Abstract
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 language | English |
---|---|
Pages (from-to) | 65-68 |
Number of pages | 4 |
Journal | Journal of Crystal Growth |
Volume | 326 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2011 Jul 1 |
Bibliographical note
Funding Information:The work at Korea University was supported by LG Innotek-Korea University Nano-Photonics Program . The work at NRL was supported by ONR and ONR-Global ( N62909-09-1-4060 ).
Keywords
- B1. Gallium compounds
- B3. Light-emitting diodes
ASJC Scopus subject areas
- Condensed Matter Physics
- Inorganic Chemistry
- Materials Chemistry