Modulation and Improvement on Separation of Photoinduced Charge Carriers in CdS−Metal Nanoheterostructures

Abstract

We demonstrate the feasibility of modulating and improving the separation of photoinduced charge carriers of CdS-M nanoheterostructures through partial replacement of S with two group 16 elements of larger atomic size, Se and Te. With the incorporation of Se or Te into the CdS nanowires (NWs), the defect states of the CdS NWs were effectively passivated, enabling a fuller extent of participation of the photoinduced electrons in the charge separation process, thus resulting in a more pronounced photoluminescence quenching and photocurrent depression for the CdS1-xSex and CdS1-xTex NWs. The present study provides a facile way of improving the photocatalytic efficiency of CdS through the improvement in retarding the recombination of photoinduced charge carriers.