We studied external and internal patterns for boosting light extraction from GaN light-emitting diodes (LEDs). With a transparent conductive layer (TCL) inserted between an external pattern and an upper GaN plane, light extraction increased in a thin, high-refractive-index TCL. A periodic array of air voids embedded in a GaN medium yielded an extraction efficiency similar to the external pattern's one. For double-layer patterns, as the internal pattern was close to multiple quantum wells within a wavelength, the extraction efficiency was enhanced ∼30% over that of a single-layer pattern. This work will be useful for designing blue-to-ultraviolet-emitting GaN-based LEDs with multi-layer patterns.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation (NRF) of Korea grant No. 2009-0081565 funded by the Korean government Ministry of Science, Information Communications Technology, and Future Planning (MSIP).
- Finite-difference time-domain method
- Light-emitting diodes
- Photonic crystal
ASJC Scopus subject areas
- General Physics and Astronomy