层状graphene/WSSe范德瓦耳斯异质结电子特性和界面接触的理论研究

摘要/Abstract

摘要： 利用第一性原理计算方法研究了层间距和外部电场对graphene/WSSe范德瓦耳斯异质结的电子特性和界面接触的影响规律。由于范德瓦耳斯力作用,graphene和WSSe单层的电子特性可以被保留在graphene/WSSe异质结中。当形成graphene/WSSe异质结时,在石墨烯的狄拉克锥中可以发现小的带隙值(7 meV)。电荷转移产生的内建电场在有效阻碍光激发载流子复合中起着关键作用。与两个独立单层相比,graphene/WSSe异质结在可见光区域具有增强的光吸收,在光电子器件中展现出了潜在应用价值。此外,graphene/WSSe异质结在平衡层间距处显示出n型肖特基接触特性。层间距和外部电场都可以用来改变graphene/WSSe异质结的肖特基势垒高度和接触类型,并有效调节graphene狄拉克锥的位置。本文研究内容为graphene/WSSe异质结在纳米电子和光电子器件领域的应用提供理论依据。

关键词: 二维材料, 异质结, 第一性原理计算, 肖特基接触, 欧姆接触, 电子特性, 外部电场

Abstract: The electronic properties and interface contact of graphene/WSSe van der Waals heterojunction by means of tuning the interlayer distance and external electric field were studied by the first-principles calculation method. The electronic properties of constituent monolayers can be retained in graphene/WSSe heterojunction because of the van der Waals force. A small band gap value (7 meV) can be found in the Dirac cone of graphene in graphene/WSSe heterojunction. The built-in electric field generated by the charge transfer plays a key role in the effective hindrance of photoexcited carrier recombination. The graphene/WSSe heterojunction possesses enhanced optical absorption in the visible light range compared with two freestanding monolayers, implying its potential application in optoelectronic device. Besides, the graphene/WSSe heterojunction displays the n-type Schottky contact characteristics at the equilibrium interlayer distance. Both the interlayer distance and external electric field can be used to modify the Schottky barrier height and contact types of graphene/WSSe heterojunction, and effectively adjust the Dirac cone position of graphene. The research in this paper provides a theoretical basis for the fascinating applications of graphene/WSSe heterojunction in the fields of nanoelectronic and optoelectronic devices.

Key words: two-dimensional material, heterojunction, first-principle calculation, Schottky contact, Ohmic contact, electronic property, external electric field

中图分类号:

TB34
O469

赵婷婷. 层状graphene/WSSe范德瓦耳斯异质结电子特性和界面接触的理论研究[J]. 人工晶体学报, 2022, 51(12): 2080-2089.

ZHAO Tingting. Theoretical Study on Electronic Properties and Interfacial Contact of Layered Graphene/WSSe Van der Waals Heterojunction[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2022, 51(12): 2080-2089.

