by Impedance 
Spectroscopy (IS), we provide detailed understanding of the factors determining the cell 
performance and explain why using ordered one-dimensional PEDOT like counterelectrode 
and Graphene-Titania in the working electrode is possible increase the efficiency of the DSC.15, 
21 
 
References 
[1] O´Regan, B.; Grätzel, M. Nature, 1991, 353, 737. 
[2] Kay, A.; Nazeeruddin, M. K.; Rodicio, I.; Humphry - Baker, R.; Muller, E.; Linska, P.; Vlachopoulus, N.; 
Grätzel, M. J. Am. Chem. Soc, 1993, 115, 6382. 
[3] P. Pechy, F. P. R.; Nazeeruddin, M.K.; Kohle, O.; Zakeeruddin, S. M.; Humphry – Baker, R.; Grätzel, M. J. 
Am. Chem. Soc., 1995, 65. 
[4] Yu, Q.; Wang, Y.; Yi, Z.; Zu, N.; Zhang, J.; Zhang, M.; Wang, P. ACS Nano, 4, 6032. 
[5] Kim, S.; Lee, J. K.; Kang, S. O.; Ko, J.; Yum, J. H.; Fantacci, S.; De Angelis, F.; Di Censo, D.; Nazeeruddin, M. 
K.; Grätzel, M. J. Am. Chem. Soc., 2006, 128, 16701. 
[6] Liang, M.; Xu, W.; Cai, F.; Chen, P.; Peng, B.; Chen, J.; Li, Z. The Journal of Physical Chemistry C, 2007, 111, 
4465. 
[7] Marinado, T.; Hagberg, D. P.; Karlsson, K. M.; Nonomura, K.; Qin, P.; Boschloo, G.; Brinck, T.; A., H.; Sun, L. 
J. Org. Chem, 2007, 72, 9550. 
[8] Edvinsson, T.; Hagberg, D. P.; Marinado, T.; Boschloo, G.; Hagfeldt, A.; Sun, L. Chem. Commun, 2006, 21, 
2245. 
[9] Hagberg, D. P.; Yum, J. H.; Lee, H.; De Angelis, F.; Marinado, T.; Karlsson, K. M.; Humphry-Baker, R.; Sun, L.; 
Hagfeldt, A.; Grätzel, M.; Nazeeruddin, M. K. J. Am. Chem. Soc., 2008, 130, 6259. 
[10] Hara, K.; Sato, T.; Katoh, R.; Furube, A.; Yoshihara, T.; Murai, M.; Kurashige, M.; Ito, S.; Shinpo, A.; Suga, S.; 
Arakawa, H. Adv. Funct. Materials, 2005, 15, 246. 
[11] Hara, K.; Sato, T.; Katoh, R.; Furube, A.; Ohga, Y.; Shinpo, A.; Suga, S.; Sayama, K.; Sugihara, H.; Arakawa, H. 
J. Phys. Chem. B, 2003, 107, 597. 
[12] Barea, E.; Ortiz, J.; Payá, F. J.; Fernández-Lázaro, F.; Fabregat Santiago, F.; Sastre-Santos, A.; Bisquert, J. 
Energy Environ. Sci., 2010, 3, 1985. 
[13] Waltera, M. G.; Rudineb, A. B.; Wamser, C. C. J. Porphyrins Phthalocyanines, 2010, 14, 759. 
[14] Martínez-Díaz, M. V.; de la Torrea, G.; Torres, T. Chem. Commun., 2010, 46, 7090. 
[15] Trevisan, R.; Döbbelin, M.; Boix, P. P.; Barea, E. M.; Tena-Zaera, T.; Mora-Seró, I.; Bisquert, J., Adv. Energy 
Mater., 2011, 1, 781–784. 
[16] Mingfei, X.; Difei, Z.; Ning, C.; Jingyuan, L.; Renzhi, L.; Peng, W. Energy & Environmental Science, 2011, DOI: 
10.1039/c1ee02432a. 
[17] Yang, N.; Zhai, J.; Wang, D.; Chen, Y.; Jiang, L., ACS Nano, 2010, 4(2), 887–89. 
[18] Song, J.; Yin, Z.; Yang, Z.; Amaladass, P.; Wu, S.; Ye, J.; Zhao, Y.; Deng, W.-Q.; Zhang, H.; Liu, X.-W. 
Chemistry – A European Journal 17(39), 10832-10837. 
[19] Murakami, T. N.; Grätzel, M. Inorg. Chim. Acta, 2008 , 361 , 572. 
[20] Tian, H.; Yu, Z.; Hagfeldt, A.; Kloo, L.; Sun, L. J. Am. Chem. Soc., 2011, DOI: 10.1021/ja2030933. 
[21] Durantini, J.; Boix, P. P.; Gervaldo, M.; Morales, G. M.; Otero, L.; Bisquert, J.; Barea, E. M. Journal of 
Electroanalytical Chemistry, 2012, 683, 43-46. 
 
 
 
 
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2.2. Nanostructured CuxO-TiO2 three dimensional interface fabricated on 
mesoporous TiO2 
Elena Vigil,*,a Sixto Giménezb, Francisco Fabregat-Santiagob, Pau Rodenasb, Roberto Trevisanb, 
Bernardo Gonzálezc, Deni Fernándezc 
a, Physics Faculty, University of La Habana, Colina Universitaria, La Habana, 10400, Cuba 
b, University Jaume I, Castellon, Valencia, Spain 
c, Inst. of Materials Science and Technology, Zapata casi esq a G, 10400, Cuba 
 
