Quantitative Mapping of Nanothermal Transport via Scanning Thermal Microscopy (eBook)

Supervisor’s Foreword 7
Abstract 9
Acknowledgements 10
Contents 12
Abbreviations 15
Symbols 16
1 Introduction 17
1.1 Existing Techniques and Limitations 18
1.2 Heat Conduction at the Nanoscale 19
1.2.1 Diffusive Transport and Its Nanoscale Limit 20
1.2.2 Transport at Interfaces 23
1.3 Outline and Motivations 24
References 25
2 Background Review 26
2.1 Scanning Thermal Microscopy (SThM) 26
2.1.1 Scanning Probe Microscopy 26
2.1.2 History and Principles of SThM 28
2.1.3 Basic Operation Possibilities 32
2.1.4 Heat Transfer Mechanisms in the Tip-Sample System 34
2.1.5 What Is Measured? 37
2.2 Modelling and Simulations 38
2.2.1 Finite Element Analysis Compared to Analytical Formulations 39
2.2.2 Spreading Resistance of Layered Systems 39
2.3 Summary 43
References 44
3 SThM Experimental Models and Setups for Exploring Nanoscale Heat Transport 47
3.1 Precise Nanothermal Measurements via Spatially Distributed Scanning … 47
3.1.1 Introduction 47
3.1.2 Combined Analytical Model and High-Precision SThM Setup 49
3.1.3 Results and Discussion 55
3.1.4 Summary 59
3.2 Introducing CryoSThM—Nanothermal Transport Measurements at Cryogenic Temperatures 61
3.2.1 Vacuum SThM Setup for Measurements at Cryogenic Temperatures 61
3.2.2 Measurement Model 63
3.2.3 CryoSThM Demonstration 65
3.2.4 Summary 68
3.3 Dynamic SThM: Quasi Non-contact Method for Multiparametrical Investigation 69
3.3.1 Introduction 69
3.3.2 Methodology 70
3.3.3 Results 71
3.3.4 Summary 74
References 74
4 Quantitative Thermal Transport Measurements in Nanostructures 77
4.1 Principles and Applications of Layer Analytical Model 77
4.1.1 Silicon Oxide Steps 80
4.1.2 ALD Aluminium Oxide Layers 81
4.2 Thermal Transport in Metal Covered Block Copolymers 82
4.3 Summary 89
References 90
5 Three Dimensional Mapping of Thermal Properties 91
5.1 Introduction 91
5.2 Combining BEXP and SThM 92
5.3 Quantitative Measurements of Thermal Conductivity and Interface Resistance 94
5.4 Thermal Transport in Anisotropic Media 99
5.5 Characterisation of Thermal Interface Materials 102
5.5.1 Buried Morphology and Structure 103
5.5.2 Nanoscale Thermal Mapping of Full Interface 105
5.5.3 Perspectives on Nanothermal Characterisation of TIM 110
5.6 Summary 111
References 112
6 Nanoscale Thermal Transport in Low Dimensional Materials 114
6.1 Introduction 114
6.2 Heat Transport in Two Dimensional Materials and Their Heterostructures 114
6.2.1 Franckeite 115
6.2.2 Heterostructure of MoS2 on Graphene 119
6.3 Temperature Dependent Thermal Resistance of Length Varying Vertically Aligned Carbon Nanotubes 122
6.3.1 Sample Preparation and Description 123
6.3.2 Thermal Resistance Measurement and Models 123
6.3.3 Low Temperature Thermal Transport 128
6.4 Summary 130
References 131
7 Thermoelectric Phenomena in Graphene Constrictions 132
7.1 Introduction 132
7.2 Microheater Thermometry 133
7.2.1 Temperature Mapping of the Junction Heater 133
7.2.2 Null-Point Measurement of Heater Excess Temperature 134
7.2.3 Low Temperature Thermometry 137
7.3 Exploring Thermoelectric Effects in Graphene Constrictions 138
7.3.1 Thermometry Measurement Principles 139
7.3.2 Scanning Thermal Gate Microscopy (SThGM) 140
7.3.3 Main Results 141
7.4 Summary 144
References 145
8 Conclusion and Perspectives 147
8.1 Major Achievements of This Thesis 147
8.2 Perspectives and Challenges for Nanoscale Thermal Measurements 148
Appendix Appendix 150
A.1 Estimation of the Contact Radius 150
A.2 Conical Tip Temperature Distribution Model 150
A.3 Description of Experimental Setups 152
A.3.1 General SThM Setup Components and Uses 152
A.3.2 SThM Box 153
A.3.3 Laser Management 156
A.4 Python Code for Approach-Retract Curve Analysis 157
Appendix Curriculum Vitae 162