【Device Papers】Fast-response, self-powered staggered-gap p-CuGaO₂/β-Ga₂O₃ heterojunction for large-area diagnostic X-ray imaging applications

      Researchers from the Sejong University have published a dissertation titled "Fast-response, self-powered staggered-gap p-CuGaO₂/β-Ga₂O₃ heterojunction for large-area diagnostic X-ray imaging applications" in Sensors and Actuators A: Physical.

Abstract

      Beta-gallium oxide (β-Ga₂O₃) semiconductors exhibit an extensive bandgap, elevated density, and a substantial absorption coefficient for diagnostic X-rays, rendering them highly compelling contenders for the development of diagnostic X-ray detectors with exceptional sensitivity. Hybrid X-ray detectors utilizing p-n heterojunctions (HJs) based on β-Ga₂O₃ have garnered significant interest due to the inherent difficulties associated with p-type doping of β-Ga₂O₃. Therefore, the selection of cost-effective and efficient inorganic hole transport layers (HTLs) takes precedence as a pivotal first measure in the commercialization of X-ray detectors. Due to its significant hole mobility, copper gallium oxide (p-CuGaO₂) exhibits considerable potential as a viable material for heterojunction applications with β-Ga₂O₃. Following annealing, both the dark current and photocurrent of the p-CuGaO₂/β-Ga₂O₃ HJ X-ray detector showed improvement, indicating that the annealing process enhanced the quality of the deposited layer. The linearity and response properties of the X-ray-generated photocurrent significantly increased after annealing, thereby enhancing the detector's suitability for X-ray detection applications. The annealed p-CuGaO₂/β-Ga₂O₃ HJ X-ray detector successfully generated an X-ray image of a custom-made phantom from Sejong University (SJU). This characteristic renders it highly suitable for utilization in X-ray detectors. The utilization of p-n HJs incorporating β-Ga₂O₃ is of paramount importance in the pursuit of expanded-scale, low-energy X-ray imaging applications.

DOI：

https://doi.org/10.1016/j.sna.2025.116243