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Nano Research 2021, 14(5): 1311-1318 https://doi.org/10.1007/s12274-020-3155-4
Research Article | Issue | Published: 05 January 2021

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

Show Author's Information Donglin Lu§,  Zhenqing Li§,  Congsheng Xu,  Siwei Luo,  Chaoyu He,  Jun Li,  Gang Guo,  Guolin Hao,  Xiang Qi( ),  Jianxin Zhong( )
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
Keywords:
built-in potential, surface potential, 1T′-2H MoTe2 homojunction, ohmic contact
Topics:
Density functional theoryMolybdenum compoundsScanning probe microscopySemiconductor devices Transition metals
Cite this article:
Lu D, Li Z, Xu C, et al. Robust transport of charge carriers in in-plane 1Tʹ-2H MoTe2 homojunctions with ohmic contact. Nano Research, 2021, 14(5): 1311-1318. https://doi.org/10.1007/s12274-020-3155-4
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Abstract Full text Electronic supplementary material About this article

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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Electronic supplementary material
About this article

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

Show Author's information Donglin Lu§, Zhenqing Li§, Congsheng Xu, Siwei Luo, Chaoyu He, Jun Li, Gang Guo, Guolin Hao, Xiang Qi( ), Jianxin Zhong( )
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

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.

Keywords: built-in potential, surface potential, 1T′-2H MoTe2 homojunction, ohmic contact

References(63)

