title: Breaking the phonon bottleneck in semiconductor nanocrystals via multiphonon emission induced by intrinsic nonadiabatic interactions.
abstract: We observe ultrafast 1P-to-1S intraband relaxation in PbSe and CdSe nanocrystals (NCs) that have distinct energy spectra. While ultrafast dynamics in CdSe NCs has typically been interpreted in terms of electron-hole energy transfer, this mechanism is not active in PbSe NCs because of sparse densities of states in the conduction and valence bands. Our observations of temperature activation and confinement-enhanced relaxation in PbSe NCs can be explained by efficient multiphonon emission triggered by nonadiabatic electron-phonon interactions and are indicative of large, size-dependent, intraband Huang-Rhys parameters.
authors.affiliation: Chemistry Division, C-PCS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Schaller
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Pietryga
authors.forename: Serguei V
authors.initials: SV
authors.lastname: Goupalov
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Petruska
authors.forename: Sergei A
authors.initials: SA
authors.lastname: Ivanov
authors.forename: Victor I
authors.initials: VI
authors.lastname: Klimov