Invited Speaker
Biography
Angus Hin-Lap Yip joined the Department of Materials Science and Engineering and the School of Energy and Environment at City University of Hong Kong as Professor in 2021. He also serves as the associate director for Hong Kong Institute for Clean Energy since 2022. He is an elected member of the Hong Kong Young Academy of Sciences. From 2013-2020, he was a Professor at the State Key Laboratory of Luminescent Materials and Devices (SKLLMD) and the School of Materials Science and Engineering (MSE) at South China University of Technology (SCUT). He got his BSc (2001) and MPhil (2003) degrees in Materials Science from the Chinese University of Hong Kong (CUHK), and completed his Ph.D. degree in MSE in 2008 at the University of Washington (UW), Seattle. His research focuses on the use of an integrated approach combining materials, interface, and device engineering to improve both polymer and perovskite optoelectronic devices. He has published more than 270 scientific papers with citations over 34000 and an H-index of 97. He was also honored as ESI “Highly Cited Researcher” in Materials Science for nine times from 2014-2022.
< Home
Optical Design for High-efficiency White Perovskite LEDs
Angus Hin-Lap YIP 1,2,3
Abstract
Metal halide perovskite light-emitting diodes (PeLEDs) show great potential to be the next-generation lighting technology, with external quantum efficiencies (EQEs) exceeding 20% for infrared, red and green LEDs. However, the efficiencies of blue and white devices severely lag behind. To improve the performance of blue PeLEDs, we employed an integrated strategy combining dimensional engineering of perovskite film and recombination zone modulation in the LED device to obtain an EQE of up to 5 %. While further incorporating the strategy of interfacial engineering, highly efficient blue PeLEDs with EQEs over 10% have been successfully realized in our group, establishing an excellent platform for white-light emission. In our latest work, we demonstrated efficient white PeLEDs by optically coupling a blue PeLED with a red-emitting perovskite nanocrystal layer in an advanced device structure, which allows extracting the trapped optical modes (waveguide and SPP modes) of blue photons in the device to the red perovskite layer via near-field effects. As a result, white PeLEDs with EQE over 12% are achieved, representing the state-of-the-art performance for white PeLEDs.
References
[1] Z. Li, Z. Chen, H.-L. Yip et al. Nat. Commun. 2019, 10, 1027
[2] Z. Chen, Z. Li, H.-L. Yip et al. Joule 2021, 5, 456