[1]
A. Allain,; J. B. Kang,; K. Banerjee,; A. Kis, Electrical contacts to two-dimensional semiconductors. Nat. Mater. 2015, 14, 1195-1205.
DOI Google Scholar
[2]
D. Jena,; K. Banerjee,; G. H. Xing, 2D crystal semiconductors: Intimate contacts. Nat. Mater. 2014, 13, 1076-1078.
DOI Google Scholar
[3]
Y. Liu,; J. Guo,; E. B. Zhu,; L. Liao,; S. J. Lee,; M. N. Ding,; I. Shakir,; V. Gambin,; Y. Huang,; X. F. Duan, Approaching the Schottky-Mott limit in van der Waals metal-semiconductor junctions. Nature 2018, 557, 696-700.
DOI Google Scholar
[4]
R. T. Tung, The physics and chemistry of the Schottky barrier height. Appl. Phys. Rev. 2014, 1, 011304.
DOI Google Scholar
[5]
G. Fiori,; F. Bonaccorso,; G. Iannaccone,; T. Palacios,; D. Neumaier,; A. Seabaugh,; S. K. Banerjee,; L. Colombo, Electronics based on two-dimensional materials. Nat. Nanotechnol. 2014, 9, 768-779.
DOI Google Scholar
[6]
J. Bardeen, Surface states and rectification at a metal semi-conductor contact. Phys. Rev. 1947, 71, 717-727.
DOI Google Scholar
[7]
J. H. Kang,; W. Liu,; D. Sarkar,; D. Jena,; K. Banerjee, Computational study of metal contacts to monolayer transition-metal dichalcogenide semiconductors. Phys. Rev. X 2014, 4, 031005.
DOI Google Scholar
[8]
R. T. Tung, Chemical bonding and Fermi level pinning at metal-semiconductor interfaces. Phys. Rev. Lett. 2000, 84, 6078-6081.
DOI Google Scholar
[9]
C. R. Dean,; A. F. Young,; I. Meric,; C. Lee,; L. Wang,; S. Sorgenfrei,; K. Watanabe,; T. Taniguchi,; P. Kim,; K. L. Shepard, et al. Boron nitride substrates for high-quality graphene electronics. Nat. Nanotechnol. 2010, 5, 722-726.
DOI Google Scholar
[10]
L. K. Li,; Y. J. Yu,; G. J. Ye,; Q. Q. Ge,; X. D. Ou,; H. Wu,; D. L. Feng,; X. H. Chen,; Y. B. Zhang, Black phosphorus field-effect transistors. Nat. Nanotechnol. 2014, 9, 372-377.
DOI Google Scholar
[11]
N. R. Pradhan,; D. Rhodes,; S. M. Feng,; Y. Xin,; S. Memaran,; B. H. Moon,; H. Terrones,; M. Terrones,; L. Balicas, Field-effect transistors based on few-layered α-MoTe2. ACS Nano 2014, 8, 5911-5920.
DOI Google Scholar
[12]
C. Ruppert,; O. B. Aslan,; T. F. Heinz, Optical properties and band gap of single- and few-layer MoTe2 crystals. Nano Lett. 2014, 14, 6231-6236.
DOI Google Scholar
[13]
Q. H. Wang,; K. Kalantar-Zadeh,; A. Kis,; J. N. Coleman,; M. S. Strano, Electronics and optoelectronics of two-dimensional transition metal dichalcogenides. Nat. Nanotechnol. 2012, 7, 699-712.
DOI Google Scholar
[14]
Y. Zhang,; T. R. Chang,; B. Zhou,; Y. T. Cui,; H. Yan,; Z. K. Liu,; F. Schmitt,; J. Lee,; R. Moore,; Y. L. Chen, et al. Direct observation of the transition from indirect to direct bandgap in atomically thin epitaxial MoSe2. Nat. Nanotechnol. 2014, 9, 111-115.
DOI Google Scholar
[15]
D. Xiao,; G. B. Liu,; W. X. Feng,; X. D. Xu,; W. Yao, Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides. Phys. Rev. Lett. 2012, 108, 196802.
DOI Google Scholar
[16]
Y. Liu,; X. D. Duan,; Y. Huang,; X. F. Duan, Two-dimensional transistors beyond graphene and TMDCs. Chem. Soc. Rev. 2018, 47, 6388-6409.
DOI Google Scholar
[17]
C. N. R. Rao,; K. Gopalakrishnan,; U. Maitra, 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.
DOI Google Scholar
[18]
