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Title: Heat Transfer at Hybrid Interfaces: Interfacial Ligand-to-Nanocrystal Heating Monitored with Infrared Pump, Electronic Probe Spectroscopy

Abstract

The transfer of thermal energy from the ligand passivating layer to the inorganic core of colloidal nanocrystals is observed using infrared-pump, electronic-probe (IPEP) spectroscopy. Inorganic nanocrystals are excellent model systems for organic-inorganic hybrid interfaces as they have much larger surface-to-volume ratios than bulk solids, which facilitates spectroscopic measurements of weak signals. Such interfaces between disparate materials are challenging to probe by traditional methods. In this work, resonant excitation of the hydrocarbon ligand vibrational absorptions results in a transient red-shift of the CdSe nanocrystal excitonic features consistent with heating, as demonstrated by steady-state absorption measurements, which provide a calibration of the pump-induced temperature rise. The time constant associated with heating ranges from 10 ps to 30 ps depending on the sample morphology, static temperature, input fluence, and environment, all of which are studied in this work. Heat transfer speeds up and the magnitude of nanocrystal heating decreases at higher temperatures. Unlike chemical modulation of electrical conductivity, ligand exchange for several common organic ligands does not dramatically change the interfacial conductivity of the nanocrystal-ligand interface. However, changes in the medium (e.g. solvent) do change the rate of heat outcoupling from the nanocrystal-ligand complex. Lastly, although applied here to nanocrystals to measure interfacialmore » heat transfer, IPEP spectroscopy is readily applicable for any heterogeneous system in which one component has spectrally-isolated phonon modes.« less

Authors:
ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [2]
  1. Argonne National Lab. (ANL), Lemont, IL (United States)
  2. Argonne National Lab. (ANL), Lemont, IL (United States); Northwestern Univ., Evanston, 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)
OSTI Identifier:
1493881
Grant/Contract Number:  
AC02-06CH11357
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Nano Letters
Additional Journal Information:
Journal Volume: 18; Journal Issue: 12; Journal ID: ISSN 1530-6984
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; heating; infrared; ligand; nanocrystal; thermal transport

Citation Formats

Diroll, Benjamin T., Guo, Peijun, and Schaller, Richard D. Heat Transfer at Hybrid Interfaces: Interfacial Ligand-to-Nanocrystal Heating Monitored with Infrared Pump, Electronic Probe Spectroscopy. United States: N. p., 2018. Web. doi:10.1021/acs.nanolett.8b03640.
Diroll, Benjamin T., Guo, Peijun, & Schaller, Richard D. Heat Transfer at Hybrid Interfaces: Interfacial Ligand-to-Nanocrystal Heating Monitored with Infrared Pump, Electronic Probe Spectroscopy. United States. doi:10.1021/acs.nanolett.8b03640.
Diroll, Benjamin T., Guo, Peijun, and Schaller, Richard D. Thu . "Heat Transfer at Hybrid Interfaces: Interfacial Ligand-to-Nanocrystal Heating Monitored with Infrared Pump, Electronic Probe Spectroscopy". United States. doi:10.1021/acs.nanolett.8b03640.
@article{osti_1493881,
title = {Heat Transfer at Hybrid Interfaces: Interfacial Ligand-to-Nanocrystal Heating Monitored with Infrared Pump, Electronic Probe Spectroscopy},
author = {Diroll, Benjamin T. and Guo, Peijun and Schaller, Richard D.},
abstractNote = {The transfer of thermal energy from the ligand passivating layer to the inorganic core of colloidal nanocrystals is observed using infrared-pump, electronic-probe (IPEP) spectroscopy. Inorganic nanocrystals are excellent model systems for organic-inorganic hybrid interfaces as they have much larger surface-to-volume ratios than bulk solids, which facilitates spectroscopic measurements of weak signals. Such interfaces between disparate materials are challenging to probe by traditional methods. In this work, resonant excitation of the hydrocarbon ligand vibrational absorptions results in a transient red-shift of the CdSe nanocrystal excitonic features consistent with heating, as demonstrated by steady-state absorption measurements, which provide a calibration of the pump-induced temperature rise. The time constant associated with heating ranges from 10 ps to 30 ps depending on the sample morphology, static temperature, input fluence, and environment, all of which are studied in this work. Heat transfer speeds up and the magnitude of nanocrystal heating decreases at higher temperatures. Unlike chemical modulation of electrical conductivity, ligand exchange for several common organic ligands does not dramatically change the interfacial conductivity of the nanocrystal-ligand interface. However, changes in the medium (e.g. solvent) do change the rate of heat outcoupling from the nanocrystal-ligand complex. Lastly, although applied here to nanocrystals to measure interfacial heat transfer, IPEP spectroscopy is readily applicable for any heterogeneous system in which one component has spectrally-isolated phonon modes.},
doi = {10.1021/acs.nanolett.8b03640},
journal = {Nano Letters},
issn = {1530-6984},
number = 12,
volume = 18,
place = {United States},
year = {2018},
month = {11}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on November 15, 2019
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