【Device Papers】Band and contact engineering in Ga₂O₃ UV photodetectors and X-ray detectors

      Researchers from Hubei University have published a dissertation titled " Band and contact engineering in Ga₂O₃ UV photodetectors and X-ray detectors " in Journal of Materials Chemistry C.

Abstract

      Gallium oxide (Ga₂O₃), an emerging ultra-wide-bandgap semiconductor (bandgap ≈ 4.9 eV), demonstrates significant application potential in solar-blind ultraviolet photodetection and X-ray detection. However, the slow response time of several hundred milliseconds and limited weak-light detection capability significantly hinder the commercial applications of gallium oxide detectors. Here, we carefully investigate the critical roles of band and contact engineering in overcoming these difficulties. Band engineering, specifically through heterostructures such as p-GaN/n-Ga₂O₃, can suppress persistent photoconductivity (PPC) effect and accelerate carrier separation via strong built-in electric fields, drastically shortening response times. Concurrently, contact engineering by employing high-work-function metals, such as Pd or Au, for optimized Schottky junctions alongside an interdigital-electrode structure can minimize dark current noise and lower injection barriers, enabling high-sensitivity collection of weak-light signals. This study discusses the recent research on two engineering techniques for Ga₂O₃ detectors, compares the device performance, and identifies future development challenges.

DOI：

https://doi.org/10.1039/D6TC01702A