IMPORTANT DEFECT ASPECTS IN OPTOELECTRONIC APPLICATIONS OF SI- AND SIGE SI-HETEROSTRUCTURES/

We have carried out a systematic investigation of non-radiative defect s in Si-epilayers and SiGe/Si-heterostructures grown by molecular beam epitaxy (MBE). A number of non-radiative defects are observed, by the optically detected magnetic resonance (ODMR) technique, and are shown to depend critically on the sample structures and growth conditions. Experimental evidence on the mechanisms for the introduction of these defects are provided. These defects provide efficient non-radiative ch annels for carrier recombination and, to a large extent, control the c arrier lifetime.