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Robust transport of charge carriers in in-plane 1T′-2H MoTe2 homojunctions with ohmic contact

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Abstract

Metal-semiconductor ohmic contacts are required to reduce the energy dissipation for two-dimensional (2D) electronic devices, and phase engineering of 2D transition-metal dichalcogenides (TMDCs) is a promising approach for building ohmic contacts. Here, 2D in-plane 1T′-2H MoTe2 homojunctions were prepared by direct epitaxy via vapor deposition. The interface properties of in-plane 1T′-2H MoTe2 homojunction were investigated in detail by combining experiments, calculations and theories. The ohmic contact properties of 1T′-2H MoTe2 homojunction were proved according to Kelvin force probe microscopy and density functional theory calculations. The charge carriers robust transport in in-plane 1T′-2H MoTe2 homojunction without Fermi-level pinning can be well described by Poisson equation and band alignment. These results indicate that phase engineering of 2D TMDCs is promising to construct ohmic contacts for device applications.

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References

  1. Allain, A.; Kang, J. B.; Banerjee, K.; Kis, A. Electrical contacts to two-dimensional semiconductors. Nat. Mater. 2015, 14, 1195–1205.

    CAS  Google Scholar 

  2. Jena, D.; Banerjee, K.; Xing, G. H. 2D crystal semiconductors: Intimate contacts. Nat. Mater. 2014, 13, 1076–1078.

    CAS  Google Scholar 

  3. Liu, Y.; Guo, J.; Zhu, E. B.; Liao, L.; Lee, S. J.; Ding, M. N.; Shakir, I.; Gambin, V.; Huang, Y.; Duan, X. F. Approaching the Schottky-Mott limit in van der Waals metal-semiconductor junctions. Nature 2018, 557, 696–700.

    CAS  Google Scholar 

  4. Tung, R. T. The physics and chemistry of the Schottky barrier height. Appl. Phys. Rev. 2014, 1, 011304.

    Google Scholar 

  5. Fiori, G.; Bonaccorso, F.; Iannaccone, G.; Palacios, T.; Neumaier, D.; Seabaugh, A.; Banerjee, S. K.; Colombo, L. Electronics based on two-dimensional materials. Nat. Nanotechnol. 2014, 9, 768–779.

    CAS  Google Scholar 

  6. Bardeen, J. Surface states and rectification at a metal semi-conductor contact. Phys. Rev. 1947, 71, 717–727.

    Google Scholar 

  7. Kang, J. H.; Liu, W.; Sarkar, D.; Jena, D.; Banerjee, K. Computational study of metal contacts to monolayer transition-metal dichalcogenide semiconductors. Phys. Rev. X 2014, 4, 031005.

    Google Scholar 

  8. Tung, R. T. Chemical bonding and Fermi level pinning at metal-semiconductor interfaces. Phys. Rev. Lett. 2000, 84, 6078–6081.

    CAS  Google Scholar 

  9. Dean, C. R.; Young, A. F.; Meric, I.; Lee, C.; Wang, L.; Sorgenfrei, S.; Watanabe, K.; Taniguchi, T.; Kim, P.; Shepard, K. L. et al. Boron nitride substrates for high-quality graphene electronics. Nat. Nanotechnol. 2010, 5, 722–726.

    CAS  Google Scholar 

  10. Li, L. K.; Yu, Y. J.; Ye, G. J.; Ge, Q. Q.; Ou, X. D.; Wu, H.; Feng, D. L.; Chen, X. H.; Zhang, Y. B. Black phosphorus field-effect transistors. Nat. Nanotechnol. 2014, 9, 372–377.

    CAS  Google Scholar 

  11. Pradhan, N. R.; Rhodes, D.; Feng, S. M.; Xin, Y.; Memaran, S.; Moon, B. H.; Terrones, H.; Terrones, M.; Balicas, L. Field-effect transistors based on few-layered α-MoTe2. ACS Nano 2014, 8, 5911–5920.

    CAS  Google Scholar 

  12. Ruppert, C.; Aslan, O. B.; Heinz, T. F. Optical properties and band gap of single- and few-layer MoTe2 crystals. Nano Lett. 2014, 14, 6231–6236.

