Mechanism of optical degradation in microstructured InGaN light-emitting diodes

– ZL Li, KH Li, and HW Choi

Electroluminescent LEDs of different geometries: (a) large-area; (b) μhexagon array; and (c) μdisk array.

Journal of Applied Physics, vol. 108, 11, pp. 114511 (2010)

While the enhancement of light extraction efficiency from microstructured InGaN light-emitting diodes (?LED) has been firmly established, there is concern over the effect of microstructuring on the device lifetimes. A study on the electrical characteristics and reliability of ?LED arrays has been carried out. Despite improved optical performance, expanded device sidewalls served to accelerate the rate of optical degradation, adversely affect the lifetimes of devices. Through current-voltage plots and noise spectrum measurements, vertical current conduction along the plasma-damaged sidewalls was identified as the key degradation mechanism.

DOI: 10.1063/1.3517829