Projects per year
Abstract
Large-area two-dimensional (2D) heterojunctions are promising building blocks of 2D circuits. Understanding their intriguing electrostatics is pivotal but largely hindered by the lack of direct observations. Here graphene-WS2 heterojunctions are prepared over large areas using a seedless ambient-pressure chemical vapor deposition technique. Kelvin probe force microscopy, photoluminescence spectroscopy, and scanning tunneling microscopy characterize the doping in graphene-WS2 heterojunctions as-grown on sapphire and transferred to SiO2 with and without thermal annealing. Both p-n and n-n junctions are observed, and a flat-band condition (zero Schottky barrier height) is found for lightly n-doped WS2, promising low-resistance ohmic contacts. This indicates a more favorable band alignment for graphene-WS2 than has been predicted, likely explaining the low barriers observed in transport experiments on similar heterojunctions. Electrostatic modeling demonstrates that the large depletion width of the graphene-WS2 junction reflects the electrostatics of the one-dimensional junction between two-dimensional materials.
Original language | English |
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Pages (from-to) | 2785-2793 |
Number of pages | 9 |
Journal | ACS Nano |
Volume | 11 |
Issue number | 3 |
DOIs | |
Publication status | Published - 28 Mar 2017 |
Keywords
- electrostatics
- graphene
- heterostructure
- ohmic contacts
- transition-metal dichalcogenides
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ARC Centre of Excellence in Future Low-energy Electronics Technologies
Fuhrer, M. (Primary Chief Investigator (PCI)), Bao, Q. (Chief Investigator (CI)), Culcer, D. (Chief Investigator (CI)), Davis, M. (Chief Investigator (CI)), Davis, J. A. (Chief Investigator (CI)), Hamilton, A. (Chief Investigator (CI)), Helmerson, K. (Chief Investigator (CI)), Klochan, O. (Chief Investigator (CI)), Medhekar, N. (Chief Investigator (CI)), Ostrovskaya, E. A. (Chief Investigator (CI)), Parish, M. (Chief Investigator (CI)), Schiffrin, A. (Chief Investigator (CI)), Seidel, J. (Chief Investigator (CI)), Sushkov, O. (Chief Investigator (CI)), Valanoor, N. (Chief Investigator (CI)), Wang, X. (Chief Investigator (CI)), Galitskiy, V. (Partner Investigator (PI)), Gurarie, V. (Partner Investigator (PI)), Hannon, J. (Partner Investigator (PI)), Höfling, S. (Partner Investigator (PI)), Hone, J. (Partner Investigator (PI)), Rule, K. C. (Partner Investigator (PI)), Krausz, F. (Partner Investigator (PI)), Littlewood, P. (Partner Investigator (PI)), MacDonald, A. (Partner Investigator (PI)), Neto, A. (Partner Investigator (PI)), Oezyilmaz, B. (Partner Investigator (PI)), Paglione, J. (Partner Investigator (PI)), Phillips, W. (Partner Investigator (PI)), Spielman, I. (Partner Investigator (PI)), Tadich, A. (Partner Investigator (PI)), Xue, Q. (Partner Investigator (PI)), Cole, J. (Chief Investigator (CI)), Perali, A. (Partner Investigator (PI)), Neilson, D. (Partner Investigator (PI)), Sek, G. (Partner Investigator (PI)), Gaston, N. (Partner Investigator (PI)), Hodgkiss, J. M. (Partner Investigator (PI)), Tang, M. (Partner Investigator (PI)), Karel, J. (Chief Investigator (CI)), Nguyen, T.-L. (Project Manager), Adam, S. (Partner Investigator (PI)), Granville, S. (Partner Investigator (PI)), Kumar, P. V. (Chief Investigator (CI)) & Daeneke, T. (Chief Investigator (CI))
ARC - Australian Research Council, Monash University – Internal School Contribution, Monash University – Internal Department Contribution, Monash University – Internal Faculty Contribution, Monash University – Internal University Contribution, University of Wollongong, University of Queensland , Tsinghua University, University of New South Wales (UNSW), Australian National University (ANU), RMIT University, Swinburne University of Technology
29/06/17 → 28/06/24
Project: Research
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Semiconductor quantum wells at the atomic scale
Fuhrer, M. (Primary Chief Investigator (PCI)) & Adam, S. (Partner Investigator (PI))
ARC - Australian Research Council, Monash University, National University of Singapore (NUS)
1/01/15 → 31/12/20
Project: Research
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Making every electron count in atomic resolution microscopy
Findlay, S. (Primary Chief Investigator (PCI)), Allen, L. (Chief Investigator (CI)), D'Alfonso, A. (Chief Investigator (CI)) & Weyland, M. (Chief Investigator (CI))
ARC - Australian Research Council, Monash University
2/01/14 → 1/06/18
Project: Research
Equipment
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Melbourne Centre for Nanofabrication (MCN)
Langelier, S. (Manager)
Office of the Vice-Provost (Research and Research Infrastructure)Facility/equipment: Facility