TY - JOUR
T1 - Enhanced light extraction efficiency via double nano-pattern arrays for high-efficiency deep UV LEDs
AU - Zheng, Zhihua
AU - Chen, Qian
AU - Dai, Jiangnan
AU - Wang, Ange
AU - Liang, Renli
AU - Zhang, Yi
AU - Shan, Maocheng
AU - Wu, Feng
AU - Zhang, Wei
AU - Chen, Changqing
AU - Li, Xiaohang
N1 - KAUST Repository Item: Exported on 2021-08-06
Acknowledged KAUST grant number(s): BAS/1/1664-01-01, REP/1/3189-01-01, URF/1/3437-01-01, URF/1/3771-01-01
Acknowledgements: This work is supported by the Key Project of Chinese National Development Programs (Grant No. 2019YFA0708203), the National Natural Science Foundation of China (Grant No. 61774065, 61974174), the Center for Nanoscale Characterization & Devices (CNCD), WNLO of HUST, and the Center of Micro-Fabrication and Characterization (CMFC) of WNLO for the support in EL tests. The KAUST authors would like to acknowledge the support of KAUST Baseline Fund BAS/1/1664-01-01, GCC Research Council Grant REP/1/3189-01-01, and Competitive Research Grants URF/1/3437-01-01 and URF/1/3771-01-01.
PY - 2021/6/27
Y1 - 2021/6/27
N2 - This work reports on the packaging structure of double-layer nano-pattern arrays (NPAs) for AlGaN-based deep ultraviolet (DUV) light-emitting diodes (LEDs), which can significantly enhance the light extraction efficiency (LEE), a major device performance bottleneck. The double-layer NPAs were fabricated on the surface of the flip-chip DUV LED by etching sapphire and coating the fluoropolymer resin, which can alleviate the total internal reflection (TIR) at the top interfaces and enhance light extraction on sidewalls, leading to the great improvement of both TE and TM-polarized light. As a result, the 273 nm DUV LED with double-layer NPAs realized 28.3% enhancement in light output power (LOP) compared with the reference device without the NPA at large current of 100 mA. High peak external quantum efficiency (EQE) and wall-plug efficiency (WPE) of 5.19% and 4.38% were demonstrated, respectively. Combined with the finite element analysis (FEA), it is further confirmed that the double-layer NPAs have higher external coupling efficiency to enhance LEE. The proposed LEE enhancement strategy comes from the combination of nanostructured materials and packaging technology, which is cost-effective and meets mass production, providing efficient value in practical applications of UV devices.
AB - This work reports on the packaging structure of double-layer nano-pattern arrays (NPAs) for AlGaN-based deep ultraviolet (DUV) light-emitting diodes (LEDs), which can significantly enhance the light extraction efficiency (LEE), a major device performance bottleneck. The double-layer NPAs were fabricated on the surface of the flip-chip DUV LED by etching sapphire and coating the fluoropolymer resin, which can alleviate the total internal reflection (TIR) at the top interfaces and enhance light extraction on sidewalls, leading to the great improvement of both TE and TM-polarized light. As a result, the 273 nm DUV LED with double-layer NPAs realized 28.3% enhancement in light output power (LOP) compared with the reference device without the NPA at large current of 100 mA. High peak external quantum efficiency (EQE) and wall-plug efficiency (WPE) of 5.19% and 4.38% were demonstrated, respectively. Combined with the finite element analysis (FEA), it is further confirmed that the double-layer NPAs have higher external coupling efficiency to enhance LEE. The proposed LEE enhancement strategy comes from the combination of nanostructured materials and packaging technology, which is cost-effective and meets mass production, providing efficient value in practical applications of UV devices.
UR - http://hdl.handle.net/10754/670435
UR - https://linkinghub.elsevier.com/retrieve/pii/S0030399221004485
UR - http://www.scopus.com/inward/record.url?scp=85111048639&partnerID=8YFLogxK
U2 - 10.1016/j.optlastec.2021.107360
DO - 10.1016/j.optlastec.2021.107360
M3 - Article
SN - 0030-3992
VL - 143
SP - 107360
JO - Optics and Laser Technology
JF - Optics and Laser Technology
ER -