Nonpolar m-Plane Blue-Light-Emitting Diode Lamps with Output Power of 23.5 mW under Pulsed Operation

Abstract
We report on the DC and pulsed performance of nonpolar m-plane InGaN/GaN multiple-quantum-well light-emitting diode (LED) lamps. LED structures were grown on free-standing m-plane GaN substrates by metalorganic chemical vapor deposition. LEDs with an area of 300×300 µm2 were packaged into conventional epoxy-encapsulated lamps. The emission wavelength of the LEDs was 452 nm. A CW output power as high as 0.6 mW was achieved at a drive current of 20 mA, corresponding to an external quantum efficiency of 1.09%. Pulsed power measurement on the lamps yielded an output power of 23.5 mW at a drive current of 1 A for a duty cycle of 0.25%.