Enhancing Thermal Transport in Layered Nanomaterials

Abstract

A comprehensive rational thermal material design paradigm requires the ability to reduce and enhance the thermal conductivities of nanomaterials. In contrast to the existing ability to reduce the thermal conductivity, methods that allow to enhance heat conduction are currently limited. Enhancing the nanoscale thermal conductivity could bring radical improvements in the performance of electronics, optoelectronics, and photovoltaic systems. Here, we show that enhanced thermal conductivities can be achieved in semiconductor nanostructures by rationally engineering phonon spectral coupling between materials. By embedding a germanium film between silicon layers, we show that its thermal conductivity can be increased by more than 100% at room temperature in contrast to a free standing thin-film. The injection of phonons from the cladding silicon layers creates the observed enhancement in thermal conductivity. We study the key factors underlying the phonon injection mechanism and find that the surface conditions and layer thicknesses play a determining role. The findings presented here will allow for the creation of nanomaterials with an increased thermal conductivity.

Impact of Atomic Coating on Thermal Conductivity of Nano Materials

“…For example, when a 10 nm germanium thin-film is embedded between two 1 μm-thick silicon layers, it is found to double the thermal conductivity of germanium thin film with respect to a free-standing counterpart [61]. This significant increase in thermal conductivity is explained by a phonon injection mechanism instead of the effective medium model.…”

Topology Effects on Phonons and Thermal Conductivity in Rolled‐Up Nanotubes

“…Nanoscale materials suggest a plethora of opportunities to control and modify the physical properties (e.g., optical, electric and thermal) or even create new ones (e.g., plasmonic) using topology, geometry, and metastructuring. Particularly, the phonon transport is important for many applications of nanodevices, for example, the enhanced thermal conductivity is advantageous for computing devices and devices with densely packed interfaces, [1,2] and the diminished one is beneficial for thermoelectric devices. [3][4][5][6] Rolled-up nanostructures are one of the nanoarchitecures that attract attention for the thermoelectric purposes, [7] batteries, fuel cells, supercapacitors, sensors, oscillators, photocatalytic materials.…”

High Performance of Low‐Temperature‐Cofired Ceramic with Al2O3/BN Biphasic Ceramics Based on B2O3–Bi2O3–SiO2–ZnO Glass

“…At present, the methods for enhancing the thermal conductivity of LTCC are extensive but still limited. Among them, improving the nanoscale heat conduction has a great influence on the overall performance of the material …”

“…Among them, improving the nanoscale heat conduction has a great influence on the overall performance of the material. [24,25] In this article, to obtain LTCC materials with excellent thermal conductivity and dielectric properties, we have prepared LTCC materials containing binary ceramics. The composition of LTCC materials is BBSZ glass/Al 2 O 3 /BN.…”