'All-inorganic Lead Halide Perovskites as a Gain Material for Lasers' Dr Handong Sun, Nanyang Technological University, Singapore
Date: 18 October 2019 Time: 15:00 - 16:00
We welcome Dr Handong Sun, from the Nanyang Technological University in Singapore to Queen Mary. He will be giving a talk on optical materials and photonic applications with perovskite lasing materials, which is a hot topic.
All-inorganic cesium lead halide perovskite nanostructures have been emerging as a new class of quantum materials for lasing. I will report on low-threshold and ultrastable stimulated emission under atmospheric conditions from CsPbX3 nanocrystals. The gain mechanism can be attributed to biexcitonic recombination and a reasonable slow Auger recombination rate is observed. The nonlinear optical properties including the multi-photon absorption and resultant photoluminescence of the CsPbX3 nanocrystals were investigated. A large two-photon absorption cross-section of up to ~1.2×105 GM is determined from 9 nm-sized CsPbBr3 nanocrystals. Low-threshold frequency-upconverted stimulated emission by multi-photon absorption was also observed from the thin films of close-packed CsPbBr3 nanocrystals. Moreover, I will report the breakthrough in realizing the challenging while practically desirable vertical cavity surface emitting lasers (VCSELs) based on the CsPbX3 inorganic perovskite nanocrystals. These laser devices feature record low threshold, unidirectional output and superb stability. Both single-mode and multimode lasing operation are achievable in the device. We further explore on-chip optoelectronic devices fabricated from a CsPbBr3 single crystal by means of FIB.
Dr Sun is currently working as an Associate Professor in the School of Physical & Mathematical Sciences, Nanyang Technological University (NTU), Singapore. He received his Bachelor degree in Physics from Dalian University of Technology, Master and PhD degrees from Huazhong University of Science & Technology, and Hong Kong University of Science & Technology, respectively. Before joining NTU, he did postdoctoral research works at RIKEN, Japan and Institute of Photonics, The University of Strathclyde, UK. Dr Sun is an elected Fellow of American Physical Society. His research theme exists at the interface between optical physics and material science, i.e. light-matter interaction. His current research works focus on Optical Spectroscopic Characterization, Optoelectronic Materials and Devices, Plasmonics Optics, and Applications of Photonics.
|Location:||G.O. Jones Room 410 A&B, Mile End Campus, Queen Mary University of London|
|Contact:||Dr Huanqing Ye|