Thermal Conduction Measurements in Low Dimensional Materials and Heterostructures

Oluwaseyi Balogun, PhD
Associate Professor of Civil and Mechanical Engineering
Northwestern University

Abstract:

Understanding thermal conduction in two-dimensional (2D) and mixed-dimensional (2D+1D, 2D+0D, 2D+1D, 2D+3D) heterostructures is critical to controlling the reliability and performance of emerging nanoelectronics and semiconducting materials. Mixed-dimensional heterostructures offer new opportunities to design nanocomposite materials where inter-component interactions can be tuned through interface chemistry, dimensionality, component spacing, integration of stimuli-responsive components, etc., leading to unprecedented electronic device functionality such as ambipolar transistors, gate tunable photovoltaics, and ultrafast thermal switches.   This lecture will highlight some recent experimental measurements from my research group, where we explore different techniques including, frequency-domain thermoreflectance, (FDTR), time-domain thermoreflectance (TDTR), and optothermal Raman to study the thermal conductance of 2D materials including MoS₂ and graphene, self-assembled monolayers heterojunctions, and 3D+3D materials with self-assembled molecular interlayers. Special attention will be devoted to interface interactions and the accompanying effects on heat transport in the heterostructures. I will also discuss several fundamental challenges limiting the study of heat conduction in mixed-dimensional (2D+1D & 2D+0D) heterostructures and the potential for addressing these challenges using advanced scanning probe methods such as tip-enhanced Raman spectroscopy.

Bio:

Oluwaseyi Balogun, PhD: Oluwaseyi Balogun has a PhD in Mechanical Engineering from Boston University and he is currently an Associate Professor of Civil and Mechanical Engineering at Northwestern University. His research background are in the areas of experimental mechanics, elastic wave modeling, and photoacoustic and photothermal phenomena. His research group has developed novel characterization tools with high spatial and temporal resolution to investigate light-matter interaction for applications in thermal and elastic materials characterization, super-resolution imaging, elastic and plasmonic metamaterials, and experimental mechanical of soft biological materials. He is a member of the IEEE UFFC and IEEE Nanotechnology Societies.