Ultra-Low Noise and Self-Powered β-Ga2O3 Deep Ultraviolet Photodetector Array with Large Linear Dynamic Range

Self-powered ultraviolet (UV) photodetectors are the need of the hour for the current technology to harvest the charge carriers without power consumption. β-Ga2O3 deep UV photodetectors working at zero bias have been investigated here for potential applications in high-definition imaging. The photodetector exhibits an ultralow dark current of 8.6 ± 3.4 fA at zero bias. The initial results of low frequency noise measurements are reported for β-Ga2O3 deep UV photodetectors. An ultralow noise current of 9.1 × 10–16 A/Hz1/2 at 1 Hz is obtained in the self-powered condition. Such an ultralow noise current suggests the potential of this device in detecting very weak optical signals. The thermal noise current limited transport mechanism is found to dominate in comparison to shot noise and flicker noise in the self-powered mode. The linear dynamic range (LDR) of 88.5 dB is achieved which is very useful for high-resolution imaging. The dark current, noise floor, and LDR of the photodetector are the benchmark for β-Ga2O3 self-powered deep UV photodetectors. A 3 × 4 two-dimensional photodetector array with uniform dark and photocurrent across all of the pixels is also demonstrated. The outcomes of the present work are encouraging for imaging applications of β-Ga2O3 based energy-efficient deep UV photodetectors.