Low-Frequency Noise Characteristics of Gallium-Doped ZnO Nanosheets as Photodetectors

Abstract

This study reports the growth of vertically aligned gallium (Ga)-doped ZnO (GZO) nanosheets (NSs) on a glass substrate using low temperature (90°C) hydrothermal method. The GZO NSs exhibited hexagonal wurtzite structures with a sharp morphology, with average length and diameter of approximately 720 and 26 nm, respectively. A GZO NS metal-semiconductor-metal (MSM) ultraviolet photodetector (PD) was also fabricated. The UV-to-visible rejection ratio of the fabricated PD was approximately 81 when biased at 1 V with a sharp cutoff at 340 nm. With an incident light wavelength of 340 nm and an applied bias of 1 V, the measured responsivity of the PD was 2.83 × 10−5 A/W. Furthermore, the noise equivalent power (NEP) and detectivity of the fabricated GZO NS MSM PD were 5.92 × 10−9 W and 2.24 × 109 cm • Hz0.5 • W−1, respectively.