Recent interest in the three dimensional interface CuxO-TiO2, fabricated with either cuprous 
or cupric oxide is reflected in the literature. This is due to promising perspectives of these 
structures for different applications like photovoltaic solar cells, photoelectrochemical cells for 
water photolysis using sun radiation and different types of sensors [1-5]. Besides ease for 
fabrication of these structures, an additional advantage with respect to other reported low-
bandgap-high-bandgap three dimensional heterostructures is that the oxides employed are 
innocuous. 
Regarding cuprous oxide, i.e., the Cu2O-TiO2 interface, relative position of these 
semiconductor bandgaps has been shown to be adequate for the mentioned applications. 
Cu2O absorbs the solar spectrum much better than TiO2 although its energy bandgap value 
Eg=2.2eV determines that the yellow to infrared part of the solar spectrum will not be 
absorbed. The cupric oxide heterostructure (CuO-TiO2) has not been studied sufficiently. 
Disagreements exist in the literature with respect to both, CuO bandgap value and electron 
affinity value which define its conduction and valence band positions relative to vacuum. The 
values reported for CuO bandgap vary between 1.2 and 1.9eV. This makes CuO a better solar 
light absorber than Cu2O but also band positions relative to TiO2 would have to be adequate 
regarding possible applications mentioned before. 
A simple technique is used for the first time to obtain the CuxO-TiO2 three dimensional 
heterostructure.The purpose of this technique is that CuxO completely penetrates 
mesoporous TiO2 and that it either forms very small nanocrystals, quantum dots or practically 
a CuxO monolayer. It is desired that in all three cases CuxO critical dimension is less than 
carriers diffusion length. Besides, inner coverage of pores must be as complete as possible but 
without clogging mesopores; hole transporting medium must penetrate mesopores to allow 
their transport. These conditions are necessary for carriers to reach both, the TiO2 and the 
counter-electrode rather than recombining in CuxO before. The purpose of this simple 
technique is to eliminate the difficulties inherent to other techniques which cover mostly the 
external surface with poor penetration of deeper underlying porous material. 
To oxidize Cu species, impregnated samples were heat treated in air at 500°C, which is the 
highest temperature allowed for the glass substrate. According to the highest number of Cu 
species that could be adsorbed on TiO2 for the given experimental parameters, the process 
was repeated for some samples in order to increase concentration of adsorbed Cu species. 
The effectiveness of increasing adsorbed Cu species with process repetition was studied 
using optical transmittance (see Fig. 1a). The spectral absorption analysis from these 
experiments shows the presence of CuO and Cu2O. Heat treatment time and temperature 
were not enough to fully oxidize the copper oxide. CuO and Cu2O bandgaps were obtained. 
Scanning electron microscopy (SEM) analysis, as well as, optical microscopy show high 
reduction of surface crystallization with respect to other techniques previously used (6). This 
implies that optical absorption is due to CuO and Cu2O inside the pores. Sample surface is 
practically free of CuxO crystals except that in some points, very distant from each other, one 
can observe the appearance of ribbon shaped crystals which grow from a common origin 
forming a flower-like structure (see Fig. 1b). Ribbons (flower petals) can be longer that 50 µm. 
Petals widths are much smaller but also in the micrometer range. Only ribbons thickness is 
nanometric. The appearance of these crystals is discussed. 
 
Nanotecnología para Energías en Latinoamérica 18 
 
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Figure 1 a) Optical transmittance spectra corresponding to CuxO-TiO2 samples with different number of processes of immersion 
and heat treatment: 1, 3, and 5 repetitions. TiO2 transmittance spectrum is also shown as reference. b) Ribbon-like crystals which 
form a flower-like structure. The white line in the lower right corner is 30 µm long. 
 
The CuxO-TiO2 interface is also studied using X-ray diffraction. XRD spectra show the 
presence of Cu2O and CuO in agreement with results from optical absorption spectra. 
CuxO-TiO2 samples on SnO2:F conducting glass were used as photoelectrodes in a 
photoelectrochemical cell. Cyclic voltametry was used to study light response of the 
photoelectrodes using different aqueous electrolytes. Photocurrent obtained for the visible 
part of the spectrum shows that photons are absorbed in the copper oxide. Possible carrier-
loss mechanisms in the studied interface are discussed and recommendations to improve 
photocurrent are proposed. 
 
References 
[1] Tripathi, M.; Pandey, K.; Kumar, S.D. Sol. Energy Mater. Sol. Cells, 2007, 91, 1663. 
[2] Bandara, J.; Udawatta, C.P.K.; Rajapakse, C.S.K. Photochem. Photobiol. Sci., 2005, 4, 857. 
[3] Jin, Z.; Zhang, X.; Li, Y.; Li, S.; Lu, G. Catal. Commun., 2007, 8, 1267. 
[4] Senevirathna, M.K.I.; Pitigala, P.K.D.D.P.; Tennakone, K. J. Photochem. Photobiol. A: Chemistry, 2005, 171, 
257–259. 
[5] Shankar, K.; Basham, J. I.; Allam, N. K.; Varghese, O. K.; Mor, G. K.; Feng, X.; Paulose, M.; Seabold, J. A.; 
Choi, K.-S.; Grimes, C. A. J. Phys. Chem. C, 2009, 113, 6327–6359. 
[6] Vigil, E.; Gonzalez, B.; Zumeta, I.; Domingo, C.; Domenech, X.; Ayllon, J. A. Thin Solid Films, 2005, 489, 50-
55. 
 
 
 
 
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2.3. Development of supramolecular dyes with application in optoelectronics 
Luis Otero,*,a Miguel Gervaldoa, Javier Durantinia, Marisa Santoa, Lorena Macora, Gabriela 
Marzaria, Luciana Fernandeza, Edgardo Durantinia, Daniel Herediaa, Fernando Fungoa, Ken-
Tsung Wongd, Eva Bareab, Juan Bisquertb, Thomas Dittrichc 
a, Universidad Nacional de Río Cuarto, Guatemala 570, Río Cuarto, 5800, Argentina 
b, Departament de Fisica Universitat Jaume I, 12071 Castello, Spain 
c, Helmholtz Center Berlin for Materials and Energy, Institute of Heterogeneous Materials, Hahn-Meitner-Platz 1, D-14109 Berlin, 
Germany 
d, Department of Chemistry, National Taiwan University, Taipei 106, Taiwan 
 
