Two-dimensional material inks and composites for printed electronics and energy
Creators: name: Carey, Tian
Publisher: name: Apollo - University of Cambridge Repository
Year: 2018
Subjects: Two-dimensional material
Graphene
Printed Electronics
Energy Composites
Printed Heterostructure
Saturable Absorbers
Microbial Fuel Cell
Three-Dimensional Electronics
Printed Logic
Liquid Phase Exfoliation
Inks
Hexagonal Boron Nitride

description: This thesis explores the application of two-dimensional (2D) materials such as graphene and single layer hexagonal boron nitride (h-BN) which are produced by liquid phase exfoliation for use in printed electronics and energy composite applications. In Chapter 2 I give a broad overview of the electrical, mechanical and optical properties of 2D materials among other nanomaterials that were used in the thesis such as carbon nanotubes and conductive polymers. Additionally I review the techniques and theory behind the exfoliation and dispersion of functional layered materials. In Chapter 3 I present the coating and printing techniques which were used in this thesis along with the experimental techniques and methods which I use to characterise my inks, films and devices. Chapter 4 is the first experimental chapter of the thesis and demonstrates the printing of 2D material heterostructures to create fully printed dieletrically gated field effect transistors with 2D materials on textile and polymer substrates. In this chapter I also demonstrate reprogrammable volatile memory, p and n type inverters, complementary inverters, and logic gates which pave the way to fully printed integrated circuits, operational at room temperature and pressure with 2D materials processed in liquid. In Chapter 5, I review spray coating (a highly industrial scalable printing technique), in terms of the optimisation of its parameters to achieve thin films of nanomaterials on three-dimensional (3D) surfaces. I then demonstrate that it is possible to create large area (∼750 cm2) transparent conducting films around curved surfaces with spray coating enabling a semi-transparent (around 360°) spherical touch sensor for interactive devices. Chapter 6 explores printed photonics for applications in terahertz (THz) frequencies. Here I demonstrate the feasibility of liquid phase exfoliated graphene to create THz saturable absorbers (SAs) which could enable many applications in THz frequencies such as tomography or time-resolved spectroscopy that require mode-locked (i.e. enabling a train of short pulses to be derived from continuous-wave operation) THz pulses. I also demonstrate that these SAs can be inkjet printed on demand providing unprecedented compactness in a quantum cascade laser system. Finally in Chapter 7, I look at the application of graphene in microbial fuel cells (MFC). I demonstrate that enhanced MFC output arises from the interplay of the improved surface area, enhanced conductivity, and catalytic surface groups of a graphene based electrode. As a final step graphene based anodes and cathodes which were entirely platinum free were combined to create an environmentally sustainable energy source.
description: European Research Council Grant (Hetero2D)