本論文透過第一原理計算，系統地研究了過渡金屬硫族化物和一元碳化物的電子和拓撲性質。首先，在本研究中探討了兩種單層三元過渡金屬硫族化物的電子與拓撲性質，第一種ABX4，其中A與B元素為鈦(Ti)、鋯(Zr)或鉿(Hf)而X元素為硫(S)、硒(Se)或碲(Te)；第二種MM'X4，其中M元素為釩(V)、鈮(Nb)或鉭(Ta)而M'元素為鈷(Co)、銠(Rh)或銥(Ir)而X為硒(Se)或碲(Te)。對於 ABX4來說，其中的三種化合物 ZrTiTe4、HfTiTe4 和 HfZrTe4 經過判斷後具有 p-d 軌道能帶反轉的拓撲性。這些化合物的結構穩定性透過聲子能譜證實，沒有出現負頻率，這意味著這些系統在結構上是穩定的，而且可以經由實驗合成。至於 MM'X4，共有五種化合物被證實為二維拓撲絕緣體，其中有四種材料為磁性材料。此外，在單層VCoTe4中觀察到可以經由外加應力而產生鐵磁金屬到非磁性拓撲絕緣體相變。最後，在本研究中探討塊材和單層過渡金屬碳化物 M2C的電子和拓撲性質，其中M元素為釩(V)、鈮(Nb)或鉭(Ta)。在塊材中，所有M2C化合物是半金屬，具有非平凡拓撲能帶結構。另外透過改變系統厚度的計算發現，材料厚度由雙層到單層李佛西茲(Lifshitz)的電子特性相變使得V2C由非平凡半金屬轉變為拓撲絕緣體，且具有 0.32 電子伏特(eV)的電子能隙，而Nb2C和Ta2C從塊材到單層保持半金屬性質並分別表現出非平凡和平凡的拓撲態。所有上述材料中的非平凡拓撲都通過計算Z2拓撲不變量和拓撲保護的表面態與邊緣態來確認。

In this dissertation, we systematically studied the electronic and topological properties of transition metal chalcogenides and monocarbides using first-principles calculations. Firstly, we investigated the electronic and topological characteristics of two monolayer ternary transition metal chalcogenides families ABX4 (A/B= Ti, Zr, or Hf; and X= S, Se, or Te) and MM’Te4 (M= V, Nb, or Ta; M’=Co, Rh, or Ir; and X= Se or Te). For ABX4, three compounds, ZrTiTe4, HfTiTe4, and HfZrTe4, are identified to be topologically nontrivial with p-d type band inversion. The structural phase stability of these compounds was confirmed by phonon spectra, which exhibit no negative frequencies, implying that these systems are structurally stable and can be experimentally synthesized. As for MM’X4, a total of five compounds are identified as two-dimensional (2D) topological insulators (TIs) while four of them are magnetic. Furthermore, a strain-induced ferromagnetic metal to nonmagnetic topological insulator phase transition was observed in monolayer VCoTe4. Finally, we also investigated the electronic and topological properties of bulk and monolayer transition metal monocarbides M2C (M= V, Nb, or Ta). The bulk M2C compounds are semi-metallic with a non-trivial band topology. The thickness-dependent calculations show a Lifshitz electronic transition from non-trivial semimetal to topological insulator in V2C from bilayer to monolayer with a large bandgap of 0.32 eV. The monolayer Nb2C and Ta2C remain semi-metallic and exhibit non-trivial and trivial topologies, respectively. The non-trivial topologies in all the materials were confirmed by calculating the Z2 topological invariant and topologically protected edge/surface states.

Thesis Validation Letter i
Acknowledgement ii
摘要 iii
Abstract iv
Chapter 1 1
General introduction 1
1.1 Introduction 1
1.2 Dissertation organization 4
Chapter 2 5
Tuning topological phases and electronic properties of alloyed monolayer ternary transition metal chalcogenides (ABX4, A/B =Zr, Hf, or Ti; X=S, Se, or Te) 5
2.1 Summary of Chapter 2 5
2.2 Introduction and literature review 6
2.3 Computational methods 8
2.4 Results and discussion 9
2.5 Conclusion 18
Chapter 3 19
Theoretical prediction of topological insulators in two-dimensional ternary transition metal chalcogenides (MM’X4, M = Ta, Nb, or V; M’= Ir, Rh, or Co; X = Se or Te) 19
3.1 Summary of Chapter 3 19
3.2 Introduction and literature review 20
3.3 Computational methods 22
3.4 Results and discussions 23
3.4.1 Atomic structure and stabilities 23
3.4.2 Overview of the MM’X4 family 23
3.4.3 Topological properties of TaCoTe4 24
3.4.4 Strain-induced phase transition 25
3.5 Conclusion 33
Chapter 4 34
Electronic and topological properties of VB-group Transition-Metal Monocarbides M2C (M=V, Nb, or Ta) bulk and monolayer 34
4.1 Summary of Chapter 4 34
4.2 Introduction and literature review 35
4.3 Computational methods 37
4.4 Results and discussion 39
4.4.1 Atomic structure 39
4.4.2 Results for bulk M2C 40
4.4.3 Results for monolayer M2C 42
4.4.4 Thickness dependent electronic properties of V2C 43
4.5 Conclusion 50
Chapter 5 51
Concluding remarks 51
Bibliography 53
Appendixes 73

[1] M. Z. Hasan and C. L. Kane, Colloquium: Topological Insulators, Rev. Mod. Phys. 82, 3045 (2010).
[2] C. L. Kane and E. J. Mele, Z2 Topological Order and the Quantum Spin Hall Effect, Phys. Rev. Lett. 95, 146802 (2005).
[3] C. L. Kane and E. J. Mele, Quantum Spin Hall Effect in Graphene, Phys. Rev. Lett. 95, 226801 (2005).
[4] A. Bansil, H. Lin, and T. Das, Colloquium: Topological Band Theory, Rev. Mod. Phys. 88, 021004 (2016).
[5] B. A. Bernevig, T. L. Hughes, and S.-C. Zhang, Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells, Science 314, 1757 (2006).
[6] R.-J. Slager, A. Mesaros, V. Juričić, and J. Zaanen, The Space Group Classification of Topological Band-Insulators, Nat. Phys. 9, 98 (2013).
[7] D. Kong and Y. Cui, Opportunities in Chemistry and Materials Science for Topological Insulators and Their Nanostructures, Nat. Chem. 3, 845 (2011).
[8] J. E. Moore, The Birth of Topological Insulators, Nature 464, 194 (2010).
[9] X.-L. Qi and S.-C. Zhang, Topological Insulators and Superconductors, Rev. Mod. Phys. 83, 1057 (2011).
