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

Nanophotonics

article

Satoshi Ishii¹  Osamu Takayama⁴  Shunsuke Murai⁵  Makoto Higashino⁵  Shinya Goya⁵  Evgeniy Shkondin⁶  Katsuhisa Tanaka⁵  Tadaaki Nagao¹ 

[1] International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS);Faculty of Pure and Applied Physics, University of Tsukuba;Japan Science and Technology Agency;DTU Fotonik—Department of Photonics Engineering, Technical University of Denmark;Department of Material Chemistry, Graduate School of Engineering, Kyoto University;DTU Nanolab—National Center for Micro- and Nanofabrication, Technical University of Denmark;Department of Condensed Matter Physics, Graduate School of Science, Hokkaido University

关键词: effective medium theory;    nanostructure;    photothermal effect;    surface plasmon;    transition metal nitride;   

DOI  :  10.1515/nanoph-2020-0569

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

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

【 授权许可】

CC BY