In situ Raman scattering studies of the amorphous and crystalline Si nanoparticl

2019-11-12 16:39:08

Si amorphous Raman nanoparticles phonon

责任者: Sienko, A.A.;Fox, J.R.;Akimov, I.A.;Xi, X.X.;Ruvimov, S.;Liliental-Weber, Z. 单位: Dept. of Phys., Pennsylvania State Univ., University Park, PA, USA 来源出处: Solid State Communications(Solid State Commun. (USA)),2000//,113(10):553-8 摘要: We report on in situ studies of the vibrational properties of Si nanoparticles and ultrathin layers grown by dc magnetron sputtering in ultrahigh vacuum on amorphous MgO and Ag buffer layers. The average thickness of the Si layers ranged from monolayer coverage up to 200 Å. Transmission electron microscopy has been used to determine size and shape of the Si nanoparticles. Changes in the phonon spectra of Si nanoparticles during the crystallization process have been studied by interference enhanced Raman scattering technique. Marked size-dependences in the phonon density of states and the relaxation of the k-vector conservation with decrease in size of the Si nanoparticles have been detected. The transition between crystalline- and amorphous-like behavior takes place in the particles with an average number of Si atoms equal to (7±2)×102 关键词: amorphous semiconductors;elemental semiconductors;monolayers;nanostructured materials;phonon spectra;Raman spectra;semiconductor thin films;silicon;sputtered coatings;transmission electron microscopy;Raman scattering;crystalline Si nanoparticles;amorphous Si nanoparticles;vibrational properties;ultrathin layers;dc magnetron sputtering;amorphous MgO;Ag buffer layer;monolayer coverage;transmission electron microscopy;phonon spectra;size-dependences;phonon density of states;k-vector conservation;200 A;Si