Low-Frequency Noise Characteristics of GaN Schottky Barrier Photodetectors Prepared With Nickel Annealing

In this paper, GaN Schottky barrier photodetectors (PDs) prepared with and without Ni treatment were fabricated. I-V and noise characteristics of these devices were then investigated. Comparing the GaN PDs with and without Ni treatment, it was found that GaN PDs prepared with Ni treatment can not only reduce dark current, but also enhance the UV-to-Vis rejection ratio. With an applied bias of -2 V, it was found that noise equivalent power (NEP) and detectivity (D*) for the PDs prepared without Ni treatment were 9.95 × 10^-8 W and 1.59 × 10⁷ cmHz^0.5W^-1, respectively. At the same applied bias, it was also found that NEP and D* for PDs prepared with Ni treatment were 1.74 × 10^-11 W and 9.07 × 10¹⁰ cmHz^0.5W^-1, respectively.