An ab-initio investigation of novel double halide perovskite Cs2InCoX6(X=F, Cl, Br) materials with direct band structure and broadband light absorption

Abstract

In this paper, the electronic, mechanical and optical properties of Cs 2 InCoX 6 (X = F, Cl, Br) have been studied by first-principle calculation method. The results show that both Cs 2 InCoCl 6 and Cs 2 InCoBr 6 are brittle while Cs 2 InCoF 6 tends to be ductile. Cs 2 InCoF 6 , Cs 2 InCoCl 6 and Cs 2 InCoBr 6 are direct bandgap semiconductors with bandgap values of 3.002eV, 1.129eV and 0.865eV, respectively. Compared with other commonly used perovskite materials, Cs 2 InCoX 6 (X = F, Cl, Br) material has lower effective mass, which is beneficial to improve carrier transport and photoelectric device performance. In addition, Cs 2 InCoF 6 is more suitable as photodetector and photocatalyst, and the absorption curves of Cs 2 InCoCl 6 and Cs 2 InCoBr 6 are well matched with the spectral irradiance of AM1.5. Because Cs 2 InCoCl 6 has a more suitable band gap, it is a potential candidate for absorbing layer materials in solar cells. (a) Cs 2 InCoX 6 (X = F, Cl and Br) is a stable vacancy ordered double halide perovskite direct band gap semiconductor material.(b) The absorption curves of Cs 2 InCoCl 6 and Cs 2 InCoBr 6 match well with the spectral irradiance of AM1.5. • The Cs 2 InCoX 6 (X = F, Cl, Br) are stable direct bandgap semiconductors with bandgap values of 3.002eV, 1.129eV and 0.865eV, respectively. • The absorption curves of Cs 2 InCoCl 6 and Cs 2 InCoBr 6 have good match with AM1.5 spectral irradiance. • Cs 2 InCoCl 6 is a good candidate material for solar cell absorption layer.