Piezo-phototronic effect triggered flexible UV photodetectors based on ZnO nanosheets/GaN nanorods arrays

Abstract

Here in, we report on the fabrication of a flexible ultraviolet photodetector composed of two dimensional (2D) ZnO nanosheets (NSs) and one dimensional (1D) GaN nanorods (NRs). ZnO NSs were grown on the surface of GaN NRs to form 2D/1D heterojunction via simple hydrothermal method. A striking photoresponse was observed across 2D-ZnO/1D-GaN heterojunction under UV illumination. The photoresponsitivity and detectivity of the photodetector enhanced by two order magnitude than that of 1D GaN NRs. Furthermore, under a tensile strain the photoresponsivity of this photodetector was also tuned through piezo-phototronic effect arising from ZnO NSs. Due to lowering of barrier height under the application of strain, more photogenerated electron-hole pairs can transport through the heterojunction without recombination, resulting in enhanced photorespositivity.