Interface optical phonons in spheroidal dots: Raman selection rules

2019-12-13 01:51:41

interface Raman DOTS phonon phonons

责任者: Comas, F.;Trallero-Giner, C.;Studart, N.;Marques, G.E. 单位: Dept. de Fisica, Univ. Fed. de Sao Carlos, Brazil 来源出处: Physical Review B (Condensed Matter and Materials Physics)(Phys. Rev, B, Condens, Matter Mater. Phys. (USA)),2002/02/15,65(7):073303-1 摘要: The contribution of interface phonons to first-order Raman scattering in nanocrystals with nonspherical geometry is analyzed. Interface optical phonons in the spheroidal geometry are discussed and the corresponding Fröhlich-like electron-phonon interaction is reported in the framework of the dielectric continuum approach. It is shown that the interface phonon modes are strongly dependent on the nanocrystal geometry, particularly on the ellipsoids semiaxis ratio. The new Raman selection rules have revealed that solely interface phonon modes with even angular momentum are allowed to contribute to the first-order phonon-assisted scattering of light. On this basis we are able to give an explanation for the observed low-frequency “shoulders” present in the Raman cross section of several II-VI semiconductor nanostructures 关键词: electron-phonon interactions;II-VI semiconductors;interface phonons;nanostructured materials;Raman spectra;semiconductor quantum dots;quantum dots;interface optical phonons;spheroidal dots;Raman selection rules;first-order Raman scattering;nanocrystals;nonspherical geometry;Frohlich-like electron-phonon interaction;dielectric continuum;II-VI semiconductor