Polycrystalline GexSi1 − x thin film formation by chemical vapor deposition using silicon difluoride and germanium tetrachloride as precursors

Monolithic Axial and Radial Metal–Semiconductor Nanowire Heterostructures

“…For unambiguous Raman spectra interpretation, the core–shell NW heterostructures were fabricated on a 4H-SiC substrate, with the respective substrate peak at 203.5 cm –1 , far from the expected Raman signals of Ge and Si . The Raman spectrum of the intrinsic Ge–Si core–shell NW (red) displays three distinct Raman transverse optical (TO) modes at 301, 405, and 475 cm –1 assigned to Ge–Ge vibrations in the Ge core NW, Ge–Si vibrations in the SiGe interlayer, and Si–Si vibrations in the outermost Si shell, respectively. , The peak-broadening and frequency downshift of the first-order Si–Si optical phonon mode from 520 cm –1 for bulk Si to 475 cm –1 is attributed to quantum confinement in the ultrathin Si shell. , …”