Using a micro-Raman setup, in-plane Raman scattering was performed on short-period (001)-Si/Ge superlattices, and the complete phonon spectrum (longitudinal and transverse, optical and acoustic modes) could be studied. In the relevant wave-vector range, the in-plane dispersion was found to affect the frequencies of folded-acoustic modes, while being negligible for confined optical modes. The comparison with theoretical spectra, calculated by means of first-principles interatomic force constants, shows that the observed deviations of ''unfolded'' confined optical modes from the bulk dispersions can be attributed to interface roughness and is well described by a simple alloy layer model (2-3 intermixed SiGe atomic layers at interfaces).
|Titolo:||INPLANE RAMAN-SCATTERING OF (001)-SI/GE SUPERLATTICES - THEORY AND EXPERIMENT|
|Autori:||SCHORER R; ABSTREITER G; DE GIRONCOLI S; MOLINARI E; KIBBEL H; PRESTING H|
|Data di pubblicazione:||1994|
|Digital Object Identifier (DOI):||10.1103/PhysRevB.49.5406|
|Appare nelle tipologie:||1.1 Journal article|