    CAS  Google Scholar 

  13. Wang, Q. H.; Kalantar-Zadeh, K.; Kis, A.; Coleman, J. N.; Strano, M. S. Electronics and optoelectronics of two-dimensional transition metal dichalcogenides. Nat. Nanotechnol. 2012, 7, 699–712.

    CAS  Google Scholar 

  14. Zhang, Y.; Chang, T. R.; Zhou, B.; Cui, Y. T.; Yan, H.; Liu, Z. K.; Schmitt, F.; Lee, J.; Moore, R.; Chen, Y. L. et al. Direct observation of the transition from indirect to direct bandgap in atomically thin epitaxial MoSe2. Nat. Nanotechnol. 2014, 9, 111–115.

    CAS  Google Scholar 

  15. Xiao, D.; Liu, G. B.; Feng, W. X.; Xu, X. D.; Yao, W. Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides. Phys. Rev. Lett. 2012, 108, 196802.

    Google Scholar 

  16. Liu, Y.; Duan, X. D.; Huang, Y.; Duan, X. F. Two-dimensional transistors beyond graphene and TMDCs. Chem. Soc. Rev. 2018, 47, 6388–6409.

    CAS  Google Scholar 

  17. Rao, C. N. R.; Gopalakrishnan, K.; Maitra, U. Comparative study of potential applications of Graphene, MoS2, and other two-dimensional materials in energy devices, sensors, and related areas. ACS Appl. Mater. Interfaces 2015, 7, 7809–7832.

    CAS  Google Scholar 

  18. Bao, X. Z.; Ou, Q. D.; Xu, Z. Q.; Zhang, Y. P.; Bao, Q. L.; Zhang, H. Band structure engineering in 2D materials for optoelectronic applications. Adv. Mater. Technol. 2018, 3, 1800072.

    Google Scholar 

  19. Zhang, J. C.; Huang, Y. C.; Tan, Z. J.; Li, T. R.; Zhang, Y. C.; Jia, K. C.; Lin, L.; Sun, L. Z.; Chen, X. W.; Li, Z. Z. et al. Low-temperature heteroepitaxy of 2D PbI2/Graphene for large-area flexible photodetectors. Adv. Mater. 2018, 30, 1803194.

    Google Scholar 

  20. Das, S.; Chen, H. Y.; Penumatcha, A. V.; Appenzeller, J. High performance multilayer MoS2 transistors with scandium contacts. Nano Lett. 2013, 13, 100–105.

    CAS  Google Scholar 

  21. Leong, W. S.; Luo, X.; Li, Y. D.; Khoo, K. H.; Quek, S. Y.; Thong, J. T. L. Low resistance metal contacts to MoS2 devices with nickel-etched-graphene electrodes. ACS Nano 2015, 9, 869–877.

    CAS  Google Scholar 

  22. Kappera, R.; Voiry, D.; Yalcin, S. E.; Branch, B.; Gupta, G.; Mohite, A. D.; Chhowalla, M. Phase-engineered low-resistance contacts for ultrathin MoS2 transistors. Nat. Mater. 2014, 13, 1128–1134.

    CAS  Google Scholar 

  23. Keum, D. H.; Cho, S.; Kim, J. H.; Choe, D. H.; Sung, H. J.; Kan, M.; Kang, H.; Hwang, J. Y.; Kim, S. W.; Yang, H. et al. Bandgap opening in few-layered monoclinic MoTe2. Nat. Phys. 2015, 11, 482–486.

    CAS  Google Scholar 

  24. Yoo, Y.; DeGregorio, Z. P.; Su, Y.; Koester, S. J.; Johns, J. E. Inplane 2H-1T† MoTe2 homojunctions synthesized by flux-controlled phase engineering. Adv. Mater. 2017, 29, 1605461.

    Google Scholar 

  25. Cho, S.; Kim, S.; Kim, J. H.; Zhao, J.; Seok, J.; Keum, D. H.; Baik, J.; Choe, D. H.; Chang, K. J.; Suenaga, K. et al. Phase patterning for ohmic homojunction contact in MoTe2. Science 2015, 349, 625–628.

