Exciton-plasmon interactions in metal-semiconductor nanostructures
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Semiconductor quantum dots and metal nanoparticles feature very strong light-matter interactions, which has led to their use in many photonic applications such as photodetectors, biosensors, components for telecommunications etc.Under illumination both structures exhibit collective electron-photon resonances, described in the frameworks of quasiparticles as exciton-polaritons for semiconductors and surface plasmon-polaritons for metals.To date these two approaches to controlling light interactions have usually been treated separately, with just a few simple attempts to consider exciton-plasmon interactions in a system consisting of both semiconductor and metal nanostructures.In this work, the exciton-polaritons and surface \\plasmon-polaritons are first considered separately, and then combined using the Finite Difference Time Domain numerical method coupled with a master equation for the exciton-polariton population dynamics.To better understand the properties of excitons and plasmons, each quasiparticle is used to investigate two open questions - the source of the Stokes shift between the absorption and luminescence peaks in quantum dots, and the source of the photocurrent increase in quantum dot infrared photodetectors coated by a thin metal film with holes. The combined numerical method is then used to study a system consisting of multiple metal nanoparticles close to a quantum dot, a system which has been predicted to exhibit quantum dot-induced transparency, but is demonstrated to just have a weak dip in the absorption.
Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2012. , viii, 50 p.
Trita-BIO-Report, ISSN 1654-2312 ; 2012:4
plasmons, excitons, quantum dots, nanoparticles, FDTD, surface plasmon polaritons, QDIP, quantum dot infrared photodetector, polaritons
Nano Technology Theoretical Chemistry
IdentifiersURN: urn:nbn:se:kth:diva-93306ISBN: 978-91-7501-301-5OAI: oai:DiVA.org:kth-93306DiVA: diva2:515634
2012-04-26, B2, Brinellvägen 23, KTH, Stockholm, 14:00 (English)
Käll, Mikael, Professor
Fu, Ying, Docent
FunderSwedish e‐Science Research Center
QC 201204172012-04-172012-04-132013-04-09Bibliographically approved
List of papers