Flip-Chip p(GaN)-i(GaN)-n(AlGaN) Narrowband UV-A Photosensors

Flip-chip p(GaN)-i(GaN)-n(AlGaN) photosensors with extremely low dark currents were fabricated and characterized. It was found that the sensor with a 0.5-mum-thick Si-doped n
⁺
-Al
_0.15
Ga
_0.85
N layer could only detect optical signals with wavelength in between 325 and 360 nm. With an incident wavelength of 355 nm, the authors achieved a peak responsivity of 0.16 A/W at zero bias, which corresponds to an external quantum efficiency of 56%