Elevated temperature performance of Si-implanted solar-blind β-Ga2O3 photodetectors

The temperature dependent photoresponse of planar photodetectors fabricated on β-Ga2O3 films grown on Al2O3 by metalorganic chemical vapor deposition to 254 nm wavelength, and blindness to 365 nm light, are reported over the range of 25–350 °C. Ohmic contacts were formed by Si-implantation and annealing at 900 °C, followed by deposition of Ti/Au metallization. The photocurrent induced by 254 nm illumination increased monotonically with temperature, from ∼2.5 × 10−7 A at 25 °C to ∼2.2 × 10−6 A at 350 °C at a fixed 254 nm light intensity of 760 μW/cm2. The photosensitivity decreases at high temperatures in many photoconductors (thermal quenching), in sharp contrast to the photosensitivity increase with high temperatures in this study. This is ascribed to the presence of states in the gap of Ga2O3, whose presence was proven by exposure to below band-gap energy. In this case, the current sti…