Ultrahigh-Performance Solar-Blind Photodetectors Based on High Quality Heteroepitaxial Single Crystalline β-Ga2O3 Film Grown by Vacuumfree, Low-Cost Mist Chemical Vapor Deposition

Due to the suitable bandgap, superior chemical and physical properties, the beta-phase gallium oxide (beta-Ga2O3) has the great potential to fabricate the deep ultraviolet solar-blind photodetectors (DUV PDs). However, the low material quality, high material growth cost, and insufficient device performance, are urgently required to be solved for practical applications. In this work, by using a vacuumfree, low-cost mist chemical vapor deposition method, the high quality beta-Ga2O3 single crystal films are successfully heteroepitaxially grown on (0001) sapphire substrates. X-ray diffraction and transmission electron microscopy measurements identify the heteroepitaxial relationship with (2 over bar 01) beta-Ga2O3||(0001) sapphire. At the optimal growth temperature of 800 degrees C, the film shows a high quality pure beta-Ga2O3 phase with the small full width at half maximum of 0.71 degrees. Furthermore, the metal-semiconductor-metal DUV PDs are fabricated based on such single crystal beta-Ga2O3 films, which exhibit excellent photoelectric performance. A very high photoresponsivity 22 000 A W-1 under 254 nm light illumination, which corresponds to a quantum efficiency of 1.07 x 10(7)% and a high detectivity of 1.1 x 10(16) Jones, almost the highest ever reported. The low-cost film heteroepitaxial growth method and the ultrahigh device performance pave an alternative way for the fabrication of high-performance beta-Ga2O3 solar-blind DUV PDs.

Automated summary

This study successfully epitaxially grew high-quality beta-Ga2O3 single crystal films on sapphire substrates using a low-cost method and fabricated deep ultraviolet solar-blind photodetectors with excellent photoelectric performance.