Unraveling the Excitonic Transition and Associated Dynamics in Confined Long Linear Carbon-chains with Time-Resolved Resonance Raman Scattering

TL;DR

This study uses time-resolved Raman spectroscopy to investigate excitonic transitions and relaxation dynamics in confined long linear carbon-chains, revealing slow exciton relaxation and strong host-chain coupling crucial for nanotechnology applications.

Contribution

It provides the first detailed characterization of exciton dynamics in confined long linear carbon-chains, highlighting their relaxation times and interaction with nanotube hosts.

Findings

Exciton relaxation occurs over hundreds of picoseconds.

Strong coupling between the chain and nanotube host is observed.

Energy transfer from host to chain is highly efficient.

Abstract

Long linear carbon-chains have been attracting intense interest arising from the remarkable properties predicted and their potential applications in future nanotechnology. Here we comprehensively interrogate the excitonic transitions and the associated relaxation dynamics of nanotube confined long linear carbon-chains by using steady state and time-resolved Raman spectroscopies. The exciton relaxation dynamics on the confined carbon-chains occurs on a hundreds of picoseconds timescale, in strong contrast to the host dynamics that occurs on a few picosecond timescale. A prominent time-resolved Raman response is observed over a broad energy range extending from 1.2 to 2.8 eV, which includes the strong Raman resonance region around 2.2 eV. Evidence for a strong coupling between the chain and the nanotube host is found from the dynamics at high excitation energies which provides a clear evidence for an efficient energy transfer from the host carbon nanotube to the chain. Our experimental study presents the first unique characterization of the long linear carbon-chain exciton dynamics, providing indispensable knowledge for the understanding of the interactions between different carbon allotropes.