Jianfang Wabg : Plasmonic Nanocavities and Chiral Plasmonic Nanoparticles

I will present our recent works on plasmonic nanocavities and chiral plasmonic nanoparticles. We have synthesized circular Au nanodisks with excellent size control and fabricated plasmonic Au nanodisk-on-mirror (NDoM) cavities. NDoM cavities exhibit well-controlled anapole and magnetic plasmon modes. Two-dimensional (2D) transition metal dichalcogenide (TMDC) monolayers are successfully sandwiched within NDoM cavities. NDoM cavities have been found to be able to enhance the emissions of bright excitons, switch on dark excitons, and enhance the coherence of valley excitons. We have also developed recipes for the synthesis of chiral Au nanoparticles in the presence of small peptide enantiomers, including chiral Au nanocubes, nanotriskelions, and nanorods. The scattering dissymmetry factors of these chiral nanoparticles can reach +0.57 and −0.49 at 650 nm, respectively. Efficient circularly polarized (CP) organic light-emitting diodes (OLEDs) are further fabricated through the assembly of chiral plasmonic Au nanoparticles and supramolecular aggregates. The emissions of the OLEDs are dominated by either chiral excitons or chiral plasmons, dependning on the type of chiral plasmonic nanoparticle. The CP-OLED showing a high external quantum efficiency of 2.5% and a large dis-symmetry factor of 0.31 is achieved, as a result of multiscale chirality transfer, plasmonic enhancement, and the suppression of the overshoot effect.

Biography

WANG Jianfang obtained his BS degree in inorganic chemistry and software design in 1993 from University of Science and Technology of China, his MS degree in inorganic chemistry in 1996 from Peking University, and his PhD degree in physical chemistry in 2002 from Harvard University. He did postdoctoral study in University of California Santa Barbara from 2002 to 2005. He joined Department of Physics at The Chinese University of Hong Kong (CUHK) in

2005 as an assistant professor. He became an associate professor in 2011 and a full professor in 2015. He was the Assistant Dean of the Faculty of Science of CUHK from August 2015 to July 2021 and has been the Chairperson of the Department of Physics of CUHK since August 2021. His current research interests are nanoplasmonics, nanophotonics, and photocatalysis. According to Google Scholar, he has published more than 320 papers with a total citation of more than 51,200 and an h-index of 106.