Vibrational properties of near-surface regions of silicon nanocrystallites

2019-10-16 06:26:15

surface CM phonons peaks

责任者: Wu, X.L.;Yuan, X.Y.;Tong, S.;Liu, X.N.;Bao, X.M.;Jiang, S.S.;Zhang, X.K.;Feng, D. 单位: Lab. of Solid State Microstruct., Nanjing Univ., China 来源出处: Solid State Communications(Solid State Commun. (USA)),1997/11/,104(6):355-9 摘要: Raman spectra of hydrogenated nanocrystalline silicon films clearly exhibit two size- and crystalline-fraction-dependent spectral regions related to the structural properties of nanocrystals. One is the crystalline band from crystallite core consisting of two neighbouring peaks at 513 and 519 cm-1. The appearance of the two peaks is attributed to the contribution of both LO and TO phonons at phonon wavevector q≠0 due to phonon confinement. The other consists of several small peaks superposed on the broad band at ~480 cm-1. Based on a three-region model of the nanocrystallites, the existence of these small peaks is proposed to be due to atomic vibrations of the near-surface regions in silicon nanocrystallites, sandwiched between the crystalline core and disordered outer surface 关键词: crystallites;elemental semiconductors;hydrogen;nanostructured materials;phonons;plasma CVD coatings;Raman spectra;silicon;vibrational properties;near-surface regions;nanocrystallites;hydrogenated nanocrystalline Si films;structural properties;LO phonons;TO phonons;phonon confinement;three-region model;atomic vibrations;crystalline core;disordered outer surface;PECVD films;Raman spectra;480 cm-1;513 cm-1;519 cm-1;Si:H