[10] Y. Ma, L. Kou, A. Du, and T. Heine, Group 14 Element-Based Non-Centrosymmetric Quantum Spin Hall Insulators with Large Bulk Gap, Nano Res. 8, 3412 (2015).
[11] H. Min, J. E. Hill, N. A. Sinitsyn, B. R. Sahu, L. Kleinman, and A. H. MacDonald, Intrinsic and Rashba Spin-Orbit Interactions in Graphene Sheets, Phys. Rev. B 74, 165310 (2006).
[12] Y. Yao, F. Ye, X.-L. Qi, S.-C. Zhang, and Z. Fang, Spin-Orbit Gap of Graphene: First-Principles Calculations, Phys. Rev. B 75, 041401 (2007).
[13] M. Gmitra, S. Konschuh, C. Ertler, C. Ambrosch-Draxl, and J. Fabian, Band-Structure Topologies of Graphene: Spin-Orbit Coupling Effects from First Principles, Phys. Rev. B 80, 235431 (2009).
[14] M. König, S. Wiedmann, C. Brüne, A. Roth, H. Buhmann, L. W. Molenkamp, X.-L. Qi, and S.-C. Zhang, Quantum Spin Hall Insulator State in HgTe Quantum Wells, Science (2007).
[15] Q. H. Wang, K. Kalantar-Zadeh, A. Kis, J. N. Coleman, and M. S. Strano, Electronics and Optoelectronics of Two-Dimensional Transition Metal Dichalcogenides, Nat. Nanotechnol. 7, 699 (2012).
[16] X. Yin, C. S. Tang, Y. Zheng, J. Gao, J. Wu, H. Zhang, M. Chhowalla, W. Chen, and A. T. S. Wee, Recent Developments in 2D Transition Metal Dichalcogenides: Phase Transition and Applications of the (Quasi-)Metallic Phases, Chem. Soc. Rev. 50, 10087 (2021).
[17] X. Xu, W. Yao, D. Xiao, and T. F. Heinz, Spin and Pseudospins in Layered Transition Metal Dichalcogenides, Nat. Phys. 10, 343 (2014).
[18] F. Xia, H. Wang, D. Xiao, M. Dubey, and A. Ramasubramaniam, Two-Dimensional Material Nanophotonics, Nat. Photonics 8, 899 (2014).
[19] M. A. Cazalilla, H. Ochoa, and F. Guinea, Quantum Spin Hall Effect in Two-Dimensional Crystals of Transition-Metal Dichalcogenides, Phys. Rev. Lett. 113, 077201 (2014).
[20] X. Qian, J. Liu, L. Fu, and J. Li, Quantum Spin Hall Effect in Two-Dimensional Transition Metal Dichalcogenides, Science (2014).
[21] S. Tang, C. Zhang, D. Wong, Z. Pedramrazi, H.-Z. Tsai, C. Jia, B. Moritz, M. Claassen, H. Ryu, S. Kahn, J. Jiang, H. Yan, M. Hashimoto, D. Lu, R. G. Moore, C.-C. Hwang, C. Hwang, Z. Hussain, Y. Chen, M. M. Ugeda, Z. Liu, X. Xie, T. P. Devereaux, M. F. Crommie, S.-K. Mo, and Z.-X. Shen, Quantum Spin Hall State in Monolayer 1T’-WTe2, Nat. Phys. 13, 683 (2017).
[22] P. Chen, W. W. Pai, Y.-H. Chan, W.-L. Sun, C.-Z. Xu, D.-S. Lin, M. Y. Chou, A.-V. Fedorov, and T.-C. Chiang, Large Quantum-Spin-Hall Gap in Single-Layer 1T′ WSe2, Nat. Commun. 9, 2003 (2018).
[23] N. Katsuragawa, M. Nishizawa, T. Nakamura, T. Inoue, S. Pakdel, S. Maruyama, S. Katsumoto, J. J. Palacios, and J. Haruyama, Room-Temperature Quantum Spin Hall Phase in Laser-Patterned Few-Layer 1T′- MoS2, Commun. Mater. 1, 1 (2020).
[24] S. Tang, C. Zhang, C. Jia, H. Ryu, C. Hwang, M. Hashimoto, D. Lu, Z. Liu, T. P. Devereaux, Z.-X. Shen, and S.-K. Mo, Electronic Structure of Monolayer 1T′-MoTe2 Grown by Molecular Beam Epitaxy, APL Mater. 6, 026601 (2018).
[25] J. Liu, H. Wang, C. Fang, L. Fu, and X. Qian, Van Der Waals Stacking-Induced Topological Phase Transition in Layered Ternary Transition Metal Chalcogenides, Nano Lett. 17, 467 (2017).
[26] A. VahidMohammadi, J. Rosen, and Y. Gogotsi, The World of Two-Dimensional Carbides and Nitrides (MXenes), Science 372, eabf1581 (2021).
[27] K. J. Harris, M. Bugnet, M. Naguib, M. W. Barsoum, and G. R. Goward, Direct Measurement of Surface Termination Groups and Their Connectivity in the 2D MXene V2CTx Using NMR Spectroscopy, J. Phys. Chem. C 119, 13713 (2015).
[28] D. Magne, V. Mauchamp, S. Célérier, P. Chartier, and T. Cabioc’h, Site-Projected Electronic Structure of Two-Dimensional Ti3C2 MXene: The Role of the Surface Functionalization Groups, Phys. Chem. Chem. Phys. 18, 30946 (2016).
[29] Z. Li, L. Wang, D. Sun, Y. Zhang, B. Liu, Q. Hu, and A. Zhou, Synthesis and Thermal Stability of Two-Dimensional Carbide MXene Ti3C2, Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. (2015).
[30] H. Weng, A. Ranjbar, Y. Liang, Z. Song, M. Khazaei, S. Yunoki, M. Arai, Y. Kawazoe, Z. Fang, and X. Dai, Large-Gap Two-Dimensional Topological Insulator in Oxygen Functionalized MXene, Phys. Rev. B 92, 075436 (2015).
[31] S. Zhang, W. Ji, C. Zhang, S. Zhang, P. Li, S. Li, and S. Yan, Discovery of Two-Dimensional Quantum Spin Hall Effect in Triangular Transition-Metal Carbides, Chin. Phys. Lett. 35, 087303 (2018).
[32] C. Si, K.-H. Jin, J. Zhou, Z. Sun, and F. Liu, Large-Gap Quantum Spin Hall State in MXenes: D-Band Topological Order in a Triangular Lattice, Nano Lett. 16, 6584 (2016).
