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Kesterites—a challenging material for solar cells
Author(s) -
Siebentritt Susanne,
Schorr Susan
Publication year - 2012
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.2156
Subject(s) - kesterite , czts , acceptor , band gap , materials science , crystallography , chemistry , condensed matter physics , optoelectronics , physics
Kesterite materials (Cu 2 ZnSn(S,Se) 4 ) are made from non‐toxic, earth‐abundant and low‐cost raw materials. We summarise here the structural and electronic material data relevant for the solar cells. The equilibrium structure of both Cu 2 ZnSnS 4 and Cu 2 ZnSnSe 4 is the kesterite structure. However, the stannite structure has only a slightly lower binding energy. Because the band gap of the stannite is predicted to be about 100 meV lower than the kesterite band gap, any admixture of stannite will hurt the solar cells. The band gaps of Cu 2 ZnSnS 4 and Cu 2 ZnSnSe 4 are 1.5 and 1.0 eV, respectively. Hardly any experiments on defects are available. Theoretically, the Cu Zn antisite acceptor is predicted as the most probable defect. The existence region of the kesterite phase is smaller compared with that of chalcopyrites. This makes secondary phases a serious challenge in the development of solar cells. Copyright © 2012 John Wiley & Sons, Ltd.