Revisiting the Plasmon Radiation Damping of Gold Nanorods

TL;DR

This paper provides a theoretical and experimental analysis of radiation damping in gold nanorods, revealing a simple analytical model that accurately predicts damping based on geometry and material properties, aiding in nanostructure design.

Contribution

It introduces a simple analytical equation for radiation damping in gold nanorods, validated by experiments, enhancing understanding for optical applications.

Findings

Analytical model accurately predicts radiation damping.

Good agreement between theory and experimental data.

Design insights for optimizing nanorod optical signals.

Abstract

Noble metal nanoparticles have been utilized for a vast amount of optical applications. For the applications that used metal nanoparticles as nanosensors and optical labeling, larger radiation damping is preferred (higher optical signal). To get a deeper knowledge about the radiation damping of noble metal nanoparticles, we used gold nanorods with different geometry factors (aspect ratios) as the model system to study. We investigated theoretically how the radiation damping of a nanorod depends on the material, and shape of the particle. Surprisingly, a simple analytical equation describes radiation damping very accurately and allow to disentangle the maximal radiation damping parameter for gold nanorod with resonance energy E_res around 1.81 eV (685 nm). We found very good agreement with theoretical predictions and experimental data obtained by single-particle spectroscopy. Our results and approaches may pave the way for designing and optimizing gold nanostructure with higher optical signal and better sensing performance.