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Bandgap optimization of submicron‐thick Cu(In,Ga)Se 2 solar cells
Author(s) -
Yang Shihang,
Zhu Jiakuan,
Zhang Xieqiu,
Ma Xuhang,
Luo Hailin,
Yin Ling,
Xiao Xudong
Publication year - 2015
Publication title -
progress in photovoltaics: research and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.286
H-Index - 131
eISSN - 1099-159X
pISSN - 1062-7995
DOI - 10.1002/pip.2543
Subject(s) - copper indium gallium selenide solar cells , materials science , optoelectronics , absorption (acoustics) , fabrication , solar cell , band gap , wavelength , open circuit voltage , energy conversion efficiency , voltage , composite material , electrical engineering , medicine , alternative medicine , pathology , engineering
Reducing Cu(In,Ga)Se 2 (CIGS) absorber thickness into submicron regime provides an opportunity for reducing CIGS solar cell manufacturing time and cost. However, CIGS with submicron‐thick absorber would suffer strong absorption loss in the long‐wavelength region. In this paper, we report a new fabrication route for CIGS solar cells on soda‐lime glass substrates with different Ga content (0.3 < [Ga]/([Ga] + [In]) < 0.6), all with absorber thicknesses around 0.9 µm. Efficiency of 17.52% has been achieved for cells with high Ga content of [Ga]/([Ga] + [In]) = 41%, which is currently the best reported efficiency for submicron‐thick CIGS solar cells. Unlike the normal‐thickness absorber (2–3 µm) that has an optimal [Ga]/([Ga] + [In]) of ~32%, the increased value of optimal [Ga]/([Ga] + [In]) in submicron‐thick absorber greatly enhances the open‐circuit voltage, by nearly 15% compared with that of samples with Ga content optimized at normal absorber thickness. This large gain in V OC well compensates the absorption loss in the long‐wavelength region and contributes to the enhancement of final solar cell efficiency. Copyright © 2014 John Wiley & Sons, Ltd.