The development of new organic materials with applications in electro-optical devices is 
one of the most active fields of research in the last years. The continuous growing of 
worldwide requirements of environmental friendly energy sources has led to a greater 
increment in the research for new solar energy conversion devices. In this frame, dye-
sensitized solar cells (DSSCs) are one of great research interested systems all around the world. 
A crucial issue in DSSC design is the used dye. Until now, Ru(II) polypyridyl complexes still 
dominated the most successful systems. However, the limited availability and environmental 
issues could limit the extensive applications of Ru-based DSSCs. Furthermore, Ru-based dyes 
are expensive and hard to purify as compared to organic sensitizers. Thus, the search of new 
highly efficient dyes is one of the most active research subjects in DSSCs development. Organic 
dyes exhibit many advantages, such as the huge diversity of molecular structures and the 
possibility of obtaining materials at relatively low cost. Moreover, organic dyes normally 
exhibit high molar extinction coefficients as compared to those of Ru dyes (< 20 000 M-1 cm-1), 
allowing to use thinner nano-structured oxide semiconductor films with comparable light-
harvesting efficiency, a key factor in solid-state DSSC development. (1-3) 
On the other hand, the use of organic polymers in electronic and optoelectronic holds the 
advantages to obtain large area flexible devices, replacing rigid Si and glass substrates. It is 
expected that the use of polymers will introduce a significantly advance in the construction 
and application of devices for energy generation, image display, lighting systems and others. 
The improvement and application of flexible devices are directly associated to the 
development of new suitable materials and deposition processes. At present two major 
approaches are used to deposit optoelectronic organic materials layers: thermal evaporation 
and solution processing. Although thermal evaporation through the use of mask can produce 
well-ordered patterned films, the throughput is slow and involves expensive vacuum systems. 
Also, thermal evaporation demands materials with sublimation capability and excellent 
thermal stability, properties that are not easy to obtain in polymers. Furthermore, low-cost 
solution processes, as spin coating, deep coating and drop coating, usually produce non-
patterned films that cover the entire substrate. A promising technique for conducting polymer 
film production is the electropolymerization of electroactive monomers. The polymer films 
made through this way is an alternative and attractive film formation method to build highly 
efficient optoelectronic devices. The formation and characterization of a series of polymer 
films with optoelectronic properties obtained by electropolymerization will be showed. 
Polymers containing porphyrins, a powerful optical and redox active center, were synthesized 
and analyzed in our laboratory. Likewise, polymers with electron donor-acceptor moieties, 
linked by fluorene centre were developed and applied in electro-optical devices. (4-6)References 
[1] Heredia, D.; Natera, J.; Otero, L.; Fungo, F.; Yen, Gh-L.; Lin, Wong K-T Spirobisfluorene-bridged Donor 
Acceptor Organic Sensitizer for Dye-Sensitized Solar Cells. Organic Letter, 2010, 12, 12-15. 
[2] Macor, L.; Gervaldo, M.; Fungo, F.; Otero, L.; Dittrich, Th.; Lin, Ch-Y.; Chi, L-Ch.; Fang, F-Ch.; Lii, Sh-W.; 
Wong, K-T.; Tsai, Ch-H.; Wu Ch-Ch. Photoinduced charge separation in donor-acceptor spiro compounds 
at metal and metal oxide surfaces. Application in Dye Sensitized Solar Cell. Royal Society of Chemistry 
Advances, 2012, 2, 4869–4878. 
Nanotecnología para Energías en Latinoamérica 20 
 
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[3] Durantini, J.; Boix, P.P.; Gervaldo, M.; Morales, G.M.; Otero, L.; Bisquert, J.; Barea E.M. Photocurrent 
Enhancement in Dye-Sensitized Photovoltaic Devices with Titania-Graphene Nanoparticles. Electroanal. 
Chem. (Submitted 2012). 
[4] Gervaldo, M.; Funes, M.; Durantini, J.; Fernandez, L.; Fungo F.; Otero, L. Electrochemical polymerization of 
palladium (II) and free base 5,10,15,20-tetrakis(4-N,N-diphenylaminophenyl)porphyrins: Its applications as 
electrochromic and photoelectric materials . Electrochem Acta, 2010, 55, 1948-1957. 
[5] Durantini, J.; Otero, L.; Funes, M.; Durantini, E.N.; Fungo, F.; Gervaldo M. Electrochemical oxidation-
induced polymerization of 5,10,15,20-tetrakis[3-(N-ethylcarbazoyl)]porphyrin. Formation and 
characterization of a novel electroactive porphyrin thin film. Electrochimica Acta, 2011, 56, 4126–4134. 
[6] Durantini, J.; Morales, G.M.; Santo, M.; Funes, M.; Durantini, E.N.; Fungo, F.; Dittrich, Th.; Otero, L.; 
Gervaldo, M. Synthesis and characterization of porphyrin electrochromic and photovoltaic 
electropolymers. Organic Electronics, 2012, 13, 604–614. 
 
 
 
 
 
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2.4. Materiales unidimensionales de baja toxicidad para aplicaciones fotovoltaicas 
Marina Rincon,* Mauricio Solis, Julio Cesar Calva, German Alvarado 
CIE-UNAM, Priv. Xochicalco S/N Col. Centro, Temixco, Morelos, 62580, MX 
 