[33] L. Li, Lattice Dynamics and Electronic Structures of Ti3C2O2 and Mo2TiC2O2 (MXenes): The Effect of Mo Substitution, Comput. Mater. Sci. 124, 8 (2016).
[34] M. Khazaei, A. Ranjbar, M. Arai, and S. Yunoki, Topological Insulators in the Ordered Double Transition Metals M'2M''C2 MXenes (M'=Mo, W; M''= Ti, Zr, Hf), Phys. Rev. B 94, 125152 (2016).
[35] M. Wang, M. Khazaei, Y. Kawazoe, and Y. Liang, First-Principles Study of a Topological Phase Transition Induced by Image Potential States in MXenes, Phys. Rev. B 103, 035433 (2021).
[36] Z.-Q. Huang, M.-L. Xu, G. Macam, C.-H. Hsu, and F.-C. Chuang, Large-Gap Topological Insulators in Functionalized Ordered Double Transition Metal Carbide MXenes, Phys. Rev. B 102, 075306 (2020).
[37] Y. Liang, M. Khazaei, A. Ranjbar, M. Arai, S. Yunoki, Y. Kawazoe, H. Weng, and Z. Fang, Theoretical Prediction of Two-Dimensional Functionalized MXene Nitrides as Topological Insulators, Phys. Rev. B 96, 195414 (2017).
[38] P. Hohenberg and W. Kohn, Inhomogeneous Electron Gas, Phys. Rev. 136, B864 (1964).
[39] G. Kresse and D. Joubert, From Ultrasoft Pseudopotentials to the Projector Augmented-Wave Method, Phys. Rev. B 59, 1758 (1999).
[40] H. J. Monkhorst and J. D. Pack, Special Points for Brillouin-Zone Integrations, Phys. Rev. B 13, 5188 (1976).
[41] A. V. Krukau, O. A. Vydrov, A. F. Izmaylov, and G. E. Scuseria, Influence of the Exchange Screening Parameter on the Performance of Screened Hybrid Functionals, J. Chem. Phys. 125, 224106 (2006).
[42] F.-C. Chuang, L.-Z. Yao, Z.-Q. Huang, Y.-T. Liu, C.-H. Hsu, T. Das, H. Lin, and A. Bansil, Prediction of Large-Gap Two-Dimensional Topological Insulators Consisting of Bilayers of Group III Elements with Bi, Nano Lett. 14, 2505 (2014).
[43] C. Liu, T. L. Hughes, X.-L. Qi, K. Wang, and S.-C. Zhang, Quantum Spin Hall Effect in Inverted Type-II Semiconductors, Phys. Rev. Lett. 100, 236601 (2008).
[44] L. Fu and C. L. Kane, Josephson Current and Noise at a Superconductor/Quantum-Spin-Hall-Insulator/Superconductor Junction, Phys. Rev. B 79, 161408 (2009).
[45] C. Nayak, S. H. Simon, A. Stern, M. Freedman, and S. Das Sarma, Non-Abelian Anyons and Topological Quantum Computation, Rev. Mod. Phys. 80, 1083 (2008).
[46] A. Yu. Kitaev, Fault-Tolerant Quantum Computation by Anyons, Ann. Phys. 303, 2 (2003).
[47] L.-Y. Feng, R. A. B. Villaos, H. N. Cruzado, Z.-Q. Huang, C.-H. Hsu, H.-C. Hsueh, H. Lin, and F.-C. Chuang, Magnetic and Topological Properties in Hydrogenated Transition Metal Dichalcogenide Monolayers, Chin. J. Phys. 66, 15 (2020).
[48] M. Chhowalla, H. S. Shin, G. Eda, L.-J. Li, K. P. Loh, and H. Zhang, The Chemistry of Two-Dimensional Layered Transition Metal Dichalcogenide Nanosheets, Nat. Chem. 5, 263 (2013).
[49] M.-K. Lin, R. A. B. Villaos, J. A. Hlevyack, P. Chen, R.-Y. Liu, C.-H. Hsu, J. Avila, S.-K. Mo, F.-C. Chuang, and T.-C. Chiang, Dimensionality-Mediated Semimetal-Semiconductor Transition in Ultrathin PtTe2 Films, Phys. Rev. Lett. 124, 036402 (2020).
[50] C. Chen, B. Singh, H. Lin, and V. M. Pereira, Reproduction of the Charge Density Wave Phase Diagram in 1T-TiSe2 Exposes Its Excitonic Character, Phys. Rev. Lett. 121, 226602 (2018).
[51] B. Singh, C.-H. Hsu, W.-F. Tsai, V. M. Pereira, and H. Lin, Stable Charge Density Wave Phase in a 1T-TiSe2 Monolayer, Phys. Rev. B 95, 245136 (2017).
[52] P. Sriram, A. Manikandan, F.-C. Chuang, and Y.-L. Chueh, Hybridizing Plasmonic Materials with 2D-Transition Metal Dichalcogenides toward Functional Applications, Small 16, 1904271 (2020).
[53] R. A. B. Villaos, C. P. Crisostomo, Z.-Q. Huang, S.-M. Huang, A. A. B. Padama, M. A. Albao, H. Lin, and F.-C. Chuang, Thickness Dependent Electronic Properties of Pt Dichalcogenides, Npj 2D Mater. Appl. 3, 1 (2019).
[54] L.-Y. Feng, R. A. B. Villaos, Z.-Q. Huang, C.-H. Hsu, and F.-C. Chuang, Layer-Dependent Band Engineering of Pd Dichalcogenides: A First-Principles Study, New J. Phys. 22, 053010 (2020).
[55] S. Cho, S. Kim, J. H. Kim, J. Zhao, J. Seok, D. H. Keum, J. Baik, D.-H. Choe, K. J. Chang, K. Suenaga, S. W. Kim, Y. H. Lee, and H. Yang, Phase Patterning for Ohmic Homojunction Contact in MoTe2, Science (2015).
[56] Z. Fei, T. Palomaki, S. Wu, W. Zhao, X. Cai, B. Sun, P. Nguyen, J. Finney, X. Xu, and D. H. Cobden, Edge Conduction in Monolayer WTe2, Nat. Phys. 13, 677 (2017).
[57] K. Dolui, I. Rungger, C. Das Pemmaraju, and S. Sanvito, Possible Doping Strategies for MoS2 Monolayers: An Ab Initio Study, Phys. Rev. B 88, 075420 (2013).
[58] Y. Qu, H. Pan, and C. T. Kwok, Hydrogenation-Controlled Phase Transition on Two-Dimensional Transition Metal Dichalcogenides and Their Unique Physical and Catalytic Properties, Sci. Rep. 6, 34186 (2016).
