Open AccessHigh optical power and low‐efficiency droop blue light‐emitting diodes using compositionally step‐graded InGaN barrier
Author(s) -
Pan ChihChien,
Yan Qimin,
Fu Houqiang,
Zhao Yuji,
Wu YuhRenn,
Van de Walle Chris,
Nakamura Shuji,
DenBaars Steven P.
Publication year - 2015
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
ISSN - 1350-911X
DOI - 10.1049/el.2015.1647
Subject(s) - light emitting diode , optoelectronics , materials science , voltage droop , diode , blueshift , voltage , blue light , wide bandgap semiconductor , photoluminescence , electrical engineering , voltage source , engineering
A compositionally step‐graded (CSG) InGaN barrier is designed for the active region of c ‐plane blue light‐emitting diodes (LEDs). High external quantum efficiencies of 45, 42, 39 and 36% are achieved at current densities of 100, 200, 300 and 400 A/cm 2 , respectively. Compared with GaN barrier devices, LEDs with CSG InGaN barriers showed higher power, lower operating voltage and smaller wavelength blueshift, compared with GaN barrier LEDs. Owing to the low‐voltage performance, higher wall‐plug efficiency can be achieved for blue LEDs with CSG InGaN barriers.