Title :
High optical power and low-efficiency droop blue light-emitting diodes using compositionally step-graded InGaN barrier
Author :
Chih-Chien Pan ; Qimin Yan ; Houqiang Fu ; Yuji Zhao ; Yuh-Renn Wu ; Van de Walle, Chris ; Nakamura, Shuji ; DenBaars, Steven P.
Author_Institution :
Mater. Dept., Univ. of California, Santa Barbara, Santa Barbara, CA, USA
Abstract :
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.
Keywords :
III-V semiconductors; gallium compounds; indium compounds; light emitting diodes; wide band gap semiconductors; CSG; InGaN; LEDs; WPE; c-plane blue light-emitting diodes; compositionally step-graded barrier; efficiency 36 percent; efficiency 39 percent; efficiency 42 percent; efficiency 45 percent; high optical power light-emitting diodes; low-efficiency droop blue light-emitting diodes; low-voltage performance; wall-plug efficiency;
Journal_Title :
Electronics Letters
DOI :
10.1049/el.2015.1647
