【Domestic Papers】Robust Deep UV Photodetectors Based on One-Step-Grown Polycrystalline Ga₂O₃ Film via Pulsed Laser Deposition toward Extreme-Environment Application

      Researchers from the University of Science and Technology of China have published a dissertation titled "Robust Deep UV Photodetectors Based on One-Step-Grown Polycrystalline Ga₂O₃ Film via Pulsed Laser Deposition toward Extreme-Environment Application " in Advanced Optical Materials.

Abstract

      Gallium oxide (Ga₂O₃), with an ultrawide bandgap corresponding to the deep ultraviolet (DUV) range, has attracted significant attention in optical filter-free photodetectors. In practical terms, DUV photodetectors employed in extreme conditions, for example, flame detection and space exploration, face the challenges of performance degradation caused by high/low-temperature transformation. Here, DUV photodetectors are tailored with high durability and stability by one-step-grown β-Ga₂O₃ films via pulsed laser deposition. A high-oxygen-pressure scheme effectively addresses the issue of film-free deposition at specifically high temperatures, facilitating the formation of polycrystalline high-resistivity β-Ga₂O₃ films. As a result, the devices exhibit outstanding performance, including a low dark current (4.4 pA @30 V), high photoresponsivity (147.36 A W⁻¹), and fast response time (3.1/22.6 ms). Additionally, the photoresponse performance shows minimal degradation at high temperatures up to 300 °C and even improves at low temperatures down to −100 °C, ranking it among the most robust DUV photodetectors. The mechanism of photoresponse, involving the exciton formation, bandgap evolution, carrier-phonon scatter, etc., is also elucidated in a wide temperature range. This work provides an efficient solution for developing robust Ga₂O₃ DUV photodetectors with excellent performance for extreme-condition applications.

DOI：doi.org/10.1002/adom.202400788