Enhancing the photodetectivity of TFT based on atomic layer deposited Ga-Zn-O thin film through laser annealing

Amorphous Ga-Zn-O (a-GZO) thin films were synthesized via atomic layer deposition (ALD) and subsequently processed using laser annealing (LA) techniques. The investigation demonstrates that the films maintain their amorphous state across varying laser irradiation energy intensities. This study systematically evaluates the modulation of microstructure, oxygen vacancy (Vo) concentration, and optoelectronic properties induced by LA. Results indicate that as the laser energy intensity increases, the Vo content rises from 22.4% to 40.63%. An optimal Vo concentration is found to trigger trap-assisted gain, significantly enhancing the photoresponsivity of the device; however, excessive Vo leads to a surge in the dark current and a degradation of device uniformity. The film treated at 0.3 J/cm2 exhibits the most superior comprehensive performance, achieving a field-effect mobility of 9.6 cm2/V s and an on/off ratio of 106, while demonstrating improved uniformity and stability. Furthermore, the TFT-based photodetector achieves an ultrahigh responsivity (R) of 235.42 A/W under 0.02 mW/cm2 of 310 nm ultraviolet (UV) illumination. This work highlights the dual advantages of amorphous oxide thin films in maintaining high uniformity while achieving ultrasensitive UV detection.