Visible-Light Self-Driven Photodetector with Enhanced Performance Based on CdS /Si Nanowire Heterojunction

In this article, the appealing application of the CdS/Si nanowire heterostructure as the self-driven photodetector was presented based on a facile successive ionic layer absorption and reaction. Compared to CdS /Si planar based device, photocurrent illuminated with light (532 nm) to dark-current ratio was enhanced significantly for CdS/Si nanowire based detector. Measurements of time resolved responses at zero bias were conducted, and the result also demonstrated that CdS/Si nanowire heterostructure had a high photosensitivity and fast photo-response as the self-driven visible light photodetector. Additionally, the corresponding mechanism for the phenomenon was discussed, and it is believed that such a high photoresponse comes from the improved optical absorption as well as the good carrier transfer and collection capability. The present CdS/Si core-shell heterojunction architectures are envisaged as potentially valuable candidates for next-generation photodectors.