Universal temperature dependence of optical excitation life-time and band-gap in chirality assigned semiconducting single-wall carbon nanotubes

TL;DR

This study reveals a universal temperature dependence of optical excitation lifetime and band-gap in semiconducting single-wall carbon nanotubes, driven by electron-phonon interactions, regardless of chirality or sample type.

Contribution

It demonstrates that the temperature dependence of optical properties is universal across different SWCNT samples and attributes this to electron-phonon interactions, with implications for nanotube optoelectronics.

Findings

Temperature dependence of Gamma and E_ii is identical for SWCNTs and DWCNTs.

Electron-phonon interaction causes the temperature dependence of E_ii(T).

Inner tube Gamma in DWCNTs is comparable to individual SWCNTs.

Abstract

The temperature dependence of optical excitation life-time, Gamma, and transition energies, E_ii, were measured for bucky-papers of single-wall carbon nanotubes (SWCNTs) and inner tubes in double-wall carbon nanotubes (DWCNTs) using resonant Raman scattering. The temperature dependence of Gamma and E_ii is the same for both types of samples and is independent of tube chirality. The data proves that electron-phonon interaction is responsible for temperature dependence of E_ii(T). The temperature independent inhomogeneous contribution to Gamma is much larger in the SWCNT samples, which is explained by the different SWCNT environment in the two types of samples. Gamma of the inner tubes for the bucky-paper DWCNT sample is as low as \sim 30 meV, which is comparable to that found for individual SWCNTs.