Exciton diffusion in air-suspended single-walled carbon nanotubes

TL;DR

This study directly measures exciton diffusion lengths in air-suspended single-walled carbon nanotubes using photoluminescence microscopy, revealing significantly longer diffusion lengths than in micelle-encapsulated nanotubes.

Contribution

It provides the first direct measurement of exciton diffusion length in air-suspended nanotubes, highlighting the impact of environmental conditions on exciton transport.

Findings

Longer exciton diffusion lengths in air-suspended nanotubes compared to encapsulated ones.

Use of photoluminescence microscopy for precise measurement.

Numerical modeling to interpret diffusion behavior.

Abstract

Direct measurements of the diffusion length of excitons in air-suspended single-walled carbon nanotubes are reported. Photoluminescence microscopy is used to identify individual nanotubes and to determine their lengths and chiral indices. Exciton diffusion length is obtained by comparing the dependence of photoluminescence intensity on the nanotube length to numerical solutions of diffusion equations. We find that the diffusion length in these clean, as-grown nanotubes is significantly longer than those reported for micelle-encapsulated nanotubes.