Construction of branched SnS2/Te heterostructure film for self-powered high-performance photodetector application

Abstract

Effective design and construction of heterostructure can conduce to charges transportation/separation and simultaneously improve light absorption ability of photoelectrochemical (PEC) photoelectrode. In this work, the p-type Te nanorods were directly grown on the surface of ultra-thin SnS2 nanoflakes via a facile and low-cost electrochemical deposition (ED) method. The PEC performance of mixed-dimensional branched SnS2/Te nanoflakes/nanorods (NFRs) heterostructure composites film was optimized by varying the ED time. Under simulated light illumination of 40 mW/cm2, the optimal photocurrent density of the SnS2/Te NFRs photoanode significantly reached up to 0.95 mA/cm2, approximately 5.2 times and 3.5 times larger than those of bare SnS2 and Te film, respectively. The improved performance was attributed to appropriate energy band matching and intensive light absorption property. In particular, it presented good stability and high light on/off ratio of about 4.1 ×106 at the 0 bias voltages, suggesting an excellent self-powered characteristic of the device. Furthermore, the SnS2/Te NFRs photodetector exhibited photoresponsivity of 127 mA/W at 0.8 V bias and photodetectivity of 1.33 ×1011 Jones, respectively. This study presents a rational strategy to improve the photodetection performance of SnS2-based PEC-type photodetector and opens a new avenue for designing high-efficiency photoelectronics device.