Improvement of Reliability of GaN-Based Light-Emitting Diodes by Selective Wet Etching With p-GaN

• Published in: IEEE photonics technology letters Vol. 19; no. 11; pp. 813 - 815
• Main Authors: Ha, Ga-Young, Park, Tae-Young, Kim, Ja-Yeon, Kim, Dong-Joon, Min, Kyeong-Ik, Park, Seong-Ju
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2007; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Anti-freeze; Chemicals; Degradation; Etching; Ethylene glycol; GaN; Injection current; Leakage current; leakage currents; Light emitting diodes; light output power; light-emitting diodes (LEDs); Power generation; Rough surfaces; selective wet etching; Surface defects; Surface roughness; Voltage; Wet etching
• ISSN: 1041-1135; 1941-0174
• DOI: 10.1109/LPT.2007.897291

In an attempt to enhance the reliability of GaN-based light-emitting diodes (LEDs), the selective wet chemical etching of p-GaN surface in the GaN-based LEDs using KOH+NaOH in an ethylene glycol solution was investigated. The leakage currents of the etched LED under forward and reverse bias voltages were much lower, compared to those of a nonetched LED. The etched LED also showed improved light extraction efficiency and the degradation rate of light output power at a high injection current of 300 mA was slower than that for a nonetched LED. These results can be attributed to a decrease in the surface defects, an increase in hole concentration, and the increased surface roughness of the etched p-GaN