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 \times \hbox{10}^{-16}\ \hbox{W}$ and larger detectivity 3.2 \times \hbox{10}^{13}\ \hbox{cm}\cdot\hbox{Hz}^{0.5}\cdot \hbox{W}^-1 from the PD with the Be-implanted isolation ring.