Interfacial confinement in core-shell nanowires due to high dielectric   mismatch
  We theoretically investigate the role of the dielectric mismatch between materials on the energy levels and recombination energies of a core-shell nanowire. Our results demonstrate that when the dielectric constant of the core material is lower than that of the shell material, the self-image potential pushes the charge carriers towards the core-shell interface, in such a way that the ideal confinement model is no longer suitable. The effects of this interfacial confinement on the electronic properties of such wires, as well as on its response to applied magnetic fields, are discussed. 
A. A. Sousa, T. A. S. Pereira, A. Chaves, J. S. de Sousa and G. A.   Farias
cond-mat.mes-hall cond-mat.mtrl-sci physics.comp-ph