SOLAR CELLS – NEW ASPECTS AND SOLUTIONS Edited by Leonid A. Kosyachenko Solar Cells – New Aspects and Solutions Edited by Leonid A. Kosyachenko Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2011 InTech All chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which permits to copy, distribute, transmit, and adapt the work in any medium, so long as the original work is properly cited. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. 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Used under license from Shutterstock.com First published October, 2011 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechweb.org Solar Cells – New Aspects and Solutions, Edited by Leonid A. Kosyachenko p. cm. ISBN 978-953-307-761-1 free online editions of InTech Books and Journals can be found at www.intechopen.com Contents Preface IX Chapter 1 Effects of Optical Interference and Annealing on the Performance of Polymer/Fullerene Bulk Heterojunction Solar Cells 1 Chunfu Zhang, Hailong You, Yue Hao, Zhenhua Lin and Chunxiang Zhu Chapter 2 A New Guide to Thermally Optimized Doped Oxides Monolayer Spray-Grown Solar Cells: The Amlouk-Boubaker Optothermal Expansivity AB 27 M. Benhaliliba, C.E. Benouis, K. Boubaker, M. Amlouk and A. Amlouk Chapter 3 Flexible Photovoltaic Textiles for Smart Applications 43 Mukesh Kumar Singh Chapter 4 Dilute Nitride GaAsN and InGaAsN Layers Grown by Low-Temperature Liquid-Phase Epitaxy 69 Malina Milanova and Petko Vitanov Chapter 5 Organic-Inorganic Hybrid Solar Cells: State of the Art, Challenges and Perspectives 95 Yunfei Zhou, Michael Eck and Michael Krüger Chapter 6 Relation Between Nanomorphology and Performance of Polymer-Based Solar Cells 121 Almantas Pivrikas Chapter 7 One-Step Physical Synthesis of Composite Thin Film 149 Seishi Abe Chapter 8 Cuprous Oxide as an Active Material for Solar Cells 167 Sanja Bugarinović, Mirjana Rajčić-Vujasinović, Zoran Stević and Vesna Grekulović VI Contents Chapter 9 Bioelectrochemical Fixation of Carbon Dioxide with Electric Energy Generated by Solar Cell 187 Doo Hyun Park, Bo Young Jeon and Il Lae Jung Chapter 10 Semiconductor Superlattice-Based Intermediate-Band Solar Cells 211 Michal Mruczkiewicz, Jarosław W. Kłos and Maciej Krawczyk Chapter 11 Solar to Chemical Conversion Using Metal Nanoparticle Modified Low-Cost Silicon Photoelectrode 231 Shinji Yae Chapter 12 Progress in Organic Photovoltaic Fibers Research 255 Ayse Bedeloglu Chapter 13 Ultrafast Electron and Hole Dynamics in CdSe Quantum Dot Sensitized Solar Cells 287 Qing Shen and Taro Toyoda Chapter 14 Transparent Conducting Polymer/Nitride Semiconductor Heterojunction Solar Cells 307 Nobuyuki Matsuki, Yoshitaka Nakano, Yoshihiro Irokawa, Mickael Lozac’h and Masatomo Sumiya Chapter 15 High Efficiency Solar Cells via Tuned Superlattice Structures: Beyond 42.2% 325 AC Varonides Chapter 16 AlSb Compound Semiconductor as Absorber Layer in Thin Film Solar Cells 341 Rabin Dhakal, Yung Huh, David Galipeau and Xingzhong Yan Chapter 17 Photons as Working Body of Solar Engines 357 V.I. Laptev and H. Khlyap Chapter 18 Hybrid Solar Cells Based on Silicon 397 Hossein Movla, Foozieh Sohrabi, Arash Nikniazi, Mohammad Soltanpour and Khadije Khalili Chapter 19 Organic Bulk Heterojunction Solar Cells Based on Poly(p-Phenylene-Vinylene) Derivatives 415 Cigdem Yumusak and Daniel A. M. Egbe Chapter 20 Towards High-Efficiency Organic Solar Cells: Polymers and Devices Development 433 Enwei Zhu, Linyi Bian, Jiefeng Hai, Weihua Tang and Fujun Zhang Contents VII Chapter 21 Conjugated Polymers for Organic Solar Cells 453 Qun Ye and Chunyan Chi Chapter 22 Optical Absorption and Photocurrent Spectra of CdSe Quantum Dots Adsorbed on Nanocrystalline TiO 2 Electrode Together with Photovoltaic Properties 475 Taro Toyoda and Qing Shen Chapter 23 Investigation of Lattice Defects in GaAsN Grown by Chemical Beam Epitaxy Using Deep Level Transient Spectroscopy 489 Boussairi Bouzazi, Hidetoshi Suzuki, Nobuaki Kijima, Yoshio Ohshita and Masafumi Yamaguchi Preface Photovoltaics covers an extremely wide range of different fields of science and technology that are in a state of continuous development and improvement for decades. Solar cells and models that have been developed to the level of industrial production or prototype samples, as well as the devices of exploratory types are divided into the so-called generations of photovoltaics. Chapters, which concern the problems of the first, second and third generations of solar cells are included in the relevant three books of this edition. Chapters that are general in nature or not related specifically to these generations, some novel scientific ideas and technical solutions, which has not properly approved, new methods of research and testing of solar cells and modules have been collected in the fourth book of the four-volume edition of “Solar cells”. General issues of the efficiency of a direct conversion of solar radiation into electrical energy in solar cell and through hydrogen production in photoelectrochemical solar cell are discussed in several chapters of the book. Considerable attention is paid to the quantum-size effects in solar cells both in general and on specific examples of AlGaAs superlattices, CdSe quantum dots, etc. New materials, such as cuprous oxide as an active material for solar cells, AlSb for use as an absorber layer in p-i-n junction solar cells, InGaAsN as a promising