El uso de nanoestructuras unidimensionales (1D) en celdas fotoelectroquímicas se ha 
reportado como una estrategia efectiva para aumentar la eficiencia de los dispositivos [1]. En 
el Centro de Investigación en Energía de la Universidad Nacional Autónoma de México, 
estamos explorando el uso de nanocarbono y materiales unidimensionales en conversión 
fotovoltaica. Ya sea como colectores, capas buffer o como parte de la capa activa, en los 
últimos años hemos avanzado en la fabricación y caracterización de electrodos de CNT/TiO2. 
Algunos ejemplos del trabajo realizado comprenden el estudio del efecto que tiene la 
fracción metálica o semiconductora de nanotubos de carbono unipared (SWCNT) cuando se 
incorporan a semiconductores mesoscópicos como el TiO2. Aunque se ha reportado que 
facilitan la separación y transporte de carga hacía los colectores, aumentando así la eficiencia 
de celdas solares [2-4], en la mayoría de los trabajos publicados, los SWCNT son una mezcla de 
nanotubos semiconductores y metálicos y no hay un claro entendimiento del efecto de cada 
fase ni de los procesos interfaciales determinantes. En el grupo hemos iniciado estudios 
experimentales de electrodos basados en nanotubos semiconductores (s-SWCNT) y metálicos 
(m-SWCNT). Fabricamos fotoánodos transparentes con configuración m o s-SWCNT/TiO2 por 
métodos sencillos, y contrastamos la función de trabajo y las propiedades fotoelectroquímicas 
para explorar su potencial en celdas solares. 
También hemos estudiado el potencial de los arreglos multicapa Acero304/MWCNT-TiO2 en 
almacenamiento y conversión de energía [5]. La fabricación de electrodos mesoporosos de 
MWCNT-TiO2 sensibilizados con sulfuro de bismuto (Bi2S3), con brecha de bandas entre 1.2 y 
1.6 eV [6], pretende estructuras unidimensionales que redunden en un aumento sustancial en 
la fotocorriente por el efecto combinado de mayor área y mejor transporte de portadores. El 
posicionamiento de los niveles energéticos y/o la presencia de estados entre bandas o centros 
de color, son factores importantes que se han comentado de manera cualitativa en el 
desempeño de celdas solares sensibilizadas con semiconductores (CSSS), pero cuyo estudio no 
se ha abordado en forma rigurosa o sistemática. 
 A la fecha hemos comprobando que la incorporación de una película de nanotubos de 
carbono multipared (MWCNT) crecida de manera in-situ sobre el electrodo conductor Acero 
304, en efecto aumenta el área de depósito del TiO2 y del sensibilizador Bi2S3, favoreciendo el 
aumento en la fotocorriente [5]. Más aún, la remoción casi completa de la matriz de MWCNT 
por el tratamiento térmico en aire da como resultado recubrimientos de TiO2 en forma de 
cintas o listones, con evidencia aparente de impurificado con carbono. Mediante estudios con 
el microscopio electroquímico de barrido con sonda Kelvin, determinamos las funciones de 
trabajo (f) de las diferentes capas que conforman el electrodo Acero304/MWCNT-TiO2/Bi2S3. 
Las mediciones se compararon con los niveles de Fermi de electrodos compactos de TiO2/Bi2S3, 
para determinar el efecto que tiene la inclusión de la matriz de MWCNT, así como para calificar 
algunos parámetros de síntesis (grado de recubrimiento e impurificado). 
 Las características geométricas del CNT permiten que fotoánodos de CNT/TiO2 puedan 
considerarse equivalentes y compararse con arreglos de nanotubos de TiO2 obtenidos por 
anodización. La sensibilización de TiO2 (1D) con CdS, CdSe, PbS, CdTe, ha dado buenos 
resultados, pero no ha mejorado significativamente la eficiencia de celdas solares 
sensibilizadas con semiconductores (SSSC), la cual es tan sólo del 2.8%, muy por debajo del 
11% reportado en las celdas solares sensibilizadas con tinte (DSSC) [7]. La sensibilización de las 
estructuras unidimensionales con Bi2S3 tiene la ventaja de que el Bi es menos tóxico que el Cd 
y Pb y mucho más abundante en la corteza terrestre, particularmente en México. 
 
 
 
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Figura 1 TiO2/Bi2S3, tiempo de depósito: A) 0h, B) 1h, C) 3h 
 
Para sensibilizar el área interna de los nanotubos de TiO2 se han utilizado diferentes 
métodos (electroquímico, sublimación, SILAR), siendo la problemática el grado de penetración 
de los precursores en el arreglo [Figura 1]. En el caso particular del depósito por baño químico 
(BQ), y a diferencia del depósito de nanopartículas ya formadas, se tiene que equilibrar el 
tiempo de penetración de los precursores con el tiempo de formación de la película. En 
estudios recientes encontramos las condiciones óptimas del depósito de Bi2S3 sobre el arreglo 
de TiO2 (1-D), variando el tiempo y la temperatura de BQ. Estamos en la etapa de estudiar los 
cuellos de botella de las estructuras fotovoltaicas elaboradas, aplicando los modelos 
pertinentes, pero somos optimistas de la versatilidad de los fotoánodos CNT/TiO2 (1-D) 
obtenidos, los cuales serán utilizados en celdas solares poliméricas y con otros puntos 
cuánticos de baja toxicidad. 
 
Referencias 
[1] Yu, K; Chen, J. Enhancing Solar Cell Efficiencies through 1-D Nanostructures. Nanoscale Res Lett, 2008, 4, 
1-10. 
[2] Kongkanand, A.; Martínez, R.; Kamat, P.V. Single wall carbon nanotube scaffolds for photoelectrochemical 
solar cells. Capture and transport of photogenerated electrons. Nanoletters, 2007, 7, 676-680. 
[3] Jang, S.R.; Vittal, R.; Kim, K.J. Incorporation of functionalized single-wall carbon nanotubes in dye-
sensitized TiO2 solar cells. Langmuir, 2004, 20, 9807-9810. 
[4] Alvarado Tenorio, G.; Rincón, M.E.; Calva Yáñez, J.C.; Solís de la Fuente, M. Photoanodes Based on Carbon 
Nanotubes Deposited by Drop Casting and Filtration Methods: Photoelectrochemical Characterization. ECS 
Trans., 2011, 36, 511-517. 
[5] Calva, J.C.; Rincón, M.E.;Solís, M.; Alvarado, G. Photoelectrochemical characterization of CNT-TiO2 
electrodes sensitized with Bi2S3. ECS Transactions, 2011, 36, 581-589. 
[6] Moreno, H.; Nair, M.T.S.; Nair P.K. Chemically deposited lead sulfide and bismuth sulfide thinfilms and 
Bi2S3/PbS solar cells. Thin Solid Films, 2011, 519, 2287-2295. 
[7] Hodes, G. Comparison of Dye- and Semiconductor-Sensitized Porous Nanocrystalline Liquid Junction Solar 
Cells. J. Phys. Chem, 2008, 112, 17778–17787. 
 
