Enhanced light output of angled sidewall light-emitting diodes with reflective silver films

K. N. Hui, K. S. Hui, Heesoo Lee, Dong-Hyun Hwang, Young-Guk Son

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


A proof-of-concept of applying laser micro-machining to fabricate high performance GaN light-emitting diode (LED) was presented in this study. Laser micro-machining was applied to fabricate GaN LED chip with angled sidewalls (ALED). The inclined sapphire sidewalls were coated with highly reflective silver film which functions as an efficient light out-coupling medium for photons within the LED structure. Thus, more laterally-propagating photons can be redirected to the upward direction of the ALED with silver coating (Ag-ALED). Performances of the Ag-ALED, ALED and conventional planar GaN LED were evaluated. At an injection current of 30 mA, the light output intensity of Ag-ALED was significantly improved by 97% and 195% as compared to ALED and conventional planar LED, respectively. The corresponding wall-plug efficiency of Ag-ALED was remarkably increased by 95% and 193% as compared to ALED and conventional planar LED, respectively. The results of this study demonstrated that the Ag-ALED showed a pronounced increase in light output intensity compared to conventional planar LED, which may have many potential applications in the field of display engineering.

Original languageEnglish
Pages (from-to)2504-2507
Number of pages4
JournalThin Solid Films
Issue number8
Early online date8 Dec 2010
Publication statusPublished - 1 Feb 2011


  • Gallium nitride
  • High light extraction efficiency
  • Inclined sidewalls
  • Light-emitting diodes

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