High-performance solar-blind UV photodetector based on single p-type Cu-doped β-Ga2O3 microwire

Abstract

β-Ga₂O₃ is a ideal material for fabricating solar-blind UV photoelectric detectors.

However, since the intrinsic β-Ga₂O₃ shows n-type conductivity, achieving p-type has been challenging, thereby hindering the development of β-Ga₂O₃ optoelectronic devices. In this study, we fabricated a photoconductive ultraviolet photodetector based on single Cu-doped β-Ga₂O₃ microwire. Centimeter-scale β-Ga₂O₃ microwires with varying Cu doping contents were synthesized using chemical vapor deposition method. These microwires had a diameter of approximately 30 nm and a length of up to about 0.8 cm. The p-type conductivity of the Cu-doped β-Ga₂O₃ microwires was confirmed through thermoelectric effect testing. Futhermore, we found that the photodetector composed of microwire with Cu molar percentage of 3.4 % demonstrated the best UV detection performance. The single Cu-doped β-Ga₂O₃ microwire detector exhibited excellent solar-blind photodetector performance, characterized by a high responsivity (57.7 A/W under a bias of 10 V), and external quantum efficiency of 28215 % (under a bias of 10 V), and an I_photo/I_dark ratio of 2.66 × 10⁴ @ 10 V, as well as good stability and repeatability. This work provide a simple and efficient method to preparing p-type β-Ga₂O₃ nano/microstructure and high-performance, stable β-Ga₂O₃-based photodetectors.