 
 
 
 
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2.5. Synthesis, characterization and simulation of TiO2 and related nanostructures for 
dye sensitized solar cells 
Helena Pardo* 
Centro NanoMat, Polo Tecnológico de Pando, Cátedra de Física, Facultad de Química, UdelaR Cno. Aparicio Saravias s/n Pando 
 
 The dye sensitized solar cell is an emerging alternative for the production of electricity from 
solar energy. It is based on a junction between a n-type wide gap semiconductor and a p-type 
light absorbing material. The selected material for the first one, in most cases, corresponds to 
TiO2 nanoparticles, while the second one consists on an organic or inorganic dye. The open-
circuit voltage generated in the cell corresponds to the difference between the Fermi level of 
the electron in the solid and the redox potential of the electrolyte used in order to regenerate 
the dye molecule. Thus, the electronic structure, and in particular the band gap of the n-type 
nanoparticles, influence the efficiency of the cell [1]. In this work we will describe the 
implications of the morphological and structural properties of different titanates, all of them 
obtained by hydrothermal synthesis [1]. Several variables have been adjusted in this process: 
starting TiO2 crystallographic phases, reaction time, temperature and acid post treatment. 
Adittionally, other kind chemical synthesis were evaluated, such as hydrothermal treatment at 
atmospheric pressure, hydrolysis of glicolated precursors and sonication methods [2], but 
without good results in terms of crystallographic phases and morphological expectations. After 
preparation, all the obtained phases were evaluated in terms of thermal stability, in order to 
study the effect of water absorption, phases transformation and final porosity. The structural 
characterization was performed by x-ray powder diffraction, using Cu K alpha radiation using a 
Rigaku Ultima IV diffractometer operating in Bragg-Brentano geometry. The microstructure 
was study by Scanning Electronic Microcopy (SEM) and Transmission Electronic Microscopy 
(TEM), confirming both that different morphologies, such as nanotubes or nanorods, can be 
obtained by adjusting of the synthesis conditions. See Figure 1. It is noteworthy that in all the 
cases important amounts of bronze titanate TiO2(B) were detected, suggesting a possible 
implications of TiO2(B) based titanates in the growing mechanism of the different obtained 
nanostructures. This fact motivated deeper research around the possibility of having different 
kind of TiO2 nanostructures, based in the presence of TiO2(B). For this reason we included 
structural and electronic properties of bulk polymorph of TiO2 as a first step, and then 
proceeding with the evaluation of electronic structure implication of the related 
nanostructures by simulation of thick slabs. The evaluated bulk structures corresponds to: 
Rutile, Anatase and Monoclinic TiO2(B). We present the band gaps and surface energies, 
including relevant discussion in terms of possible geometrical reconstruction in the surface of 
the simulated nanostructures. As was mentioned before, the TiO2(B) phase is included due to 
experimental results, which agrees with an early report by Chen et al. [2] who obtained at least 
one of such phases performing the hydrothermal synthesis of the nanostructures [2], which 
was verified in this work. Since there is no much work on this kind of nanostructure, we 
present relevant information for DSSC implications. The simulations were performed using the 
Density Functional Theory[3], utilizing the exchange-correlation potential GGA-PBE, using 
SIESTA code[4], VASP[5], WIEN2k [6] and Gaussian 09[7]. SIESTA calculations were used for the 
structural optimization of bulk and slab models. After this surface energy was obatined by 
means of the plane wave code VASP, which adopts a plane-wave basis set. For bulk structures, 
we performed all-electron-full- potential-plane-wave code WIEN2k, in order to apply the 
recent modified-Becke-Johnson exchange potential + LDA-correlation [8], which allows better 
estimation for band gaps, closer to experimental ones. The comparison between these models 
is also based on the corresponding band gaps, and surface energy [9-10]. Finally, Gaussian 09 
calculations were performed in order to obtain the UV/Vis spectra utilizing Time Dependent 
Density Fucnitonal Theory. 
 
 
Nanotecnología para Energías en Latinoamérica 24 
 
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Figure 1 TEM images obtained for TiO2-nanorods and nanotubes. 
 
According to our results, TiO2(B) (00l) surface presents an extremely low surface energy 
value, comparable to anatase (101). This results is extremely important, since it allow us to 
understand the reason of appearance of this phase during the synthesis of the TiO2 based 
nanostructures. 
 
References 
[1] Grätzel, M. Journal of Photochemistry and Photobiology C: Photochemistry Reviews 4, 2003, 145. 
[2] Chen, X. et al, Chem. Rev., 2007, 107, 2891. 
[3] Kohn, W.; Sham, L. J. Phys. Rev., 1965, 140, A1133. 
[4] Soler, J. M.; Artacho, E.; Gale, J. D.; García, A.; Junquera, J.; Ordejón, P.; Sánchez-Portal, D. J. Phys.: 
Condens. Matter, 2002, 14, 2745. 
[5] Kresse, G.; Hafner, J. Ab initio molecular dynamics for liquid metals. Phys. Rev. B,1993, 47:558. 
[6] Blaha, P.; Schwartz, K.; Madsen, G.K.H; Kvasnicka, D.; Luitz, J. WIEN2K, an augmented-plane-wave + local 
orbitals program for calculating crystal properties, Techn. Univ. Wien, Viena, Austria, 2001 
http://www.wien2k.at. 
[7] Frisch, M. J. et al. Gaussian, Inc., Wallingford CT, 2009. 
[8] Tran, F.; Blaha, P. Phys. Rev. Lett., 2009, 102, 226401. 
[9] Prezhdo, O. V. et al, Progress in Surface. Science, 2009, 84, 30. 
[10] Casarin, V. et al, ACS Nano 3, 2009, 317. 
 
