Exciton-optical phonon coupling in non-spherical quantum dots: A resonant Raman study of InP/ZnSe nanocrystals

[Display omitted] •Exciton-polar optical phonon scattering in non-spherical colloidal quantum dot.•Fine spectrum calculation with non-sphericity and electron-hole exchange coupling.•Exciton-phonon matrix elements calculation with phonon confinement.•Non-sphericity and exchange coupling influence on formation of Stokes shift.•Agreement of Raman spectrum with experimental data for InP/ZnSe nanocrystals. A theory of first-order resonance Raman scattering by exciton-polar optical phonon (confined and interface) interaction in a core/shell colloidal quantum dot is developed including corrections for non-sphericity. For this purpose both hole energy correction due to the non-sphericity of the quantum dot core and the effect of the electron-hole exchange coupling on the exciton states have been taken into account to calculate the matrix elements of the exciton-phonon Fröhlich interaction. Considering the exciton fine structure, the Raman scattering efficiency and the differential cross- section have subsequently been computed both for confined and interface phonon modes. It is shown that increase of the ellipticity of the dot core strongly alters the resonant Raman spectral profile stressing its key importance in analysis of the experimental data.