# Dipolar and charged localized excitons in carbon nanotubes

## TL;DR

This study combines experimental and theoretical approaches to understand localized excitons in carbon nanotubes, revealing their dipolar nature, charge interactions, and potential for sensing and quantum dot applications.

## Contribution

It provides new insights into the microscopic properties of localized excitons and demonstrates their controllability via electric fields and doping in carbon nanotubes.

## Key findings

- Localized excitons are permanent electric dipoles with moments up to 1eÅ.
- Field-effect doping can create defect-localized trions.
- Insights may guide molecular engineering of exciton-based quantum dots.

## Abstract

We study both experimentally and theoretically the fundamental interplay of exciton localization and polarization in semiconducting single-walled carbon nanotubes. From Stark spectroscopy of individual carbon nanotubes at cryogenic temperatures we identify localized excitons as permanent electric dipoles with dipole moments of up to 1e{\AA}. Moreover, we demonstrate field-effect doping of localized excitons with an additional charge which results in defect-localized trions. Our findings provide not only fundamental insight into the microscopic nature of localized excitons in carbon nanotubes, they also signify their potential for sensing applications and may serve as guidelines for molecular engineering of exciton-localizing quantum dots in other atomically thin semiconductors including transition metal dichalcogenides.