Fabrication and characterization of Nitride base photodiodes with nanostructure

In this study, we achieved nanoscale InGaN self-assembled quantum dots (SAQDs) in the well layers of the active region by using an interrupted growth method. And then nitride base photodiodes with nanostructure were successfully fabricated by metal-organic chemical vapor deposition (MOCVD) growth. It was found that the turn on voltage in forward bias and the break down voltage in reverse bias are about 3 and -13.5 V, respectively. The RT PL spectrum peak position for the fabricated InGaN/GaN multi-QDs p-n junction PDs is located at 464.6 nm and FWHM is 24.2 nm. Furthermore, with 1 V to 3 V applied bias, the maximum responsivity of the fabricated multi-QDs p-n junction PD was observed at 350 nm, and the minimum of spectral response was measured at 465 nm. It was also found that the responsivity was nearly a constant from 390 to 440 nm It seems to suggest that the spectral response in the range of 390-440 nm is due to the effect of the InGaN dots in a well active layers.