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HL: Fachverband Halbleiterphysik

HL 36: Ge, GeSi, and Si

HL 36.8: Vortrag

Mittwoch, 24. März 2010, 11:30–11:45, H14

Towards efficient Silicon-based light sources using tailored photonic materials — •Norman Hauke¹, Thomas Zabel¹, Dominique Bougeard¹, Gerhard Abstreiter¹, Yasuhiko Arakawa², and Jonathan Finley¹ — ¹Walter Schottky Institut, Garching — ²University of Tokyo, Japan

We present optical investigations of two-dimensional (2D) silicon (Si) photonic crystal (PhC) defect nanocavities. Temperature dependent spatially resolved µ-photoluminescence (µPL) measurements in the range 20K-300K show that the emission in the cavity mode stems mainly from the bulk Si phonon satellites. Unlike in bulk and nanopatterned Si, emission from the cavity can be observed up to room-temperature. Moreover, quantitative analysis of the temperature stability spectrally in- and out-of-resonance with the cavity mode suggests that the enhanced emission at the cavity reflects enhanced internal quantum efficiency due to the Purcell-effect.
We also present temperature dependent µPL studies on 2D Si PhC slabs with epitaxial grown high-density (10¹¹ cm⁻²) Ge-islands acting as an internal light source. We demonstrate strong enhancement of the quantum dot emission at cavity mode resonance and interpret our findings as being due to a combination of spatial redistribution of the emitted light and Purcell-effect. We also present first time-resolved µPL measurements that compare the radiative lifetime when detecting on the PhC with the unpatterned region of our devices.
Supported financially by the DFG via NIM, TUM IGSSE and TUM IAS.