High‐Performance Self‐Powered Deep Ultraviolet Photodetector Based on NiO/β‐Ga2O3 Heterojunction with High Responsivity and Selectivity

• Published in: Physica status solidi. A, Applications and materials science Vol. 221; no. 18
• Main Authors: Woo, Sola, Lee, Taeeun, Song, Chang Woo, Park, Jun Young, Jung, Yusup, Hong, Jeongsoo, Kyoung, Sinsu
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.09.2024
• Subjects: Annealing; Carrier density; deep ultraviolet; Energy bands; Gallium oxides; heterojunction; Heterojunctions; Nickel oxides; NiO/β‐Ga2O3; Performance degradation; photodetector; Photometers; post‐annealing; Response time; Ultraviolet detectors
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.202400310

A high‐performance self‐powered deep ultraviolet (DUV) photodetector based on the NiO/β‐Ga2O3 heterojunction is fabricated and analyzed. The NiO/β‐Ga2O3 heterojunction photodetectors are fabricated both with and without a post‐annealing process following NiO film deposition. Each photodetector structure is investigated through technology computer‐aided design simulations, including energy band diagram, trap density, and carrier concentration. The pristine self‐powered NiO/β‐Ga2O3 photodetector, lacking a post‐annealing process, exhibits partial Schottky contact formation between metal and NiO film, leading to performance degradation, including reduced responsivity, detectivity, and response time. On the other hand, the post‐annealed self‐powered NiO/β‐Ga2O3 photodetector demonstrates high performance such as a responsivity of 592.0 mA W−1, a detectivity of 4.30 × 1012 Jones, and response times of 30.93 ms and 72.32 ms, respectively. Therefore, the fabricated NiO/β‐Ga2O3 photodetector shows a promising potential for various applications requiring DUV detection without an external voltage bias. In this article, a self‐powered NiO/β‐Ga2O3 heterojunction photodetector is successfully demonstrated. As a result, the NiO/β‐Ga2O3 photodetector with post‐annealing process offers superior performance, including a high responsivity of 592.0 mA W−1, a detectivity of 4.3 × 1012 Jones, and fast response times of 30.93 ms and 77.32 ms under a wavelength of 254 nm at zero bias.