参考文献

[1] NOVOSELOV K S, GEIM A K, MOROZOV S V, et al. Electric field effect in atomically thin carbon films[J]. Science, 2004, 306(5696): 666-669.
[2] ZHANG Y B, TAN Y W, STORMER H L, et al. Experimental observation of the quantum Hall effect and Berry's phase in graphene[J]. Nature, 2005, 438(7065): 201-204.
[3] NOVOSELOV K S, GEIM A K, MOROZOV S V, et al. Two-dimensional gas of massless Dirac fermions in graphene[J].Nature, 2005, 438(7065): 197-200.
[4] DU X, SKACHKO I, BARKER A, et al. Approaching ballistic transport in suspended graphene[J]. Nature Nanotechnology, 2008, 3(8): 491-495.
[5] BERGER C, SONG Z M, LI X B, et al. Electronic confinement and coherence in patterned epitaxial graphene[J]. Science, 2006, 312(5777): 1191-1196.
[6] ZHANG W J, LIN C T, LIU K K, et al. Opening an electrical band gap of bilayer graphene with molecular doping[J]. ACS Nano, 2011, 5(9): 7517-7524.
[7] SON J, LEE S, KIM S J, et al. Hydrogenated monolayer graphene with reversible and tunable wide band gap and its field-effect transistor[J]. Nature Communications, 2016, 7: 13261.
[8] XIA C X, DU J, FANG L Z, et al. PtSe₂/graphene hetero-multilayer: gate-tunable Schottky barrier height and contact type[J]. Nanotechnology, 2018, 29(46): 465707.
[9] SHIM J, KANG D H, KIM Y, et al. Recent progress in van der Waals (vdW) heterojunction-based electronic and optoelectronic devices[J]. Carbon, 2018, 133: 78-89.
[10] LIU Z, SONG L, ZHAO S Z, et al. Direct growth of graphene/hexagonal boron nitride stacked layers[J]. Nano Letters, 2011, 11(5): 2032-2037.
[11] SUN M L, CHOU J P, REN Q Q, et al. Tunable Schottky barrier in van der Waals heterostructures of graphene and g-GaN[J]. Applied Physics Letters, 2017, 110(17): 173105.
[12] PHUC H V, HIEU N N, HOI B D, et al. Interlayer coupling and electric field tunable electronic properties and Schottky barrier in a graphene/bilayer-GaSe van der Waals heterostructure[J]. Physical Chemistry Chemical Physics, 2018, 20(26): 17899-17908.
[13] LU A K A, HOUSSA M, RADU I P, et al. Toward an understanding of the electric field-induced electrostatic doping in van der Waals heterostructures: a first-principles study[J]. ACS Applied Materials & Interfaces, 2017, 9(8): 7725-7734.
[14] NIE Y F, HONG S, WALLACE R M, et al. Theoretical demonstration of the ionic barristor[J]. Nano Letters, 2016, 16(3): 2090-2095.
[15] PHAM K D, HIEU N N, PHUC H V, et al. Layered graphene/GaS van der Waals heterostructure: controlling the electronic properties and Schottky barrier by vertical strain[J]. Applied Physics Letters, 2018, 113(17): 171605.
[16] XIA C, XUE B, WANG T X, et al. Interlayer coupling effects on Schottky barrier in the arsenene-graphene van der Waals heterostructures[J]. Applied Physics Letters, 2015, 107: 193107.
[17] ZHANG F, LI W, MA Y Q, et al. Schottky barrier tuning of the graphene/SnS₂ van der Waals heterostructures through electric field[J]. Solid State Communications, 2018, 271: 56-61.
[18] GHORBANI-ASL M, BRISTOWE P D, KOZIOL K, et al. Effect of compression on the electronic, optical and transport properties of MoS₂/graphene-based junctions[J]. 2D Materials, 2016, 3(2): 025018.
[19] LU A Y, ZHU H Y, XIAO J, et al. Janus monolayers of transition metal dichalcogenides[J]. Nature Nanotechnology, 2017, 12(8): 744-749.
[20] DUAN X D, WANG C, FAN Z, et al. Synthesis of WS_2xSe_2-2x alloy nanosheets with composition-tunable electronic properties[J]. Nano Letters, 2016, 16(1): 264-269.
[21] DONG L, LOU J, SHENOY V B. Large In-plane and vertical piezoelectricity in Janus transition metal dichalchogenides[J]. ACS Nano, 2017, 11(8): 8242-8248.
[22] ZHOU W Z, CHEN J Y, YANG Z X, et al. Geometry and electronic structure of monolayer, bilayer, and multilayer Janus WSSe[J]. Physical Review B, 2019, 99(7): 075160.
[23] PALSGAARD M, GUNST T, MARKUSSEN T, et al. Stacked Janus device concepts: abrupt pn-junctions and cross-plane channels[J]. Nano Letters, 2018, 18(11): 7275-7281.
[24] DENG S, LI L J, REES P. Graphene/MoXY heterostructures adjusted by interlayer distance, external electric field, and strain for tunable devices[J]. ACS Applied Nano Materials, 2019, 2(6): 3977-3988.
[25] YU C, CHENG X X, WANG C Y, et al. Tuning the n-type contact of graphene on Janus MoSSe monolayer by strain and electric field[J]. Physica E: Low-Dimensional Systems and Nanostructures, 2019, 110: 148-152.
[26] YU S Q, WEI W, LI F P, et al. Electronic properties of Janus MXY/graphene (M=Mo, W; X≠Y=S, Se) van der Waals structures: a first-principles study[J]. Physical Chemistry Chemical Physics, 2020, 22(44): 25675-25684.
[27] PERDEW J P, BURKE K, ERNZERHOF M. Generalized gradient approximation made simple[J]. Physical Review Letters, 1996, 77(18): 3865-3868.
[28] CHEN H, ZHAO J F, HUANG J D, et al. Computational understanding of the structural and electronic properties of the GeS-graphene contact[J]. Physical Chemistry Chemical Physics, 2019, 21(14): 7447-7453.
[29] JU L, BIE M, TANG X, et al. Janus WSSe monolayer: an excellent photocatalyst for overall water splitting[J]. ACS Applied Materials & Interfaces, 2020, 12(26): 29335-29343.
[30] WANG S K, REN C D, TIAN H Y, et al. MoS₂/ZnO van der Waals heterostructure as a high-efficiency water splitting photocatalyst: a first-principles study[J]. Physical Chemistry Chemical Physics, 2018, 20(19): 13394-13399.
[31] ZHANG W X, YIN Y, HE C. Lowering the Schottky barrier height of G/WSSe van der Waals heterostructures by changing the interlayer coupling and applying external biaxial strain[J]. Physical Chemistry Chemical Physics, 2020, 22(45): 26231-26240.
[32] DIN H U, IDREES M, ALBAR A, et al. Rashba spin splitting and photocatalytic properties of GeC-MSSe (M=Mo, W) van der Waals heterostructures[J]. Physical Review B, 2019, 100(16): 165425.
[33] GUO Q, WANG G X, PANDEY R, et al. Robust band gaps in the graphene/oxide heterostructure: SnO/graphene/SnO[J]. Physical Chemistry Chemical Physics: PCCP, 2018, 20(26): 17983-17989.
[34] LV L L, SHEN Y Q, MA Y Y, et al. Schottky barrier modification of GaSSe/graphene heterojunctions based on density functional theory[J]. Journal of Physics D: Applied Physics, 2021, 54(15): 155104.
[35] BEN AZIZA Z, PIERUCCI D, HENCK H, et al. Tunable quasiparticle band gap in few-layer GaSe/graphene van der Waals heterostructures[J]. Physical Review B, 2017, 96(3): 035407.
[36] TONGAY S, FAN W, KANG J, et al. Tuning interlayer coupling in large-area heterostructures with CVD-grown MoS₂ and WS₂ monolayers[J]. Nano Letters, 2014, 14(6): 3185-3190.
[37] HU W, LI Z Y, YANG J L. Electronic and optical properties of graphene and graphitic ZnO nanocomposite structures[J]. The Journal of Chemical Physics, 2013, 138(12): 124706.
[38] WANG X L, QUHE R G, LIU Z, et al. Interfacial properties of two-dimensional graphene/ZrS₂ and ScS₂/ZrS₂ contacts[J]. Applied Surface Science, 2019, 476: 778-788.
[39] MAK K F, LUI C H, SHAN J, et al. Observation of an electric-field-induced band gap in bilayer graphene by infrared spectroscopy[J]. Physical Review Letters, 2009, 102(25): 256405.