Gallium oxide thin film-based deep ultraviolet photodetector array with large photoconductive gain

Abstract

Gallium oxide (Ga<sub>2</sub>O<sub>3</sub>) has the natural advantages in deep ultraviolet absorbance for performing deep ultraviolet photodetection. Owing to the vital application of photodetector array in optical imaging, in this work, we introduce a 4×4 Ga<sub>2</sub>O<sub>3</sub>-based photodetector array with five-finger interdigital electrodes, in which the high-quality and uniform Ga<sub>2</sub>O<sub>3</sub> thin film is grown by using metal-organic chemical vapor deposition technique, and the device is fabricated by using the following methods: ultraviolet photolithography, lift-off, and ion beam sputtering . The photodetector cell possesses a responsivity of 2.65×10<sup>3</sup> A/W, a detectivity of 2.76×10<sup>16</sup> Jones, an external quantum efficiency of (1.29×10<sup>6</sup>)%, and a photoconductive gain as high as 12900. The 16-cells in this array show good uniformity. In this work the great application potential of gallium oxide deep ultraviolet detector array is illustrated from the perspective of optoelectronic performance and application prospect.