아주대학교

목차

Chapter 1 Introduction 1
Chapter 2 Background 3
2.1 Transition metal chalcogenides (TMCs) 3
2.1.1 Transition metal dichalcogenides (TMDCs) 3
2.1.2 Transition metal monochalcogenides (TMMCs) 4
2.1.3 Mixed-dimensional heterostructures 6
2.2 Contact in TMCs for electronics and optoelectronics 7
2.3 Catalysis for hydrogen evolution reaction (HER) 9
2.3.1 Fundamentals of HER 9
2.3.2 TMCs for HER 11
2.4 Chemical vapor deposition (CVD) 12
Chapter 3 Composition- and dimension-controlled Mo/Te compounds for low contact resistance 14
3.1 Introduction 14
3.2 Methods 16
3.2.1 Growth of low-dimensional Mo/Te compounds 16
3.2.2 Characterizations 17
3.3 Composition- and dimension-controlled Mo/Te compounds 18
3.4 Interface of in-plane 1D/2D Mo6Te6/MoTe2 heterostructures 30
3.5 Conclusion 31
Chapter 4 Phase-controlled Mo/Te compounds for low contact resistance 33
4.1 Introduction 33
4.2 Method 34
4.2.1 Growth of phase-controlled ultrathin MoTe2 films 34
4.2.2 Characterizations 36
4.3 Phase-controlled Mo/Te compounds 37
4.4 Interface of lateral hetero-phase 1T'/2H MoTe2 films 41
4.5 Conclusion 42
Chapter 5 In-plane mixed-dimensional heterostructures for optoelectronics with low contact resistance 44
5.1 Introduction 44
5.2 Methods 46
5.2.1 Growth of in-plane heterostructures composed of monolayer MoS2 and Mo/Te compounds 46
5.2.2 Fabrication of devices 48
5.2.3 Characterizations 48
5.3 In-plane heterostructures composed of MoS2 and Mo/Te compounds 50
5.4 The device with the in-plane mixed-dimensional heterostructures 60
5.5 Conclusion 68
Chapter 6 Weyl semimetal WTe2 nanowire (NW) arrays for highly efficient HER 70
6.1 Introduction 70
6.2 Methods 73
6.2.1 Synthesis of NW arrays 73
6.2.2 Synthesis of WO2.9 NW arrays 74
6.2.3 Synthesis of WO3-x-WTe2 NWs and WTe2 NWs 75
6.2.4 Characterizations 76
6.2.5 Electrochemical measurements 76
6.3 Weyl semimetal WTe2 NW arrays 77
6.4 Electrochemical performance of WTe2 NWs 86
6.5 Conclusion 90
Chapter 7 TMDC hetero-nanotree (HNT) arrays for enhanced HER 91
7.1 Introduction 91
7.2 Method 93
7.2.1 Growth pathways for TMDC HNTs 93
7.2.2 Synthesis of MoO3-x/WO3-x HNTs 94
7.2.3 Synthesis of TMDC HNTs 95
7.2.4 Characterizations 96
7.2.5 Electrochemical measurements 97
7.3 TMDC HNTs 98
7.4 Electrochemical performance of TMDC HNTs 106
7.5 Conclusion 108
Chapter 8 Conclusion 109
Bibliography 111
국문요약 121
List of publications 123