Flexible ultraviolet–visible photodetector based on HfS3 nanobelt film

Abstract

HfS3 nanobelts with a width of 700 − 70 nm, a thickness of about 10–30 nm and a length of more than 10 μm, were directly synthesized at 650 °C for 5 h by a facile chemical vapor transport (CVT) method. The direct and indirect optical energy gaps of the nanobelts were measured as 2.19 and 1.73 eV, respectively. The nanobelts have good photoluminescence (PL), i. e. there are strong emissions at 483, 540 and 600 nm under excitation at 400 nm. The nanobelts were dispersed in enthanol and adhered to a transparent polypropylene (PP) film by double-side adhesive tape, and then two separate electrodes (Ti/Au) were evaporated on the surface with a mask, removing the mask to form a flexible photodetector. The detector demonstrated an excellent photoresponse from ultraviolet to visible light. Under illumination of 405 nm with 6.32 mW, the light on/off current ratio is 12, and response time is less than 0.2 s. It suggested that the HfS3 nanobelts are promising for applications in optoelectronic nanodevices, and the flexible photodetector can be used in practical photodetection.