GaN-Based Planar p-i-n Photodetectors With the Be-Implanted Isolation Ring

The authors report the fabrication of GaN-based planar p-i-n photodetectors (PDs) with and without the Be-implanted isolation ring. With the isolation ring, we achieved a much smaller leakage current below 10 pA. It was also found that the responsivity for the PD with the Be-implanted isolation ring was almost independent of the applied reverse bias. Furthermore, it was found that we could achieve a bias independent and much larger ultraviolet-to-visible rejection ratio to three orders of magnitude. Furthermore, smaller noise-equivalent-power value 8.18 × 10^-16 W and larger detectivity 3.2 × 10¹³ cm·Hz^0.5 · W^-1 from the PD with the Be-implanted isolation ring.