A Review of Ga₂O₃ Heterojunctions for Deep-UV Photodetection: Current Progress, Methodologies, and Challenges

Abstract

In recent years, gallium oxide (Ga₂O₃) has drawn considerable research interest as an ultrawide-bandgap semiconductor due to its promising applications in the power electronics, photodetection, and gas sensing. Moreover, Ga₂O₃ heterojunctions have emerged as a promising approach to address key limitations of Ga₂O₃ as a standalone material—most notably, its lack of p-type doping capability. One of the key application areas for Ga₂O₃ and its heterojunctions is ultraviolet (UV) photodetection, which has gained significant attention yet remains a relatively nascent field with vast potential for further exploration and optimization. This review provides a detailed overview of the current state-of-the-art in Ga₂O₃ technology, highlighting recent research advancements, key challenges, and emerging strategies aimed at overcoming these challenges. Specifically, it examines Ga₂O₃ heterojunctions for deep-UV photodetection, analysing compatible electrode materials and assessing various substrates suitable for Ga₂O₃ growth to enhance device performance. This comprehensive review is designed to serve as an essential resource for researchers and engineers working with Ga₂O₃-based heterojunctions, especially for applications in UV photodetection. Written with the needs of new entrants in mind, it aims to build a robust foundational understanding of Ga₂O₃ technology, supporting ongoing innovation and application expansion in this field.