Open AccessHigh-voltage thin-film GaN LEDs fabricated on ceramic substrates: the alleviated droop effect at 670 W/cm^2
Author(s) -
Meng-Lun Tsai,
Jian-Jie Liao,
Jui-Hung Yeh,
Ta-Cheng Hsu,
S. J. Hon,
Te Yuan Chung,
K. Robert Lai
Publication year - 2013
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.21.027102
Subject(s) - materials science , light emitting diode , voltage droop , optoelectronics , ceramic , passivation , substrate (aquarium) , thin film , voltage , diode , optics , electrical engineering , composite material , voltage source , nanotechnology , layer (electronics) , oceanography , physics , geology , engineering
High-voltage thin-film GaN LEDs with the emission wavelength of 455 nm were fabricated on ceramic substrates (230 W/m · K). The high-voltage operation was achieved by three cascaded sub-LEDs with dielectric passivation and metal bridges conformally deposited on the side walls. Under the driving power of 670 W/cm(2), the high-voltage LEDs exhibit much alleviated efficiency droop and the operative temperature below 80 °C. The excellent performances were attributed to the improved current spreading within each sub-LED and the superior heat sinking of the ceramic substrate.