High reliability GaN-based light-emitting diodes with photo-enhanced wet etching

Abstract

This study concerns the generation of GaN-based light-emitting diodes (LEDs), whose n-GaN surfaces were processed using photo-enhanced chemical etching (PEC) by illumination using an unfiltered Hg arc lamp. Etching rates of 29.8 Å/min were obtained using KOH solution at a volume concentration of 45% and an illumination intensity of 50 mW/cm 2. The GaN light-emitting diodes with PEC process using KOH solution for 10 min, exhibit reverse currents of 4.83 × 10 −10 and 4.06 × 10 −8 A at reverse biases of 5 and 10 V, respectively. The GaN-based LEDs have an ideality factor n of 1.17 at a forward bias of 1.1 V. The degradation rate of the output power of light did not exceed 0.3% after burning-in for 500 h in a reliability test at 50 mA and room temperature.