Temperature effects on the surface plasmon resonance in copper nanoparticles

TL;DR

This study investigates how temperature influences the energy and width of surface plasmon resonance in copper nanoparticles, revealing thermal expansion causes red shift while electron-phonon scattering broadens the resonance.

Contribution

It provides a detailed analysis of temperature effects on plasmon resonance in copper nanoparticles, highlighting thermal expansion and electron-phonon scattering as key mechanisms.

Findings

Thermal expansion causes a red shift of plasmon resonance.

Electron-phonon scattering increases with temperature, broadening the resonance.

Thermal volume expansion coefficient is size-independent.

Abstract

The temperature dependences of the energy and the width of a surface plasmon resonance are studied for copper nanoparticles 17 - 59 nm in size in the silica host matrix in the temperature interval 293 - 460 K. An increase of the temperature leads to the red shift and the broadening of the surface plasmon resonance in Cu nanoparticles. The obtained dependences are analyzed within the framework of a theoretical model considering the thermal expansion of a nanoparticle, the electron-phonon scattering in a nanoparticle, and the temperature dependence of the dielectric permittivity of the host matrix. The thermal expansion is shown to be the main mechanism responsible for the temperature-induced red shift of the surface plasmon resonance in copper nanoparticles. The thermal volume expansion coefficient for Cu nanoparticles is found to be size-independent in the studied size range. Meanwhile, the increase of the electron-phonon scattering rate with the temperature is shown to be the dominant mechanism of the surface plasmon resonance broadening in copper nanoparticles.