Vertically trigonal WS2 layer embedded heterostructure for enhanced ultraviolet-visible photodetector

High-performing photodetector was achieved by using vertically standing WS2 layers to provide significant enhancement for photoelectric applications. Type-I heterostructure of WS2/ZnO was fabricated using large-scale sputtering on FTO coated glass substrate; and exhibits substantially enhanced performance compared to the case of using solely ZnO, for ultraviolet as well as visible photodetection. The performance of the WS2/ZnO device was comprehensively studied through optoelectronic properties and was described well in a simulated energy band diagram. The WS2/ZnO combination showed superior light absorption in ultraviolet and visible range light and a reduction of surface reflectance, resulting in photocurrent gain. The WS2/ZnO device exhibits a photodetection performance with responsivity of 2.7 A W−1, detectivity of 5.8 × 1012 Jones and fast speed photoresponses (τr = 0.8 ms and τf = 2.2 ms). According to the analyzed results, the device proposed in this work may provide a simple and feasible way to enhance broadband photodetection via embedding WS2 as well transition metal dichalcogenide material for advanced optoelectronics.