Fig. 1
a Cross-sectional transmission electron microscopy (CTEM) images as well as EDX elemental b line-scan spectra and c X-ray mapping micrographs of a SiO2/Ge QD/SiO2/SiGe shell heterostructure over the Si substrate. d Selected area diffraction patterns were generated by applying a fast Fourier transform to the local high-resolution CTEM images of the SiGe shell. The interplanar spacing is approximately 3.16 nm, corresponding to Si0.28Ge0.72 {111} planes