Here, we experimentally demonstrate thermal transport in amorphous atomic-scale superlattices that can provide lower thermal conductivity value than amorphous limit.
Investigating phonon transport in phononic crystals, nanowires, and membranes.
We propose a cost-effective, large-area, and maskless nanofabrication method that creates external nanocones on the silicon surface while preserving its interior. Our experiments show that these nanocones reduce the thermal conductivity of thin silicon membranes by more than 40%.
Here, we experimentally probed ballistic thermal transport at distances of 400–800 nm and temperatures of 4–250 K. Measuring thermal properties of straight and serpentine silicon nanowires, we found that at 4 K heat conduction is quasi-ballistic with stronger ballisticity at shorter length scales.
We measure the thermal conductivity of silicon phononic crystals with asymmetric holes at room and liquid helium temperatures and study the effect of thermal rectification, phonon boundary scattering, neck transmission, and hole positioning.
Here, we experimentally demonstrate quasi-ballistic heat conduction in silicon nanowires (NWs). We show that the ballisticity is the strongest in short NWs at low temperatures but weakens as the NW length or temperature is increased.