title: An improvement of light extraction efficiency for GaN-based light emitting diodes by selective etched nanorods in periodic microholes.
abstract: We have demonstrated the enhancement of a GaN-based light emitting diode (LED) by means of a selective etching technique. A conventional LED structure was periodically etched, to form periodic microholes. It showed an improvement of the light extraction efficiency (LEE) of approximately 15%, compared to that of a conventional LED. Furthermore, nano-sized rods inside the microholes were randomly formed by using a powder mask, resulting in an LEE of 43%. From the result of confocal scanning electroluminescence measurement, the light emission arises mainly from the vicinity of the nanorods in the periodic microholes. Therefore, we found that nanorods randomly distributed in periodic microholes in a LED structure play a significant role in the reduction of total internal reflection, by acting as photon wave-guides and scattering centers. This method would be valuable for the fabrication of high efficiency GaN-based LED, in terms of technical simplification and cost.
authors.affiliation: School of Semiconductor and Chemical Engineering, Semiconductor Physics Research Center, Chonbuk National University, Jeonju 561-756, South Korea.
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Kim
authors.forename: Hyun Ho
authors.initials: HH
authors.lastname: Park
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Song
authors.forename: Hyung Jo
authors.initials: HJ
authors.lastname: Park
authors.forename: Jae Beom
authors.initials: JB
authors.lastname: Kim
authors.forename: Seong Ran
authors.initials: SR
authors.lastname: Jeon
authors.forename: Hyun
authors.initials: H
authors.lastname: Jeong
authors.forename: Mun Seok
authors.initials: MS
authors.lastname: Jeong
authors.forename: Gye Mo
authors.initials: GM
authors.lastname: Yang
mesh_terms: D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005708:Gallium / Q000737:chemistry*; D008029:Lighting / Q000295:instrumentation*; D036103:Nanotechnology / Q000295:instrumentation*; D043942:Nanotubes / Q000737:chemistry*; D012666:Semiconductors; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: C473348:gallium nitride; D005708:Gallium