Low-Frequency Noise Characteristics of In-Doped ZnO Ultraviolet Photodetectors

We report the growth of vertically aligned indium-doped ZnO (IZO) nanorods on a glass substrate using a low-temperature hydrothermal method. An IZO nanorod metal-semiconductor-metal (MSM) ultraviolet (UV) photodetector (PD) was also fabricated. It was found that the UV-to-visible rejection ratio of the fabricated PD was ~109 when biased at 1 V with a sharp cutoff at 390 nm. With an incident light wavelength of 390 nm and an applied bias of 1 V, it was found that measured responsivity of the PD was 2.5 A/W. Furthermore, it was also found that the noise equivalent power and detectivity of the fabricated IZO nanorod MSM PD were 1.42×10^-10 W and 1.44×10¹¹ cm·Hz^0.5·W^-1, respectively.