Study of self-powered UV detector based on Sb-doped β-Ga2O3 thin film/P-Si heterojunction

Sb-doped beta-Ga2O3 thin films with different contents were grown on p-type Si substrates by chemical vapor deposition (CVD). It is found that the surface morphology and crystal quality of beta-Ga2O3 films are improved with increasing Sb contents, which is mainly caused by the fact that amount of Sb can act as surface activator. The self powered solar-blind UV photodetectors base on Sb-doped beta-Ga2O3 thin films/Si heterojunction was fabricated. The heterojunction device exhibited high Ilight/Idark ratio of up to-1.6 x 103 and relatively fast photoresponse speed (0.07/0.09 s). Furthermore, the heterojunction photodetectors also show excellent photosensitive characteristics with responsivity of 210 mA/W, and external quantum efficiency of 103% under 254 nm illumination (60 mu W/cm2) at 0 V. This doping technique provided a feasible method for n-type beta-Ga2O3 doping and the preparation of ultraviolet photodetectors.