X. Z. Bao,; Q. D. Ou,; Z. Q. Xu,; Y. P. Zhang,; Q. L. Bao,; H. Zhang, Band structure engineering in 2D materials for optoelectronic applications. Adv. Mater. Technol. 2018, 3, 1800072.
DOI Google Scholar
[19]
J. C. Zhang,; Y. C. Huang,; Z. J. Tan,; T. R. Li,; Y. C. Zhang,; K. C. Jia,; L. Lin,; L. Z. Sun,; X. W. Chen,; Z. Z. Li, et al. Low-temperature heteroepitaxy of 2D PbI2/Graphene for large-area flexible photodetectors. Adv. Mater. 2018, 30, 1803194.
DOI Google Scholar
[20]
S. Das,; H. Y. Chen,; A. V. Penumatcha,; J. Appenzeller, High performance multilayer MoS2 transistors with scandium contacts. Nano Lett. 2013, 13, 100-105.
DOI Google Scholar
[21]
W. S. Leong,; X. Luo,; Y. D. Li,; K. H. Khoo,; S. Y. Quek,; J. T. L. Thong, Low resistance metal contacts to MoS2 devices with nickel-etched-graphene electrodes. ACS Nano 2015, 9, 869-877.
DOI Google Scholar
[22]
R. Kappera,; D. Voiry,; S. E. Yalcin,; B. Branch,; G. Gupta,; A. D. Mohite,; M. Chhowalla, Phase-engineered low-resistance contacts for ultrathin MoS2 transistors. Nat. Mater. 2014, 13, 1128-1134.
DOI Google Scholar
[23]
D. H. Keum,; S. Cho,; J. H. Kim,; D. H. Choe,; H. J. Sung,; M. Kan,; H. Kang,; J. Y. Hwang,; S. W. Kim,; H. Yang, et al. Bandgap opening in few-layered monoclinic MoTe2. Nat. Phys. 2015, 11, 482-486.
DOI Google Scholar
[24]
Y. Yoo,; Z. P. DeGregorio,; Y. Su,; S. J. Koester,; J. E. Johns, In-plane 2H-1T' MoTe2 homojunctions synthesized by flux-controlled phase engineering. Adv. Mater. 2017, 29, 1605461.
DOI Google Scholar
[25]
S. Cho,; S. Kim,; J. H. Kim,; J. Zhao,; J. Seok,; D. H. Keum,; J. Baik,; D. H. Choe,; K. J. Chang,; K. Suenaga, et al. Phase patterning for ohmic homojunction contact in MoTe2. Science 2015, 349, 625-628.
DOI Google Scholar
[26]
J. H. Sung,; H. Heo,; S. Si,; Y. H. Kim,; H. R. Noh,; K. Song,; J. Kim,; C. S. Lee,; S. Y. Seo,; D. H. Kim, et al. Coplanar semiconductor-metal circuitry defined on few-layer MoTe2 via polymorphic heteroepitaxy. Nat. Nanotechnol. 2017, 12, 1064-1070.
DOI Google Scholar
[27]
Z. J. Wang,; D. Gresch,; A. A. Soluyanov,; W. W. Xie,; S. Kushwaha,; X. Dai,; M. Troyer,; R. J. Cava,; B. A. Bernevig, MoTe2: A type-II Weyl topological metal. Phys. Rev. Lett. 2016, 117, 056805.
DOI Google Scholar
[28]
Y. Sun,; S. C. Wu,; M. N. Ali,; C. Felser,; B. H. Yan, Prediction of Weyl semimetal in orthorhombic MoTe2. Phys. Rev. B 2015, 92, 161107.
DOI Google Scholar
[29]
Y. P. Qi,; P. G. Naumov,; M. N. Ali,; C. R. Rajamathi,; W. Schnelle,; O. Barkalov,; M. Hanfland,; S. C. Wu,; C. Shekhar,; Y. Sun, et al. Superconductivity in Weyl semimetal candidate MoTe2. Nat. Commun. 2016, 7, 11038.
DOI Google Scholar
[30]
S. Q. Liu,; J. Z. Li,; B. W. Shi,; X. Y. Zhang,; Y. Y. Pan,; M. Ye,; R. Quhe,; Y. Y. Wang,; H. Zhang,; J. H. Yan, et al. Gate-tunable interfacial properties of in-plane ML MX2 1T′-2H heterojunctions. J. Mater. Chem. C 2018, 6, 5651-5661.
DOI Google Scholar
[31]
Z. P. Dong,; J. Guo, On low-resistance contacts to 2-D MoTe2 by crystalline phase junctions. IEEE Trans. Electron Dev. 2018, 65, 1583-1588.
DOI Google Scholar
[32]
X. Zhang,; Z. H. Jin,; L. Q. Wang,; J. A. Hachtel,; E. Villarreal,; Z. X. Wang,; T. Ha,; Y. Nakanishi,; C. S. Tiwary,; J. W. Lai, 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.
DOI Google Scholar
[33]
