Tellurene—the 2D form of elemental tellurium—provides an attractive alternative to conventional 2D semiconductors due to its high bipolar mobilities, facile solution processing, and the possibility of dopant intercalation into its 1D van der Waals lattice. Here, we study the microscopic origin of transport anisotropy in lithographically defined four-terminal tellurene devices using spatially resolved near-field scanning microwave microscopy (SMM). Our conductivity- and carrier type-sensitive SMM imaging reveals that the overall p-type transport measured between adjacent and opposite terminals originates from strong p-type character at the device edges. Despite using an atomic layer deposition-grown conformal overcoat that n-dopes the device interior, we observe only weak n-type transport along the main device channel at positive backgate voltages. This weak n-type transport along the device channel is shown to arise from local p-doping within a few micrometers of the electrodes, which produces a transport barrier from the n-type interior to the electrodes. These results reveal how the backgate-dependent conduction anisotropy could be leveraged to weigh different inputs for non-von Neumann architectures.
References
1.
B. W. H.
Baugher
, H. O. H.
Churchill
, Y.
Yang
, and P.
Jarillo-Herrero
, “Optoelectronic devices based on electrically tunable p-n diodes in a monolayer dichalcogenide
,” Nat. Nanotechnol.
9
, 262
(2014
).2.
Z.
Lin
, A.
McCreary
, N.
Briggs
, S.
Subramanian
, K.
Zhang
, Y.
Sun
, X.
Li
, N. J.
Borys
, H.
Yuan
, S.
Fullterton-Shirey
, A.
Chernikov
, H.
Zhao
, S.
McDonnell
, A. M.
Lindeberg
, K.
Xiao
, B. J.
LeRoy
, M.
Drndić
, J. C. M.
Hwang
, J.
Park
, M.
Chhowalla
, R. E.
Schaak
, A.
Javey
, M. C.
Hersam
, J.
Robinson
, and M.
Terrones
, “2D materials advances: From large scale synthesis and controlled heterostructures to improved characterization techniques, defects and applications
,” 2D Mater.
3
, 042001
(2016
).3.
D.
Edelberg
, D.
Rhodes
, A.
Kerelsky
, B.
Kim
, J.
Wang
, A.
Zangiabadi
, C.
Kim
, A.
Abhinadan
, J.
Ardelean
, M.
Scully
, D.
Scullion
, L.
Embon
, R.
Zu
, E. J. G.
Santos
, L.
Balicas
, C.
Marianetti
, K.
Barmak
, X.
Zhu
, J.
Hone
, and A. N.
Pasupathy
, “Approaching the intrinsic limit in transition metal diselenides via point defect control
,” Nano Lett.
19
, 4371
–4379
(2019
).4.
V. K.
Sangwan
and M. C.
Hersam
, “Neuromorphic nanoelectronic materials
,” Nat. Nanotechnol.
15
, 517
(2020
).5.
F.
Zhang
, H.
Zhang
, S.
Krylyuk
, C. A.
Milligan
, Y.
Zhu
, D. Y.
Zemlyanov
, L. A.
Bendersky
, B. P.
Burton
, A. V.
Davydov
, and J.
Appenzeller
, “Electric-field induced structural transition in vertical MoTe2- and WxTe2-based resistive memories
,” Nat. Mater.
18
, 55
(2019
).6.
B.
Huang
, G.
Clark
, D. R.
Klein
, D.
MacNeill
, E.
Navarro-Moratalla
, K. L.
Seyler
, N.
Wilson
, M. A.
McGuire
, D. H.
Cobden
, D.
Xiao
, W.
Yao
, P.
Jarillo-Herrero
, and X.
Xu
, “Electrical control of 2D magnetism in bilayer CrI3
,” Nat. Nanotechnol.
13
, 544
(2018
).7.
D. K.
Bediako
, M.
Rezaee
, H.
Yoo
, D. T.
Larson
, S. Y. F.
Zhao
, T.
Taniguchi
, K.
Watanabe
, T. L.
Brower-Thomas
, E.
Kaxiras
, and P.
