Au Nanoparticles-Decorated Surface Plasmon Enhanced ZnO Nanorods Ultraviolet Photodetector on Flexible Transparent Mica Substrate

Abstract

An ultraviolet (UV) photodetector based on hydrothermally processed ZnO nanorods (ZnO NRs) decorated by gold nanoparticles (Au NPs) was demonstrated to exhibit extraordinary optoelectronic properties. Due the implementation of Au NPs, the UV responsivity and specific detectivity reached 70 A/W and 3.41 $\times$ 1012 cm Hz1/2 W−1, respectively, which were enhanced by approximately four times at an excitation wavelength of 365 nm compared with those of pristine ZnO NRs. Moreover, such photodetector shows good flexibility as well due to the mica substrate, which maintains almost constant performances under different bending radii of curvature and repeatable bending test more than 200 cycles. The photodetector also exhibits good transparency, giving it the potential of integration with other light photodetectors. In addition, a schematic band-diagram and the accompanying finite-difference time-domain analysis were performed to reveal the electron transfer and electric field distribution of ZnO NRs decorated with Au NPs. Our results revealed that the noble metal modified plasmon-enhanced ZnO NRs photodetector with high responsivity, low cost has a great potential for application in manufacturing flexible and transparent integrated optoelectronics.

Keywords

• ZnO nanorods
• Au nanoparticles
• ultraviolet photodetector
• mica substrate
• flexible bending