Characterization of Thermal and Electrical Transport in 6.4\u2009nm Au Films on Polyimide Film and Fiber Substrates

Huan Lin,Jian Cheng,Siyi Luo,Jingkui Zhang,Shen Xu,Aijing Kou,Hua Dong

doi:10.1038/s41598-020-66174-8

Huan Lin, Jian Cheng + Show 5 more

Open Access

https://doi.org/10.1038/s41598-020-66174-8

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Abstract

The surface and grain boundary scattering impact on the electrical and thermal conduction in the thin metallic films coated on organic substrates has not been studied thoroughly. In this work, we study heat and electron transport in the 6.4 nm thin Au films supported by polyimide (PI) substrate using the transient electro-thermal technique. Thermal and electrical conductivities of 6.4 nm thin Au film are much smaller than bulk value. The thermal and electrical conductivities of 6.4 nm Au film deposited on the PI fiber are reduced by 59.3% and 76.8% in the comparison with the value of bulk Au. For PI film, the reduction of thermal and electrical conductivities is 47.9% and 46.3%. Lorenz numbers of 6.4 nm Au film supported by PI fiber and PI film are 4.51 × 10−8 WΩK−2 and 2.12 × 10−8 WΩK−2, respectively. The thermal conductivities of PI fiber and PI film are 0.87 Wm−1K−1 and 0.44 Wm−1K−1. The results reveal that PI is a suitable substrate material in the flexible electronic devices field.

Highlights

The surface and grain boundary scattering impact on the electrical and thermal conduction in the thin metallic films coated on organic substrates has not been studied thoroughly
We have investigated the thermal and electrical conduction in the 6.4 nm Au films deposited on the PI fiber and PI film
The thermal conductivities of Au films coated on the PI fiber and PI film are 129 Wm−1K−1and 165 Wm−1K−1, reduced by 59.3% and 47.9% in the comparison with bulk Au

Summary

Introduction

The surface and grain boundary scattering impact on the electrical and thermal conduction in the thin metallic films coated on organic substrates has not been studied thoroughly. PI is an organic material with high performance, which possesses a series of great features, such as low thermal conductivity, high tensile strength, tensile modulus[4], thermal stability[5], chemical stability, radiation resistance[6] and insulativity It is widely used in the fields of high temperature dust removal[7], marine adiabatic fire protection[8], aerospace[9] and machines. When the size of grains in the metallic films is approximately equal to the electron mean free path, the interface scattering causes the phenomenon where the electrical and thermal conductivity of the metallic films is much less than the corresponding value of the bulk materials[2,12,13,14,15,16,17,18]. The Au films are coated on the substrate of PI film and fiber by a vacuum sputtering coating apparatus (Q150 TS)

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