1. From kesterite to stannite photovoltaics: Stability and band gaps of the Cu2(Zn,Fe)SnS4 alloy.
- Author
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Shibuya, Taizo, Goto, Yosuke, Kamihara, Yoichi, Matoba, Masanori, Yasuoka, Kenji, Burton, Lee A., and Walsh, Aron
- Subjects
KESTERITE ,SEMICONDUCTORS ,THIN films ,SOLAR cells ,SOLID solutions - Abstract
Kesterite semiconductors, particularly Cu
2 ZnSnS4 (CZTS), have attracted attention for thin-film solar cells. We investigate the incorporation of Fe into CZTS to form the Cu2 (Zn,Fe)SnS4 solid-solution for tuning the lattice spacing and band gap. First-principles calculations confirm a phase transition from kesterite (Zn-rich) to stannite (Fe-rich) at Fe/Zn∼0:4. The exothermic enthalpy of mixing is consistent with the high solubility of Fe in the lattice. There is a linear band-gap bowing for each phase, which results in a blue-shift of photo-absorption for Fe-rich alloys due to the confinement of the conduction states. We propose compositions optimal for Si tandem cells. [ABSTRACT FROM AUTHOR]- Published
- 2014
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