[59] K. Koepernik, D. Kasinathan, D. V. Efremov, S. Khim, S. Borisenko, B. Büchner, and J. van den Brink, TaIrTe4: A Ternary Type-II Weyl Semimetal, Phys. Rev. B 93, 201101 (2016).
[60] W. Chen, X. Hou, X. Shi, and H. Pan, Two-Dimensional Janus Transition Metal Oxides and Chalcogenides: Multifunctional Properties for Photocatalysts, Electronics, and Energy Conversion, ACS Appl. Mater. Interfaces 10, 35289 (2018).
[61] A. B. Maghirang, Z.-Q. Huang, R. A. B. Villaos, C.-H. Hsu, L.-Y. Feng, E. Florido, H. Lin, A. Bansil, and F.-C. Chuang, Predicting Two-Dimensional Topological Phases in Janus Materials by Substitutional Doping in Transition Metal Dichalcogenide Monolayers, Npj 2D Mater. Appl. 3, 1 (2019).
[62] T.-R. Chang, S.-Y. Xu, G. Chang, C.-C. Lee, S.-M. Huang, B. Wang, G. Bian, H. Zheng, D. S. Sanchez, I. Belopolski, N. Alidoust, M. Neupane, A. Bansil, H.-T. Jeng, H. Lin, and M. Zahid Hasan, Prediction of an Arc-Tunable Weyl Fermion Metallic State in MoxW1-xTe2, Nat. Commun. 7, 10639 (2016).
[63] R. Schönemann, Y.-C. Chiu, W. Zheng, V. L. Quito, S. Sur, G. T. McCandless, J. Y. Chan, and L. Balicas, Bulk Fermi Surface of the Weyl Type-II Semimetallic Candidate NbIrTe4, Phys. Rev. B 99, 195128 (2019).
[64] R.-J. Chang, Y. Sheng, G. H. Ryu, N. Mkhize, T. Chen, Y. Lu, J. Chen, J. K. Lee, H. Bhaskaran, and J. H. Warner, Postgrowth Substitutional Tin Doping of 2D WS2 Crystals Using Chemical Vapor Deposition, ACS Appl. Mater. Interfaces 11, 24279 (2019).
[65] X. Zhou, Q. Liu, Q. Wu, T. Nummy, H. Li, J. Griffith, S. Parham, J. Waugh, E. Emmanouilidou, B. Shen, O. V. Yazyev, N. Ni, and D. Dessau, Coexistence of Tunable Weyl Points and Topological Nodal Lines in Ternary Transition-Metal Telluride TaIrTe4, Phys. Rev. B 97, 241102 (2018).
[66] F. Cui, Q. Feng, J. Hong, R. Wang, Y. Bai, X. Li, D. Liu, Y. Zhou, X. Liang, X. He, Z. Zhang, S. Liu, Z. Lei, Z. Liu, T. Zhai, and H. Xu, Synthesis of Large-Size 1T′ ReS2xSe2(1-x) Alloy Monolayer with Tunable Bandgap and Carrier Type, Adv. Mater. 29, 1705015 (2017).
[67] S. Susarla, V. Kochat, A. Kutana, J. A. Hachtel, J. C. Idrobo, R. Vajtai, B. I. Yakobson, C. S. Tiwary, and P. M. Ajayan, Phase Segregation Behavior of Two-Dimensional Transition Metal Dichalcogenide Binary Alloys Induced by Dissimilar Substitution, Chem. Mater. 29, 7431 (2017).
[68] S. Susarla, J. A. Hachtel, X. Yang, A. Kutana, A. Apte, Z. Jin, R. Vajtai, J. C. Idrobo, J. Lou, B. I. Yakobson, C. S. Tiwary, and P. M. Ajayan, Thermally Induced 2D Alloy-Heterostructure Transformation in Quaternary Alloys, Adv. Mater. 30, 1804218 (2018).
[69] J. Park, M. S. Kim, B. Park, S. H. Oh, S. Roy, J. Kim, and W. Choi, Composition-Tunable Synthesis of Large-Scale Mo1-xWxS2 Alloys with Enhanced Photoluminescence, ACS Nano 12, 6301 (2018).
[70] Y. Chen, J. Xi, D. O. Dumcenco, Z. Liu, K. Suenaga, D. Wang, Z. Shuai, Y.-S. Huang, and L. Xie, Tunable Bandgap Photoluminescence from Atomically Thin Transition-Metal Dichalcogenide Alloys, ACS Nano 7, 4610 (2013).
[71] I. Belopolski, D. S. Sanchez, Y. Ishida, X. Pan, P. Yu, S.-Y. Xu, G. Chang, T.-R. Chang, H. Zheng, N. Alidoust, G. Bian, M. Neupane, S.-M. Huang, C.-C. Lee, Y. Song, H. Bu, G. Wang, S. Li, G. Eda, H.-T. Jeng, T. Kondo, H. Lin, Z. Liu, F. Song, S. Shin, and M. Z. Hasan, Discovery of a New Type of Topological Weyl Fermion Semimetal State in MoxW1-xTe2, Nat. Commun. 7, 13643 (2016).
[72] Z. Zhu, Y. Cheng, and U. Schwingenschlögl, Topological Phase Diagrams of Bulk and Monolayer TiS2-xTex , Phys. Rev. Lett. 110, 077202 (2013).
[73] J. Mann, Q. Ma, P. M. Odenthal, M. Isarraraz, D. Le, E. Preciado, D. Barroso, K. Yamaguchi, G. von S. Palacio, A. Nguyen, T. Tran, M. Wurch, A. Nguyen, V. Klee, S. Bobek, D. Sun, T. F. Heinz, T. S. Rahman, R. Kawakami, and L. Bartels, 2-Dimensional Transition Metal Dichalcogenides with Tunable Direct Bandgaps: MoS2(1-x)Se2x Monolayers, Adv. Mater. 26, 1399 (2014).
[74] Y. Gong, Z. Liu, A. R. Lupini, G. Shi, J. Lin, S. Najmaei, Z. Lin, A. L. Elías, A. Berkdemir, G. You, H. Terrones, M. Terrones, R. Vajtai, S. T. Pantelides, S. J. Pennycook, J. Lou, W. Zhou, and P. M. Ajayan, Bandgap Engineering and Layer-by-Layer Mapping of Selenium-Doped Molybdenum Disulfide, Nano Lett. 14, 442 (2014).
