Measuring Nanoscale Interface Thermal Resistance via Electron Microscope

Rapid technological advancements drive miniaturization and high energy density in devices, thereby increasing nanoscale thermal management demands and urging development of higher spatial resolution technologies for thermal imaging and transport research. Here, we introduce an approach to measure nanoscale thermal resistance using in-situ inelastic scanning transmission electron microscopy. By constructing unidirectional heating flux with controlled temperature gradients and analyzing electron energy-loss/gain signals under optimized acquisition conditions, nanometer-resolution in mapping phonon apparent temperature is achieved. Thus, interfacial thermal resistance is determined by calculating the ratio of interfacial temperature difference to bulk temperature gradient. This methodology enables direct measurement of thermal transport properties for atomic-scale structural features (e.g., defects, heterointerfaces), resolving critical structure-performance relationships, providing a useful tool for investigating thermal phenomena at the (sub-)nanoscale.