Title: Surface Plasmon Coupled Light-emitting Diode 

Speaker: Prof. C. C. (Chih-Chung) Yang (Institute of Photonics and Optoelectronics, National Taiwan University, Taiwan, China）  

Time: Sept. 20, 2016 09:30AM 

Venue: Academic Conference Center, IOS, CAS 

Abstract: Based on Purcell’s theory, the emission efficiency of a light emitter can be enhanced when it is placed in a resonance cavity. The near field distribution of surface plasmon (SP) resonance around a metal/dielectric interface can be regarded as the field confined in a resonance cavity. Therefore, when a light emitter or radiating dipole is close to a metal/dielectric interface, SP coupling phenomenon can be observed that results in emission enhancement. Such a coupling process has been applied to nitride-based light-emitting diodes (LEDs) for increasing their internal quantum efficiencies, reducing their efficiency droop effects, and increasing their modulation bandwidths. In other words, SP coupling creates an alternative light emission channel through SP radiation for enhancing the effective radiative recombination rate such that the carrier decay rate in a quantum well becomes higher. In this presentation, the basic mechanisms of SP coupling together with simulation results are first discussed. Then, the implementations of SP-coupled LEDs in different spectral ranges (from deep-UV through green color) with various metal nanostructures are reviewed. Besides, the SP behaviors of the metal nanostructures when they are surrounded by different dielectric and metal materials are reported.

Biography：Professor Yang received his BS and Ph.D. degrees, both in electrical engineering, from National Taiwan University and University of Illinois at Urbana-Champaign, in 1976 and 1984, respectively. After nine year service as a faculty member at the Pennsylvania State University, he returned to Taiwan in 1993 and became a faculty member in the Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University, in which he is currently a distinguished professor. Professor Yang has published about 275 SCI journal papers and made more than 680 presentations at prestigious international conferences, including over 110 invited talks. His research areas include MBE and MOCVD growths of wide-band-gap semiconductor nanostructures, LED fabrication, plasmonics, and bio-photonics. Professor Yang is a fellow of Optical Society of America and a fellow of SPIE. He is also a recipient of the MOST outstanding research award.