High-performance ultraviolet photodetectors based on CdS/CdS:SnS2 superlattice nanowires

摘要

CdS heterostructure nanomaterials are attractive for their potential applications in integrated opto-electronic devices. Herein, the high-quality CdS/CdS:SnS2 superlattice nanowires were synthesized through a micro-environmental controlled co-evaporation technique, which shows periodic emission properties and that their structures are periodic and alternating. For the first time, we demonstrate the fabrication of high-performance ultraviolet photodetectors using unique CdS/CdS:SnS2 superlattice nanowires. The optoelectronic properties of the photodetectors were studied and compared to those devices based on pure CdS nanowires. The as-fabricated photodetectors (under 365 nm) based on CdS/CdS:SnS2 superlattice nanowires showed a high photocurrent to dark current ratio of 10(5), a large photoresponsivity of 2.5 x 10(3) A W-1, a fast response time of 10 ms and an excellent external quantum efficiency of 8.6 x 10(5) at room temperature, which shows better performance than pure CdS nanowires photodetectors. The results indicate that CdS/CdS:SnS2 superlattice nanowires are very promising potential candidates in nanoscale electronic and optoelectronic devices.