【Device Papers】High performance polycrystalline β-Ga₂O₃/GaN solar blind photodetector realized via simple one step air ambient thermal oxidation process

      Researchers from the Chonnam National University have published a dissertation titled "High performance polycrystalline β-Ga₂O₃/GaN solar blind photodetector realized via simple one step air ambient thermal oxidation process" in Applied Surface Science.

Abstract

      A broadband (200–400 nm) ultraviolet photoresponse encompassing β-Ga₂O₃/GaN photodetectors (PDs) has been fabricated by applying one-step thermal oxidization to counter complex and traditional sophisticated growth techniques. A feasible, low cost, and simple muffle box furnace for an air-ambient thermal oxidization approach has been demonstrated in this work. XRD, AFM, and SEM characterizations were performed on fabricated Ga₂O₃ layers from annealed single crystalline GaN (0001) wafers at various temperatures. A polycrystalline β-Ga₂O₃ layer was formed with highly (-201) orientation, having low FWHM value of 0.22 and a surface roughness of 11.41 nm with well-formed, rhombohedral-shaped morphology at optimal 900 ˚C. XPS and EDS analysis also confirmed the transition of GaN surface layer to Ga₂O₃ thin film formation. Under the bias of −5, −4 and −3, R (responsivity) were measured as 10.86, 8.34, and 7.06 A/W, whereas D (detectivity) recorded as 1.32 × 10¹¹, 2.51 × 10¹¹ and 3.93 × 10¹¹ Jones under the 254 nm light illumination, respectively. The performance of photodetectors demonstrates repeated and stable temporal photoresponse under both UVC and UVB illumination measurements. These experimental results reveal the potential for the development of Ga₂O₃-based solar-blind photodetectors utilizing low-cost muffle furnace thermal oxidization technique.

DOI：

https://doi.org/10.1016/j.apsusc.2025.163919