Semipolar III–nitride light-emitting diodes with negligible efficiency droop up to ~1 W

Research Paper –

Sang Ho Oh1, Benjamin P. Yonkee2, Michael Cantore2, Robert M. Farrell2, James S. Speck2, Shuji Nakamura1,2 and Steven P. DenBaars1,2

Published 7 September 2016 • © 2016 The Japan Society of Applied Physics

Applied Physics Express, Volume 9, Number 10

Abstract

We demonstrate 1 mm2 blue light-emitting diodes with a negligible efficiency droop up to ~1 W. LEDs with 12- to 14-nm-thick single quantum wells were grown by metalorganic chemical vapor deposition on a free-standing semipolar $(20\bar{2}\bar{1})$ GaN substrate. Packaged devices showed an external quantum efficiency of 42.3% at 20 A/cm2 with a negligible efficiency droop up to 991 mW at 900 mA. At 900 mA, the thermal droop and hot/cold factor were 8.2% and 0.92, respectively. The adoption of a thick active region resulted in excellent optical and thermal performance characteristics that are suitable for high-power lighting applications.

Author affiliations

1 Department of Electrical and Computer Engineering, University of California, Santa Barbara, CA 93106, U.S.A.

2 Materials Department, University of California, Santa Barbara, CA 93106, U.S.A.

Dates

Received 1 August 2016

Accepted 18 August 2016

Published 7 September 2016

Source Link: 

http://iopscience.iop.org/article/10.7567/APEX.9.102102/meta;jsessionid=579625F83AAEEF54BC13AA5826E3493F.c3.iopscience.cld.iop.org