Development and characterization of MSM UV photodetector based on gallium oxide nanostructures

Abstract

Literatures reports that intrinsic Ga2O3 shows negligible response to UV wavelength longer than its optical absorption edge. Herein, we demonstrate for the first time the enhanced response of Ga2O3 to UV light with wavelength significantly longer than its optical absorption edge ≤280 nm. The responsivity of the photodetector reached 38.161 A/W and detectivity of 8.3916 ×109 Jones when the bias voltage was increased to 3 V for 365 nm light illumination. X-ray diffraction measurement confirmed mixed-phase β- α Ga2O3 with high crystallinity. Microstructural observation revealed nanoplates-like morphology, showing the high crystallization of the nanocrystals. Optical reflectance measurement showed optical bandgap of 4.67 eV which is typical of β-Ga2O3. The sensitivity of the wide bandgap semiconductor material to wavelength longer than its absorption edge could be ascribed to the high crystallinity, film density and net oxygen vacancies on the film.