High-performance (Ga,Sn)O3-based self-powered solar-blind photodetectors achieved via the sol-gel technique and modulating carrier concentrations

Currently, self-powered solar-blind ultraviolet (UV) photodetectors (PDs) based on Ga2O3 have drawn considerable attention owing to their saving energy consumption, high-precision detection, and excellent stability. High-property Ga2O3-based solar-blind UV PDs require the growth of crystalline Ga2O3 films, which usually needs expensive preparation equipment, and their photoelectric properties are limited by low conductivity of the Ga2O3. In order to address these issues, herein, a facile, effective, and low-cost sol-gel method is used to fabricate amorphous (Ga,Sn)O3-based PDs. Sn4+ possesses higher valence relative to Ga3+, and weaker Sn-O bonds in comparison with Ga-O bonds can increase oxygen vacancies, which are conductive to improving electron concentrations in Ga2O3 with intrinsic n-type conductivity, and thus the photoelectric performances of the PDs. Consequently, via adjusting reasonably Sn content, the PDs with 10 mol% Sn presents the most superior photoelectric response with simultaneously a large responsivity of 43.89 mA/W and excellent detectivity of 1.319 × 1012 Jones at a light wavelength of 240 nm and 0 V bias, which are far better than those of the PDs based on pure Ga2O3. The present work gives an effective and low-cost approach for developing high-property self-powered solar-blind UV PDs.