Giant power factors in p- and n-type large-area graphene films on a flexible plastic substrate

Kaito Kanahashi,Taishi Takenobu,Masataka Hasegawa,Masatou Ishihara,Hiromichi Ohta

doi:10.1038/s41699-019-0128-0

Abstract

This study reports on the thermoelectric properties of large-area graphene films grown by chemical vapor deposition (CVD) methods. Using the electric double layer gating technique, both the continuous doping of hole or electron carriers and modulation of the Fermi energy are achieved, leading to wide-range control of the Seebeck coefficient and electrical conductivity. Consequently, the maximum power factors of the CVD-grown large-area graphene films are 6.93 and 3.29 mW m–1 K–2 for p- and n-type carrier doping, respectively. These results are the best values among large-scale flexible materials, such as organic conducting polymers and carbon nanotubes, suggesting that CVD-grown large-area graphene films have potential for thermoelectric applications.

Highlights

The rapid development of wearable electronics and sensors has led to the concept of the “Internet of Things” (IoT).[1,2] In this idea, a network of billions of smart devices that connect people, systems and other applications collect and share data, providing key information for artificial intelligence (AI) as well as realizing a smart society
Along with the measurements of the ID – V4pp curves, we investigated the VG dependence of the Seebeck coefficient (S) in the graphene-based electric double layer transistors (EDLTs) using the method established for transition metal dichalcogenide (TMDC) monolayers.[22]
We can conclude that the chemical vapor deposition (CVD)-grown large-area polycrystalline graphene film is a strong candidate for the power generator of IoT devices

Summary

Introduction

The rapid development of wearable electronics and sensors has led to the concept of the “Internet of Things” (IoT).[1,2] In this idea, a network of billions of smart devices that connect people, systems and other applications collect and share data, providing key information for artificial intelligence (AI) as well as realizing a smart society. To the best of our knowledge, there is no report on the thermoelectric properties of large-area graphene films on a flexible substrate. To perform p- and n-type doping, we fabricated electric double layer transistors (EDLTs) of graphene films.[17,18] By combining thermoelectric measurements and the EDLT technique, we continuously controlled the Seebeck coefficient and electrical conductivity.

Results

Conclusion