Preparation and photodetection performance of high crystalline quality and large size -Ga₂O₃ microwires

Ultrawide band gap semiconductors are promising solar-blind ultraviolet (UV) photodetector materials due to their suitable bandgap, strong absorption and high sensitivity. Here, beta-Ga2O3 microwires with high crystal quality and large size were grown by the chemical vapor deposition (CVD) method. The microwires reach up to 1 cm in length and were single crystalline with low defect density. Owing to its high crystal quality, a metal-semiconductor-metal photodetector fabricated from a Ga2O3 microwire showed a responsivity of 1.2 A/W at 240 nm with an ultrahigh UV/visible rejection ratio (R (peak)/R (400 nm)) of 5.8 x 10(5), indicating that the device has excellent spectral selectivity. In addition, no obvious persistent photoconductivity was observed in the test. The rise and decay time constants of the device were 0.13 and 0.14 s, respectively. This work not only provides a growth method for high-quality Ga2O3 microwires, but also demonstrates the excellent performance of Ga2O3 microwires in solar-blind ultraviolet detection.