Nanomechanics in van der Waals Heterostructures (eBook)

Matthew Holwill (Autor)

eBook Download: PDF

2019 | 1st ed. 2019
XVII, 97 Seiten
Springer International Publishing (Verlag)
978-3-030-18529-9 (ISBN)

Infos

Micro/nano-mechanical systems are a crucial part of the modern world providing a plethora of sensing and actuation functionalities used in everything from the largest cargo ships to the smallest hand-held electronics; from the most advanced scientific and medical equipment to the simplest household items. Over the past few decades, the processes used to produce these devices have improved, supporting dramatic reductions in size, but there are fundamental limits to this trend that require a new production paradigm.

The 2004 discovery of graphene ushered in a new era of condensed matter physics research, that of two-dimensional materials. Being only a few atomic layers thick, this new class of materials exhibit unprecedented mechanical strength and flexibility and can couple to electric, magnetic and optical signals. Additionally, they can be combined to form van der Waals heterostructures in an almost limitless number of ways. They are thus ideal candidates to reduce the size and extend the capabilities of traditional micro/nano-mechanical systems and are poised to redefine the technological sphere.

This thesis attempts to develop the framework and protocols required to produce and characterise micro/nano-mechanical devices made from two-dimensional materials. Graphene and its insulating analogue, hexagonal boron nitride, are the most widely studied materials and their heterostructures are used as the test-bed for potential device architectures and capabilities. Interlayer friction, electro-mechanical actuation and surface reconstruction are some of the key phenomena investigated in this work.

Matthew Holwill graduated from the University of Exeter with an M.Sc. in 2014. He then moved to the University of Manchester and began his PhD working in the National Graphene Institute under the supervision of Nobel Laureate Prof. Sir. Konstantin Novoselov. During his PhD, a research secondment was undertaken at the National University of Singapore. Currently he is a research associate at the National Graphene Institute in Manchester. 

Inhalt

Supervisor’s Foreword 8
Abstract 9
Acknowledgements 11
Contents 12
Abbreviations 14
1 Introduction 15
1.1 Outline 18
References 19
2 Properties of Two-Dimensional Materials 21
2.1 Introduction 21
2.2 Electronic bandstructures 21
2.2.1 Graphene Tight Binding 21
2.2.2 hBN bandstructure 25
2.3 Mechanical Properties 26
2.4 Capacitance and Field Effect 28
2.5 Closing Remarks 29
References 29
3 van der Waals Heterostructures 32
3.1 Introduction 32
3.2 van der Waals Forces 32
3.3 Graphene on Hexagonal Boron Nitride—A Short History 34
3.3.1 Moiré Superlattice 35
3.3.2 Electronic Characteristics 36
3.3.3 Mechanical Characteristics 38
3.4 Intentions of This Thesis 42
References 42
4 Fabrication and Characterisation Techniques 45
4.1 Introduction 45
4.2 Fabrication Techniques 45
4.2.1 Flake Preparation, Selection and Alignment 45
4.2.2 Lithography 50
4.2.3 Etching Techniques 51
4.2.4 Metal Deposition, Lift-Off and Bonding 53
4.3 Characterisation Techniques 54
4.3.1 Electron Transport 54
4.3.2 Raman Spectroscopy 55
4.3.3 Scanning Electron Microscopy 57
4.3.4 Atomic Force Microscopy 59
4.3.5 Scanning Tunnelling Microscopy/Spectroscopy 61
4.4 Closing Remarks 62
References 62
5 Studying Superlattice Kinks via Electronic Transport 64
5.1 Introduction 64
5.2 Concept and Design 64
5.3 Device Fabrication 65
5.4 Initial Characterisation 66
5.5 Redesigned Devices 69
5.5.1 Measurement Process and Results 70
5.6 Discussion 75
5.6.1 Future Work 79
5.7 Conclusions 80
References 80
6 Atomic Force Microscopy Studiespg of Superlattice Kinks 82
6.1 Introduction 82
6.2 Concept, Design and Fabrication 82
6.3 Initial Device Characterisation and Measurement Process 84
6.3.1 Measurement Process 86
6.4 Results 87
6.5 Discussion 89
6.5.1 Drift 91
6.6 Conclusions 93
References 93
7 Additional Work 95
7.1 Introduction 95
7.2 Scanning Tunnelling Microscopy 95
7.3 Umklapp Devices 96
7.4 Molybdenum Ditelluride (MoTe2) 97
References 100
8 Conclusions and Future Work 102
A Thermal Drift and Additional Resultspg for Chap. [ThermalExpansionCoefficientDevices]6 104

Produkt-Details

• Erscheint lt. Verlag: 4.5.2019
• Reihe/Serie: Springer Theses
• Reihe/Serie: Springer Theses
• Zusatzinfo: XVII, 97 p. 50 illus., 49 illus. in color.
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Physik / Astronomie ► Atom- / Kern- / Molekularphysik
• Themenwelt: Naturwissenschaften ► Physik / Astronomie ► Theoretische Physik
• Themenwelt: Technik ► Maschinenbau
• Schlagworte: Graphene Nanomechanics • Moire Superlattice • Nanofabrication of Van Der Waals Heterostructures • Nano-Mechanics • Nanostructure fabrication protocols • Van Der Waals Superlattice
• ISBN-10: 3-030-18529-X / 303018529X
• ISBN-13: 978-3-030-18529-9 / 9783030185299