32/spl times/32 ultraviolet Al/sub 0.1/Ga/sub 0.9/N/GaN p-i-n photodetector array

We report the fabrication and performance of a 32/spl times/32 Al/sub 0.1/Ga/sub 0.9/N-GaN ultraviolet p-i-n photodetector array. The devices exhibit very low dark current, the mean dark current density is /spl sim/4 nA/cm/sup 2/ at 5-V reverse bias, and the dark current distribution is very uniform (/spl sim/98% of the devices exhibit dark current density <90 nA/cm/sup 2/). Owing to the design of the p-Al/sub 0.13/Ga/sub 0.87/N window layer, the external quantum efficiency is as high as 72% at 357 nm. The photocurrent distribution is also presented. The detectivity is estimated to be as high as 8/spl times/10/sup 14/ cm/spl middot/Hz/sup 1/2//spl middot/W/sup -1/.