Deterministic direct growth of WS2 on CVD graphene arrays
arXiv:1911.01101 · doi:10.1088/2053-1583/ab49f0
Abstract
The combination of the exciting properties of graphene with those of monolayer tungsten disulfide (WS2) makes this heterostack of great interest for electronic, optoelectronic and spintronic applications. The scalable synthesis of graphene/WS2 heterostructures on technologically attractive substrates like SiO2 would greatly facilitate the implementation of novel two-dimensional (2D) devices. In this work, we report the direct growth of monolayer WS2 via chemical vapor deposition (CVD) on single-crystal graphene arrays on SiO2. Remarkably, spectroscopic and microscopic characterization reveals that WS2 grows only on top of the graphene crystals so that the vertical heterostack is selectively obtained in a bottom-up fashion. Spectroscopic characterization indicates that, after WS2 synthesis, graphene undergoes compressive strain and hole doping. Tailored experiments show that such hole doping is caused by the modification of the SiO2 stoichiometry at the graphene/SiO2 interface during the WS2 growth. Electrical transport measurements reveal that the heterostructure behaves like an electron-blocking layer at large positive gate voltage, which makes it a suitable candidate for the development of unipolar optoelectronic components.
30 pages, main text and supplementary information
References in corpus (18)
- Ultrahigh electron mobility in suspended graphene
- Boron nitride substrates for high-quality graphene electronics
- Electrochemically Top Gated Graphene: Monitoring Dopants by Raman Scattering
- Uniaxial Strain in Graphene by Raman Spectroscopy: G peak splitting, Gruneisen Parameters and Sample Orientation
- Control and Characterization of Individual Grains and Grain Boundaries in Graphene Grown by Chemical Vapor Deposition
- Optical Separation of Mechanical Strain from Charge Doping in Graphene
- Negative Thermal Expansion Coefficient of Graphene Measured by Raman Spectroscopy
- Raman Fingerprint of Charged Impurities in Graphene
- Spin-Orbit Proximity Effect in Graphene
- Phonon anharmonicities in graphite and graphene
- Measurement of high exciton binding energy in the monolayer transition-metal dichalcogenides WS2 and WSe2
- Residual Metallic Contamination of Transferred Chemical Vapor Deposited Graphene
- MoS2 Quantum Dot/Graphene Hybrids for Advanced Interface Engineering of CH3NH3PbI3 Perovskite Solar Cell with Efficiency over 20%
- Opto-Valleytronic Spin Injection in Monolayer MoS2/Few-Layer Graphene Hybrid Spin Valves
- Rapid CVD growth of millimetre-sized single crystal graphene using a cold-wall reactor
- Electrostatic interactions between graphene layers and their environment
- Superlubricity of epitaxial monolayer WS2 on graphene
- Scalable synthesis of WS2 on graphene and h-BN: an all-2D platform for light-matter transduction