Design and fabrication of electrothermal measurement devices to probe coulomb heat transfer across two-dimensional heterostructures

Heat transfer across two-dimensional (2D) layers is a fundamental transport process that influences the operating temperature and performance of emerging 2D heterostructure electronic and optoelectronic devices. The weak van der Waals interactions in 2D heterostructures can limit cross-plane transport of phonons, the energy quanta of lattice vibrations. Consequently, Coulomb interaction between charge carriers in 2D layers separated by a dielectric can play a key role to mediate interlayer heat transport. The Coulomb heat transfer can potentially be enhanced by engineering two-level flat electron bands in the 2D system with the use of a twist angle in 2D bilayers to form moiré structures. In addition, the Coulomb heat transport mechanism can tune the interlayer heat transport by using a gate electric field to vary the charge carrier concentration in the 2D layers. If realized, this electric-field tunable thermal transport can be used to produce solid-state thermal switches for a variety of applications. This thesis describes the design and fabrication of an electro-thermal measurement device to detect Coulomb heat transport in 2D heterostructures made of graphene and hexagonal boron nitride (hBN). Theoretical analysis is used to show that the Coulomb heat transfer is detectable, even without the use of Moiré patterns to achieve resonant heat transport. A fabrication process is established to demonstrate that the measurement device can be fabricated with the use of a dry transfer technique, electron beam lithography, and metal evaporation and liftoff. A measurement procedure is established to probe the electrical property of the multilayer graphene and different metal gate layers as a function of temperature. These progresses build a foundation for further investigations of Coulomb heat transfer in other 2D heterostructures and Moiré superstructures.