UNDERSTANDING AND ENGINEERING HEAT TRANSPORT ACROSS INTERFACES OF TWO-DIMENSIONAL MATERIALS

Abstract

This thesis presents systematic and comprehensive experimental studies of heat transport across interfaces and nanostructures of 2D materials. First, I developed a differential time-domain thermoreflectance (TDTR) approach to extend the capability of conventional TDTR method. Second, I investigated the role of non-equilibrium phonon thermal resistance in accurate measurements of thermal conductance of 2D/oxide interfaces. In addition, I carefully studied the intrinsic thermal conductance of metal/graphene/metal interfaces to identify the heat transport mechanisms across graphene interfaces. I also studied the enhancement of heat transport across graphene/aluminium oxide interfaces of graphene field-effect transistor under electrostatic field. Finally, I studied the heat transport in graphene/metal heterostructures and transferred graphene multilayers to achieve ultralow thermal conductivity. Most importantly, I experimentally elucidated the twist angle dependence of thermal conductance for twisted bilayer graphene interfaces. My investigations provide vital insights and guidelines for understanding and engineering heat transport across interfaces of 2D materials.