Regensburg 2013 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 87: Goup IV elements and their compounds II
HL 87.6: Vortrag
Donnerstag, 14. März 2013, 17:00–17:15, H15
Photonic crystal microcavities for the luminescence enhancement of Si/Ge-Quantum dots around 1550nm wavelength — •Viktoriia Rutckaia1, Benjamin Koehler1, Vadim Talalaev2, Frank Heyroth3, and Joerg Schilling2 — 1Martin-Luther University, Halle (Saale), Germany — 2Centre for Innovation Competence SiLi-nano, Halle (Saale), Germany — 3Interdisciplinary Center of Materials Science, Halle (Saale), Germany
Defects in two dimensional photonic crystal slabs represent microcavities with small mode volumes and can exhibit large Q-factors. This can lead to a large enhancement of spontaneous emission rate causing an overall enhancement of radiative recombination efficiency. This was also already observed for the photoluminescence of Ge quantum dots in Si [1]. The aim of this work is to show how the Q-factor of certain defect modes can be altered by adjusting the geometry of the pores adjacent to the cavity. This involves changing their diameter and variation of their positions. We present band gap and defect resonance calculations for 2D photonic crystal cavities using MIT mpb program [2], and COMSOL multiphysics. From the field distribution the mode volume is determined and theoretically possible Purcell factors are obtained. Experimental studies of the luminescence enhancements in the micro cavities involve micro-photoluminescence measurements on Ge quantum dots embedded in Si. Defect resonances are observed and their Q-factors were obtained from the luminescence spectra. [1] J.S.Xia,Y.Ikegami, and Y.Shiraki, Appl.Phys.Let.89,201102(2006),[2] Steven G.Johnson and J.D.Joannopoulos, Opt.Exp.8,3,173-190(2001)