Breaking the phonon bottleneck in semiconductor nanocrystals via multiphonon emission induced by intrinsic nonadiabatic interactions.
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.
Schaller
Richard D
RD
Chemistry Division, C-PCS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Pietryga
Jeffrey M
JM
Goupalov
Serguei V
SV
Petruska
Melissa A
MA
Ivanov
Sergei A
SA
Klimov
Victor I
VI