Light-output enhancement of GaN-based vertical light-emitting diodes using periodic and conical nanopillar structures

Su Jin Kim, Kyeong Heon Kim, Ho Young Chung, Hee Woong Shin, Byeong Ryong Lee, Tak Jeong, Hyung Jo Park, Tae Geun Kim

Research output: Contribution to journalArticle

6 Citations (Scopus)


We investigated GaN-based vertical light-emitting diodes (VLEDs) with periodic and conical nanopillar arrays (CNAs) to improve the light-output efficiency. We found that a 470 nm diameter and 0.8-0.9 μm height increased the light output, and the devices suffered no significant electrical property degradations. The light-output power was 272% and 5.1% greater than flat- and rough-surface VLEDs at 350 mA, respectively. These improved optical properties are attributed to the optimized CNAs, which increase the effective photon escape cone and reduce the total internal reflection at the n-GaN-air interface. We also investigated the emission characteristics and mechanisms with finite-difference time-domain simulations.

Original languageEnglish
Pages (from-to)3464-3467
Number of pages4
JournalOptics Letters
Issue number12
Publication statusPublished - 2014 Jun 15


ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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