High-temporal dynamic β-Ga203 ultraviolet solar-blind photodetector via heteroepitaxy single crystalline film

In this report, we successfully fabricate a high performance β-phase Ga203 single-crystalline film deep ultraviolet (DUV) solar-blind photodetector. The hybrid Ga/GaO buffer layer method is proposed to promote the quality of β-Ga203 film that hetero-grown on sapphire substrates using plasma-assisted molecular beam epitaxy (PA-MBE). Based on the 2-inch and smooth β-Ga203 single crystalline film, the solar-blind detector is constructed by interdigitated Au-electrode with metal-semiconductor-metal structure. The dark-state current of device is low as 40 pA, meanwhile the UV photon responsibility > 234 mA/W at peak of 219 nm. Moreover, the device exhibites an ultrafast transient characteristic for DUV signals with a fast-rising time of 3 μs and decay time of 23 μs. High contrast two-dimension scanning image has been recorded using such DUV photodetector as a sensor in an imaging system. The excellent performances of device could be attributed to the high crystalline quality of β-Ga2O3, and giant field mobility in Schottky junction. Our results present a significant step towards future application of two-dimension array DUV photodetector based on larger scale β-Ga203 heteroepitaxy film.