Fig. 2: Doping effect of carbon nanotubes by protonic acids.
From: Complex chemistry of carbon nanotubes toward efficient and stable p-type doping
a Variations of electrical conductivity (σ) and Seebeck coefficient (S) of the doped CNT films according to the applied protonic acids. b Variations of σ and S of CNT films doped by aqueous HNO3 solutions with different concentrations (0.1–13 M). c Work function shifts of CNT films after protonic-acid doping. Data statistics: n = 3. Error bars indicate the corresponding standard deviations (SD). d UV-vis-NIR spectra recorded before and after doping. S11 and S22, and M11 indicate that these absorption bands represent the interband transitions in semiconducting and metallic CNTs, respectively.
