Title :
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
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;
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
DOI :
10.1109/IPGC.2008.4781319