 
 
 
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2.6. Electrical characterization and temperature-dependent of porous silicon/p-Si 
heterojunction 
Edward Steven Oliveros,* Mario Andres Chavarria, Faruk Fonthal Rico 
Grupo de Materiales Avanzados para Micro y Nanotecnología, IMAMNT - Universidad Autónoma de Occidente, Calle 25 No. 115 - 
85, Cali, 760030, CO 
 
In this paper we present the DC and AC electrical characterization and temperature 
dependence of Au/porous silicon/p-Si, in order to investigate the conduction mechanisms in 
resistive and diode structures. The Porous Silicon layers were prepared by electrochemical 
etching in p-type silicon <100> substrates, with two resistivities. In the I-V characteristic we 
obtained an ohmic behavior for DC electrical analysis and in the impedance measurements we 
obtained the geometric and depletion capacitance, for the AC electrical analysis. The 
calculated activation energies were ~ 0,25 eV. Electrical equivalent circuits were used to fit the 
experimental frequency response of the magnitude and the phase. 
The DC and AC electrical characterization technique permits to separate the dielectric 
permittivity properties corresponding to the capacitances present in the relaxation region in 
the porous silicon layers (1). The AC impedance analysis is interpreted in terms of the 
admittance or impedance measurement and the equivalent electrical circuits is formed by RC 
networks in parallel, connected in series (2,3). AC impedance analysis is a powerful tool andhas been widely used to analyze the electrical performance of both metal-semiconductor 
junctions and p-n junctions (4). The analysis of the frequency-capacitance-voltage 
characteristics present in an ideal abrupt junction has to be studied to understand the three 
capacitances effects in the heterojunction PS/c-Si as Low-Frequency Dispersion phenomenon 
(LFD), depletion capacitance (Cdep) and geometric capacitance (C0) (5). An important aspect in 
these structures is the electrical contacts analysis on the PS layer and what is the dependence 
behavior when the voltage and temperature is variable. Various authors have been reported 
different mechanism, Schottky junctions symmetric in both voltages (6), the Ohmic conduction 
is dominated by the bulk resistance (7) and the power law SCLC (8). 
 
Figure 1 Temperature dependence in the conductor structure (left); Conductance and Capacitance characteristics fit using the 
CEALab®, in the diode structure at 333 K (right). 
 
Nanotecnología para Energías en Latinoamérica 26 
 
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We obtained the typical electrical characteristic of conductor and diode structures. The use 
of the characterization software CEALab® for fitting the parameter values of electrical and 
mathematical models was successfully developed using MatLab® in order to get the most 
accurate behavior of the simulated models. The electrical model was the shunt combination of 
one RC network related to the porous layer (geometric capacitance), with another shunt RC 
network related to the silicon rod (depletion capacitance) and a series capacitance related to 
the Low-Frequency Dispersion phenomenon (LFD). The calculated average slopes in the log-log 
scale are 1.17, which implies that we can assume a quasi ohmic behavior in the conductor type 
for all samples studied. Finally, the parameters that represent the conduction mechanisms 
were determined. 
 
References 
[1] Axelrod, E. et al Dielectric relaxation and transport in porous silicon. Phys. Rev. B, 2002, 65, 165429-1-7. 
[2] Jonscher, A. K. Dielectric Relaxation in Solids. Chelsea Dielectrics, London, 1983. 
[3] Chavarria, M. A.; Fonthal, F. Electrical characterization and dielectric relaxation in Au/porous silicon 
contacts. Advances in Electroceramic Materials, Ceramic Transactions, 2009, 204, 113-119. 
[4] Sze, S. M. Physics of Semiconductor Devices. Wiley, New York, 1981. 
[5] Fonthal, F.; Chavarria, M. A. Impedance spectra under forward and reverse bias conditions in gold/porous 
silicon/p-Si structures. Phys. Status Solidi C, 2011, 8, 1913-1917. 
[6] Rossi, A. M.; Bohn, H. G. Photodetectors from Porous Silicon. Phys. Status Solidi A, 2005, 202, 1644-1647. 
[7] Theodoropoulou, M. et al Transient and ac electrical transport under forward and reverse bias conditions 
in aluminum/porous silicon/p-cSi structures. J. Appl. Phys., 2004, 96, 7637-7642. 
[8] Matsumoto, T. et al The density of states in silicon nanostructures determined by space-charge-limited 
current measurements. J. Appl. Phys., 1998, 84, 6157-6161. 
 
 
 
 
 
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2.7. Transparent conducting oxide-free dye-sensitized solar cells based solely on 
flexible foils 
Caio Bonilha,*,a João Benedettib, Ana Nogueirab, Agnaldo Gonçalvesa 
a, Tezca P&D de Células Solares Ltda, Rua Lauro Vannucci, 1020 Jardim Santa Cândida, Campinas, 13087548 Tel: 55 19 3756 5433 
Ext. 2400, BR 
b, Institute of Chemistry, University of Campinas – UNICAMP, Campinas, SP, Brazil. Fax: 55 19 3521 3023; Tel: 55 19 3521 3029, BR 
 