[75] A. Chaves, J. G. Azadani, H. Alsalman, D. R. da Costa, R. Frisenda, A. J. Chaves, S. H. Song, Y. D. Kim, D. He, J. Zhou, A. Castellanos-Gomez, F. M. Peeters, Z. Liu, C. L. Hinkle, S.-H. Oh, P. D. Ye, S. J. Koester, Y. H. Lee, P. Avouris, X. Wang, and T. Low, Bandgap Engineering of Two-Dimensional Semiconductor Materials, Npj 2D Mater. Appl. 4, 1 (2020).
[76] B. Tang, J. Zhou, P. Sun, X. Wang, L. Bai, J. Dan, J. Yang, K. Zhou, X. Zhao, S. J. Pennycook, and Z. Liu, Phase-Controlled Synthesis of Monolayer Ternary Telluride with a Random Local Displacement of Tellurium Atoms, Adv. Mater. 31, 1900862 (2019).
[77] G. Kresse and J. Hafner, Ab Initio Molecular Dynamics for Liquid Metals, Phys. Rev. B 47, 558 (1993).
[78] G. Kresse and J. Furthmüller, Efficient Iterative Schemes for Ab Initio Total-Energy Calculations Using a Plane-Wave Basis Set, Phys. Rev. B 54, 11169 (1996).
[79] J. P. Perdew, K. Burke, and M. Ernzerhof, Generalized Gradient Approximation Made Simple, Phys. Rev. Lett. 77, 3865 (1996).
[80] D. Gresch, G. Autès, O. V. Yazyev, M. Troyer, D. Vanderbilt, B. A. Bernevig, and A. A. Soluyanov, Z2Pack: Numerical Implementation of Hybrid Wannier Centers for Identifying Topological Materials, Phys. Rev. B 95, 075146 (2017).
[81] Q. Wu, S. Zhang, H.-F. Song, M. Troyer, and A. A. Soluyanov, WannierTools: An Open-Source Software Package for Novel Topological Materials, Comput. Phys. Commun. 224, 405 (2018).
[82] X. Li, Z. Zhang, Y. Yao, and H. Zhang, High Throughput Screening for Two-Dimensional Topological Insulators, 2D Mater. 5, 045023 (2018).
[83] C. Gong, H. Zhang, W. Wang, L. Colombo, R. M. Wallace, and K. Cho, Band Alignment of Two-Dimensional Transition Metal Dichalcogenides: Application in Tunnel Field Effect Transistors, Appl. Phys. Lett. 103, 053513 (2013).
[84] L. Fu and C. L. Kane, Topological Insulators with Inversion Symmetry, Phys. Rev. B 76, 045302 (2007).
[85] M. Z. Hasan and C. L. Kane, Colloquium: Topological Insulators, Rev. Mod. Phys. 82, 3045 (2010).
[86] Z.-Q. Huang, C.-H. Hsu, C. P. Crisostomo, G. Macam, J.-R. Su, H. Lin, A. Bansil, and F.-C. Chuang, Quantum Anomalous Hall Insulator Phases in Fe-Doped GaBi Honeycomb, Chin. J. Phys. 67, 246 (2020).
[87] Z.-Q. Huang, W.-C. Chen, G. M. Macam, C. P. Crisostomo, S.-M. Huang, R.-B. Chen, M. A. Albao, D.-J. Jang, H. Lin, and F.-C. Chuang, Prediction of Quantum Anomalous Hall Effect in MBi and MSb (M:Ti, Zr, and Hf) Honeycombs, Nanoscale Res. Lett. 13, 43 (2018).
[88] R. Yu, W. Zhang, H.-J. Zhang, S.-C. Zhang, X. Dai, and Z. Fang, Quantized Anomalous Hall Effect in Magnetic Topological Insulators, Science (2010).
[89] C. P. Crisostomo, Z.-Q. Huang, C.-H. Hsu, F.-C. Chuang, H. Lin, and A. Bansil, Chemically Induced Large-Gap Quantum Anomalous Hall Insulator States in III-Bi Honeycombs, Npj Comput. Mater. 3, 1 (2017).
[90] C.-H. Hsu, Y. Fang, S. Wu, Z.-Q. Huang, C. P. Crisostomo, Y.-M. Gu, Z.-Z. Zhu, H. Lin, A. Bansil, F.-C. Chuang, and L. Huang, Quantum Anomalous Hall Insulator Phase in Asymmetrically Functionalized Germanene, Phys. Rev. B 96, 165426 (2017).
[91] T. Zhang, Y. Jiang, Z. Song, H. Huang, Y. He, Z. Fang, H. Weng, and C. Fang, Catalogue of Topological Electronic Materials, Nature 566, 475 (2019).
[92] M. G. Vergniory, L. Elcoro, C. Felser, N. Regnault, B. A. Bernevig, and Z. Wang, A Complete Catalogue of High-Quality Topological Materials, Nature 566, 480 (2019).
[93] C. P. Crisostomo, L.-Z. Yao, Z.-Q. Huang, C.-H. Hsu, F.-C. Chuang, H. Lin, M. A. Albao, and A. Bansil, Robust Large Gap Two-Dimensional Topological Insulators in Hydrogenated III–V Buckled Honeycombs, Nano Lett. 15, 6568 (2015).
[94] S. Wu, V. Fatemi, Q. D. Gibson, K. Watanabe, T. Taniguchi, R. J. Cava, and P. Jarillo-Herrero, Observation of the Quantum Spin Hall Effect up to 100 Kelvin in a Monolayer Crystal, Science (2018).
[95] S. Manzeli, D. Ovchinnikov, D. Pasquier, O. V. Yazyev, and A. Kis, 2D Transition Metal Dichalcogenides, Nat. Rev. Mater. 2, 1 (2017).
[96] H. H. Huang, X. Fan, D. J. Singh, and W. T. Zheng, Recent Progress of TMD Nanomaterials: Phase Transitions and Applications, Nanoscale 12, 1247 (2020).
[97] B. Singh, C.-H. Hsu, W.-F. Tsai, V. M. Pereira, and H. Lin, Stable Charge Density Wave Phase in a 1T-TiSe2 Monolayer, Phys. Rev. B 95, 245136 (2017).
[98] A. B. Maghirang, Z.-Q. Huang, R. A. B. Villaos, C.-H. Hsu, L.-Y. Feng, E. Florido, H. Lin, A. Bansil, and F.-C. Chuang, Predicting Two-Dimensional Topological Phases in Janus Materials by Substitutional Doping in Transition Metal Dichalcogenide Monolayers, Npj 2D Mater. Appl. 3, 1 (2019).
