Electron-phonon interaction in rare earth doped nanocrystals

Nanoscale materials exhibit properties which differ considerably from their bulk counterparts due to modifications of their phonon density of states due to finite size effects. Rare earth doped insulating nanoparticles provide an ideal model system for studying the fundamental interactions between electronic states and phonons since the narrow lines due to rare earth 4f(n) --> 4f(n) transitions provide a high-resolution probe, while the insulating host eliminates the additional complications of collective electronic interactions. In this paper we investigate how the size restricted geometry of the nanoparticle influences (i) electronic relaxation by the one-phonon emission process and (ii) optical dephasing by the two-phonon Raman process. (C) 1999 Elsevier Science B.V. All rights reserved.