Enhanced Performance of a Self-Powered ZnO Photodetector by Coupling LSPR-Inspired Pyro-Phototronic Effect and Piezo-Phototronic Effect

Ultraviolet detection is overriding priority in many military and civilian fields. A photodetector can be effectively enhanced by introducing piezo-phototronic effect, pyro-phototronic effect, and localized surface plasmon resonance (LSPR). Coupling piezo-phototronic, pyro-phototronic, and LSPR effect can be realized in a self-powered photodetector based on ZnO/CuO nanorods covered with Au nanoparticles (NPs). The influences of LSPR, pyroelectric and external pressure on the performance of devices are thoroughly investigated, respectively. ZnO/CuO/Au devices display the most attractive performance under pressure of 73.7 N. The maxima of responsivity and detectivity are obtained as 0.81 mA W-1 and 3.3 x 10(13) Jones, respectively, under pressure of 73.7 N when detecting weak ultraviolet radiation (140 nW cm(-2)). Responsivity and detectivity are dramatically enhanced by 17x and 12x compared to CuO/ZnO devices. Moreover, rise time and fall time reduce from 114/75 ms of a ZnO/CuO device to 18/12 ms of a ZnO/CuO/Au device under pressure of 64.7 N. These results demonstrate that LSPR, pyro-phototronic, and piezo-phototronic coupled effect makes greater improvement than the individual effects in the performance of photodetectors. This work probably can be a cornerstone of designing high-performance photodetectors using other nanomaterial systems as well.