Berlin 2018 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 24: Poster Session II

HL 24.7: Poster

Tuesday, March 13, 2018, 18:30–20:30, Poster F

Spectroscopy of Single Silicon quantum dots in the vicinity of metal films — •Aswin Asaithambi, Guenther Prinz, and Axel Lorke — Lotharstrasse 1, Faculty of Physics, CENIDE, University of Duisburg-Essen, Duisburg 47057

Silicon is the most important and extensively used semiconductor concerning industrial production of electronic devices. However, the indirect band nature of Silicon makes it a poor light emitter. Light emitting efficiency can be increased by different methods such as use of III/V integration or using Si quantum dots (SiQDs).

In this contribution, we focus on photo-luminescence (PL) spectroscopy of single SiQDs. For this purpose, we use fluoride passivated SiQDs with a good ensemble PL quantum yield. We choose flourinated SiQDs because of their stable luminescence from 100K to RT. This makes them promising for building devices. These SiQDs are immobilized in a PMMA matrix on top of different metal films namely Au, Ag and Al. The optically excited SiQDs can couple to the metal film which can alter their luminescence behavior. We find that suitable metal films can couple effectively with SiQDs located at an optimal distance and can enhance the luminescence of the SiQDs. This makes it possible to measure time traces of PL spectra of single SiQDs to obtain data showing single dot optical phenomena such as PL intermittency and spectral jitter of the emission line. The measured data is discussed within the framework of the Efros-Rosen model and compared to the results available for CdSe QDs.