High optical power and low-efficiency droop blue light-emitting diodes using compositionally step-graded InGaN barrier

Chih Chien Pan, Qimin Yan, Houqiang Fu, Yuji Zhao, Yuh Renn Wu, Chris Van De Walle, Shuji Nakamura, Steven P. Denbaars

Research output: Contribution to journalArticle

18 Scopus citations


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/cm2, 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.

Original languageEnglish (US)
Pages (from-to)1187-1189
Number of pages3
JournalElectronics Letters
Issue number15
StatePublished - Jul 23 2015
Externally publishedYes


ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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