Proceedings of the National Academy of Sciences, 2019, vol 116, 35, pp. 17163-17168
Polymer crystals that are good conductors of heat are highly desirable for thermal management applications. Although thermally conductive polymer crystals are well known, the microscopic thermal transport processes that enable these properties have been challenging to probe experimentally. We used an optical method to probe heat conduction at submicrometer length scales, allowing us to obtain the distribution of mean free paths of heat carriers in oriented polyethylene. Our work provides key experimental insight into thermal transport in molecular solids that will aid in the synthesis of materials with higher thermal conductivity.