Chi Sin Tang, PhD, is currently Research Fellow at the Singapore Synchrotron Light Source, National University of Singapore (NUS) under the NUS Emerging Scientist Fellowship.Xinmao Yin is Professor at the Physics Department of Shanghai University, China.Andrew T. S. Wee is a class of '62 Professor of Physics at the National University of Singapore.

• Preface xi1 Two-dimensional Transition Metal Dichalcogenides: A General Overview 1Chi Sin Tang and Xinmao Yin1.1 Introduction to 2D-TMDs 11.2 Crystal Structures of 2D-TMDs in Different Phases 21.3 Electronic Band Structures of 2D-TMDs 71.4 Excitons (Coulomb-Bound Electron-Hole Pairs) 151.5 Experimental Studies and Characterization of 2D-TMDs 202 Synthesis and Phase Engineering of Low-Dimensional TMDs and Related Material Structures 61Bijun Tang, Jiefu Yang, and Zheng Liu2.1 Introduction 612.2 Structure of 2D TMDs 622.3 Synthesis of 2D TMDs 642.4 Phase Engineering of 2D TMDs 662.5 Conclusion 823 Thermoelectric Properties of Polymorphic 2D-TMDs 87H. K. Ng, Yunshan Zhao, Dongzhi Chi, and Jing Wu3.1 Introduction to 2D Thermoelectrics 873.2 Thermoelectric Transport 893.3 Experimental Characterization TE in 2D 953.4 Manipulation of TE Properties in 2D 1063.5 Future Outlook and Perspective 1154 Emerging Electronic Properties of Polymorphic 2D-TMDs 127Tong Yang, Zishen Wang, Jiaren Yuan, Jun Zhou, and Ming Yang4.1 Electronic Structure and Optical Properties of 2D-TMDs 1274.2 Polaron States of 2D-TMDs 1334.3 Valley Properties of 2D-TMDs 1434.4 Charge Density Waves of 2D-TMDs 1514.5 Janus Structures of 2D-TMDs 1594.6 Moiré Superlattices of 2D-TMDs 1615 Magnetism and Spin Structures of Polymorphic 2D TMDs 181Meizhuang Liu, Zuxin Chen, Jingbo Li, Yuli Huang, Kuan Eng Johnson Goh, and Andrew T. S. Wee5.1 Two-dimensional Ferromagnetism 1825.2 Cr-based Magnetic Materials and Device Applications 1835.3 Polymorphic 2D Cr-based Magnetic TMDs 1915.4 Magnetism in 2D Vanadium, Ion, Manganese Chalcogenides 2005.5 Conclusions and Outlook 2046 Recent Progress of Mechanical Exfoliation and the Application in the Study of 2D Materials 211Yunyun Dai, Xinyu Huang, Xu Han, Jiangang Guo, Xiangfan Xu, Lei Wang, Luqi Liu, Ningning Song, Yeliang Wang, and Yuan Huang6.1 Introduction 2116.2 Different Ways for Preparing 2D Materials 2136.3 New Mechanical Exfoliation Methods 2146.4 Application of Mechanical Exfoliation Method 2226.5 Summary and Outlook 2497 Applications of Polymorphic Two-Dimensional Transition Metal Dichalcogenides in Electronics and Optoelectronics 267Yao Yao, Siyuan Li, Jiajia Zha, Zhuangchai Lai, Qiyuan He, Chaoliang Tan, and Hua Zhang7.1 Field-Effect Transistors (FETs) 2687.2 Memory and Neuromorphic Computing 2727.3 Energy Harvesting 2757.4 Photodetectors 2777.5 Solar Cells 2827.6 Perspectives 2848 Polymorphic Two-dimensional Transition Metal Dichalcogenides: Modern Challenges and Opportunities 293Chi Sin Tang, Xinmao Yin, and Andrew T. S. Wee8.1 Summing up the Chapters 2938.2 Projecting the Future: Challenges and Opportunities 2958.3 Global Challenges and Threats 2968.4 Exponential Growth in Demands for Modern Computation 3078.5 Conclusion 312References 312Index 325

Chi Sin Tang, PhD, is currently Research Fellow at the Singapore Synchrotron Light Source, National University of Singapore (NUS) under the NUS Emerging Scientist Fellowship.Xinmao Yin is Professor at the Physics Department of Shanghai University, China.Andrew T. S. Wee is a class of '62 Professor of Physics at the National University of Singapore.

