Single-crystalline ZnS nanobelts with sharp ultraviolet (UV) emission at room temperature as UV-light sensors

Abstract

We have demonstrated an effective approach for the synthesis of single-crystalline ZnS nanobelts possessing sharp UV emission at RT via right selection of source materials and controlling their evaporation and agglomeration rates. Individual ZnS nanobelt-based UV-light sensors were fabricated, these showed a high potential as visible-blind UV photodetectors and ultra-fast optoelectronic switches. The sensor characteristics, including a spectral response, I-V curves under various light illuminations, and a time response were studied. The photoresponsivity of an individual ZnS nanobelt-based UV sensor exhibited over three orders of magnitude gain under the UV light illumination as compared to a visible light. The high spectral selectivity combined with high photosensitivity and fast time response (< 0.3 s) make the present single-crystalline ZnS nanobelts particularly valuable for new ¿visible-blind¿ UV photodetectors, especially in the UV-A region.