Temperature-Dependent Study of β -Ga ₂ O ₃ Solar-Blind Photodetectors

Abstract

In this paper, the electrical and ultraviolet optoelectronic properties of the interdigitated finger geometry β -Ga 2 O 3 photodetector were investigated from the temperature of 40 K to 300 K. Under different light illumination conditions, when the temperature increased from 40 K to 300 K, the maximum current of the β -Ga 2 O 3 photodetector was obtained around 180 K, which is related to the carrier mobility of β -Ga 2 O 3 . Under 365-nm illumination, when the temperature increased from 40 K to 300 K, the photo-to-dark current ratio (PDCR) of the β -Ga 2 O 3 photodetector increased by 924%. Under 254-nm illumination, the PDCR decreased by 87%. Besides, the temperature point corresponding to the photoresponse peak under 365-nm illumination moved to the right under 254-nm illumination, indicating that the photodetector had a redshift at low temperature. Moreover, the fast photoresponse time under 365-nm and 254-nm illumination decreased when the temperature increased. This indicated that the defect concentration of Ga 2 O 3 decreased gradually as the temperature increased, leading to the faster response time of the photodetector.