Wet etching of non-polar gallium nitride light-emitting diode structure for enhanced light extraction

Hong Yeol Kim, Younghun Jung, Sung Hyun Kim, Jaehui Ahn, Michael A. Mastro, Jennifer K. Hite, Charles R. Eddy, Ji Hyun Kim

Research output: Contribution to journalArticle

12 Citations (Scopus)


The surface of a non-polar a-plane GaN light-emitting diode (LED) was intentionally damaged with a KOH wet etch to enhance the extraction of light. This roughening technique has been commonly applied to c-plane polar GaN LEDs to extract photons that would otherwise suffer from total internal refraction. We show that wet etching of the non-polar LED does create a textured surface that increases the light extraction efficiency; however, the mechanism of the etch is quite dissimilar to the etch mechanism observed for c-plane LEDs. In fact, the etch proceeds perpendicular to the a-plane surface along unstable N-face (0 0 0 -1) plane with the Ga-face plane resistant to the etch. The photoluminescence intensity from a-plane non-polar LED after KOH-based wet etching was increased by 83% in our experiments. Therefore, surface roughening by KOH-based wet etch was found to be very effective to extract photons from a-plane non-polar GaN-based LEDs.

Original languageEnglish
Pages (from-to)65-68
Number of pages4
JournalJournal of Crystal Growth
Issue number1
Publication statusPublished - 2011 Jul 1



  • B1. Gallium compounds
  • B3. Light-emitting diodes

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Materials Chemistry
  • Inorganic Chemistry

Cite this