Improved performance of GaN metal-semiconductor-metal ultraviolet detectors by depositing $SiO2$ nanoparticles on a GaN surface Available to Purchase

GaN metal-semiconductor-metal (MSM) ultraviolet detectors were investigated by depositing different density of $SiO2$ nanoparticles (SNPs) on the GaN. It was shown that the dark current of the detectors with SNPs was more than one order of magnitude lower than that without SNPs and the peak responsivity was enhanced after deposition of the SNPs. Atomic force microscopy observations indicated that the SNPs usually formed at the termination of screw and mixed dislocations, and further current-voltage measurements showed that the leakage of the Schottky contact for the GaN MSM detector decreased with deposited the SNPs. Moreover, the leakage obeyed the Frenkel–Poole emission model, which meant that the mechanism for improving the performance is the SNPs passivation of the dislocations followed by the reduction in the dark current.