Investigation of transport properties of transition metal dichalcogenides for electronic applications

Abstract

The main goal of this thesis is INVESTIGATION OF TRANSPORT PROPERTIES OF TRANSITION METAL DICHALCOGENIDES FOR ELECTRONIC APPLICATIONS . Keeping the demand, scope, and challenges in mind, the present thesis involves synthesis of MoS2 and MoSe2 QDs through modifications in hydrothermal synthesis. Hydrothermal synthesis method of MoS2 has been optimized with respect to temperature, time and molar ratio. After finding the optimum conditions for growth of MoS2 nanosheets, the hydothermal process is carried out for different molybdenum precursors under similar conditions. The samples are characterized using different techniques and their behavior is explained. The samples from different precursors of molybdenum are further processed to obtain quantum dots (QDs). Then hydrothermal synthesis of MoSe2 using different precursors is done and finally MoSe2 QDs are also obtained. Various transport properties of the synthesized QDs are obtained through I-V measurements and Hall measurements. The interaction of QDs with a globular protein trypsin is studied. Structural characterization of the QD-protein conjugates has been done using particle size analyzer, Zeta-potential and FT-IR. The nature of forces responsible for conjugation, the stoichiometry of the conjugates, the forces acting for the conjugation has been probed on the basis of ultrasensitive fluorescence spectroscopy. Energy transfer from proteins to QDs and the effect of fluorescent QDs on the enzymatic activity of proteins newline