Open AccessOperating behavior of micro-LEDs on a GaN substrate at ultrahigh injection current densities
Author(s) -
C. C. Li,
Jing Zhan,
Z. Z. Chen,
Fei Jiao,
Y. F. Chen,
Jingxin Nie,
Xiaoning Kang,
S. F. Li,
Qi Wang,
G. Y. Zhang,
Bo Shen
Publication year - 2019
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.27.0a1146
Subject(s) - light emitting diode , current crowding , materials science , current density , optoelectronics , current (fluid) , electroluminescence , diffusion , substrate (aquarium) , diffusion current , optics , nanotechnology , physics , oceanography , layer (electronics) , quantum mechanics , geology , thermodynamics
Near-ultraviolet micro-LEDs with different diameters were fabricated on GaN substrates. The electroluminescence and the light output power-current density and current density-voltage relationships were measured. A saturated current density of 358 kA/cm 2 was achieved with a 20 µm LED. The ideality factor curves showed steps and peaks when the injection current density was increased from 20 to 150 kA/cm 2 and an abnormal efficiency increase. The transport and recombination processes of micro-LEDs at high injection current densities were simulated, and the many-body effect and phase space filling in the integrated quantum drift-diffusion model were considered. Serious current crowding was observed above 100 kA/cm 2 , even for the 20 µm LED.