Collaborative Paper Published: Modulation of Heat Flow via Electrochemical Doping in Conducting Polymer PBTTT

Summary

This paper demonstrates that the thermal conductivity of conducting polymer PBTTT thin films along the lamellar stacking direction (i.e., the through-thickness direction) can be continuously and reversibly modulated by electrochemical dopint. Au-TDTR measurements under gate bias showed that the thermal conductivity increased by up to 28% from 0.198 W m^-1 K^-1 in the undopted state to 0.253 W m^-1 K^-1 in the dopted state, and that this moduation was repeatable over multiple cycles. Furthremore, comparison between experiments and theoretical calculations revealed that this change in thermal conductivity orignates primarily not from carrier transport, but from local structural changes associated with TFSI ion intercalation and the resulting variation in phonon-mediated heat transport. This work is a collaborative research outcome with the group of Professor Kazuhiro Yanagi at Tokyo Metropolitan University, the group of Professor Taishi Takenobu at Nagoya University, the group of Shun Watanabe team director at RIKEN Center for Emergent Matter Science, and Advanced Thermal Analysis Research Group, Research Institute for Material Measurement, National Institute of Advanced Industrial Science and Technology (AIST).