title: Light extraction enhancement from nano-imprinted photonic crystal GaN-based blue light-emitting diodes.
abstract: The nano-imprint lithography method was employed to incorporate wide-area (375 x 330 mum(2)) photonic-crystal (PC) patterns onto the top surface of GaN-based LEDs. When the 280-nm-thick p-GaN was partly etched to ~140 nm, the maximal extraction-efficiency was observed without deteriorating electrical properties. After epoxy encapsulation, the light output of the PC LED was enhanced by 25% in comparison to the standard LED without pattern, at a standard current of 20 mA. By three-dimensional finite-difference time-domain method, we found that the extraction efficiency of the LED tends to be saturated as the etch-depth in the GaN epitaxial-layer becomes larger than the wavelength of the guided modes.
authors.forename: Hyun Kyong
authors.initials: HK
authors.lastname: Cho
authors.forename: Junho
authors.initials: J
authors.lastname: Jang
authors.forename: Jeong-Hyeon
authors.initials: JH
authors.lastname: Choi
authors.forename: Jaewan
authors.initials: J
authors.lastname: Choi
authors.forename: Jongwook
authors.initials: J
authors.lastname: Kim
authors.forename: Jeong Soo
authors.initials: JS
authors.lastname: Lee
authors.forename: Beomseok
authors.initials: B
authors.lastname: Lee
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Choe
authors.forename: Ki-Dong
authors.initials: KD
authors.lastname: Lee
authors.forename: Sang Hoon
authors.initials: SH
authors.lastname: Kim
authors.forename: Kwyro
authors.initials: K
authors.lastname: Lee
authors.forename: Sun-Kyung
authors.initials: SK
authors.lastname: Kim
authors.forename: Yong-Hee
authors.initials: YH
authors.lastname: Lee