Y. Y. Yu,; G. Wang,; S. Q. Qin,; N. N. Wu,; Z. Y. Wang,; K. He,; X. A. Zhang, Molecular beam epitaxy growth of atomically ultrathin MoTe2 lateral heterophase homojunctions on graphene substrates. Carbon 2017, 115, 526-531.
DOI Google Scholar
[34]
Y. Tan,; F. Luo,; M. J. Zhu,; X. L. Xu,; Y. Ye,; B. Li,; G. Wang,; W. Luo,; X. M. Zheng,; N. N. Wu, et al. Controllable 2H-to-1T' phase transition in few-layer MoTe2. Nanoscale 2018, 10, 19964-19971.
DOI Google Scholar
[35]
W. Kohn,; L. J. Sham, Self-consistent equations including exchange and correlation effects. Phys. Rev. 1965, 140, A1133-A1138.
DOI Google Scholar
[36]
G. Kresse,; J. Furthmüller, Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 1996, 54, 11169-11186.
DOI Google Scholar
[37]
G. Kresse,; J. Furthmüller, Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput. Mater. Sci. 1996, 6, 15-50.
DOI Google Scholar
[38]
J. P. Perdew,; K. Burke,; M. Ernzerhof, Generalized gradient approximation made simple. Phys. Rev. Lett. 1996, 77, 3865-3868.
DOI Google Scholar
[39]
P. E. Blöchl, Projector augmented-wave method. Phys. Rev. B 1994, 50, 17953-17979.
DOI Google Scholar
[40]
G. Kresse,; D. Joubert, From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. Rev. B 1999, 59, 1758-1775.
DOI Google Scholar
[41]
H. J. Monkhorst,; J. D. Pack, Special points for Brillouin-zone integrations. Phys. Rev. B 1976, 13, 5188-5192.
DOI Google Scholar
[42]
S. Grimme, Semiempirical GGA-type density functional constructed with a long-range dispersion correction. J. Comput. Chem. 2006, 27, 1787-1799.
DOI Google Scholar
[43]
L. Yang,; W. F. Zhang,; J. Li,; S. Cheng,; Z. J. Xie,; H. X. Chang, 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.
DOI Google Scholar
[44]
T. R. Wu,; G. Q. Ding,; H. L. Shen,; H. M. Wang,; L. Sun,; D. Jiang,; X. M. Xie,; M. C. Jiang, Triggering the continuous growth of graphene toward millimeter-sized grains. Adv. Funct. Mater. 2013, 23, 198-203.
DOI Google Scholar
[45]
T. Chen,; G. L. Hao,; G. Wang,; B. Li,; L. Z. Kou,; H. Yang,; X. M. Zheng,; J. X. Zhong, Controlled growth of atomically thin MoSe2 films and nanoribbons by chemical vapor deposition. 2D Mater. 2019, 6, 025002.
DOI Google Scholar
[46]
J. C. Park,; S. J. Yun,; H. Kim,; J. H. Park,; S. H. Chae,; S. J. An,; J. G. Kim,; S. M. Kim,; K. K. Kim,; Y. H. Lee, Phase-engineered synthesis of centimeter-scale 1T′-and 2H-molybdenum ditelluride thin films. ACS Nano 2015, 9, 6548-6554.
DOI Google Scholar
[47]
J. Y. Wang,; X. Luo,; S. S. Li,; I. Verzhbitskiy,; W. J. Zhao,; S. F. Wang,; S. Y. Quek,; G. Eda, Determination of crystal axes in semimetallic T′-MoTe2 by polarized Raman spectroscopy. Adv. Funct. Mater. 2017, 27, 1604799.
DOI Google Scholar
[48]
M. Yamamoto,; S. T. Wang,; M. Y. Ni,; Y. F. Lin,; S. L. Li,; S. Aikawa,; W. B. Jian,; K. Ueno,; K. Wakabayashi,; K. Tsukagoshi, Strong enhancement of Raman scattering from a bulk-inactive vibrational mode in few-layer MoTe2. ACS Nano 2014, 8, 3895-3903.
DOI Google Scholar
[49]
G. L. Hao,; L. Z. Kou,; D. L. Lu,; J. Peng,; J. Li,; C. Tang,; J. X. Zhong, Electrostatic properties of two-dimensional WSe2 nanostructures. J. Appl. Phys. 2016, 119, 035301.
DOI Google Scholar
[50]
J. Guan,; H. J. Chuang,; Z. X. Zhou,; D. Tománek, Optimizing charge injection across transition metal dichalcogenide heterojunctions: Theory and experiment. ACS Nano 2017, 11, 3904-3910.
