Profiling Nanowire Thermal Resistance with a Spatial Resolution of Nanometers

We report a new technique to profile the thermal resistance along a nanowire with a spatial resolution of better than 20 nm. Using this technique, we mapped the thermal conductivity along a Si0.7Ge0.3/NiSi0.7Ge0.3 heterostructured nanowire. We also measured the interfacial thermal resistance (ITR) across the Si/NiSi2 interface embedded in Si/NiSi2 heterostructured nanowires. The ITR does not change even for adjacent interfaces as close as ∼50 atomic layers.