Fabrication of Metal Alloy‐Deposited Flexible MWCNT Buckypaper for Thermoelectric Applications

Jih-Hsin Liu,Ren-Hui Tsai,Li-Chih Wang,Saravanan Lakshmanan,Hsin-Yuan Miao

doi:10.1155/2013/635647

Abstract

We report the fabrication of a flexible network of multiwall carbon nanotubes (MWCNTs) known as buckypaper (BP) for thermoelectric (TE) applications. A thermal evaporation method was used to deposit TE metal alloys onto the BP. The TE properties were improved primarily by increasing the Seebeck coefficient values (50 and 75 μV/K) and the electrical conductivity by approximately 10 000 S/m. High‐temperature resistivity studies were performed to confirm the semiconductivity of buckypaper. Variations in resistivity were observed to be the result of the metal alloys coated on the BP surface. We also demonstrated that a substantial increase in the Seebeck coefficient values can be obtained by connecting 3 and 5 layers of metal‐deposited BP in series, thereby enhancing the TE efficiency of MWCNT‐based BP for application in thermoelectric devices.

Highlights

A considerable amount of effort has been devoted to developing thermoelectric (TE) devices that are capable of generating electricity from heat
It reveals that the deposition of metal nanoparticles on the surface caused a densely packed network structure of carbon nanotubes (CNTs) in the buckypaper
The network structures of the multiwall carbon nanotubes (MWCNTs) BP were unaltered by the deposition of the metal particles

Summary

Introduction

A considerable amount of effort has been devoted to developing thermoelectric (TE) devices that are capable of generating electricity from heat. TE devices that conserve heat energy should be cost-efficient and possess a high thermoelectric figure of merit [1]. Good TE materials must have a high Seebeck coefficient, which enhances thermoelectricity, low electrical resistivity, which minimizes Joule heating, and low thermal conductivity, which sustains a large temperature gradient [2]. The performance of a TE material is determined by its dimensionless figure of merit ZT = S2T/ρκ, where S, ρ, and κ are the Seebeck coefficient, electrical resistivity, and thermal conductivity of the materials, respectively. Previous studies have focused on semimetallic nanomaterials such as Bi, Sb, Te, and Bi-Sb alloys because of their promising thermoelectric properties [3,4,5]. Zhang et al [7]

Objectives

Methods

Results

Conclusion