12/16(一)專題演講公告

演講人呂宥蓉   教授

服務單位中央研究院應用科學研究中心 & 國立臺灣大學物理學系

演講題目Controlling Light-matter Interactions at Nanoscale with Plasmonics: From Spontaneous Emission to Lasing

演講時間1081216(星期一)早上1020

演講地點工綜館203國際演講廳

個人經歷

中央研究院 / 應用科學研究中心 (RCAS) / 助研究員

國立臺灣大學 / 物理學系 / 助理教授

演講摘要

In this talk, I will present an overview of my research works in recent five years. My previous works mainly focus on wavelength-tunable on-chip nanoemitters, such as InGaN nano-LEDs and InGaN plasmonic nanolasers. Here, I will specifically present my recent work during my 2-years Postdoc research in Caltech. I have developed a research project focusing on “Gate Tunable Spontaneous Emission Decay Rate of InP Quantum Dots” and “Organo-lead Halide Perovskite Nanolasers”. I have performed electromagnetic simulations to design gate tunable heterostructures for tuning spontaneous emission from quantum dots, which have been also fabricated and experimentally characterized. The idea is by electrically modulating the titanium nitride (TiN) in the designed plasmonic heterostructure, we demonstrated the field-effect modulated spontaneous emission rate of semiconductor quantum dots due to novel electric-field induced refractive index change mechanism. We demonstrate gate tunable spontaneous emission rate of InP quantum dots (QDs) due to bias induced modification of the local density of optical states (LDOS). The modulation is due to the large change in complex dielectric function at TiN/gate dielectric interface in the bias-induced accumulation/depletion layer. The underlying physics is very promising since by using electric-field induced LDOS modulation, not only bias-induced PL quenching but also bias-induced PL enhancing of semiconductor QDs can be observed. Unlike conventional LED structure which require special doping to make p-n junction or complex growth, this work opens the door towards optoelectronic applications that are simple to implement. This LDOS modulation effect provides an insight in development of tunable on-chip optical light sources for potential future application on electrically driven plasmonic nanolasers, ultracompact on-chip optical information processing, electrical controlled single photon emission, and thin film display.

20191216