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

Abstract

CdS heterostructure nanomaterials are attractive for their potential applications in integrated optoelectronic 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 10⁵, a large photoresponsivity of 2.5 × 10³ A W⁻¹, a fast response time of 10 ms and an excellent external quantum efficiency of 8.6 × 10⁵ 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.