Strain and Electric Field Controllable Schottky Barriers and Contact Types in Graphene-MoTe2 van der Waals Heterostructure

Abstract

Two-dimensional (2D) transition metal dichalcogenides with intrinsically passivated surfaces are promising candidates for ultrathin optoelectronic devices that their performance is strongly affected by the contact with the metallic electrodes. Herein, first-principle calculations are used to construct and investigate the electronic and interfacial properties of 2D MoTe2 in contact with a graphene electrode by taking full advantage of them. The obtained results reveal that the electronic properties of graphene and MoTe2 layers are well preserved in heterostructures due to the weak van der Waals interlayer interaction, and the Fermi level moves toward the conduction band minimum of MoTe2 layer thus forming an n type Schottky contact at the interface. More interestingly, the Schottky barrier height and contact types in the graphene-MoTe2 heterostructure can be effectively tuned by biaxial strain and external electric field, which can transform the heterostructure from an n type Schottky contact to a p type one or to Ohmic contact. This work provides a deeper insight look for tuning the contact types and effective strategies to design high performance MoTe2-based Schottky electronic nanodevices.

Recent Advances on Tuning the Interlayer Coupling and Properties in van der Waals Heterostructures

“…Reproduced with permission. [ 167 ] Copyright 2020, Springer Nature. b) Experimental illustration of the electric field engineering of WSe 2 /graphene vdW heterostructure and c) the corresponding Raman spectrum under different gate bias values.…”

“…The band gap was demonstrated to change linearly with the applied electric field, and the MoS 2 /PbI 2 vdW structure transits along the track of type-II→type-I→type-II under different external electric fields, providing new perspective in the application of nanodevices. Besides the above noted 2D heterostructures, other types of vdW heterostructures, such as graphene/ MoS 2 , [161] MoSe 2 /WSe 2 , [162] SnS 2 /PbI 2 , [163] 2D alkaline-earth metal hydroxide/graphene, [164] GaSe/MoSe 2 , [137] graphene/ GeTe, [134] BP/MoSSe, [138] GaTe/CdS, [140] InSb/InSe, [165] MoS 2 / WS 2 , [166] graphene/MoTe 2 , [167] etc., have also been studied in detail regarding the modulation of the structure and property under external electric field. During these studies, the influence of various parameters such as electric field strength, interlayer distance, layer number, were systematically discussed.…”

The Photodetectors Based on Lateral Monolayer MoS2/WS2 Heterojunctions

“…Considering the almost half-a-trillion-dollar semiconductor-chip market, two-dimensional (2D) materials are currently one of the most feasible and promising candidates for extending Moore's law [1][2][3][4][5]. As a representative member of the 2D family, transition metal dichalcogenides (TMDs) have been intensively studied due to their distinctive optoelectronic properties and potential applications [6][7][8][9][10][11][12] in photodetection and lightemitting devices [13,14].…”

High-Performance Photodetectors Based on Lateral Monolayer MoS2/WS2 Heterojunctions

“…2 the College of Energy, Soochow Institute for Energy and Materials Innovations, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou 215006, China. 3 the State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China 4 School of Physics, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China. 5 the 36th Research Institute of China Electronics Technology Group Corporation, Jiaxing, 314033, P. R. China.…”

“…promising candidates for extending Moore's law [1][2][3][4][5]. As a representative member of the 2D family, transition metal dichalcogenides (TMDs) have been intensively studied due to their distinctive optoelectronic properties and potential applications [6][7][8][9][10][11][12] in photodetection and light-emitting devices [13,14].…”