【International Papers】Growth of Low-defect Si-Doped Ga₂O₃ Film on Fluorine-doped Tin Oxide Substrate for Self-powered and High-performance Ultraviolet Photodetector

      Researchers from the Department of Electrical Engineering, Gachon University of South Korea have published a dissertation titled " Growth of Low-defect Si-Doped Ga₂O₃ Film on Fluorine-doped Tin Oxide Substrate for Self-powered and High-performance Ultraviolet Photodetector " in ACS Applied Electronic Materials.

Abstract

      In this study, an efficient ultraviolet photodetector (UV PD) is prepared based on a p–n junction that is metal-electrode-free and with a vertical configuration. Briefly, n-type Si-doped Ga₂O₃ was grown by using RF sputtering, and p-type [9,9-dioctylfluorene-co-N-[4-(3-methylpropyl)]-diphenylamine] was deposited by using a spin-coating process. We utilized a very thin TiO₂ compact layer, covered on the fluorine-doped tin oxide (FTO)/glass, to modify the morphology of the FTO surface for supporting the growth of the Si-doped Ga₂O₃ film. Therefore, a Si-doped Ga₂O₃ film with a low number of defects was formed. The self-powered PD exhibited a comparative performance with high responsivity (R = 1.02 mA/W) and a good on/off ratio of 242.56. In addition, the device performance can be significantly improved when a reverse bias is applied. Under −1 V bias, the responsivity and specific detectivity of the PD achieved 2.31 mA/W and 6.7 × 10¹⁰ Jones, respectively. Moreover, the device showed a fast response speed (t_rise = 122 ms, t_fall = 241 ms) and stable photoresponse under 254 nm UV illumination. This finding is expected to facilitate the production of cost-effective UV PD for many applications.

Figure S1. The XRD pattern of a compact TiO₂ thin film on the FTO-coated glass substrate.

Figure S2. The SEM image of a compact TiO₂ thin film on the FTO-coated glass substrate.

Paper Link：https://doi.org/10.1021/acsaelm.3c01332