Open AccessEffect of current spreading on the efficiency droop of InGaN light-emitting diodes
Author(s) -
Han-Youl Ryu,
JongIn Shim
Publication year - 2011
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.19.002886
Subject(s) - voltage droop , current crowding , materials science , diode , optoelectronics , light emitting diode , current (fluid) , current density , indium gallium nitride , optics , equivalent series resistance , quantum efficiency , layer (electronics) , gallium nitride , voltage , electrical engineering , physics , composite material , quantum mechanics , voltage divider , engineering
We investigate the effects of current spreading on the efficiency droop of InGaN blue light-emitting diodes with lateral injection geometry based on numerical simulation. Current crowding near the mesa edge and the decrease in the current spreading length with current density are shown to cause significant efficiency droop. It is found that the efficiency droop can be reduced considerably as the uniformity of current spreading is improved by increasing the resistivity of the p-type current spreading layer or decreasing the sheet resistance of the n-GaN layer. The droop reduction is well interpreted by the uniformity of carrier distribution in the plane of quantum wells.