Dye-sensitized solar cells (DSCs) have attracted worldwide attention due to their potential 
low production cost, power conversion efficiency higher than 10%1 and ability to work at low 
light intensities. Moreover, they are Cd-free and do not use scarce elements (Ga, Se, Te, In). 
Nowadays, there are various Pt-free catalytic materials for the counter-electrode (CE)2, Ru-
free dyes3 and iodide-free electrolytes4. Since relatively cheap materials are employed in 
small amounts for assembling DSCs, the transparent conducting oxide (TCO) glass substrate 
contribution to the bill of materials becomes relatively high. Earlier calculations estimate the 
substrate could account for 24% or even up to 64%5 of the total materials costs for DSCs. 
Therefore, substrates should be carefully chosen in order to have low-cost DSCs. 
Relatively cheap substrates are available to replace ITO (In2O3:Sn). Among them, metal 
foils are interesting in light of their low cost, high electrical conductivity, and high-temperature 
processing ability, being effective barriers against O2 and water vapor diffusion, and 
presenting flexibility, proper mechanical stability and roll-to-roll (R2R) compatibility. Ultralow-
cost DSCs could be achieved by constructing both PE and CE on cheap metal foils, without any 
TCO glass substrate. Due to the opacity of metal foils, one way to circumvent illumination 
issues can be an architecture that employs a substrate endowed with thousands of through 
holes (via holes or vias), which would somewhat resemble the emitter wrap-through (EWT) 
approach in terms of the number of vias6. The metallization wrap-through (MWT) approach 
employs a smaller number of vias, but this could provide electrolyte mass transport problems 
when employing highly viscous iodide-free electrolytes. Vias allow metallization for bus bars to 
the back of some Si-based solar cells. In this work, vias allow an ionic pathway between 
photoelectrode (PE) and CE through the electrolyte. Even though this configuration resembles 
mesh-based DSCs7, it might provide some advantages, such as better mechanical properties of 
the PE, allowing highly efficient, truly flexible devices. The aim of this work is to improve the 
performance of DSCs based on metal foils for constructing both PE and CE. The influence of 
hole diameter on DSC performance was studied and preliminary optimization is also reported. 
 
Experimental section 
Stainless steel (SS) foils (AISI 301) were used as substrates for both PE and CE. Thousands of 
through holes were laser-drilled into an area of 4.8 cm2. TiO2 slurry was prepared according to 
a procedure reported elsewhere8. TiO2 paste was applied by doctor blading onto perforated 
SS foils and sintered at 450 ºC for 30 min. Electrodes were sensitized in a 0.25 mmol L-
1 ethanolic solution of the complex N719 (cis-bis(isothiocyanate)bis(2,2’-bipyridyl-4,4’-
dicarboxylate)-Ru(II) bis-tetrabutylammonium, Everlight Chemical Ind. Corp.) for ca. 16 h. The 
electrolyte was 0.1 mol L-1 NaI, 0.8 mol L-1 tetrabutylammonium iodide, 0.05 mol L-1 I2 in 
methoxypropionitrile:acetonitrile (50:50 v/v). CE was a platinized, non-perforated SS foil. 
A metal oxide film was spray-coated over the metal foil, which serves as a Pt underlayer, to 
avoid short-circuiting. The CE was then prepared by the polyol method9 by using 
hexachloroplatinic acid. A 60-µm-thick double-faced adhesive was used as spacer between SS 
foils. A Li-ion battery separator was employed between the PE and the CE to avoid short-
circuiting. 
 
Nanotecnología para Energías en Latinoamérica 28 
 
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A polyethylene terephthalate (PET) transparent foil was used as a window layer, which was 
attached to the PE by using a 60-µm-thick double-faced adhesive. In the optimization studies, a 
TiO2 blocking layer (BL) was spray-coated onto the perforated foil. I-V curves of the DSCs were 
measured under AM 1.5 illumination using a solar simulator (Sciencetech Inc. model 550.5 KW, 
class A) and a Keithley electrometer (model 2410-C), at the Centro de Tecnologia da 
Informação (CTI - Campinas, Brazil). 
 
Results and Discussion 
The choice of SS foils as the substrate was based on previous studies, which have shown its 
relatively higher corrosion stability in iodide-based electrolytes comparedto other metal 
foils10. I-V curves of DSCs based on perforated SS foils with hole diameters of 0.10, 0.12, and 
0.15 mm as PE substrate are shown in Fig. 1. When hole diameter increased from 0.1 to 0.15 
mm, the open-circuit voltage (Voc) values were practically the same (ca. 0.62 V), as well as the 
photocurrent, even though the fill factor (FF) was improved significantly, probably due to 
better electrolyte mass transport properties. The performance of DSCs was improved by: 
treating the surface of the perforated SS foil with a gel chemical remover prior to porous 
TiO2 layer deposition, using a TiO2 BL (DSC 0.15A), and optimizing porous TiO2 layer 
deposition and electrolyte injection (DSC 0.15B). 
It can be seen in Fig. 1 that surface treatment of the perforated SS foil with a gel chemical 
remover and a TiO2 BL (DSC 0.15A) provided a ca. two-fold increase in performance. The gel 
chemical remover can strip oxide layers present on the surface of the SS foil, significantly 
improving charge collection at the substrate. The barrier effect of some oxide layers on metal 
foils has already been reported11. Additional performance improvement was observed by 
optimizing porous TiO2 layer deposition and electrolyte injection (DSC 0.15B, Fig. 1). 
 
Figure 1 I-V curves of DSCs based on flexible metal foils for the construction of both electrodes. DSCs were based on 6-µm-thick 
porous TiO2 layers on perforated SS foils with through hole diameters of 0.1 (DSC 0.10), 0.12 (DSC 0.12) or 0.15 mm (DSC 0.15) 
and liquid electrolyte. Measurements were carried out under 100 mW cm-2 (AM1.5) and the geometrical active area was 4.8 cm2. 
I-V curves represent the average behavior for at least 3 devices. DSC 0.15A and DSC 0.15B were the result of preliminary 
optimization of DSC 0.15 devices. 
 
Nanotecnología para Energías en Latinoamérica 29 
 
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In this work, FF is still rather poor (ca. 0.4). Experiments to improve FF include a thinner 
spacer between metal foils, thinner PE substrate foil, better electrolyte composition, use of an 
insulating oxide layer at the back of the perforated foil, more porous membrane separators, 
among others. 
The use of protection layers (SiO2, for example) might also lead to higher performances11. 
Even using relatively thin porous TiO2 layer, photocurrent densities higher than 5 mA cm-
2 could be successfully achieved in this initial study. The use of less expensive via drilling 
techniques compared to laser micromachining (chemical etching, for example) could make 
perforated metal foils very competitive compared to TCO glass. 
 
