Improvement of the deep UV sensor performance of a β-Ga2O3 photodiode by coupling of two planar diodes

β-Ga2O3 is one of promising semiconductor materials that has been widely used in power electronics and ultraviolet
(UV) detectors due to its wide bandgap and high sensitivity to UV light. Specifically, for the UV detection application, it has
been reported that the photocurrent was in the scale of micro Amps (μA), which normally requires sophisticated signal
processing units. In this work, a novel approach based upon coupling of two Schottky diodes is reported, leads to a substantial
increase in photocurrent (~186 times) when benchmarked against a conventional planar UV photodiode. The detectivity and
responsivity of the new device have also been significantly increased; the rectification ratio of this device was measured to be 1.7
x 107 with ultra-low dark current, when measured in the reverse bias. The results confirm the approach of coupling two Schottky
diodes has enormous potential for improving the optical performance of deep UV sensors.