    CAS  Google Scholar 

  26. Sung, J. H.; Heo, H.; Si, S.; Kim, Y. H.; Noh, H. R.; Song, K.; Kim, J.; Lee, C. S.; Seo, S. Y.; Kim, D. H. et al. Coplanar semiconductor-metal circuitry defined on few-layer MoTe2 via polymorphic heteroepitaxy. Nat. Nanotechnol. 2017, 12, 1064–1070.

    CAS  Google Scholar 

  27. Wang, Z. J.; Gresch, D.; Soluyanov, A. A.; Xie, W. W.; Kushwaha, S.; Dai, X.; Troyer, M.; Cava, R. J.; Bernevig, B. A. MoTe2: A type-II Weyl topological metal. Phys. Rev. Lett. 2016, 117, 056805.

    Google Scholar 

  28. Sun, Y.; Wu, S. C.; Ali, M. N.; Felser, C.; Yan, B. H. Prediction of Weyl semimetal in orthorhombic MoTe2. Phys. Rev. B 2015, 92, 161107.

    Google Scholar 

  29. Qi, Y. P.; Naumov, P. G.; Ali, M. N.; Rajamathi, C. R.; Schnelle, W.; Barkalov, O.; Hanfland, M.; Wu, S. C.; Shekhar, C.; Sun, Y. et al. Superconductivity in Weyl semimetal candidate MoTe2. Nat. Commun. 2016, 7, 11038.

    CAS  Google Scholar 

  30. Liu, S. Q.; Li, J. Z.; Shi, B. W.; Zhang, X. Y.; Pan, Y. Y.; Ye, M.; Quhe, R.; Wang, Y. Y.; Zhang, H.; Yan, J. H. et al. Gate-tunable interfacial properties of in-plane ML MX2 1T‣-2H heterojunctions. J. Mater. Chem. C 2018, 6, 5651–5661.

    CAS  Google Scholar 

  31. Dong, Z. P.; Guo, J. On low-resistance contacts to 2-D MoTe2 by crystalline phase junctions. IEEE Trans. Electron Dev. 2018, 65, 1583–1588.

    CAS  Google Scholar 

  32. Zhang, X.; Jin, Z. H.; Wang, L. Q.; Hachtel, J. A.; Villarreal, E.; Wang, Z. X.; Ha, T.; Nakanishi, Y.; Tiwary, C. S.; Lai, J. W. et al. Low contact barrier in 2H/1T′ MoTe2 in-plane heterostructure synthesized by chemical vapor deposition. ACS Appl. Mater. Interfaces 2019, 11, 12777–12785.

    CAS  Google Scholar 

  33. Yu, Y. Y.; Wang, G.; Qin, S. Q.; Wu, N. N.; Wang, Z. Y.; He, K.; Zhang, X. A. Molecular beam epitaxy growth of atomically ultrathin MoTe2 lateral heterophase homojunctions on graphene substrates. Carbon 2017, 115, 526–531.

    CAS  Google Scholar 

  34. Tan, Y.; Luo, F.; Zhu, M. J.; Xu, X. L.; Ye, Y.; Li, B.; Wang, G.; Luo, W.; Zheng, X. M.; Wu, N. N. et al. Controllable 2H-to-1T′ phase transition in few-layer MoTe2. Nanoscale 2018, 10, 19964–19971.

    CAS  Google Scholar 

  35. Kohn, W.; Sham, L. J. Self-consistent equations including exchange and correlation effects. Phys. Rev. 1965, 140, A1133–A1138.

    Google Scholar 

  36. Kresse, G.; Furthmüller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 1996, 54, 11169–11186.

    CAS  Google Scholar 

  37. Kresse, G.; Furthmüller, J. Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput. Mater. Sci. 1996, 6, 15–50.

    CAS  Google Scholar 

  38. Perdew, J. P.; Burke, K.; Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 1996, 77, 3865–3868.

    Article  CAS  Google Scholar 

  39. Blöchl, P. E. Projector augmented-wave method. Phys. Rev. B 1994, 50, 17953–17979.

    Google Scholar 

  40. Kresse, G.; Joubert, D. From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. Rev. B 1999, 59, 1758–1775.

    Article  CAS  Google Scholar 

  41. Monkhorst, H. J.; Pack, J. D. Special points for Brillouin-zone integrations. Phys. Rev. B 1976, 13, 5188–5192.

    Google Scholar 

  42. Grimme, S. Semiempirical GGA-type density functional constructed with a long-range dispersion correction. J. Comput. Chem. 2006, 27, 1787–1799.

