Characteristics of III-nitride MSM photodiodes with SAQDs Original Research Article

A novel metal-semiconductor-metal photodiode with InGaN self-assembled quantum dots was fabricated and compared with a conventional InGaN metal-semiconductor-metal photodiode. It was found that the InGaN QD photodiode with lower dark current can operate in the normal incidence mode. We achieved a much larger photocurrent to dark current contrast ratio from the fabricated photodiodes with nanoscale InGaN self-assembled quantum dots. The scanning near-field optical microscopy results revealed that the devices made by InGaN nanostructures could have better absorption for the near-field light with the wavelength of 457–514 nm.