The electronic properties of as-prepared and purified unoriented single-walled carbon nanotube films were studied by transmission measurements over a broad frequency range (far-infrared up to visible) as a function of temperature (15 K - 295 K) and external pressure (up to 8 GPa). Both the as-prepared and the purified SWCNT films exhibit nearly temperature-independent properties. With increasing pressure the low-energy absorbance decreases suggesting an increasing carrier localization due to pressure-induced deformations. The energy of the optical transitions in the SWCNTs decreases with increasing pressure, which can be attributed to pressure-induced hybridization and symmetry-breaking effects. We find an anomaly in the pressure-induced shift of the optical transitions at ∼2 GPa due to a structural phase transition.
@article{arxiv.0910.0185,
title = {Infrared spectroscopic studies on unoriented single-walled carbon nanotube films under hydrostatic pressure},
author = {K. Thirunavukkuarasu and F. Hennrich and K. Kamarás and C. A. Kuntscher},
journal= {arXiv preprint arXiv:0910.0185},
year = {2018}
}