    CAS  Google Scholar 

  43. Yang, L.; Zhang, W. F.; Li, J.; Cheng, S.; Xie, Z. J.; Chang, H. X. Tellurization velocity-dependent metallic-semiconducting-metallic phase evolution in chemical vapor deposition growth of large-area, few-layer MoTe2. ACS Nano 2017, 11, 1964–1972.

    CAS  Google Scholar 

  44. Wu, T. R.; Ding, G. Q.; Shen, H. L.; Wang, H. M.; Sun, L.; Jiang, D.; Xie, X. M.; Jiang, M. C. Triggering the continuous growth of graphene toward millimeter-sized grains. Adv. Funct. Mater. 2013, 23, 198–203.

    CAS  Google Scholar 

  45. Chen, T.; Hao, G. L.; Wang, G.; Li, B.; Kou, L. Z.; Yang, H.; Zheng, X. M.; Zhong, J. X. Controlled growth of atomically thin MoSe2 films and nanoribbons by chemical vapor deposition. 2D Mater. 2019, 6, 025002.

    CAS  Google Scholar 

  46. Park, J. C.; Yun, S. J.; Kim, H.; Park, J. H.; Chae, S. H.; An, S. J.; Kim, J. G.; Kim, S. M.; Kim, K. K.; Lee, Y. H. Phase-engineered synthesis of centimeter-scale 1T′-and 2H-molybdenum ditelluride thin films. ACS Nano 2015, 9, 6548–6554.

    CAS  Google Scholar 

  47. Wang, J. Y.; Luo, X.; Li, S. S.; Verzhbitskiy, I.; Zhao, W. J.; Wang, S. F.; Quek, S. Y.; Eda, G. Determination of crystal axes in semimetallic T′-MoTe2 by polarized Raman spectroscopy. Adv. Funct. Mater. 2017, 27, 1604799.

    Google Scholar 

  48. Yamamoto, M.; Wang, S. T.; Ni, M. Y.; Lin, Y. F.; Li, S. L.; Aikawa, S.; Jian, W. B.; Ueno, K.; Wakabayashi, K.; Tsukagoshi, K. Strong enhancement of Raman scattering from a bulk-inactive vibrational mode in few-layer MoTe2. ACS Nano 2014, 8, 3895–3903.

    CAS  Google Scholar 

  49. Hao, G. L.; Kou, L. Z.; Lu, D. L.; Peng, J.; Li, J.; Tang, C.; Zhong, J. X. Electrostatic properties of two-dimensional WSe2 nanostructures. J. Appl. Phys. 2016, 119, 035301.

    Google Scholar 

  50. Guan, J.; Chuang, H. J.; Zhou, Z. X.; Tománek, D. Optimizing charge injection across transition metal dichalcogenide heterojunctions: Theory and experiment. ACS Nano 2017, 11, 3904–3910.

    CAS  Google Scholar 

  51. Mashford, B. S.; Stevenson, M.; Popovic, Z.; Hamilton, C.; Zhou, Z. Q.; Breen, C.; Steckel, J.; Bulovic, V.; Bawendi, M.; Coe-Sullivan, S. et al. High-efficiency quantum-dot light-emitting devices with enhanced charge injection. Nat. Photonics 2013, 7, 407–412.

    CAS  Google Scholar 

  52. Mortreuil, F.; Villeneuve-Faure, C.; Boudou, L.; Makasheva, K.; Teyssedre, G. Charge injection phenomena at the metal/dielectric interface investigated by Kelvin probe force microscopy. J. Phys. D Appl. Phys. 2017, 50, 175302.

    Google Scholar 

  53. Tosun, M.; Fu, D. Y.; Desai, S. B.; Ko, C.; Kang, J. S.; Lien, D. H.; Najmzadeh, M.; Tongay, S.; Wu, J. Q.; Javey, A. MoS2 heterojunctions by thickness modulation. Sci. Rep. 2015, 5, 10990.