Conclusions 
In summary, the use of metal foils to assemble both electrodes of DSCs was demonstrated, 
providing lightweight, thin and truly flexible devices. Even though the performance from such 
a DSC configuration has not yet been fully optimized, it was observed that the treatment of the 
perforated SS foil surface provided a significant improvement in photocurrent. Preliminary 
optimization in TiO2 layer deposition and electrolyte injection provided further enhancement 
of performance, even though FF still needs to be improved significantly. 
 
Acknowledgments 
The authors thank FAPESP for financial support (09/53726-3). ASG (10/1682-3) and JEB 
(11/080304-6) thank FAPESP for scholarships. Two authors (CB, ADG) thank the company 
Celgard® for providing Li-ion battery separator samples and CTI for technical support. JEB and 
AFN thank LNNano for technical support. 
 
References 
[1] Chiba, Y.; Islam, A.; Watanabe, Y.; Komiya, R.; Koide, N.; Han, L. Dye-sensitized solar cells with conversion 
efficiency of 11.1%. Jpn. J. Appl. Phys., 2006, 45, L638-L640. 
[2] Sun, H.; Qin, D.; Huang, S.; Guo, X.; Li, D.; Luo, Y.; Meng, Q. Dye-sensitized solar cells with NiS counter 
electrodes electrodeposited by a potential reversal technique. Energy Environ. Sci., 2011, 4, 2630-2637. 
[3] Bessho, T.; Zakeeruddin, S. M.; Yeh, C.-Y.; Diau, E. W.-G.; Grätzel, M. Highly efficient mesoscopic dye-
sensitized solar cells based on donor–acceptor-substituted porphyrins. Angew. Chem. Int. Ed., 2010, 49, 
6646-6649. 
[4] Daeneke, T.; Kwon, T.-H.; Holmes, A. B.; Duffy, N. W.; Bach, U.; Spiccia, L. High-efficiency dye-sensitized 
solar cells with ferrocene-based electrolytes. Nat. Chem., 2011, 3, 211-215. 
[5] Kalowekamo, J.; Baker, E. Estimating the manufacturing cost of purely organic solar cells. Sol. Energy, 
2009, 83, 1224-1231. 
[6] Mingirulli, N.; Stüwe, D.; Specht, J.; Fallisch, A.; Biro, D. Screen-printed emitter-wrap-through solar cell 
with single step side selective emitter with 18.8% efficiency. Prog. Photovolt: Res. Appl., 2010, 19, 366-
374. 
[7] Fan, X.; Wang, F.; Chu, Z.; Chen, L.; Zhang, C.; Zou, D. Conductive mesh based flexible dye-sensitized solar 
cells. Appl. Phys. Lett., 2007, 90, 073501. 
[8] Avellaneda, C. O.; Gonçalves, A. D.; Benedetti, J. E.; Nogueira, A. F. Preparation and characterization of 
core-shell electrodes for application in gel electrolyte-based dye-sensitized solar cells. Electrochim. Acta, 
2010, 55, 1468-1474. 
[9] Sun, K.; Fan, B.; Ouyang, J. Nanostructured platinum films deposited by polyol reduction of a platinum 
precursor and their application as counter electrode of dye-sensitized solar cells. J. Phys. Chem. C, 2010, 
114, 4237-4244. 
[10] Toivola, M.; Ahlskog, F.; Lund, P. Industrial sheet metals for nanocrystalline dye-sensitized solar cell 
structures. Sol. Energy Mater. Sol. Cells, 2006, 90, 2881-2893. 
[11] Kang, M. G.; Park, N.-G.; Ryu, K. S.; Chang, S. H.; Kim, K.-J. A 4.2% efficient flexible dye-sensitized TiO2 
solar cells using stainless steel substrate. Sol. Energy Mater. Sol. Cells, 2006, 90, 574-581. 
 
 
 
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2.8. Algunos desarrollos en Latinoamérica sobre celdas solares de sensibilización 
espectral 
Lorena Macor,*,a Javier Durantinia, Miguel Gervaldoa, Luis Oteroa, Eva Bareab, Juan Bisquertb 
a, Universidad Nacional de Río Cuarto, Guatemala 570, Río Cuarto, 5800, Argentina 
b, Departament de Fisica Universitat Jaume I, Avda. Sos Baynat. Universitat Jaume I. 12071 Castelló, España 
 
El corazón de estas celdas es un fotoánodo, que está basado en una película de un oxido 
semiconductor nanoestructurado cubierto por una monocapa de sensibilizador. Bajo 
excitación por luz, las moléculas de colorante adsorbido inyectan electrones desde su estado 
excitado hacia la banda de conducción del semiconductor. Los electrones vuelven al colorante 
oxidado a través de un circuito externo, un contraelectrodeo de platino y un sistema redox. El 
uso de TiO2 nanoestructurado unido a complejos de rutenio como sensibilizadores introducido 
por Grätzel y col. en el año 1991 [1-3] fue un gran avance en términos de aplicaciones 
comerciales, logrando un 10% de eficiencia de conversión de energía. En América latina, existe 
un amplio número de países que investigan acerca de la producción de energía eléctrica a 
partir de celdas solares. En este sentido puede decirse que Brasil es el país con mayor 
contribución al estudio de esta área, contando con más de 60 publicaciones. Además, Brasil es 
el primer país de América latina que realizó estudios en celdas solares de sensibilización 
espectral. A partir de 1998 y hasta el presente mostrando interesantes avances en todas las 
partes componentes de las celdas, ya sea en fotoánodos, electrolitos y sensibilizadores, así 
como en la performance de las celdas [4-8]. En México por su parte, también ha habido una 
intensa búsqueda de optimización de las DSSC, siendo la simulación computacional 
posiblemente el área que más se ha desarrollado. [9-11] Al igual que en México, en Cuba y en 
Colombia existen extensas investigaciones sobre los fotoelectrodos, solo que en estos últimos 
países el desarrollo de las DSSC ha sido posterior. [12,13] En lo que respecta a Perú, Chile y 
Uruguay, la investigación