Raman spectra of CdS nanocrystals in Nafion: longitudinal optical and confined a

2019-11-21 16:38:08

EV modes phonon confined broadening

责任者: Nandakumar, P.;Vijayan, C.;Alakshmi, M.R.;Arora, A.K.;Murti, Y.V.G.S. 单位: Dept. of Phys., Indian Inst. of Technol., Madras, India 来源出处: Physica E(Physica E (Netherlands)),2001/11/,11(4):377-83 摘要: Quantum confinement effects on the longitudinal optical and acoustic phonons in US nanocrystals in the strongly confined regime in the polymer matrix Nation are studied using Raman spectroscopy. The LO-phonon modes show size-dependent asymmetric broadening though the broadening and asymmetry are less than those predicted by the phonon confinement models. Two types of confined acoustic modes corresponding to n = 1, l = 0 and n = 1, l = 2 spheroidal vibrations are observed. Softening of the spheroidal modes is observed in the strongly confined regime 关键词: cadmium compounds;II-VI semiconductors;nanostructured materials;phonon spectra;quantum interference phenomena;Raman spectra;semiconductor quantum dots;soft modes;spectral line broadening;Raman spectra;CdS nanocrystals;Nafion;longitudinal optical phonon modes;confined acoustic phonon modes;quantum confinement effects;size-dependent asymmetric broadening;spheroidal vibrations;spheroidal modes softening;1.6 to 6.0 nm;457.9 nm;488 nm;10 to 20 mW;240 to 340 cm-1;2.42 eV;2.5 eV;2.72 eV;2.76 eV;2.88 eV;10 to 40 cm-1;514.5 nm;CdS