We have measured the interlayer and in-plane (needle axis) thermal diffusivities of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-Pn). The needle axis value is comparable to the phonon thermal conductivities of quasi-one dimensional organic metals with excellent pi-orbital overlap, and its value suggests that a significant fraction of heat is carried by optical phonons. Furthermore, the interlayer (c-axis) thermal diffusivity is at least an order of magnitude larger, and this unusual anisotropy implies very strong dispersion of optical modes in the interlayer direction, presumably due to interactions between the silyl-containing side groups. Similar values for both in-plane and interlayer diffusivities have been observed for several other functionalized pentacene semiconductors with related structures.
@article{arxiv.1406.1113,
title = {Thermal Diffusivities of Functionalized Pentacene Semiconductors},
author = {H. Zhang and Y. Yao and Marcia M. payne and Karl J. Thorley and J. E. Anthony and J. W. Brill},
journal= {arXiv preprint arXiv:1406.1113},
year = {2015}
}
Comments
9 pages, including 4 figures; submitted to Applied Physics Letters