skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Auger Heating and Thermal Dissipation in Zero-Dimensional CdSe Nanocrystals Examined Using Femtosecond Stimulated Raman Spectroscopy

Abstract

In this paper, we report femtosecond stimulated Raman spectroscopy (FSRS) measurements on dispersions of CdSe semiconductor nanocrystals (NCs) as a function of particle size and pump fluence. Upon photoexcitation we observe depletion of stimulated Raman gain corresponding to generation of longitudinal optical (LO) phonons followed by recovery on picosecond timescales. At higher fluences, production of multiple excitons slows recovery of FSRS signals, which we attribute to sustained increases of LO phonon populations due to multiexcitonic Auger heating. Additionally, owing to discretized electronic structure of these NCs, such heating cannot be readily monitored via electronic spectroscopic analysis of high energy band tails as has been performed for higher-dimensionality materials. Notably, recovery timescales exceed those of the biexcitonic Auger recombination process and as such reveal overall thermalization timescales likely owing to an acoustic phonon thermalization bottleneck that dictates the cooling timescale.

Authors:
 [1];  [1];  [1];  [1]; ORCiD logo [1];  [1]; ORCiD logo [1]; ORCiD logo [2]
  1. Northwestern Univ., Evanston, IL (United States)
  2. Northwestern Univ., Evanston, IL (United States); Argonne National Lab. (ANL), Argonne, 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) (SC-22). Chemical Sciences, Geosciences & Biosciences Division
OSTI Identifier:
1491813
Grant/Contract Number:  
AC02-06CH11357; FG02-99ER14999
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry Letters
Additional Journal Information:
Journal Volume: 9; Journal Issue: 16; Journal ID: ISSN 1948-7185
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE

Citation Formats

Harvey, Samantha M., Phelan, Brian T., Hannah, Daniel C., Brown, Kristen E., Young, Ryan M., Kirschner, Matthew S., Wasielewski, Michael R., and Schaller, Richard D. Auger Heating and Thermal Dissipation in Zero-Dimensional CdSe Nanocrystals Examined Using Femtosecond Stimulated Raman Spectroscopy. United States: N. p., 2018. Web. doi:10.1021/acs.jpclett.8b01504.
Harvey, Samantha M., Phelan, Brian T., Hannah, Daniel C., Brown, Kristen E., Young, Ryan M., Kirschner, Matthew S., Wasielewski, Michael R., & Schaller, Richard D. Auger Heating and Thermal Dissipation in Zero-Dimensional CdSe Nanocrystals Examined Using Femtosecond Stimulated Raman Spectroscopy. United States. doi:10.1021/acs.jpclett.8b01504.
Harvey, Samantha M., Phelan, Brian T., Hannah, Daniel C., Brown, Kristen E., Young, Ryan M., Kirschner, Matthew S., Wasielewski, Michael R., and Schaller, Richard D. Mon . "Auger Heating and Thermal Dissipation in Zero-Dimensional CdSe Nanocrystals Examined Using Femtosecond Stimulated Raman Spectroscopy". United States. doi:10.1021/acs.jpclett.8b01504. https://www.osti.gov/servlets/purl/1491813.
@article{osti_1491813,
title = {Auger Heating and Thermal Dissipation in Zero-Dimensional CdSe Nanocrystals Examined Using Femtosecond Stimulated Raman Spectroscopy},
author = {Harvey, Samantha M. and Phelan, Brian T. and Hannah, Daniel C. and Brown, Kristen E. and Young, Ryan M. and Kirschner, Matthew S. and Wasielewski, Michael R. and Schaller, Richard D.},
abstractNote = {In this paper, we report femtosecond stimulated Raman spectroscopy (FSRS) measurements on dispersions of CdSe semiconductor nanocrystals (NCs) as a function of particle size and pump fluence. Upon photoexcitation we observe depletion of stimulated Raman gain corresponding to generation of longitudinal optical (LO) phonons followed by recovery on picosecond timescales. At higher fluences, production of multiple excitons slows recovery of FSRS signals, which we attribute to sustained increases of LO phonon populations due to multiexcitonic Auger heating. Additionally, owing to discretized electronic structure of these NCs, such heating cannot be readily monitored via electronic spectroscopic analysis of high energy band tails as has been performed for higher-dimensionality materials. Notably, recovery timescales exceed those of the biexcitonic Auger recombination process and as such reveal overall thermalization timescales likely owing to an acoustic phonon thermalization bottleneck that dictates the cooling timescale.},
doi = {10.1021/acs.jpclett.8b01504},
journal = {Journal of Physical Chemistry Letters},
number = 16,
volume = 9,
place = {United States},
year = {2018},
month = {7}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 3 works
Citation information provided by
Web of Science

Save / Share: