High-throughput Imaging and Spectroscopy of Individual Carbon Nanotubes in Devices with Light Microscopy

TL;DR

This paper introduces a high-throughput optical microscopy technique for real-time imaging and spectroscopy of individual carbon nanotubes, enabling detailed chirality and electronic structure analysis in devices.

Contribution

It presents a novel polarization-based microscopy method for in-situ, video-rate imaging of single nanotubes on various substrates and in functional devices.

Findings

Complete chirality profiling of hundreds of nanotubes.

Observation of broadening of optical resonances due to electrostatic doping.

Detection of strong interband electron-electron scattering processes.

Abstract

Two paramount challenges in carbon nanotube research are achieving chirality-controlled synthesis and understanding chirality-dependent device physics. High-throughput and in-situ chirality and electronic structural characterization of individual carbon nanotubes is crucial for addressing these challenges. Optical imaging and spectroscopy has unparalleled throughput and specificity, but its realization for single nanotubes on substrates or in devices has long been an outstanding challenge. Here we demonstrate video-rate imaging and in-situ spectroscopy of individual carbon nanotubes on various substrates and in functional devices using a novel high-contrast polarization-based optical microscopy. Our technique enables the complete chirality profiling of hundreds of as-grown carbon nanotubes. In addition, we in-situ monitor nanotube electronic structure in active field-effect devices, and observe that high-order nanotube optical resonances are dramatically broadened by electrostatic doping. This unexpected behaviour points to strong interband electron-electron scattering processes that can dominate ultrafast dynamics of excited states in carbon nanotubes.