A flexible ultraviolet photodetector based on single crystalline MoO3 nanosheets

Abstract

Large scale two dimensional orthorhombic structured MoO₃ single crystalline belts with a bandgap of 3.28 eV were prepared by substrate-free physical vapor deposition. Ultra-thin MoO₃ nanosheets were exfoliated from the belt and transferred to a polyethylene terephthalate substrate. A flexible ultraviolet photodetector (UVPD) based on the single crystalline MoO₃ nanosheet was fabricated, and its optoelectronic response properties were investigated in detail. The UVPD has a high responsivity of 183 mA W⁻¹, a high on/off ratio of over two orders and a response speed below 1 s. Moreover, the flexible UVPD exhibits excellent stability and reproducibility under different mechanical deformations. The excellent operating characteristics make the UVPD a potential candidate for wearable UV meters, touch sensor panels, communication devices and UV imaging cameras.