Controlling doping is essential for a successful integration of semiconductor materials into device technologies. However, the assessment of doping levels and the distribution of charge carriers in carbon nanotubes or other nanoscale semiconductor materials is often either limited to a qualitative attribution of being 'high' or 'low' or it is entirely absent. Here, we describe efforts toward a quantitative characterization of doping in redox- or electrochemically doped semiconducting carbon nanotubes (s-SWNTs) using VIS-NIR absorption spectroscopy. We discuss how carrier densities up to about 0.5 nm−1 can be quantified with a sensitivity of roughly one charge per 104 carbon atoms assuming in-homogeneous or homogeneous carrier distributions.
@article{arxiv.1909.05181,
title = {Quantifying Doping Levels in Carbon Nanotubes by Optical Spectroscopy},
author = {Klaus H. Eckstein and Florian Oberndorfer and Melanie M. Achsnich and Friedrich Schöppler and Tobias Hertel},
journal= {arXiv preprint arXiv:1909.05181},
year = {2019}
}