Influences of Sn doping on the properties of Ga2O3 thin film and ultraviolet photodetector fabricated via sol-gel and spin-coating methods

Gallium oxide (Ga2O3) has been considered as a promising ultrawide bandgap material, renowned for its exceptional breakdown electric field and stability. External doping serves as an effective method for modulating the characteristics of Ga2O3 materials and devices. In this study, Sn-doped Ga2O3 thin films and photodetectors were fabricated by sol-gel and spin-coating techniques. To minimize the usage of stabilizer and solvent, 1,2-propanediamine was incorporated into the precursor solution as a stabilizing agent. The impact of varying Sn doping concentrations on Ga2O3 thin films and detectors was investigated. The experimental findings confirm the successful formation of Sn-doped Ga2O3, wherein the external doping of Sn enhances the crystallinity of Ga2O3. Furthermore, an optimal Sn doping concentration contributes to improved film compactness. Elements O, Ga, and Sn are uniformly distributed within the Sn-doped Ga2O3. Sn doping leads to a reduction in the direct band gap, an augmentation in photoluminescence intensity, and a suppression of dark current in the detectors. However, this improvement in certain aspects comes at the cost of a reduced response speed