[99] S. Tang, C. Zhang, D. Wong, Z. Pedramrazi, H.-Z. Tsai, C. Jia, B. Moritz, M. Claassen, H. Ryu, S. Kahn, J. Jiang, H. Yan, M. Hashimoto, D. Lu, R. G. Moore, C.-C. Hwang, C. Hwang, Z. Hussain, Y. Chen, M. M. Ugeda, Z. Liu, X. Xie, T. P. Devereaux, M. F. Crommie, S.-K. Mo, and Z.-X. Shen, Quantum Spin Hall State in Monolayer 1T’-WTe2 , Nat. Phys. 13, 683 (2017).
[100] J. Mann, Q. Ma, P. M. Odenthal, M. Isarraraz, D. Le, E. Preciado, D. Barroso, K. Yamaguchi, G. von S. Palacio, A. Nguyen, T. Tran, M. Wurch, A. Nguyen, V. Klee, S. Bobek, D. Sun, T. F. Heinz, T. S. Rahman, R. Kawakami, and L. Bartels, 2-Dimensional Transition Metal Dichalcogenides with Tunable Direct Bandgaps: MoS2(1-x)Se2x Monolayers, Adv. Mater. 26, 1399 (2014).
[101] X. Dong, M. Wang, D. Yan, X. Peng, J. Li, W. Xiao, Q. Wang, J. Han, J. Ma, Y. Shi, and Y. Yao, Observation of Topological Edge States at the Step Edges on the Surface of Type-II Weyl Semimetal TaIrTe4, ACS Nano 13, 9571 (2019).
[102] G. Macam, A. Sufyan, Z.-Q. Huang, C.-H. Hsu, S.-M. Huang, H. Lin, and F.-C. Chuang, Tuning Topological Phases and Electronic Properties of Monolayer Ternary Transition Metal Chalcogenides (ABX4, A/B = Zr, Hf, or Ti; X = S, Se, or Te), Appl. Phys. Lett. 118, 111901 (2021).
[103] S. Khim, K. Koepernik, D. V. Efremov, J. Klotz, T. Förster, J. Wosnitza, M. I. Sturza, S. Wurmehl, C. Hess, J. van den Brink, and B. Büchner, Magnetotransport and de Haas--van Alphen Measurements in the Type-II Weyl Semimetal TaIrTe4 , Phys. Rev. B 94, 165145 (2016).
[104] E. Haubold, K. Koepernik, D. Efremov, S. Khim, A. Fedorov, Y. Kushnirenko, J. van den Brink, S. Wurmehl, B. Büchner, T. K. Kim, M. Hoesch, K. Sumida, K. Taguchi, T. Yoshikawa, A. Kimura, T. Okuda, and S. V. Borisenko, Experimental Realization of Type-II Weyl State in Noncentrosymmetric TaIrTe4, Phys. Rev. B 95, 241108 (2017).
[105] I. Belopolski, P. Yu, D. S. Sanchez, Y. Ishida, T.-R. Chang, S. S. Zhang, S.-Y. Xu, H. Zheng, G. Chang, G. Bian, H.-T. Jeng, T. Kondo, H. Lin, Z. Liu, S. Shin, and M. Z. Hasan, Signatures of a Time-Reversal Symmetric Weyl Semimetal with Only Four Weyl Points, Nat. Commun. 8, 942 (2017).
[106] I. Belopolski, D. S. Sanchez, Y. Ishida, X. Pan, P. Yu, S.-Y. Xu, G. Chang, T.-R. Chang, H. Zheng, N. Alidoust, G. Bian, M. Neupane, S.-M. Huang, C.-C. Lee, Y. Song, H. Bu, G. Wang, S. Li, G. Eda, H.-T. Jeng, T. Kondo, H. Lin, Z. Liu, F. Song, S. Shin, and M. Z. Hasan, Discovery of a New Type of Topological Weyl Fermion Semimetal State in MoxW1-xTe2, Nat. Commun. 7, 13643 (2016).
[107] J. Liu, H. Wang, C. Fang, L. Fu, and X. Qian, Van Der Waals Stacking-Induced Topological Phase Transition in Layered Ternary Transition Metal Chalcogenides, Nano Lett. 17, 467 (2017).
[108] P.-J. Guo, X.-Q. Lu, W. Ji, K. Liu, and Z.-Y. Lu, Quantum Spin Hall Effect in Monolayer and Bilayer TaIrTe4, Phys. Rev. B 102, 041109 (2020).
[109] H. Ma, W. Dang, X. Yang, B. Li, Z. Zhang, P. Chen, Y. Liu, Z. Wan, Q. Qian, J. Luo, K. Zang, X. Duan, and X. Duan, Chemical Vapor Deposition Growth of Single Crystalline CoTe2 Nanosheets with Tunable Thickness and Electronic Properties, Chem. Mater. 30, 8891 (2018).
[110] R. Wu, Q. Tao, W. Dang, Y. Liu, B. Li, J. Li, B. Zhao, Z. Zhang, H. Ma, G. Sun, X. Duan, and X. Duan, Van Der Waals Epitaxial Growth of Atomically Thin 2D Metals on Dangling-Bond-Free WSe2 and WS2, Adv. Funct. Mater. 29, 1806611 (2019).
[111] J. Li, B. Zhao, P. Chen, R. Wu, B. Li, Q. Xia, G. Guo, J. Luo, K. Zang, Z. Zhang, H. Ma, G. Sun, X. Duan, and X. Duan, Synthesis of Ultrathin Metallic MTe2 (M = V, Nb, Ta) Single-Crystalline Nanoplates, Adv. Mater. 30, 1801043 (2018).
[112] Z. Zhang, J. Niu, P. Yang, Y. Gong, Q. Ji, J. Shi, Q. Fang, S. Jiang, H. Li, X. Zhou, L. Gu, X. Wu, and Y. Zhang, Van Der Waals Epitaxial Growth of 2D Metallic Vanadium Diselenide Single Crystals and Their Extra-High Electrical Conductivity, Adv. Mater. 29, 1702359 (2017).
[113] D. Gao, Q. Xue, X. Mao, W. Wang, Q. Xu, and D. Xue, Ferromagnetism in Ultrathin VS2 Nanosheets, J. Mater. Chem. C 1, 5909 (2013).
[114] A. Togo and I. Tanaka, First Principles Phonon Calculations in Materials Science, Scr. Mater. 108, 1 (2015).
[115] G. Pizzi, V. Vitale, R. Arita, S. Blügel, F. Freimuth, G. Géranton, M. Gibertini, D. Gresch, C. Johnson, T. Koretsune, J. Ibañez-Azpiroz, H. Lee, J.-M. Lihm, D. Marchand, A. Marrazzo, Y. Mokrousov, J. I. Mustafa, Y. Nohara, Y. Nomura, L. Paulatto, S. Poncé, T. Ponweiser, J. Qiao, F. Thöle, S. S. Tsirkin, M. Wierzbowska, N. Marzari, D. Vanderbilt, I. Souza, A. A. Mostofi, and J. R. Yates, Wannier90 as a Community Code: New Features and Applications, J. Phys. Condens. Matter 32, 165902 (2020).
