III-nitride ultraviolet light-emitting diodes with delta doping

Abstract
We present the results on the fabrication and characterization of 340 nm UV light-emitting diodes (LEDs) based on InAlGaN quaternary alloys grown by metalorganic chemical vapor deposition. By employing δ doping in the n- and p-type layers, we have demonstrated enhanced LED structural quality and emission efficiency. Combining with our interconnected microdisk LED architecture, the output power of a 300×300 μm2 bare LED chip measured from the sapphire side reached 50 μW under a standard dc operation condition (20 mA) at 4.6 V and 1.6 mW under a pulsed driving current.