Flexible and Self-Powered Solar-Blind UV Photodetector Based on the Ti/α-Ga2O3/Electrolyte Heterojunction with High Stability

In recent years, Ga2O3 flexible solar-blind ultraviolet photodetectors (UVPDs) are gradually becoming the focus of research and the industry because of their excellent wearability, low manufacturing cost, portability, large area compatibility, and high scalability. However, the crystallization temperature required for high-quality α-phase Ga2O3 films exceeds the heat resistance of most flexible materials, so the growth of Ga2O3 films on flexible substrates is a very big challenge. In this study, a highly ordered α-Ga2O3 nanorod array and flexible solar-blind UV PDs with excellent performance were successfully prepared on a flexible titanium (Ti) substrate at 500 °C by a simple water bath heating method. When irradiated by 254 nm ultraviolet light, the α-phase Ga2O3 flexible photodetector exhibits an excellent self-power optical response at 0 V bias and exhibits excellent photoelectric performance with a responsivity of 15.3 mA/W, a fast rise and fall time of 0.104 and 0.077 s, a photocurrent density of 45.7 μA/cm2, and a high detectivity of 13.8 × 109 Jones. Bending and repeating experiments demonstrated that the detector had high stability. This study provides a simpler and less expensive method for the preparation of flexible self-powered α-Ga2O3 solar-blind UV photodetectors.