Modified Becke-Johnson exchange potential: improved modeling of lead halides for solar cell applications

AIMS Materials Science

卷:3

Radi A. Jishi¹ 

[1] Department of Physics, California State University, Los Angeles, California, U.S.A;

关键词: DFT;    lead halides;    mBJ;    perovskites;    photovoltaics;    solar cells;    spin-orbit;   

DOI  :  10.3934/matersci.2016.1.149

来源: DOAJ

【 摘 要 】

We report first-principles calculations, within density functional theory, on the lead halide compounds PbCl₂, PbBr₂, and CH₃NH₃PbBr_3−xClx, taking into account spin-orbit coupling. We show that, when the modified Becke-Johnson exchange potential is used with a suitable choice of defining parameters, excellent agreement between calculations and experiment is obtained. The computational model is then used to study the effect of replacing the methylammonium cation in CH₃NH₃PbI₃ and CH₃NH₃PbBr₃ with either N₂H₅⁺or N₂H₃⁺, which have slightly smaller ionic radii than methylammonium. We predict that a considerable downshift in the values of the band gaps occurs with this replacement. The resulting compounds would extend optical absorption down to the near-infrared region, creating excellent light harvesters for solar cells.

【 授权许可】

Unknown