First-principles study of the crystal structure, electronic and optical properties of Cu2O1-xMx (M = S, Se, Te)

Abstract

Cu2O has the advantages of low price, stable chemical properties, and high visible light absorption rate. It is a very promising hole transport material in solar cells. However, the pure phase Cu2O has a low hole transport rate, which can be improved it by means of doping or something else. In this paper, based on the first-principles, the performance of different amounts of S, Se, and Te doped Cu2O are calculated, it is found that the Te-doped Cu2O performance is pronounced, with the energy gap reduction (1.871 eV), there appear free electron generating, the valence band maximum enables energy level is matched (−5.463 eV), and the absorption coefficient in the ultraviolet and visible range improved, nearly 103.07% at 3.26 eV, the reflectance increased to, for the point 11.7 eV, 76%, and the loss function value is very small in the visible light region (less than 0.1).