Open AccessFabrication of SiN_x-based photonic crystals on GaN-based LED devices with patterned sapphire substrate by nanoimprint lithography
Author(s) -
Kyeong Jae Byeon,
Joong Yeon Cho,
Jinseung Kim,
Hyoungwon Park,
Heon Lee
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.011423
Subject(s) - nanoimprint lithography , materials science , optoelectronics , light emitting diode , sapphire , electroluminescence , etching (microfabrication) , fabrication , layer (electronics) , substrate (aquarium) , photolithography , dry etching , lithography , photonic crystal , nanolithography , optics , laser , nanotechnology , medicine , oceanography , alternative medicine , physics , pathology , geology
SiNx-based photonic crystal (PhC) patterns were fabricated on the ITO electrode layer of a GaN-based light-emitting diode (LED) device on a patterned sapphire substrate (PSS) by a UV nanoimprint lithography process in order to improve the light extraction of the device. A three-dimensional finite-difference time-domain simulation confirmed that the light extraction of a GaN LED structure on a PSS is enhanced when SiNx PhC patterns are formed on the ITO top layer. From the I-V characteristics, the electrical properties of patterned LED devices with SiNx-based PhC were not degraded compared to the unpatterned LED device, since plasma etching of the p-GaN or the ITO layers was not involved in the patterning process. Additionally, the patterned LED devices with SiNx-based PhCs showed 19%-increased electroluminescence intensity compared with the unpatterned LED device at 445 nm wavelength when a 20 mA current is driven.