DOI Google Scholar
[51]
B. S. Mashford,; M. Stevenson,; Z. Popovic,; C. Hamilton,; Z. Q. Zhou,; C. Breen,; J. Steckel,; V. Bulovic,; M. Bawendi,; S. Coe-Sullivan, et al. High-efficiency quantum-dot light-emitting devices with enhanced charge injection. Nat. Photonics 2013, 7, 407-412.
DOI Google Scholar
[52]
F. Mortreuil,; C. Villeneuve-Faure,; L. Boudou,; K. Makasheva,; G. Teyssedre, Charge injection phenomena at the metal/dielectric interface investigated by Kelvin probe force microscopy. J. Phys. D Appl. Phys. 2017, 50, 175302.
DOI Google Scholar
[53]
M. Tosun,; D. Y. Fu,; S. B. Desai,; C. Ko,; J. S. Kang,; D. H. Lien,; M. Najmzadeh,; S. Tongay,; J. Q. Wu,; A. Javey, MoS2 heterojunctions by thickness modulation. Sci. Rep. 2015, 5, 10990.
DOI Google Scholar
[54]
J. Kang,; S. Tongay,; J. Zhou,; J. B. Li,; J. Q. Wu, Band offsets and heterostructures of two-dimensional semiconductors. Appl. Phys. Lett. 2013, 102, 012111.
DOI Google Scholar
[55]
Y. J. Yu,; Y. Zhao,; S. Ryu,; L. E. Brus,; K. S. Kim,; P. Kim, Tuning the graphene work function by electric field effect. Nano Lett. 2009, 9, 3430-3434.
DOI Google Scholar
[56]
C. X. Zheng,; Q. H. Zhang,; B. Weber,; H. Ilatikhameneh,; F. Chen,; H. Sahasrabudhe,; R. Rahman,; S. Q. Li,; Z. Chen,; J. Hellerstedt, et al. Direct observation of 2D electrostatics and ohmic contacts in template-grown Graphene/WS2 heterostructures. ACS Nano 2017, 11, 2785-2793.
DOI Google Scholar
[57]
X. L. Xu,; S. L. Chen,; S. Liu,; X. Cheng,; W. J. Xu,; P. Li,; Y. Wan,; S. Q. Yang,; W. T. Gong,; K. Yuan, et al. Millimeter-scale single-crystalline semiconducting MoTe2 via solid-to-solid phase transformation. J. Am. Chem. Soc. 2019, 141, 2128-2134.
DOI Google Scholar
[58]
J. Y. Noh,; H. Kim,; Y. S. Kim, Stability and electronic structures of native defects in single-layer MoS2. Phys. Rev. B 2014, 89, 205417.
DOI Google Scholar
[59]
H. P. Komsa,; A. V. Krasheninnikov, Native defects in bulk and monolayer MoS2 from first principles. Phys. Rev. B 2015, 91, 125304.
DOI Google Scholar
[60]
I. Sharma,; B. R. Mehta, Enhanced charge separation at 2D MoS2/ZnS heterojunction: KPFM based study of interface photovoltage. Appl. Phys. Lett. 2017, 110, 061602.
DOI Google Scholar
[61]
J. E. Padilha,; A. Fazzio,; A. J. R. Da Silva, Van der Waals heterostructure of phosphorene and graphene: Tuning the Schottky barrier and doping by electrostatic gating. Phys. Rev. Lett. 2015, 114, 066803.
DOI Google Scholar
[62]
W. Hu,; T. Wang,; R. Q. Zhang,; J. L. Yang, Effects of interlayer coupling and electric fields on the electronic structures of graphene and MoS2 heterobilayers. J. Mater. Chem. C 2016, 4, 1776-1781.
DOI Google Scholar
[63]
Y. Zhang,; Y. Liu,; Z. L. Wang, Fundamental theory of piezotronics. Adv. Mater. 2011, 23, 3004-3013.
DOI Google Scholar
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Acknowledgements

Publication history

Received: 30 July 2020
Revised: 14 September 2020
Accepted: 30 September 2020
Published: 05 January 2021
Issue date: May 2021

Copyright

© Tsinghua University Press and Springer-Verlag GmbH Germany, part of Springer Nature

Acknowledgements

This work was supported by the grants from the 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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