Title :
Selective wet etching of p-GaN for efficient GaN-based light-emitting diodes
Author :
Na, Seok-In ; Ha, Ga-Young ; Han, Dae-Seob ; Kim, Seok-Soon ; Kim, Ja-Yeon ; Lim, Jae-Hong ; Kim, Dong-Joon ; Min, Kyeong-Ik ; Park, Seong-Ju
Author_Institution :
Dept. of Mater. Sci. & Eng., Gwangju Inst. of Sci. & Technol., South Korea
fDate :
7/1/2006 12:00:00 AM
Abstract :
The selective wet etching of a p-GaN layer by using a solution of KOH in ethylene glycol (KE) was studied to enhance the optical and electrical performance of the GaN-based light-emitting diodes (LEDs). The surface of the p-GaN, which was selectively etched in the KE solution, showed hexagonal-shaped etch pits. The light-output power of etched LEDs was improved by 29.4% compared to that of the nonetched LED. This improvement was attributed to the increase in the probability of photons to escape due to the increased surface area of textured surface and the reduction in contact resistance of the ohmic layer resulting from the increased contact area and hole concentration on the textured p-GaN. The reverse leakage current of the LED was also greatly decreased due to the surface passivation and the removal of defective regions from the p-GaN.
Keywords :
III-V semiconductors; contact resistance; etching; gallium compounds; light emitting diodes; ohmic contacts; passivation; probability; surface texture; GaN; GaN-based LED; KOH solution; contact resistance; ethylene glycol; hexagonal-shaped etch pits; hole concentration; light-emitting diodes; ohmic layer; p-GaN layer; photon probability; reverse leakage current; selective wet etching; surface passivation; textured surface; Dry etching; Laboratories; Leakage current; Light emitting diodes; Optical surface waves; Substrates; Surface resistance; Surface texture; Surface treatment; Wet etching; GaN; leakage currents; light-emitting diodes (LEDs); light-output power; selective wet etching;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2006.877562