Toyota Central R&D Laboratories, Incorporated, Nagakute, Aichi 480-1192, Japan.
J Phys Condens Matter. 2011 Oct 12;23(40):404203. doi: 10.1088/0953-8984/23/40/404203. Epub 2011 Sep 19.
First-principles calculations of the band offsets between Cu(2)ZnSnS(4) (CZTS) and XS (X = Cd, Zn) are performed. While the interface dipole contribution for the band offsets is calculated using the Perdew-Burke-Ernzerhof functional, the Heyd-Scuseria-Ernzerhof hybrid functional is employed to introduce the quasiparticle corrections to the band offsets. The calculated conduction band offset between CZTS and CdS is 0.2 eV, validating CdS for the buffer layer of the CZTS solar cell. The small conduction band offset stems from the band gap narrowing of CdS under the interface strain caused by the lattice misfit with CZTS. A large valence band offset over 0.9 eV between CZTS and ZnS indicates that precipitated ZnS is regarded as an inactive insulator phase in CZTS absorbers.
采用第一性原理计算了 Cu(2)ZnSnS(4)（CZTS）与 XS（X = Cd、Zn）之间的能带偏移。在使用 Perdew-Burke-Ernzerhof 泛函计算界面偶极子对能带偏移的贡献时，采用 Heyd-Scuseria-Ernzerhof 杂化泛函引入对能带偏移的准粒子修正。计算得到 CZTS 和 CdS 之间的导带偏移为 0.2 eV，表明 CdS 适合作为 CZTS 太阳能电池的缓冲层。较小的导带偏移源于界面应变导致的晶格失配引起的 CdS 能带隙变窄。CZTS 和 ZnS 之间超过 0.9 eV 的大价带偏移表明，沉淀的 ZnS 被认为是 CZTS 吸收体中的非活性绝缘相。
