Demonstration of phosphor-free polarized white light emission from monolithically integrated semipolar InGaN quantum wells

Type
Article

Authors
Kowsz, S. J.
Pynn, C. D.
Oh, S. H.
Farrell, R. M.
Speck, J. S.
DenBaars, S. P.
Nakamura, S.

KAUST Grant Number
KACST-KAUST-UCSB Solid State Lighting Program (SSLP)

Date
2015

Abstract
We report a device design that monolithically integrates an electrically injected blue light-emitting diode grown on the (202¯1¯) face of a bulk GaN substrate and yellow emitting optically pumped InGaN quantum wells (QWs) grown on the (202¯1) face. Emission peaks are observed at 440 nm and 560 nm from the electrically injected and optically pumped QWs, respectively. The ratio of blue to yellow light can be optimized to result in polarized white light emission from this phosphor-free device. We demonstrate emission with Commission Internationale de l'Eclairage x- and y-chromaticity coordinates of (0.28, 0.29) and an optical polarization ratio of 0.40.

Citation
Kowsz, S. J., Pynn, C. D., Oh, S. H., Farrell, R. M., Speck, J. S., DenBaars, S. P., & Nakamura, S. (2015). Demonstration of phosphor-free polarized white light emission from monolithically integrated semipolar InGaN quantum wells. Applied Physics Letters, 107(10), 101104. doi:10.1063/1.4930304

Acknowledgements
This work was supported by the Solid State Lighting & Energy Electronics Center (SSLEEC) and the KACST-KAUST-UCSB Solid State Lighting Program (SSLP). A portion of this work was done in the UCSB nanofabrication facility, part of the NSF funded National Nanotechnology Infrastructure Network (ECS-03357650). This work made use of the MRL Central Facilities at UCSB supported by the MRSEC Program of the NSF under Award No. DMR 1121053. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE 1144085. The authors would like to thank the contributors to the open source Python color science package Colour, which is freely distributed under the New BSD License and was used to generate the CIE diagram as well as calculate CIE coordinates and color temperature.

Publisher
AMER INST PHYSICS

Journal
APPLIED PHYSICS LETTERS

DOI
10.1063/1.4930304

Additional Links
http://aip.scitation.org/doi/10.1063/1.4930304

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