Hot-Carrier Relaxation in CdSe/CdS Core/Shell Nanoplatelets
Abstract
Here, we present time-resolved photoluminescence (PL) spectroscopy of a series of colloidal CdSe/CdS core/shell nanoplatelets with different core and shell thicknesses. Exciton numbers are determined from the integrated PI, intensities, and carrier temperatures are determined from the high-energy exponential tail of the PL spectra. For times between 10 and 1000 ps, the measured carrier relaxation dynamics are well described by a simple model of Auger reheating: biexcitonic Auger recombination continually increases the average energy of the carriers (while decreasing their number), and this reheating sets a bottleneck to cooling through electron-phonon coupling. For times between 1 and 10 ps, the relaxation dynamics are consistent with electron-phonon coupling, where the bottleneck is now the decay of the longitudinal optical phonon population. Comparison of relaxation dynamics to recombination dynamics reveals changes in the carrier-phonon coupling for shell thicknesses greater than 4 monolayers.
- Authors:
-
- Univ. of Maryland, Baltimore, MD (United States); Argonne National Lab. (ANL), Argonne, IL (United States). Center for Nanoscale Materials
- Univ. of British Columbia, Kelowna, BC (Canada)
- Univ. of Chicago, IL (United States)
- Argonne National Lab. (ANL), Argonne, IL (United States). Center for Nanoscale Materials; Univ. of Chicago, IL (United States)
- Publication Date:
- Research Org.:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities Division; Natural Sciences and Engineering Research Council of Canada (NSERC); China Scholarship Council; National Science Foundation (NSF). Directorate for Mathematical and Physical Sciences Division of Materials Research (MPS-DMR)
- OSTI Identifier:
- 1615623
- Grant/Contract Number:
- AC02-06CH11357
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Journal of Physical Chemistry. C
- Additional Journal Information:
- Journal Volume: 124; Journal Issue: 1; Journal ID: ISSN 1932-7447
- Publisher:
- American Chemical Society
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Auger recombination; CdSe; carrier cooling; carrier relaxation; core/shell; nanoplatelets; two-dimensional materials
Citation Formats
Pelton, Matthew, Wang, Yana, Fedin, Igor, Talapin, Dmitri V., and O’Leary, Stephen K. Hot-Carrier Relaxation in CdSe/CdS Core/Shell Nanoplatelets. United States: N. p., 2019.
Web. doi:10.1021/acs.jpcc.9b08006.
Pelton, Matthew, Wang, Yana, Fedin, Igor, Talapin, Dmitri V., & O’Leary, Stephen K. Hot-Carrier Relaxation in CdSe/CdS Core/Shell Nanoplatelets. United States. https://doi.org/10.1021/acs.jpcc.9b08006
Pelton, Matthew, Wang, Yana, Fedin, Igor, Talapin, Dmitri V., and O’Leary, Stephen K. Wed .
"Hot-Carrier Relaxation in CdSe/CdS Core/Shell Nanoplatelets". United States. https://doi.org/10.1021/acs.jpcc.9b08006. https://www.osti.gov/servlets/purl/1615623.
@article{osti_1615623,
title = {Hot-Carrier Relaxation in CdSe/CdS Core/Shell Nanoplatelets},
author = {Pelton, Matthew and Wang, Yana and Fedin, Igor and Talapin, Dmitri V. and O’Leary, Stephen K.},
abstractNote = {Here, we present time-resolved photoluminescence (PL) spectroscopy of a series of colloidal CdSe/CdS core/shell nanoplatelets with different core and shell thicknesses. Exciton numbers are determined from the integrated PI, intensities, and carrier temperatures are determined from the high-energy exponential tail of the PL spectra. For times between 10 and 1000 ps, the measured carrier relaxation dynamics are well described by a simple model of Auger reheating: biexcitonic Auger recombination continually increases the average energy of the carriers (while decreasing their number), and this reheating sets a bottleneck to cooling through electron-phonon coupling. For times between 1 and 10 ps, the relaxation dynamics are consistent with electron-phonon coupling, where the bottleneck is now the decay of the longitudinal optical phonon population. Comparison of relaxation dynamics to recombination dynamics reveals changes in the carrier-phonon coupling for shell thicknesses greater than 4 monolayers.},
doi = {10.1021/acs.jpcc.9b08006},
journal = {Journal of Physical Chemistry. C},
number = 1,
volume = 124,
place = {United States},
year = {Wed Dec 11 00:00:00 EST 2019},
month = {Wed Dec 11 00:00:00 EST 2019}
}
Web of Science