Kim
, “Heterointerface effects in the electrointercalation of van der Waals heterostructures
,” Nature
558
, 425
(2018
).8.
V. K.
Sangwan
, H. S.
Lee
, H.
Bergeron
, I.
Balla
, M. E.
Beck
, K. S.
Chen
, and M. C.
Hersam
, “Multi-terminal memtransistors from polycrystalline monolayer molybdenum disulfide
,” Nature
554
, 500
(2018
).9.
H.
Tian
, Q.
Guo
, Y.
Xie
, H.
Zhao
, C.
Li
, J. J.
Cha
, F.
Xia
, and H.
Wang
, “Anisotropic black phosphorous synaptic device for neuromorphic applications
,” Adv. Mater.
28
, 4991
(2016
).10.
P.
Bhaskar
, A. W.
Achtstein
, S. L.
Diedenhofen
, and L. D. A.
Siebbles
, “Mobility and decay dynamics of charge carriers in one-dimensional selenium van der Waals solid
,” J. Phys. Chem. C
121
, 18917
(2017
).11.
Q.
Zhang
, C.
Liu
, X.
Liu
, J.
Liu
, Z.
Cui
, Y.
Zhang
, L.
Yang
, Y.
Zhao
, T. T.
Xu
, Y.
Chen
, J.
Wei
, Z.
Mao
, and D.
Li
, “Thermal transport in quasi-1D van der waals crystal Ta2Pd3Se8 nanowires: Size and length dependence
,” ACS Nano
12
, 2634
(2018
).12.
C.
Zhao
, C.
Tan
, D. H.
Lien
, X.
Song
, M.
Amani
, M.
Hettick
, H. Y. Y.
Nyein
, L.
Li
, M. C.
Scott
, and A.
Javey
, “Evaporated tellurium thin films for p-type field-effect transistors and circuits
,” Nat. Nanotechnol.
15
, 53
(2020
).13.
Y.
Wang
, G.
Qiu
, R.
Wang
, S.
Huang
, Q.
Wang
, Y.
Liu
, Y.
Du
, W. A.
Goddard
III, M. J.
Kim
, X.
Xu
, P. D.
Ye
, and W.
Wu
, “Field-effect transistors made from solution-grown two-dimensional tellurene
,” Nat. Electron
1
, 228
(2018
).14.
Y.
Du
, G.
Qiu
, Y.
Wang
, M.
Si
, X.
Xu
, W.
Wu
, and P. D.
Ye
, “One-dimensional van der Waals material tellurium: Raman spectroscopy under strain and magneto-transport
,” Nano Lett.
17
, 3965
(2017
).15.
L.
Rothkirch
, R.
Link
, W.
Sauer
, and F.
Manglus
, “Anisotropy of the electric conductivity of tellurium single crystals
,” Phys. Status Solidi B
31
, 147
(1969
).16.
B.
Mayers
and Y.
Xia
, “Onde-dimensional nanostructures of trigonal tellurium wiht various morphologies can be synthesized using a solution-phase approach
,” J. Mater. Chem.
12
, 1875
(2002
).17.
V.
Iyer
, M.
Segovia
, Y.
Wang
, W.
Wu
, P.
Ye
, and X.
Xu
, “Infrared ultrafast spectroscopy of solution-grown thin film tellurium
,” Phys. Rev. B
100
, 075436
(2019
).18.
G.
Qiu
, C.
Niu
, Y.
Wang
, M.
Si
, Z.
Zhang
, W.
Wu
, and P. D.
Ye
, “Quantum Hall effect of Weyl fermions in n-type semiconducting tellurene
,” Nat. Nanotechnol.
15
, 585
(2020
).19.
S.
Berweger
, G.
Qiu
, Y.
Wang
, B.
Pollard
, K. L.
Genter
, R.
Tyrrell-Ead
, T. M.
Wallis
, W.
Wu
, P.
Ye
, and P.
Kabos
, “Imaging carrier inhomogeneities in ambipolar tellurene field-effect transistors
,” Nano Lett.
19
, 1289
–1294
(2019
).20.
Y.
Ren
, X.