[116] J. Cao, Z.-Q. Huang, G. Macam, Y. Gao, N. V. R. Nulakani, X. Ge, X. Ye, F.-C. Chuang, and L. Huang, Prediction of Massless Dirac Fermions in a Carbon Nitride Covalent Network, Appl. Phys. Lett. 118, 133104 (2021).
[117] K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, M. I. Katsnelson, I. V. Grigorieva, S. V. Dubonos, and A. A. Firsov, Two-Dimensional Gas of Massless Dirac Fermions in Graphene, Nature 438, 197 (2005).
[118] J. Kruthoff, J. de Boer, J. van Wezel, C. L. Kane, and R.-J. Slager, Topological Classification of Crystalline Insulators through Band Structure Combinatorics, Phys. Rev. X 7, 041069 (2017).
[119] Y. He, Y. Jiang, T. Zhang, H. Huang, C. Fang, and Z. Jin, SymTopo: An Automatic Tool for Calculating Topological Properties of Nonmagnetic Crystalline Materials, Chin. Phys. B 28, 087102 (2019).
[120] L. Kou, Y. Ma, Z. Sun, T. Heine, and C. Chen, Two-Dimensional Topological Insulators: Progress and Prospects, J. Phys. Chem. Lett. 8, 1905 (2017).
[121] A. Sufyan, G. Macam, C.-H. Hsu, Z.-Q. Huang, S.-M. Huang, H. Lin, and F.-C. Chuang, Theoretical Prediction of Topological Insulators in Two-Dimensional Ternary Transition Metal Chalcogenides (MM’X4, M = Ta, Nb, or V; M’= Ir, Rh, or Co; X = Se or Te), Chin. J. Phys. 73, 95 (2021).
[122] C. P. Crisostomo, L.-Z. Yao, Z.-Q. Huang, C.-H. Hsu, F.-C. Chuang, H. Lin, M. A. Albao, and A. Bansil, Robust Large Gap Two-Dimensional Topological Insulators in Hydrogenated III–V Buckled Honeycombs, Nano Lett. 15, 6568 (2015).
[123] L. Zhang, Z. Yang, T. Gong, R. Pan, H. Wang, Z. Guo, H. Zhang, and X. Fu, Recent Advances in Emerging Janus Two-Dimensional Materials: From Fundamental Physics to Device Applications, J. Mater. Chem. A 8, 8813 (2020).
[124] C.-H. Hsu, Z.-Q. Huang, G. M. Macam, F.-C. Chuang, and L. Huang, Prediction of Two-Dimensional Organic Topological Insulator in Metal-DCB Lattices, Appl. Phys. Lett. 113, 233301 (2018).
[125] F.-C. Chuang, C.-H. Hsu, C.-Y. Chen, Z.-Q. Huang, V. Ozolins, H. Lin, and A. Bansil, Tunable Topological Electronic Structures in Sb(111) Bilayers: A First-Principles Study, Appl. Phys. Lett. 102, 022424 (2013).
[126] L.-Z. Yao, C. P. Crisostomo, C.-C. Yeh, S.-M. Lai, Z.-Q. Huang, C.-H. Hsu, F.-C. Chuang, H. Lin, and A. Bansil, Predicted Growth of Two-Dimensional Topological Insulator Thin Films of III-V Compounds on Si(111) Substrate, Sci. Rep. 5, 15463 (2015).
[127] C.-H. Hsu, Z.-Q. Huang, F.-C. Chuang, C.-C. Kuo, Y.-T. Liu, H. Lin, and A. Bansil, The Nontrivial Electronic Structure of Bi/Sb Honeycombs on SiC(0001), New J. Phys. 17, 025005 (2015).
[128] F.-C. Chuang, C.-H. Hsu, H.-L. Chou, C. P. Crisostomo, Z.-Q. Huang, S.-Y. Wu, C.-C. Kuo, W.-C. V. Yeh, H. Lin, and A. Bansil, Prediction of Two-Dimensional Topological Insulator by Forming a Surface Alloy on Au/Si(111) Substrate, Phys. Rev. B 93, 035429 (2016).
[129] C.-H. Hsu, Z.-Q. Huang, C.-Y. Lin, G. M. Macam, Y.-Z. Huang, D.-S. Lin, T. C. Chiang, H. Lin, F.-C. Chuang, and L. Huang, Growth of a Predicted Two-Dimensional Topological Insulator Based on InBi-Si(111)-√7 × √7 , Phys. Rev. B 98, 121404 (2018).
[130] M. Khazaei, M. Arai, T. Sasaki, C.-Y. Chung, N. S. Venkataramanan, M. Estili, Y. Sakka, and Y. Kawazoe, Novel Electronic and Magnetic Properties of Two-Dimensional Transition Metal Carbides and Nitrides, Adv. Funct. Mater. 23, 2185 (2013).
[131] B. Anasori, M. R. Lukatskaya, and Y. Gogotsi, 2D Metal Carbides and Nitrides (MXenes) for Energy Storage, Nat. Rev. Mater. 2, 1 (2017).
[132] V. M. H. Ng, H. Huang, K. Zhou, P. S. Lee, W. Que, J. Z. Xu, and L. B. Kong, Recent Progress in Layered Transition Metal Carbides and/or Nitrides (MXenes) and Their Composites: Synthesis and Applications, J. Mater. Chem. A 5, 3039 (2017).
[133] M. Naguib, M. Kurtoglu, V. Presser, J. Lu, J. Niu, M. Heon, L. Hultman, Y. Gogotsi, and M. W. Barsoum, Two-Dimensional Nanocrystals Produced by Exfoliation of Ti3AlC2, Adv. Mater. 23, 4248 (2011).
[134] M. Naguib, V. N. Mochalin, M. W. Barsoum, and Y. Gogotsi, 25th Anniversary Article: MXenes: A New Family of Two-Dimensional Materials, Adv. Mater. 26, 992 (2014).
[135] Y. Gogotsi and B. Anasori, The Rise of MXenes, ACS Nano 13, 8491 (2019).
[136] M. Naguib, J. Halim, J. Lu, K. M. Cook, L. Hultman, Y. Gogotsi, and M. W. Barsoum, New Two-Dimensional Niobium and Vanadium Carbides as Promising Materials for Li-Ion Batteries, J. Am. Chem. Soc. 135, 15966 (2013).
