High photoresponse of gold nanorods/zinc oxide photodetector using localised surface plasmon resonance

This study demonstrated the fabrication of the gold nanorods/zinc oxide photodetector (GNRs/ZnO PD) and PEGylated GNRs were decorated onto the planar ZnO device via the microchannel relocation process. Several properties, including the sensitivity, responsibility, external quantum efficiency (EQE) and on/off switching ratio, were characterised under the 365 nm of the UV irradiation. The GNRs/ZnO PD performed stable and reproducible photocurrent responses and a high on/off switching ratio under the UV irradiation cycles. The photocurrent and I-light/I-dark current ratio increased to approximately 9 times and 167, respectively. Furthermore, the UV responsibility was enhanced to 180 A/W and the EQE was also improved to 612. These performance enhancements are dominated by the localised surface plasmon resonance (LSPR) effect of decorated GNRs. PEGylated GNRs have longitudinal and transverse LSPR peaks around 510 nm and 696 nm, respectively. The LSPR effect of decorated GNRs assists to enhance the UV emission of the ZnO PD by 25 times. (C) 2021 Elsevier B.V. All rights reserved.