Ab-initio study of the electronic and photocatalytic performances of MoS2-xSex/SiC van der Waals heterostructures with asymmetric Se doping

Abstract

Adjusting the composition and structure can be regarded as the fascinating means to regulate the electronic properties of two dimensional materials. Based on the first principles calculations, we theoretically verify the electronic and photocatalytic performances of MoS2-xSex/SiC with asymmetric Se doping. MoS2-xSex/SiC van der Waals heterostructures (vdWHs) possess the type II band alignment. The built-in electric field from SiC to MoS2-xSex induced by the charge transfer leads to effective separation of photoexcited carriers. MoS2-xSex/SiC vdWHs exhibit undesirable photocatalytic performances with Se away from interface, even if the dopant concentration increases from 0 to 100%. However, the photocatalytic properties are improved significantly if Se close to interface and the dopant concentration is not less than 50%. In conclusion, the Se doping position and concentration play a decisive role in the photocatalytic performances of MoS2-xSex/SiC. These findings expect to provide guidance for the experimental study of MoS2-xSex/SiC vdWHs from the theoretical aspect.