Characterization of Si/Si 1 -,Ge,/Si quantum wells by cathodoluminescence imaging and spectroscopy
نویسنده
چکیده
Cathodoluminescence (CL) imaging and spectroscopy have been used to characterize fully strained SiGe quantum wells grown on Si. At T-5 K, the CL spectra contain only band edge luminescence features. Monochromatic imaging with the no-phonon line attributed to the bound excitons in the quantum well, has shown that the distribution of the luminescence from the wells is not uniform. The thinnest well (33 & contained a low density of nonradiative (luminescence reduction up to 100%) spots 40-100 ,um in size. The thickest well (500 & contained similar nonradiative spots and also dark line features oriented along the (110) directions. These dark line features are areas of nonradiative recombination (up to 70%) and have been identified by transmission electron microscopy as misfit dislocations.
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