Gold nanoparticles physicochemically bonded onto tungsten disulfide nanosheet edges exhibit augmented plasmon damping

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Gregory T. Forcherio - , University of Arkansas System, United States Army Research Laboratory (Author)
  • Jeremy R. Dunklin - , University of Arkansas System (Author)
  • Claudia Backes - , Heidelberg University  (Author)
  • Yana Vaynzof - , Heidelberg University  (Author)
  • Mourad Benamara - , University of Arkansas System (Author)
  • D. Keith Roper - , University of Arkansas System (Author)

Abstract

Augmented plasmonic damping of dipole-resonant gold (Au) nanoparticles (NP) physicochemically bonded onto edges of tungsten disulfide (WS2) nanosheets, ostensibly due to hot electron injection, is quantified using electron energy loss spectroscopy (EELS). EELS allows single-particle spatial resolution. A measured 0.23 eV bandwidth expansion of the localized surface plasmon resonance upon covalent bonding of 20 nm AuNP to WS2 edges was deemed significant by Welch's t-test. Approximately 0.19 eV of the measured 0.23 eV expansion went beyond conventional radiative and nonradiative damping mechanisms according to discrete dipole models, ostensibly indicating emergence of hot electron transport from AuNP into the WS2. A quantum efficiency of up to 11±5% spanning a 7 fs transfer process across the optimized AuNP-TMD ohmic junction is conservatively calculated. Putative hot electron transport for AuNP physicochemically bonded to TMD edges exceeded that for AuNP physically deposited onto the TMD basal plane. This arose from contributions due to (i) direct physicochemical bond between AuNP and WS2; (ii) AuNP deposition at TMD edge sites; and (iii) lower intrinsic Schottky barrier. This improves understanding of photo-induced doping of TMD by metal NP which could benefit emerging catalytic and optoelectronic applications.

Details

Original languageEnglish
Article number075103
JournalAIP advances
Volume7
Issue number7
Publication statusPublished - 1 Jul 2017
Peer-reviewedYes
Externally publishedYes

Keywords