Decrease of oxygen vacancy by Zn-doped for improving solar-blind photoelectric performance in β-Ga2O3 thin films

Highly (201) oriented Zn-doped β-Ga₂O₃ thin films with different dopant concentrations were grown on (0001) sapphire substrates by radio frequency magnetron sputtering. With the increase of Zn dopant concentration, the crystal lattice expands, the energy band gap shrinks, and the oxygen vacancy concentration decreases. Both the metal semiconductor metal (MSM) structure photodetectors based on the pure and Zn-doped β-Ga₂O₃ thin films exhibit solar blind UV photoelectric property. Compared to the pure β-Ga₂O₃ photodetector, the Zn-doped one exhibits a lower dark current, a higher photo/dark current ratio, a faster photoresponse speed, which can be attributed to the decreases of oxygen vacancy concentration.