Thermal transport in semiconductor nanotubes. (March 2019)

• Record Type: Journal Article
• Authors: Malhotra, Abhinav; Maldovan, Martin
• Is Part Of: International journal of heat and mass transfer. Volume 130(2019)
• Page Start: 368
• Page End: 374
• Publication Date: 2019-03
• Subjects: Nanotubes -- Phonon transport -- Semiconductors -- Thermal conductivity -- Surfaces; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2018.10.068
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: Nanotubes present a potential avenue to obtain low thermal conductivity. Thermal transport can be manipulated due to their large surface-to-volume ratio. The dynamics of thermal vibrations (phonons) in nanotubes are described. Thermal properties of Si and SiGe nanotubes are predicted. Abstract: Semiconductor nanotubes present an exciting avenue to create very thin one-dimensional nanostructures using currently available growth techniques. Due to their large surface-to-volume ratio, nanotubes allow for an effective control over thermal energy transfer. Here, we study thermal transport in crystalline nanotubes made of silicon and germanium-alloyed-silicon by developing a methodology that accurately accounts for phonon dynamics in these nanostructures. The flexibility of the proposed approach allows considering the two nanotube boundaries as distinct from one another and is used to analyze the impact of nanotube morphology such as shell thicknesses, outer diameters, and surface properties on thermal transport. We also evaluate the frequency and mean-free-path spectra in these nanostructures to elucidate and provide insight on the phonon transport mechanisms in nanotubes. The results of this work advance the understanding of thermal conduction in nanotubes and the abilities to create rationally designed thermal materials, which are critical for obtaining high efficiency of thermoelectrics, photovoltaics, and electronic materials.