Efficient radiative cooling of low-cost BaSO paint-paper dual-layer thin films.

Many materials have been explored for the purpose of creating structures with high radiative cooling potential, such as nanocellulose-based structures and nanoparticle-based coatings, which have been reported with environmentally friendly attributes and high solar reflectance in current literature. They each have their own advantages and disadvantages in practice. It is worth noting that nanocellulose-based structures have an absorption peak in the UV wavelengths, which results in a lower total solar reflectance and, consequently, reduce radiative cooling capabilities.

Phonon Scattering Engineered Unconventional Thermal Radiation at the Nanoscale.

We show that engineering phonon scattering, such as through isotope enrichment and temperature modulation, offers the potential to achieve unconventional radiative heat transfer between two boron arsenide bulks at the nanoscale, which holds promise in applications for nonlinear thermal circuit components. A heat flux regulator is proposed, where the temperature window for stabilized heat flux exhibits a wide tunability through phonon scattering engineering. Additionally, we propose several other nonlinear thermal radiative devices, including a negative differential thermal conductance device, a temperature regulator, and a thermal diode, all benefiting from the design space enabled by isotope and temperature engineering of the phonon linewidth.