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 d ue to finite size effects. Rare earth doped insulating nanoparticles provid e an ideal model system for studying the fundamental interactions between e lectronic states and phonons since the narrow lines due to rare earth 4f(n) --> 4f(n) transitions provide a high-resolution probe, while the insulatin g host eliminates the additional complications of collective electronic int eractions. In this paper we investigate how the size restricted geometry of the nanoparticle influences (i) electronic relaxation by the one-phonon em ission process and (ii) optical dephasing by the two-phonon Raman process. (C) 1999 Elsevier Science B.V. All rights reserved.