Yang
, L.
Zhou
, J.-Y.
Mao
, X.-T.
Han
, and Y.
Zhou
, “Recent advances in ambipolar transistors for functional applications
,” Adv. Funct. Mater.
29
, 1902105
(2019
).21.
Z.
Chu
, L.
Zheng
, and K.
Lai
, “Microwave microscopy and its applications
,” Annu. Rev. Mater. Res.
50
, 105
(2020
).22.
G.
Qiu
, Y.
Wang
, Y.
Nie
, Y.
Zheng
, K.
Cho
, W.
Wu
, and P. D.
Ye
, “Quantum transport and band structure evolution under high magnetic field in few-layer tellurene
,” Nano Lett.
18
, 5760
(2018
).23.
D.
Wu
, W.
Li
, A.
Rai
, X.
Wu
, H. C. P.
Movva
, M. N.
Yogeesh
, Z.
Chu
, S. K.
Banerjee
, D.
Akinwande
, and K.
Lai
, “Visualization of local conductance in MoS2/WSe2 heterostructure transistors
,” Nano Lett.
19
, 1976
(2019
).24.
W.
Kundhikanjana
, K.
Lai
, H.
Wang
, H.
Dai
, M. A.
Kelly
, and Z. X.
Shen
, “Hierarchy of electronic properties of chemically derived and pristine graphene probed by microwave imaging
,” Nano Lett.
9
, 3762
–3765
(2009
).25.
H. P.
Huber
, I.
Humer
, M.
Hochleitner
, M.
Fenner
, M.
Moertelmaier
, C.
Rankl
, A.
Imtiaz
, T. M.
Wallis
, H.
Tanbakuchi
, P.
Hinterdorfer
, P.
Kabos
, J.
Smoliner
, J. J.
Kopanski
, and F.
Kienberger
, “Calibrated nanoscale dopant profiling using a scanning microwave microscope
,” J. Appl. Phys.
111
, 014301
(2012
).26.
E.
Seabron
, S.
MacLaren
, X.
Xie
, S. V.
Rotkin
, J. A.
Rogers
, and W. L.
Wilson
, “Scanning probe microwave reflectivity of aligned single-walled nanotubes: Imaging of electronic structure and quantum behavior at the nanoscale
,” ACS Nano
10
, 360
(2016
).27.
H.
Edwards
, V. A.
Ukraintsev
, R.
San Martin
, F. S.
Johnson
, P.
Menz
, S.
Walsh
, S.
Ashburn
, K. S.
Wills
, K.
Harvey
, and M. C.
Chang
, “pn-junction delineation in Si devices using scanning capacitance spectroscopy
,” J. Appl. Phys.
87
, 1485
–1495
(2000
).28.
H.
Peng
, N.
Kioussis
, and G. J.
Snyder
, “Elemental tellurium as a chiral p-type thermoelectric material
,” Phys. Rev. B
89
, 195206
(2014
).29.
Y.
Liu
, W.
Wu
, and W.
Goddard
III, “Tellurium: Fast electrical and atomic transport along the weak interaction direction
,” J. Am. Chem. Soc.
140
, 550
(2018
).30.
C. M.
Smyth
, R.
Addou
, C. L.
Hinkle
, and R. M.
Wallace
, “Origins of Fermi level pinning between tungsten dichalcogenides (WS2, WTe2) and bulk metal contacts: Interface chemistry and band alignment
,” J. Phys. Chem. C
124
, 14550
(2020
).31.
T.
Mueller
, F.
Xia
, M.
Freitag
, J.
Tsang
, and P.
Avouris
, “Role of contacts in graphene transistors; a scanning photocurrent study
,” Phys. Rev. B
79
, 245430
(2009
).32.
G.
Qiu
, S.
Huang
, M.
Segovia
, P. K.
Venuthurumilli
, Y.
Wang
, W.
Wu
, X.
Xu
, and P. D.
Ye
, “Thermoelectric performance of 2D tellurium with accumulation contacts
,” Nano Lett
19
, 1955
(2019
).2020
U.S. Government
You do not currently have access to this content.
