Plasmon damping depends on the chemical nature of the nanoparticle interface

Abstract

The chemical nature of surface adsorbates affects the localized surface plasmon resonance of metal nanoparticles. However, classical electromagnetic simulations are blind to this effect, whereas experiments are typically plagued by ensemble averaging that also includes size and shape variations. In this work, we are able to isolate the contribution of surface adsorbates to the plasmon resonance by carefully selecting adsorbate isomers, using single-particle spectroscopy to obtain homogeneous linewidths, and comparing experimental results to high-level quantum mechanical calculations based on embedded correlated wavefunction theory. Our approach allows us to indisputably show that nanoparticle plasmons are influenced by the chemical nature of the adsorbates 1,7-dicarbadodecaborane(12)-1-thiol (M1) and 1,7-dicarbadodecaborane(12)-9-thiol (M9). These surface adsorbates induce inside the metal electric dipoles that act as additional scattering centers for plasmon dephasing. In contrast, charge transfer from the plasmon to adsorbates—the most widely suggested mechanism to date—does not play a role here.

Taking the Heat Off of Plasmonic Chemistry

“…concomitantly or coherently 1,7,15,16 with decay of the LSPR, a phenomenon termed as chemical interface damping. 13 Plasmonic Heating.…”

Surface chemistry of quantum-sized metal nanoparticles under light illumination

“…31 In a microscopic picture, the surface adsorbates induce inside the metal electric dipoles that act as additional scattering centers for plasmon dephasing. 32 The studies of homogeneous plasmon line width of Au nanorods reveal that CID scales inversely with the effective path length of electrons, i.e., the average distance of electrons to the nanorod surface. 33 The contribution of CID to the plasmon energy decay becomes more dominant as the size of plasmonic metal nanoparticles decreases.…”

Prospects of Coupled Organic–Inorganic Nanostructures for Charge and Energy Transfer Applications

“…[163] Experimental observations have shown that a material that is chemically bound to a plasmonic nanoparticle can lead to the acceleration of the plasmon dephasing and thus CID. [164] In this case, plasmon decay can occur by directly generating hot electrons in the electron accepting states on the adsorbate, leaving a hot hole on the metal. In comparison, direct electron transfer is considered to be more efficient than indirect electron transfer, as the latter suffers from significant losses due to electron-electron scattering.…”