Ultrafast metal-semiconductor-metal photodetectors on low-temperature-grown GaN

We have fabricated and characterized ultrafast metal-semiconductor-metal photodetectors based on low-temperature-grown (LT) GaN. The photodetector devices exhibit up to 200kV∕cm electric breakdown fields and subpicosecond carrier lifetime. We recorded as short as 1.4-ps-wide electrical transients using 360-nm-wavelength and 100-fs-duration laser pulses, that is corresponding to the carrier lifetime of 720fs in our LT GaN material.