High-temperature photocurrent mechanism of β-Ca_2O_3 based metal-semiconductor-metal solar-blind photodetectors

摘要

High-temperature operation of metal-semiconductor-metal (MSM) UV photodetectors fabricated on pulsed laser deposited beta-Ga(2)O(3 )thin films has been investigated. These photodetectors were operated up to 250 degrees C temperature under 255 nm illumination. The photo to dark current ratio of about 7100 was observed at room temperature and 2.3 at a high temperature of 250 degrees C with 10 V applied bias. A decline in photocurrent was observed until a temperature of 150 degrees C beyond which it increased with temperature up to 250 degrees C. The suppression of the UV and blue band was also observed in the normalized spectral response curve above 150 degrees C temperature. Temperature-dependent rise and decay times of temporal response were analyzed to understand the associated photocurrent mechanism at high temperatures. Electronphonon interaction and self-trapped holes were found to influence the photoresponse in the devices. The obtained results are encouraging and significant for high-temperature applications of beta-Ga2O3 MSM deep UV photodetectors. Published under license by AIP Publishing.