Improved Emission Efficiency in InGaN Light-Emitting Diodes Using Reverse Bias in Pulsed Voltage Operation

Improved emission efficiency in InGaN near-ultraviolet light-emitting diodes (LEDs) was demonstrated using reverse bias in pulsed voltage operation. Pulsed voltage operation of the LEDs from 3 to 3.2 V with a duty cycle of 50% at Hz produced a radiant flux of 4.0 mW, while pulsed operation from 0 to 3.2 V showed a radiant flux of 3.2 mW. The radiant flux further increased as the reverse voltage increased, at the same forward voltage. The improved radiant flux was attributed to uniform carrier redistribution at the multiquantum wells, due to a periodically applied voltage from reverse voltage to forward voltage with a frequency ranged from to Hz, resulting in improved emission efficiency in InGaN LEDs.