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Identifier

000433219

Title

Study of luminescence of optically pumped transition metal dichalcogenides for use in polariton devices

Alternative Title

Μελέτη και βελτιστοποίηση φωταύγειας οπτικά αντλούμενων διχαλκογενιδίων μετάλλων μετάβασης για χρήση σε πολαριτονικές διατάξεις

Author

Βερβελάκη, Ανδριανή Γ.

Thesis advisor

Δεληγεώργης, Γεώργιος

Reviewer

Ηλιόπουλος, Ελευθέριος
Σαββίδης, Παύλος

Abstract

Monolayer Molybdenum Disulfide is a 2D material that belongs to the family of TMDs. It is a direct bandgap semiconductor and it exhibits promising optical properties that have attracted scientific attention. Because of the strong Coulomb interactions that result from its 2D nature, excitons are formed with very high binding energies (hundreds of meV) and dominate the optical emission even at room temperature. This opens the way towards the formation of room temperature exciton-polaritons which is a difficult task using classical 3D semiconductors that due to their exciton formation energy require cryogenic temperatures. The scope of this thesis is the study and optimization of the optical properties of CVD-grown monolayer Molybdenum Disulfide (MoS₂), so as to be used in polaritonic applications. An organic superacid, bis(trifluoromethane)- sulfonimide (TFSI), was used to improve the optical emission of the monolayer. Optical microscopy, Raman and Photoluminescence spectroscopy were the techniques used to evaluate the changes that occur in the material. Further insight to the quality of the material was given by temperature and power dependent PL measurements. Finally, we studied the interaction of the sample with the environment and the influence of exposure to the pump laser beam to the material’s response.

Language

English

Subject

Chemical treatment

Monolayer Molybdenum Disulfide

Photoluminescence spectroscopy

Polariton

Raman spectroscopy

TMDS

Διχαλκογενίδια μετάλλων μετάβασης

Μονοστρωματικό Διθειούχο Μολυβδένιο

Πολαριτόνιο