Sol-gel prepared β-Ga2O3 thin films for ultraviolet photodetectors

β - Ga 2 O 3 thin films have been prepared on (0001) sapphire substrates by the sol-gel method. X-ray diffraction showed that β-Ga2O3 polycrystalline films were formed at heat-treatment temperatures above 600°C. With increasing heat-treatment temperature above 900°C, the lattice constants of the β-Ga2O3 films decreased, while the band gap increased. Planar geometry photoconductive detectors based on the sol-gel prepared β-Ga2O3 thin films have been fabricated. They showed the photoresponse only for the wavelengths shorter than 270nm, which correspond to the solar-blind region. The peak wavelength in the spectral response depended on the heat-treatment temperature in the sol-gel process.