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

Title: First-Principles Study of Fluorescence in Silver Nanoclusters

Abstract

Mechanisms of efficient fluorescence from biocompatible, ligand-protected silver nanoclusters (AgNC) are explored with an atomistic model of an icosahedral shaped AgNC passivated with 12 cytosine molecules representing single-stranded DNA. Spin-resolved density-functional theory with varying constraints to the total charge was used as a simulation probe to explore the electronic structure and photoluminescence of AgNCs. Visible photoemission in AgNCs is modeled through a synergy of radiative and nonradiative photoinduced dynamics computed by a combination of density matrix and density functional methods with explicit treatment of spin polarization. The ab initio computed charge-to-total energy correlation, E tot( ΔN), of the modeled AgNC shows an approximate 2.2 eV discontinuity at a charge of ΔN = 5, which correlates with the DFT calculated band gap and with concept of superatom with closed shell valence electron count [PNAS 2008, 105, 9157]. UV photoexcitation of this cationic model followed by cascade thermalizations toward the band edges is modeled using Redfield theory, and the corresponding time-integrated emission is calculated. Peak emission near 610 nm is found, consistent with experimentally reported PL in AgNCs. Finally, this work gives further insight into the recombination kinetics of AgNC and can be used to aid in tailoring their optical properties tomore » maximize fluorescence efficiency and tunability.« less

Authors:
 [1]; ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [3]
  1. North Dakota State Univ., Fargo, ND (United States). Materials and Nanotechnology Program
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. North Dakota State Univ., Fargo, ND (United States). Dept. of Chemistry and Biochemistry
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1480497
Grant/Contract Number:  
[AC02-05CH11231]
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
[ Journal Volume: 121; Journal Issue: 43]; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Brown, Samuel L., Hobbie, Erik K., Tretiak, Sergei, and Kilin, Dmitri S. First-Principles Study of Fluorescence in Silver Nanoclusters. United States: N. p., 2017. Web. doi:10.1021/acs.jpcc.7b04870.
Brown, Samuel L., Hobbie, Erik K., Tretiak, Sergei, & Kilin, Dmitri S. First-Principles Study of Fluorescence in Silver Nanoclusters. United States. doi:10.1021/acs.jpcc.7b04870.
Brown, Samuel L., Hobbie, Erik K., Tretiak, Sergei, and Kilin, Dmitri S. Tue . "First-Principles Study of Fluorescence in Silver Nanoclusters". United States. doi:10.1021/acs.jpcc.7b04870. https://www.osti.gov/servlets/purl/1480497.
@article{osti_1480497,
title = {First-Principles Study of Fluorescence in Silver Nanoclusters},
author = {Brown, Samuel L. and Hobbie, Erik K. and Tretiak, Sergei and Kilin, Dmitri S.},
abstractNote = {Mechanisms of efficient fluorescence from biocompatible, ligand-protected silver nanoclusters (AgNC) are explored with an atomistic model of an icosahedral shaped AgNC passivated with 12 cytosine molecules representing single-stranded DNA. Spin-resolved density-functional theory with varying constraints to the total charge was used as a simulation probe to explore the electronic structure and photoluminescence of AgNCs. Visible photoemission in AgNCs is modeled through a synergy of radiative and nonradiative photoinduced dynamics computed by a combination of density matrix and density functional methods with explicit treatment of spin polarization. The ab initio computed charge-to-total energy correlation, Etot(ΔN), of the modeled AgNC shows an approximate 2.2 eV discontinuity at a charge of ΔN = 5, which correlates with the DFT calculated band gap and with concept of superatom with closed shell valence electron count [PNAS 2008, 105, 9157]. UV photoexcitation of this cationic model followed by cascade thermalizations toward the band edges is modeled using Redfield theory, and the corresponding time-integrated emission is calculated. Peak emission near 610 nm is found, consistent with experimentally reported PL in AgNCs. Finally, this work gives further insight into the recombination kinetics of AgNC and can be used to aid in tailoring their optical properties to maximize fluorescence efficiency and tunability.},
doi = {10.1021/acs.jpcc.7b04870},
journal = {Journal of Physical Chemistry. C},
number = [43],
volume = [121],
place = {United States},
year = {2017},
month = {9}
}

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

Figures / Tables:

Figure 1 Figure 1: The (a) total energy as a function of charge for the modeled nanocluster (inset) with the corresponding (b) first and (c) second derivative. The purple dashed lines in (b) are linear fits of the form $\frac{dE}{dN}$ $= A$1 $+BN$ and $\frac{dE}{dN}$ $= A$2 $+ BN$ such that $A$1more » $<$ $A$2. The jump discontinuity here represents a deviation from classic electrostatics as quantum mechanical effects become important. (d) Charge‐constrained DFT was used for each calculation where an electron is removed the silver nanocluster. Green circle, blue cross, and black dot stand for PBE, HSE06, and B3LYP data, respectively.« less

Save / Share:
Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.