InGaN/GaN ultraviolet LED with a
graphene/AZO transparent current spreading
layer
LI LIN,
1
YIYU OU,
1
XIAOLONG ZHU,
2
EUGEN STAMATE,
3
KAIYU WU,
2
MENG
LIANG,
4
ZHIQIANG LIU,
4
XIAOYAN YI,
4
BERIT HERSTRØM,
5
ANJA BOISEN,
2
FLEMMING JENSEN,
5
AND HAIYAN OU
1,*
1
Department of Photonics Engineering, Technical University of Denmark, Oersteds Plads, Kongens
Lyngby 345A, DK-2800, Denmark
2
Department of Micro- and Nanotechnology, Technical University of Denmark, Oersteds Plads 344 and
345, Kongens Lyngby, DK-2800, Denmark
3
Department of Energy Conversion and Storage, Technical University of Denmark, Frederiksborgvej
399, Roskilde, DK- 4000, Denmark
4
Semiconductor Lighting R&D Center of Institute of Semiconductors, Chinese Academy of Sciences,
QingHua East Road A35, Beijing, 100083, China
5
National Center for Micro- and Nano-fabrication (DTU Danchip), Technical University of Denmark,
Oersteds Plads, Kongens Lyngby 347, DK-2800, Denmark
* haou@fotonik.dtu.dk
Abstract: We report an approach of using an interlayer of single layer graphene (SLG) for
electroluminescence (EL) enhancement of an InGaN/GaN-based near-ultraviolet (NUV)
light-emitting diode (LED) with an aluminum-doped zinc oxide (AZO)-based current
spreading layer (CSL). AZO-based CSLs with and without a SLG interlayer were fabricated
on the NUV LED epi-wafers. The current-voltage (I-V) characteristic and the EL intensity
were measured and compared. We find that the LED without the SLG interlayer can possess a
40% larger series resistance. Furthermore, a 95% EL enhancement was achieved by the
employment of the SLG interlayer.
© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
OCIS codes: (230.0230) Optical devices; (230.3670) Light-emitting diodes.
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Vol. 8, No. 7 | 1 Jul 2018 | OPTICAL MATERIALS EXPRESS 1818
https://doi.org/10.1364/OME.8.001818
Received 2 Apr 2018; revised 20 May 2018; accepted 5 Jun 2018; published 8 Jun 2018