Surface KOH treatment in AlGaN-based photodiodes

KOH treatment is investigated as a method to improve the IN characteristics of AIGaN-based photodiodes. The defects in the photodiode may enhance the dark current, and cause some photocurrents with incident photon energy less than the absorption edge. With the KOH treatment in the process, the defects and whisker-like features could be reduced. High rejection ratio in the spectral responsivity could be achieved. The KOH treatment is a good method to reduce the surface defects in AlGaN-based photodiodes.