Extreme thermal anisotropy in high-aspect-ratio titanium nitride nanostructures for efficient photothermal heating

Abstract High optical absorptivity or a large absorption cross-section is necessary to fully utilize the irradiation of light for photothermal heating. Recently, titanium nitride (TiN) nanostructures have been demonstrated be robust absorbers in range owing their nonradiative decay processes enhanced by broad plasmon resonances. Because photothermally generated heat dissipates surroundings, suppressing transfer from TiN crucial maximizing temperature increase. In current work, compared planar film, high-aspect-ratio with subwavelength periodicities enhance increase 100-fold using nanotube samples. The reason attributed extremely anisotropic effective thermal conductivities. Our work has revealed that are improving heating, and they can used various applications, such as solar chemical reactions, microfluidics.