• Preface xi1 Two-dimensional Transition Metal Dichalcogenides: A General Overview 1Chi Sin Tang and Xinmao Yin1.1 Introduction to 2D-TMDs 11.2 Crystal Structures of 2D-TMDs in Different Phases 21.3 Electronic Band Structures of 2D-TMDs 71.4 Excitons (Coulomb-Bound Electron-Hole Pairs) 151.5 Experimental Studies and Characterization of 2D-TMDs 202 Synthesis and Phase Engineering of Low-Dimensional TMDs and Related Material Structures 61Bijun Tang, Jiefu Yang, and Zheng Liu2.1 Introduction 612.2 Structure of 2D TMDs 622.3 Synthesis of 2D TMDs 642.4 Phase Engineering of 2D TMDs 662.5 Conclusion 823 Thermoelectric Properties of Polymorphic 2D-TMDs 87H. K. Ng, Yunshan Zhao, Dongzhi Chi, and Jing Wu3.1 Introduction to 2D Thermoelectrics 873.2 Thermoelectric Transport 893.3 Experimental Characterization TE in 2D 953.4 Manipulation of TE Properties in 2D 1063.5 Future Outlook and Perspective 1154 Emerging Electronic Properties of Polymorphic 2D-TMDs 127Tong Yang, Zishen Wang, Jiaren Yuan, Jun Zhou, and Ming Yang4.1 Electronic Structure and Optical Properties of 2D-TMDs 1274.2 Polaron States of 2D-TMDs 1334.3 Valley Properties of 2D-TMDs 1434.4 Charge Density Waves of 2D-TMDs 1514.5 Janus Structures of 2D-TMDs 1594.6 Moiré Superlattices of 2D-TMDs 1615 Magnetism and Spin Structures of Polymorphic 2D TMDs 181Meizhuang Liu, Zuxin Chen, Jingbo Li, Yuli Huang, Kuan Eng Johnson Goh, and Andrew T. S. Wee5.1 Two-dimensional Ferromagnetism 1825.2 Cr-based Magnetic Materials and Device Applications 1835.3 Polymorphic 2D Cr-based Magnetic TMDs 1915.4 Magnetism in 2D Vanadium, Ion, Manganese Chalcogenides 2005.5 Conclusions and Outlook 2046 Recent Progress of Mechanical Exfoliation and the Application in the Study of 2D Materials 211Yunyun Dai, Xinyu Huang, Xu Han, Jiangang Guo, Xiangfan Xu, Lei Wang, Luqi Liu, Ningning Song, Yeliang Wang, and Yuan Huang6.1 Introduction 2116.2 Different Ways for Preparing 2D Materials 2136.3 New Mechanical Exfoliation Methods 2146.4 Application of Mechanical Exfoliation Method 2226.5 Summary and Outlook 2497 Applications of Polymorphic Two-Dimensional Transition Metal Dichalcogenides in Electronics and Optoelectronics 267Yao Yao, Siyuan Li, Jiajia Zha, Zhuangchai Lai, Qiyuan He, Chaoliang Tan, and Hua Zhang7.1 Field-Effect Transistors (FETs) 2687.2 Memory and Neuromorphic Computing 2727.3 Energy Harvesting 2757.4 Photodetectors 2777.5 Solar Cells 2827.6 Perspectives 2848 Polymorphic Two-dimensional Transition Metal Dichalcogenides: Modern Challenges and Opportunities 293Chi Sin Tang, Xinmao Yin, and Andrew T. S. Wee8.1 Summing up the Chapters 2938.2 Projecting the Future: Challenges and Opportunities 2958.3 Global Challenges and Threats 2968.4 Exponential Growth in Demands for Modern Computation 3078.5 Conclusion 312References 312Index 325

Chi Sin Tang, PhD, is currently Research Fellow at the Singapore Synchrotron Light Source, National University of Singapore (NUS) under the NUS Emerging Scientist Fellowship.Xinmao Yin is Professor at the Physics Department of Shanghai University, China.Andrew T. S. Wee is a class of '62 Professor of Physics at the National University of Singapore.

