High-Temperature Photocurrent Mechanism of \b{eta}-Ga2O3 Based MSM Solar-Blind Photodetectors

TL;DR

This study investigates the high-temperature performance and photocurrent mechanisms of ta-Ga2O3 MSM UV photodetectors, revealing temperature-dependent behaviors and the influence of electron-phonon interactions crucial for high-temperature applications.

Contribution

It provides new insights into the high-temperature photocurrent mechanisms of ta-Ga2O3 MSM photodetectors, including temperature effects on photocurrent and carrier dynamics.

Findings

Photocurrent to dark current ratio remains high at room temperature.

Photocurrent behavior varies with temperature, decreasing then increasing up to 2500C.

Suppression of the blue band indicates instability of self-trapped holes.

Abstract

High-temperature operation of metal-semiconductor-metal (MSM) UV photodetectors fabricated on pulsed laser deposited \b{eta}-Ga2O3 thin films has been investigated. These photodetectors were operated up to 250 {\deg}C temperature under 255 nm illumination. The photo current to dark current (PDCR) ratio of about 7100 was observed at room temperature (RT) while it had a value 2.3 at 250 {\deg}C at 10 V applied bias. A decline in photocurrent was observed from RT to 150 {\deg}C and then it increased with temperature up to 250 {\deg}C. The suppression of the blue band was also observed from 150 {\deg}C temperature which indicated that self-trapped holes in Ga2O3 became unstable. Temperature-dependent rise and decay times of carriers were analyzed to understand the photocurrent mechanism and persistence photocurrent at high temperatures. Coupled electron-phonon interaction with holes was found to influence the photoresponse in the devices. The obtained results are encouraging and significant for high-temperature applications of \b{eta}-Ga2O3 MSM deep UV photodetectors.