Here, we present the efficient strategies to achieve high-efficiency polycrystalline MHP LEDs (PeLEDs) through the stoichiometry, self-organized conducting polymeric anode, nanocrystal pinning method, and core-shell-mimicked nanograin. First, we suggest how to realize high-efficiency polycrystalline MAPbBr3 PeLEDs based on a high workfunction conducting polymer anode by controlling precursor stoichiometry and applying additive-based nanocrystal pinning process for decreasing grain size to be nanoscale polycrytals and improving surface coverage of MAPbBr3 layer. From these strategies the efficiency of 42.9 cd/A was achieved. Moreover, by unravelling working mechanism of the additive-based nanocrystal pinning method, we showed how to overcome the EL efficiency limitations in PeLEDs; we achieved external quantum efficiency efficiency of 8.79% ph el-1.

报告人简介：Tae-Woo Lee is an associate professor in the department of materials science and engineering at Seoul National University, Korea. He received his Ph.D in chemical engineering from KAIST, Korea in February 2002. Then, he joined Bell Laboratories, USA as a postdoctoral researcher in 2002. From September 2003 to August 2008, he worked in Samsung Advanced Institute of Technology, Samsung Electronics as a member of research staff. From August 2008 to August 2016, he was an assistant and then an associate professor in the department of materials science and engineering at Pohang University of Science and Technology, Korea. He received a prestigious Korea Young Scientist Award from the President of Korea in 2008 and The Scientist of the Month Award from the ministry of science, ICT and future planning in 2013. He is author and co-author of 184 papers including Science, Nature Photonics, Science Advances, Nature Communications, PNAS, Energy and Environmental Science, Angewandte Chemie, and Advanced Materials, Nano Letters, as well as inventor and co-inventor of 357 patents (169 Korean patents and 188 international patents).