High-sensitivity GaN UV photodetector integrated with graphene

Abstract

Ultraviolet (UV) photodetectors are critical for a wide range of applications, where high sensitivity and low dark current are essential for accurate detection. This study presents a graphene-based p-i-n UV photodetector with a Gr/i-GaN/n-GaN structure, aimed at improving UV detection performance by improving sensitivity and reducing dark current. Graphene, as a p-type material, enhances carrier mobility and reduces recombination, while leveraging the wide bandgap properties of i-GaN and n-GaN for efficient UV absorption. The experimental results show that the graphene/i-GaN/n-GaN photodetector achieves a maximum photoresponsivity of 20.6 A/W, detectivity of 2.0 × 1012 cm·Hz1/2·W−1, and external quantum efficiency of 75.25%, indicating efficient light-to-current conversion performance. The integration of graphene in the p-i-n structure significantly reduces the dark current to 2.68 × 10−13 A, improving both the transient response and the overall efficiency of the device. These findings underscore the effectiveness of the graphene/i-GaN/n-GaN structure in improving UV photodetection performance. By combining the high mobility of graphene and the wide bandgap properties of GaN, this work demonstrates potential for application in graphene-based p-i-n photodetectors as a viable approach for future UV sensing applications, offering enhanced performance and stability for precise UV detection across varying conditions.