Past Performance

Advanced Thermal Emission Modeling and Waveguiding in SiC Nanostructures

First-principles physics-based modeling of radiative heat transfer in silicon carbide (SiC) nanostructures, a key material for nuclear fuel cladding, high-temperature reactors, and radiation-hard components.

We found that a solitary SiC nanowire displays significant thermal emission losses. When placing nanowires in chains at specific diameters and gap spacing d, however, they show gap-dependent spectral, directional thermal emission. At small gap distances, collective localized surface phonons (cLSPhs) transition from bright (radiative) to dark (nonradiative) modes, yielding near-zero thermal emission while maintaining propagation lengths exceeding 1 μm. At large gap distances, the nanowires exhibit large thermal emission losses.

Solitary SiC Nanowire

Significant emission losses in isolation.

Thermal emission losses from a solitary nanowire

Thermal emission losses expressed as emissivity vs. frequency (left) and directional emissivity patterns at two LSPh resonance frequencies (right).

SiC Nanowire Chain

Chains support cLSPh transport.

Thermal emission losses with varying gap distance d

Thermal emission losses vanish at d = 10 nm (left) vs. strong thermal emission losses at d = 30 nm (right).