Single MoS₂ Nanotube Experimental Optical Extinction Cross Section

The experimentally retrieved value of the optical extinction cross section per unit length, σ_L,ext^NT, of individual MoS₂ multiwall nanotubes (NTs) is here reported over the 440-940 nm wavelength range for light polarization both parallel and perpendicular to the nanotube longitudinal axis. The impact of nanotube diameter and environment on σ_L,ext^NT is addressed for individual nanotubes with diameters of 120 and 220 nm in suspended, sapphire-supported, and PMMA-supported configurations. Measuring individual nanotubes is of utmost importance given the wide nanotube size dispersion intrinsic to the synthesis process. The findings are interpreted in conjunction with finite element method simulations, informed by morphological input parameters from electron microscopy, offering insight into the respective contributions of absorption and scattering cross sections per unit length to overall σ_L,ext^NT. These quantitative results are of relevance in view of optoelectronics applications involving MoS₂ nanotubes while providing benchmark values for theoretical investigations on their nano-optical response.