material for high efficiency multi-junction tandem solar cells, InP in solar cells with semiconductor- insulator-semiconductor structures are discussed in several chapters. Other chapters are devoted to the analysis of both status and perspective of organic photovoltaics as well as specific issues, such as polymer/fullerene solar cells, poly(p-phenylene- vinylene) derivatives, photovoltaic textiles, photovoltaic fibers, etc. It appears that the fourth book of the edition of "Solar Cells" will find many interested readers. The editor addresses special thanks to the contributors for their initiative and high quality work, and to the technical editors that conveyed the text into a qualitative and pleasant presentation. Professor, Doctor of Sciences, Leonid A. Kosyachenko National University of Chernivtsi Ukraine [...]... confirmed by the peaks located at the BE of 286.2 eV in the C 1s spectrum and 531 eV in the O 1s spectrum as 16 Solar Cells – New Aspects and Solutions shown in Fig 10 It has indicated that the Al-O-C bond is formed by the reaction of Al atoms and the carbonyl groups in PCBM and its existence will improve the contact between the polymer and the metal for both samples However, by using the cathode confinement... device performance is clearly shown in Fig 12 It is shown that a large Rs will induce the decrease of FF and JSC By reducing Rs, FF and JSC are increased and thus the 18 Solar Cells – New Aspects and Solutions device performance is improved At the same time, it is also noted that although both FF and JSC can be affected by Rs, their dependences on Rs are different From Fig 12, it can be seen that FF... thermal treatment, a better optical absorption and a more ideal bicontinuous interpenetrating networks can be obtained at the same time This will effectively reduce the exciton loss and improve the charge transport capability Thus an improved device performance is achieved 22 Solar Cells – New Aspects and Solutions 4 Overall optimization of polymer solar cells Because the active layer is very thin in... thick and 208 nm thick) 24 Solar Cells – New Aspects and Solutions 4.2.2 Optimization of annealing conditions The device performance depends greatly on annealing temperatures as clearly seen from Fig 19 The reasons for the performance to be improved by the annealing process have been widely investigated and discussed in section 3 It is clear that for an efficient bulk HJ polymer solar cell, D and A... Investigation of annealing effects and film thickness dependence of polymer solar cells based on poly(3-hexylthiophene) Journal of Appllied Physics.Vol 98, No 4 (August 2005), pp 43704-1-43704-5 ISSN 0021-8979 26 Solar Cells – New Aspects and Solutions Ling, Q D.; Li, S.; Kang, E T.; Neoh, K G.; Liu, B & Huang, W (2002) Interface formation between the Al electrode and poly[2,7-(9,9-dihexylfluorene)-co-alt-2,5(decylthiophene)]... lifetime is shorter than its transient time, and hole lifetime is 6.2 10 7 s , and electron lifetime is 1 10 6 s Experimental data are from [Li et al., 2005] 12 Solar Cells – New Aspects and Solutions These defects increase the exciton-to-free-carrier probability More important, the transport process becomes the dominant limiting factor for JSC, and the exciton-to-free-carrier process becomes... (b) (c) Fig 2 Energy band diagrams under short circuit condition (a) Case I: thickness is shorter than both drift lengths, (b) Case II: thickness is longer than hole drift length but shorter than electron drift length, c) Case III: thickness is longer than both hole and electron drift lengths 8 Solar Cells – New Aspects and Solutions If L is longer than drift lengths of electrons and holes, that is to... JSC, J0 and Jph: mA/cm2; FF and PCE: %; Rshand Rs: cm2 Table 1 Summary of the Parameters Extracted from the J-V Curves Shown in Fig 9 Effects of Optical Interference and Annealing on the Performance of Polymer/Fullerene Bulk Heterojunction Solar Cells 15 Fig 9 J-V characteristics of the solar cells under the AM 1.5 illumination with the light intensity of 100 mW/cm2 The devices without (circle) and with... decrease of average exciton generation rate 10 Solar Cells – New Aspects and Solutions 2.2.2 JSC and the active layer thickness Based on the calculated exciton generation rate, it is easy to predict JSC when the drift lengths of both carriers are larger than the blend layer thickness If all the generated excitons can be dissociated into free carriers, and then collected by the electrodes, JSC should... material at position z in solar spectrum are calculated by G( z ) 800 300 G( z , )d (3) 4 Solar Cells – New Aspects and Solutions Here the integration is performed from 300 nm to 800 nm, which is because that beyond this range, only very weak light can be absorbed by P3HT: PCBM active layer In inorganic solar cells, Q( z , ) is usually modeled by Q( z , ) I 0 e z (4) I 0 is the incident . SOLAR CELLS – NEW ASPECTS AND SOLUTIONS Edited by Leonid A. Kosyachenko Solar Cells – New Aspects and Solutions Edited by Leonid A thickness is longer than both hole and electron drift lengths. Solar Cells – New Aspects and Solutions 8 If L is longer than drift lengths of electrons and holes, that is to say that the. interference. Solar Cells – New Aspects and Solutions 2 Besides the serious optical interference effect, J SC also suffers from the non-ideal free carrier generation, low mobility and short