TY - JOUR
T1 - Al2O3/AlN/Al-based backside diffuse reflector for high-brightness 370-nm AlGaN ultraviolet light-emitting diodes
AU - Park, Tae Hoon
AU - Lee, Tae Ho
AU - Kim, Tae Geun
N1 - Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (No. 2016R1A3B 1908249 ).
Publisher Copyright:
© 2018 Elsevier B.V.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2019/3/5
Y1 - 2019/3/5
N2 - We report an Al2O3/AlN/Al-based backside diffuse reflector for near-ultraviolet light-emitting diodes (NUV LEDs), and its superiority compared with conventional reflectors. After fabrication of LEDs, a sapphire (Al2O3) surface was UV-irradiated to utilize the diffuse reflection effect by roughening the surface. Then, a thermally treated AlN layer was deposited on it, to obtain a mirror-like surface, before deposition of Al. The reflectance increased by 1.3% and 3.9% for these Al2O3/AlN/Al reflectors without and with surface treatment, respectively, compared with an Al reflector. These reflectors were then used with 370 nm AlGaN NUV LEDs, and the performances of LEDs without and with an Al reflector were compared. As a result, the NUV LED with both thermally and UV-treated AlN/Al reflector exhibited the best performance, and its output power and electroluminescence intensity were higher by 82.7% and 41.9%, respectively, than those of the LED without a reflector.
AB - We report an Al2O3/AlN/Al-based backside diffuse reflector for near-ultraviolet light-emitting diodes (NUV LEDs), and its superiority compared with conventional reflectors. After fabrication of LEDs, a sapphire (Al2O3) surface was UV-irradiated to utilize the diffuse reflection effect by roughening the surface. Then, a thermally treated AlN layer was deposited on it, to obtain a mirror-like surface, before deposition of Al. The reflectance increased by 1.3% and 3.9% for these Al2O3/AlN/Al reflectors without and with surface treatment, respectively, compared with an Al reflector. These reflectors were then used with 370 nm AlGaN NUV LEDs, and the performances of LEDs without and with an Al reflector were compared. As a result, the NUV LED with both thermally and UV-treated AlN/Al reflector exhibited the best performance, and its output power and electroluminescence intensity were higher by 82.7% and 41.9%, respectively, than those of the LED without a reflector.
KW - Backside reflector
KW - Light-emitting diodes
KW - Surface treatment
KW - Ultraviolet
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U2 - 10.1016/j.jallcom.2018.10.264
DO - 10.1016/j.jallcom.2018.10.264
M3 - Article
AN - SCOPUS:85055806206
VL - 776
SP - 1009
EP - 1015
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
ER -