Effect of metal electrode on electrical and optical properties ZnO quantum dot-based UV photodetector

Abstract

In this paper, we demonstrate the ZnO quantum dot thin film based UV light Photodetector with a different metal electrode. ZnO quantum dot synthesized using a colloidal synthesis method. The prepared ZnO QD thin film is characterized by X-ray diffraction (XRD), Photoluminance (PL), and UV spectroscopy. XRD result confirmed the formation hexagonal structure of ZnO, UV spectroscopy result confirm the bandgap of ZnO quantum dot is 3.25 eV using Tauc plot. Finally, ZnO quantum dot-based thin film is investigated for electrical and optical characteristics using interdigitated metal-semiconductor-metal (MSM) Ag and Au metal electrode. The comparative study of Ag and Au metal electrodes is investigated in terms of I-V characteristics under the dark condition and with a monochromator light at a wavelength of 375 nm with a power density 43µw/cm2. It is found that the ZnO quantum dot-based fabricated photodetector device using Au interdigitated electrode has better electrical and optical performance as compared to Ag electrodes. © 2020 American Institute of Physics Inc.. All rights reserved.