• Preface xi1 Two-dimensional Transition Metal Dichalcogenides: A General Overview 1Chi Sin Tang and Xinmao Yin1.1 Introduction to 2D-TMDs 11.2 Crystal Structures of 2D-TMDs in Different Phases 21.3 Electronic Band Structures of 2D-TMDs 71.4 Excitons (Coulomb-Bound Electron-Hole Pairs) 151.5 Experimental Studies and Characterization of 2D-TMDs 202 Synthesis and Phase Engineering of Low-Dimensional TMDs and Related Material Structures 61Bijun Tang, Jiefu Yang, and Zheng Liu2.1 Introduction 612.2 Structure of 2D TMDs 622.3 Synthesis of 2D TMDs 642.4 Phase Engineering of 2D TMDs 662.5 Conclusion 823 Thermoelectric Properties of Polymorphic 2D-TMDs 87H. K. Ng, Yunshan Zhao, Dongzhi Chi, and Jing Wu3.1 Introduction to 2D Thermoelectrics 873.2 Thermoelectric Transport 893.3 Experimental Characterization TE in 2D 953.4 Manipulation of TE Properties in 2D 1063.5 Future Outlook and Perspective 1154 Emerging Electronic Properties of Polymorphic 2D-TMDs 127Tong Yang, Zishen Wang, Jiaren Yuan, Jun Zhou, and Ming Yang4.1 Electronic Structure and Optical Properties of 2D-TMDs 1274.2 Polaron States of 2D-TMDs 1334.3 Valley Properties of 2D-TMDs 1434.4 Charge Density Waves of 2D-TMDs 1514.5 Janus Structures of 2D-TMDs 1594.6 Moiré Superlattices of 2D-TMDs 1615 Magnetism and Spin Structures of Polymorphic 2D TMDs 181Meizhuang Liu, Zuxin Chen, Jingbo Li, Yuli Huang, Kuan Eng Johnson Goh, and Andrew T. S. Wee5.1 Two-dimensional Ferromagnetism 1825.2 Cr-based Magnetic Materials and Device Applications 1835.3 Polymorphic 2D Cr-based Magnetic TMDs 1915.4 Magnetism in 2D Vanadium, Ion, Manganese Chalcogenides 2005.5 Conclusions and Outlook 2046 Recent Progress of Mechanical Exfoliation and the Application in the Study of 2D Materials 211Yunyun Dai, Xinyu Huang, Xu Han, Jiangang Guo, Xiangfan Xu, Lei Wang, Luqi Liu, Ningning Song, Yeliang Wang, and Yuan Huang6.1 Introduction 2116.2 Different Ways for Preparing 2D Materials 2136.3 New Mechanical Exfoliation Methods 2146.4 Application of Mechanical Exfoliation Method 2226.5 Summary and Outlook 2497 Applications of Polymorphic Two-Dimensional Transition Metal Dichalcogenides in Electronics and Optoelectronics 267Yao Yao, Siyuan Li, Jiajia Zha, Zhuangchai Lai, Qiyuan He, Chaoliang Tan, and Hua Zhang7.1 Field-Effect Transistors (FETs) 2687.2 Memory and Neuromorphic Computing 2727.3 Energy Harvesting 2757.4 Photodetectors 2777.5 Solar Cells 2827.6 Perspectives 2848 Polymorphic Two-dimensional Transition Metal Dichalcogenides: Modern Challenges and Opportunities 293Chi Sin Tang, Xinmao Yin, and Andrew T. S. Wee8.1 Summing up the Chapters 2938.2 Projecting the Future: Challenges and Opportunities 2958.3 Global Challenges and Threats 2968.4 Exponential Growth in Demands for Modern Computation 3078.5 Conclusion 312References 312Index 325