    Google Scholar 

  54. Kang, J.; Tongay, S.; Zhou, J.; Li, J. B.; Wu, J. Q. Band offsets and heterostructures of two-dimensional semiconductors. Appl. Phys. Lett. 2013, 102, 012111.

    Google Scholar 

  55. Yu, Y. J.; Zhao, Y.; Ryu, S.; Brus, L. E.; Kim, K. S.; Kim, P. Tuning the graphene work function by electric field effect. Nano Lett. 2009, 9, 3430–3434.

    CAS  Google Scholar 

  56. Zheng, C. X.; Zhang, Q. H.; Weber, B.; Ilatikhameneh, H.; Chen, F.; Sahasrabudhe, H.; Rahman, R.; Li, S. Q.; Chen, Z.; Hellerstedt, J. et al. Direct observation of 2D electrostatics and ohmic contacts in template-grown Graphene/WS2 heterostructures. ACS Nano 2017, 11, 2785–2793.

    CAS  Google Scholar 

  57. Xu, X. L.; Chen, S. L.; Liu, S.; Cheng, X.; Xu, W. J.; Li, P.; Wan, Y.; Yang, S. Q.; Gong, W. T.; Yuan, K. et al. Millimeter-scale single-crystalline semiconducting MoTe2 via solid-to-solid phase transformation. J. Am. Chem. Soc. 2019, 141, 2128–2134.

    CAS  Google Scholar 

  58. Noh, J. Y.; Kim, H.; Kim, Y. S. Stability and electronic structures of native defects in single-layer MoS2. Phys. Rev. B 2014, 89, 205417.

    Google Scholar 

  59. Komsa, H. P.; Krasheninnikov, A. V. Native defects in bulk and monolayer MoS2 from first principles. Phys. Rev. B 2015, 91, 125304.

    Google Scholar 

  60. Sharma, I.; Mehta, B. R. Enhanced charge separation at 2D MoS2/ZnS heterojunction: KPFM based study of interface photovoltage. Appl. Phys. Lett. 2017, 110, 061602.

    Google Scholar 

  61. Padilha, J. E.; Fazzio, A.; Da Silva, A. J. R. Van der Waals heterostructure of phosphorene and graphene: Tuning the Schottky barrier and doping by electrostatic gating. Phys. Rev. Lett. 2015, 114, 066803.

    CAS  Google Scholar 

  62. Hu, W.; Wang, T.; Zhang, R. Q.; Yang, J. L. Effects of interlayer coupling and electric fields on the electronic structures of graphene and MoS2 heterobilayers. J. Mater. Chem. C 2016, 4, 1776–1781.

    CAS  Google Scholar 

  63. Zhang, Y.; Liu, Y.; Wang, Z. L. Fundamental theory of piezotronics. Adv. Mater. 2011, 23, 3004–3013.

    CAS  Google Scholar 

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Acknowledgements

This work was supported by the Grants from National Natural Science Foundation of China (No. 11874316), Scientific Research Fund of Hunan Provincial Education Department (No. 18A059), the Hunan Provincial Innovation Foundation for Postgraduate (No. CX2018B321), the Project of Xiangtan Science and Technology Bureau (No. CXY-ZD20172002), and Innovative Research Team in University (No. IRT 17R91).

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  1. Donglin Lu and Zhenqing Li contributed equally to this work.

Authors and Affiliations

  1. Hunan Key Laboratory for Micro-Nano Energy Materials and Devices, Laboratory for Quantum Engineering and Micro-Nano Energy Technology, and School of Physics and Optoelectronics, Xiangtan University, Hunan, 411105, China

    Donglin Lu, Zhenqing Li, Congsheng Xu, Siwei Luo, Chaoyu He, Jun Li, Gang Guo, Guolin Hao, Xiang Qi & Jianxin Zhong

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  1. Donglin Lu
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Correspondence to Xiang Qi or Jianxin Zhong.

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Lu, D., Li, Z., Xu, C. et al. Robust transport of charge carriers in in-plane 1T′-2H MoTe2 homojunctions with ohmic contact. Nano Res. 14, 1311–1318 (2021). https://doi.org/10.1007/s12274-020-3155-4

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