Presentation Title

THERMAL ANNEALING OF FEW LAYERED GRAPHENE AND HEXAGONAL BORON NITRIDE VAN DER WAALS HETEROSTRUCTURES

Start Date

November 2016

End Date

November 2016

Location

HUB 302-183

Type of Presentation

Poster

Abstract

THERMAL ANNEALING OF FEW LAYERED GRAPHENE AND HEXAGONAL BORON NITRIDE VAN DER WAALS HETEROSTRUCTURES.

WOODS, Joshua, Senior, Materials Science and Engineering Major, Dennis Pleskot, M.S., Nathaniel Gabor, Ph.D., Department of Physics and Astronomy, University of California Riverside.

Novel properties of atomically thin semiconductors such as hexagonal boron nitride (hBN) and graphene (G) inspire new optoelectronics applications in condensed matter physics and materials science. Electrical band gaps of monolayer graphene (0 eV) and hexagonal boron nitride (~6 eV) are tunable and direct, allowing for excellent charge carrier transport when coupled. Stacking these two-dimensional (2D) materials into vertical heterostructures held together by van der Waals interactions reveals novel charge carrier transport phenomena. These materials form superior alignment in stacking order due to their symmetric hexagonal 2D lattice structures and interlayer spacing. In this study, we have successfully fabricated few-layered G - hBN - G heterostructures by micromechanical exfoliation and viscoelastic dry transfer. In order to construct these atomically thin materials, substrates are cut, cleaned, and examined for flake exfoliation. Rapid Thermal Annealing is done at intermediary steps to reduce lattice distortions and ensure better interlayer interfaces in heterostructures. With selected flakes, semi-dry transfer contact is done by the stacking of selected flakes via a custom transfer microscope to create a heterostructure. After heterostructure assembly, samples undergo initial characterization via Raman spectroscopy and Atomic Force Microscopy (AFM). With layer thickness confirmation, heterostructures are subjected to e-beam lithography and evaporation to produce device electrodes. Optoelectronic measurements are performed on these devices to understand their underlying physical behavior. In the future, we hope to fully characterize the material’s various optoelectronic properties using photocurrent and photoluminescence measurements.

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Nov 12th, 1:00 PM Nov 12th, 2:00 PM

THERMAL ANNEALING OF FEW LAYERED GRAPHENE AND HEXAGONAL BORON NITRIDE VAN DER WAALS HETEROSTRUCTURES

HUB 302-183

THERMAL ANNEALING OF FEW LAYERED GRAPHENE AND HEXAGONAL BORON NITRIDE VAN DER WAALS HETEROSTRUCTURES.

WOODS, Joshua, Senior, Materials Science and Engineering Major, Dennis Pleskot, M.S., Nathaniel Gabor, Ph.D., Department of Physics and Astronomy, University of California Riverside.

Novel properties of atomically thin semiconductors such as hexagonal boron nitride (hBN) and graphene (G) inspire new optoelectronics applications in condensed matter physics and materials science. Electrical band gaps of monolayer graphene (0 eV) and hexagonal boron nitride (~6 eV) are tunable and direct, allowing for excellent charge carrier transport when coupled. Stacking these two-dimensional (2D) materials into vertical heterostructures held together by van der Waals interactions reveals novel charge carrier transport phenomena. These materials form superior alignment in stacking order due to their symmetric hexagonal 2D lattice structures and interlayer spacing. In this study, we have successfully fabricated few-layered G - hBN - G heterostructures by micromechanical exfoliation and viscoelastic dry transfer. In order to construct these atomically thin materials, substrates are cut, cleaned, and examined for flake exfoliation. Rapid Thermal Annealing is done at intermediary steps to reduce lattice distortions and ensure better interlayer interfaces in heterostructures. With selected flakes, semi-dry transfer contact is done by the stacking of selected flakes via a custom transfer microscope to create a heterostructure. After heterostructure assembly, samples undergo initial characterization via Raman spectroscopy and Atomic Force Microscopy (AFM). With layer thickness confirmation, heterostructures are subjected to e-beam lithography and evaporation to produce device electrodes. Optoelectronic measurements are performed on these devices to understand their underlying physical behavior. In the future, we hope to fully characterize the material’s various optoelectronic properties using photocurrent and photoluminescence measurements.