Excitation dynamics in polyacene molecules on rare-gas clusters

TL;DR

This study investigates how the excitation decay dynamics of polyacene molecules vary on solid argon clusters compared to neon clusters, revealing material-dependent differences and challenging previous decay mechanism assumptions.

Contribution

It provides new experimental insights into the excitation lifetimes and decay mechanisms of polyacenes on different rare-gas clusters, highlighting the influence of cluster material.

Findings

Decay dynamics depend significantly on cluster material

Qualitative differences in dopant density effects between neon and argon clusters

Contrasting lifetime behavior of anthracene on neon versus argon clusters

Abstract

Laser-induced fluorescence spectra and excitation lifetimes of anthracene, tetracene, and pentacene molecules attached to the surface of solid argon clusters have been measured with respect to cluster size, density of molecules and excitation density. Results are compared to previous studies on the same sample molecules attached to neon clusters. A contrasting lifetime behavior of anthracene on neon and argon clusters is discussed, and mechanisms are suggested to interpret the results. Although both neon and argon clusters are considered to be weakly interacting environments, we find that the excitation decay dynamics of the studied acenes depends significantly on the cluster material. Moreover, we find even qualitative differences regarding the dependence on the dopant density. Based on these observations, previous assignments of collective radiative and non-radiative decay mechanisms are discussed in the context of the new experimental findings.