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Fabrication and characterization of two-dimensional heterostructures
Majerová, Irena ; Švec, Martin (referee) ; Procházka, Pavel (advisor)
After the experimental discovery of graphene at the beginning of the 21st century, many other interesting 2D materials have been discovered. However, the electrical and optical properties of these layers are greatly influenced by the composition and quality of the surrounding materials. In order to preserve the exceptional properties of thin films, attention has gradually been drawn to heterostructures from 2D composite materials. This thesis describes the preparation and characterization of heterostructures composed of graphene and hexagonal boron nitride. In addition, a specific focus will be placed on optimizing the production process of heterostructures by the dry thin film transfer process, prepared by micromechanical exfoliation. Characterization and quality of prepared layers are controlled by Raman spectroscopy, while morphology is examined by atomic force microscope (AFM). Furthermore, the electrical properties of the graphene-hBN device are discussed and the charge carrier of the graphene field-effect transistor is measured.
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Graphene transfer methods for high quality graphene field effect transistors
Tesař, Jan ; Kormoš, Lukáš (referee) ; Procházka, Pavel (advisor)
This bachelor thesis is focused on the influence of different graphene transfer methods on its quality. Graphene layers were grown by Chemical Vapour Deposition (CVD) method. The quality characterization of subsequently transfered graphene is based on the measurement of charge carrier mobility which has been performed on the field-effect transistors fabricated by transferring of graphene layers onto Si/SiO$_2$ surface. Chemical etching and electrolytic delamination are the transfer methods that are being compared in this thesis. Results of the measurements showed that graphene layers transferred by electrolytic delamination exhibit approximately four times higher charge carrier mobility than those transferred by the chemical etching method.
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Electrical transport properties of materials for organic electronics
Stříteský, Stanislav ; Weiter, Martin (referee) ; Přikryl, Radek (advisor)
My master thesis is focused on design and realization fully automated system which will be used for the characterization of the organic FET structure, based on DPP derivatives with follow optimization of the characterization process. Program „MeasFET“ has been created at the LabVIEW surroundings that drives hardware gadgets was build-up during last year. Furthermore, initial tests were taken for optimalization process of charge carrier mobility measurements in derivatives DPP.
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