Collaborative Research: Effect of twist angle on the interfacial thermal conductance of 2D homo- and heterojunctions

Auburn University, Auburn AL

Investigators

Abstract

Monolayered 2D materials have a thickness of less than 1 nanometer. When they are stacked to form homogeneous junctions and heterogeneous junctions with various twist angles, new exotic properties and functionalities will arise. Relevant applications include microelectronics and sensor development. Although computer modeling has uncovered very strong twist angle effect on the interlayer thermal conductance at homo- and heterojunctions, no experimental work has been reported yet. This is due to the extreme experimental challenges in measuring the temperature difference and heat flux across a homo- or heterojunction. The project is designed to overcome these extreme challenges and provide the first-time experimental understanding of twist angle effect on interfacial thermal conductance of homo- and heterojunctions. New Raman techniques with specifically designed energy transport states will be used. The overall project will involve extensive training of graduate and undergraduate students and feature tight integration with education and outreach to K-12 graders. The goal of the project is to investigate how the twist angle affects the interlayer thermal conductance and junction-substrate interfacial thermal conductance of 2D homo- and heterojunctions, investigate the effect of temperature, and provide deep physics understanding about the twist angle effect via atomistic modeling and machine learning. This project represents the first high-accuracy investigation about the twist angle effect on the thermal conductance of homo- and heterojunctions of 2D monolayers. The outcome will significantly advance current knowledge that is solely developed by modeling and theoretical analysis. It will uncover how the twist angle influences the interfacial thermal conductance, identify the angles that give the highest and lowest thermal conductance, and unravel how temperature variation will change this effect. The knowledge to be developed in this project will substantially advance the scientific understanding and provide the critical knowledge for material and device design in 2D material-related microelectronics and sensors. The broad impact activities are designed to significantly expand undergraduates' view of modern science, stimulate their interests in research, and expose K-12 graders to nanoscience and technology, especially in energy transport and control. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.