Theory of plasmon-enhanced metal photoluminescence

TL;DR

This paper develops a microscopic theory for metal photoluminescence in nanostructures, accounting for both enhancement via surface plasmons and suppression due to Auger plasmon excitation, with results matching experiments.

Contribution

It introduces a comprehensive microscopic model that captures both enhancement and suppression mechanisms in plasmon-enhanced MPL, advancing understanding of nanostructure photoluminescence.

Findings

Numerical calculations agree with experimental MPL data from Au nanoparticles.

Identification of Auger plasmon excitation as a suppression mechanism.

Derivation of an MPL quantum efficiency enhancement factor.

Abstract

Metal photoluminescence (MPL) originates from radiative recombination of photoexcited core holes and conduction band electrons. In metal nanostructures, MPL is enhanced due to the surface plasmon local field effect. We identify another essential process in plasmon-assisted MPL - excitation of Auger plasmons by core holes - that hinders MPL from small nanostructures. We develop a microscopic theory of plasmon-enhanced MPL that incorporates both plasmon-assisted enhancement and suppression mechanisms and derive the enhancement factor for MPL quantum efficiency. Our numerical calculations of MPL from Au nanoparticles are in excellent agreement with the experiment.