PHOTOLUMINESCENCE FROM SI SI0.87GE0.13 MULTIPLE-QUANTUM-WELL WIRES/

This paper reports a low temperature photoluminescence study of the op tical properties of a series of dry etched free standing strained laye r Si/Si0.87Ge0.13 multiple quantum well wires with lateral dimensions between 40nm and 500nm. The results show that dry etching induces part ial strain relaxation. An enhanced electron-hole droplets emission fro m the Si layers with reducing wire width was observed due to both the extra surface roughness introduced during the etching process, which a ccelerates the nucleation of the droplets formation, and the effect of lateral confinement. A new feature at 1.131eV at 4K related to unknow n impurity states located at the heterointerfaces was also detected.