[137] D. Sun, Q. Hu, J. Chen, X. Zhang, L. Wang, Q. Wu, and A. Zhou, Structural Transformation of MXene (V2C, Cr2C, and Ta2C) with O Groups during Lithiation: A First-Principles Investigation, ACS Appl. Mater. Interfaces 8, 74 (2016).
[138] J. Hu, B. Xu, C. Ouyang, Y. Zhang, and S. A. Yang, Investigations on Nb2C Monolayer as Promising Anode Material for Li or Non-Li Ion Batteries from First-Principles Calculations, RSC Adv. 6, 27467 (2016).
[139] L. Bao, D. Qu, Z. Kong, and Y. Duan, Anisotropies in Elastic Properties and Thermal Conductivities of Trigonal TM2C (TM = V, Nb, Ta) Carbides, Solid State Sci. 98, 106027 (2019).
[140] H. Wang, W. Luo, M. Wu, and C. Ouyang, The Effect of Strain on the Li-Storage Performance of V2C and Nb2C: From First-Principles Study, Solid State Commun. 311, 113857 (2020).
[141] A. Bhat, S. Anwer, K. S. Bhat, M. I. H. Mohideen, K. Liao, and A. Qurashi, Prospects Challenges and Stability of 2D MXenes for Clean Energy Conversion and Storage Applications, Npj 2D Mater. Appl. 5, 1 (2021).
[142] X. Sha, N. Xiao, Y. Guan, and X. Yi, Structural, Mechanical and Electronic Properties of Nb2C: First-Principles Calculations, RSC Adv. 7, 33402 (2017).
[143] A. Champagne, L. Shi, T. Ouisse, B. Hackens, and J.-C. Charlier, Electronic and Vibrational Properties of V2C-Based MXenes: From Experiments to First-Principles Modeling, Phys. Rev. B 97, 115439 (2018).
[144] Z. Zeng, X. Chen, K. Weng, Y. Wu, P. Zhang, J. Jiang, and N. Li, Computational Screening Study of Double Transition Metal Carbonitrides M′2M″CNO2-MXene as Catalysts for Hydrogen Evolution Reaction, Npj Comput. Mater. 7, 1 (2021).
[145] A. L. Bowman, T. C. Wallace, J. L. Yarnell, R. G. Wenzel, and E. K. Storms, The Crystal Structures of V2C and Ta2C, Acta Crystallogr. 19, 1 (1965).
[146] K. Hiraga and M. Hirabayashi, Modulated Structure in Metal Carbide Systems of V2C, Nb2C and Ta2C, AIP Conf. Proc. 53, 276 (1979).
[147] C. Peng, P. Wei, X. Chen, Y. Zhang, F. Zhu, Y. Cao, H. Wang, H. Yu, and F. Peng, A Hydrothermal Etching Route to Synthesis of 2D MXene (Ti3C2, Nb2C): Enhanced Exfoliation and Improved Adsorption Performance, Ceram. Int. 44, 18886 (2018).
[148] Y. Guan, S. Jiang, Y. Cong, J. Wang, Z. Dong, Q. Zhang, G. Yuan, Y. Li, and X. Li, A Hydrofluoric Acid-Free Synthesis of 2D Vanadium Carbide (V2C) MXene for Supercapacitor Electrodes, 2D Mater. 7, 025010 (2020).
[149] V. G. Hadjiev, E. G. Baburaj, and J. Guan, Phonons in Ultra-High Melting Temperature Ta2C, EPL 111, 6 (2015).
[150] N. He, Q. Zhang, L. Tao, X. Chen, Q. Qin, X. Liu, X. Lian, X. Wan, E. Hu, J. Xu, F. Xu, and Y. Tong, V₂C-Based Memristor for Applications of Low Power Electronic Synapse, IEEE Electron Device Lett. 42, 319 (2021).
[151] S. Gul, M. I. Serna, S. A. Zahra, N. Arif, M. Iqbal, D. Akinwande, and S. Rizwan, Un-Doped and Er-Adsorbed Layered Nb2C MXene for Efficient Hydrazine Sensing Application, Surf. Interfaces 24, 101074 (2021).
[152] B. Akgenc, New Predicted Two-Dimensional MXenes and Their Structural, Electronic and Lattice Dynamical Properties, Solid State Commun. 303–304, 113739 (2019).
[153] N.-N. Zhao, P.-J. Guo, X.-Q. Lu, Q. Han, K. Liu, and Z.-Y. Lu, Topological Properties of Mo2C and W2C Superconductors, Phys. Rev. B 101, 195144 (2020).
[154] L. Gao, C. Ma, S. Wei, A. V. Kuklin, H. Zhang, and H. Ågren, Applications of Few-Layer Nb2 C MXene: Narrow-Band Photodetectors and Femtosecond Mode-Locked Fiber Lasers, ACS Nano 15, 954 (2021).
[155] S. Zhao, W. Kang, and J. Xue, Manipulation of Electronic and Magnetic Properties of M2C (M = Hf, Nb, Sc, Ta, Ti, V, Zr) Monolayer by Applying Mechanical Strains, Appl. Phys. Lett. 104, 133106 (2014).
[156] G. Brauer, H. Renner, and J. Wernet, Die Carbide des Niobs, Z. Für Anorg. Allg. Chem. 277, 249 (1954).
[157] I. Salama, T. El-Raghy, and M. W. Barsoum, Synthesis and Mechanical Properties of Nb2AlC and (Ti,Nb)2AlC, J. Alloys Compd. 347, 271 (2002).
[158] M. P. L. Sancho, J. M. L. Sancho, J. M. L. Sancho, and J. Rubio, Highly Convergent Schemes for the Calculation of Bulk and Surface Green Functions, J. Phys. F Met. Phys. 15, 851 (1985).
[159] H. N. Cruzado, J. S. C. Dizon, G. M. Macam, R. A. B. Villaos, T. M. D. Huynh, L.-Y. Feng, Z.-Q. Huang, C.-H. Hsu, S.-M. Huang, H. Lin, and F.-C. Chuang, Band Engineering and Van Hove Singularity on HfX2 Thin Films (X = S, Se, or Te), ACS Appl. Electron. Mater. 3, 1071 (2021).
[160] R. A. B. Villaos, H. N. Cruzado, J. S. C. Dizon, A. B. Maghirang, Z.-Q. Huang, C.-H. Hsu, S.-M. Huang, H. Lin, and F.-C. Chuang, Evolution of the Electronic Properties of ZrX2 (X = S, Se, or Te) Thin Films under Varying Thickness, J. Phys. Chem. C 125, 1134 (2021).