Optimization and Fabrication of III-Nitride Light-Emitting Diodes with Self-assembled Colloidal-based Convex Microlens Arrays

Author

Ee, Yik-Khoon ; Kumnorkaew, Pisist ; Gilchrist, James F. ; Arif, Ronald A. ; Tong, Hua ; Tansu, Nelson

Author_Institution

Dept. of Electr. & Comput. Eng., Lehigh Univ., Bethlehem, PA

fYear

2008

fDate

8-11 Dec. 2008

Firstpage

1

Lastpage

4

Abstract

Improvement of light extraction efficiency of InGaN light emitting diodes (LEDs) using colloidal-based SiO₂ / polystyrene microlens arrays was demonstrated. The size effect of the SiO₂ microspheres and the thickness of the polystyrene layer on the light extraction efficiency were studied. Ray tracing simulations show that the use of microlens arrays leads to increase in light extraction efficiency by 2.6 times. This is consistent with experiments that demonstrated 2.7 times improvement in light extraction utilizing SiO₂/polystyrene microlens arrays. The enhancement in light extraction efficiency is attributed to increase in effective photon escape cone due to SiO₂/polystyrene microlens arrays.

Keywords

III-V semiconductors; colloids; gallium compounds; indium compounds; light emitting diodes; microlenses; optimisation; ray tracing; self-assembly; semiconductor quantum wells; size effect; III-nitride light-emitting diodes; InGaN; SiO₂; light extraction efficiency; microspheres; optimization; polystyrene layer thickness; polystyrene microlens arrays; ray tracing simulations; self-assembled colloidal-based convex microlens arrays; size effect; Chemicals; Fabrication; Gallium nitride; Lenses; Light emitting diodes; Microoptics; Optical arrays; Photonic crystals; Rough surfaces; Surface roughness;

fLanguage

English

Publisher

ieee

Conference_Titel

PhotonicsGlobal@Singapore, 2008. IPGC 2008. IEEE

Conference_Location

Singapore

Print_ISBN

978-1-4244-3901-0

Electronic_ISBN

978-1-4244-2906-6

Type

conf

DOI

10.1109/IPGC.2008.4781319

Filename

4781319