20.500.12556/RUL-178932 Modifying 2D Materials' Properties By Molecular Functionalization Spreminjanje lastnosti 2D materialov z molekulsko funkcionalizacijo This thesis explores the modification of monolayer molybdenum disulfide (MoS$_2$) with the organic molecule 6-(4,5-Dihydro-1$H$-imidazol-3-ium-2-yl)-2-(naphthalene-2-yl)benzothiazole methanesulfonate (L63MS) using a drop-casting method under ambient conditions. Given it’s planar, electron‐delocalized scaffold and bulky sulfonate counterion, L63MS is expected to adsorb via $\pi - \pi$ stacking, tuning its electronic structure while potentially preventing ordered self‐assembly and passivating the surface. MoS$_2$ samples were synthesized via CVD and characterized using AFM, Raman spectroscopy, and PL spectroscopy to assess the impact of the organic molecule on the structural and opto-electronic properties of the material. The study evaluates the effects of both the solvents used in the drop-casting process and the L63MS molecule itself on MoS$_2$. Results show that the L63MS molecule adsorbs onto the MoS$_2$ surface, inducing measurable changes in the Raman spectra, PL signal, and excitonic properties. These changes suggest potential modifications in doping levels, bandgap, and defect states, all of which are influenced by the choice of solvent in the process. The modification remains stable over time under ambient conditions, and the original optical properties of MoS$_2$ can be restored by heating, indicating the reversibility of the organic molecule's effects. Finally, we demonstrate laser-assisted formation of molecular agglomerates on MoS$_2$ surface at elevated substrate temperatures; these agglomerates remain stable after subsequent thermal treatment. This work provides insights into the stable, reversible modification of 2D MoS$_2$ through organic molecules, with an emphasis on the role of solvents in the process. Ta disertacija preučuje modifikacijo enoslojnega molibdenovega disulfida (MoS$_2$) z organsko molekulo 6-(4,5-Dihydro-1$H$-imidazol-3-ium-2-yl)-2-(naphthalene-2-yl)ben-zotiazol metansulfonat (L63MS) z metodo kapljičnega nanašanja pri normalnih sobnih pogojih. Glede na to, da je L63MS ploskovit, elektronsko delokaliziran in ima obsežen sulfonatni protiion, je pričakovati, da se bo adsorbiral prek $\pi-\pi$ zlaganja, s čimer bo prilagodil svojo elektronsko strukturo in hkrati preprečil urejeno samosestavljanje ter pasiviral površino. Vzorci MoS$_2$ so bili sintetizirani s CVD metodo in analizirani z uporabo AFM-a, Raman spektroskopije in PL spektroskopije za oceno vpliva organske molekule na strukturne in optoelektronske lastnosti materiala. Študija ocenjuje učinke tako topil, uporabljenih v procesu kapljičnega nanašanja, kot tudi same molekule L63MS na MoS$_2$. Rezultati kažejo, da se molekula L63MS adsorbira na površino MoS$_2$ in povzroča merljive spremembe v Raman spektru, PL signalu in ekscitonskih lastnostih. Te spremembe nakazujejo možne modifikacije v ravneh dopiranja, energijski vrzeli in defektnih stanjih, pri čemer je vse našteto odvisno od izbranega topila. Poleg tega modifikacija ostane stabilna skozi čas pri normalnih pogojih, optične lastnosti MoS$_2$ pa se lahko povrnejo s segrevanjem, kar kaže na reverzibilnost učinkov organske molekule. Na koncu smo prikazali lasersko podprto tvorbo molekularnih aglomeratov na površini MoS$_2$ pri povišanih temperaturah podlage; ti aglomerati ostanejo stabilni tudi po nadaljnji toplotni obdelavi. Ta disertacija nudi vpogled v stabilno in reverzibilno modifikacijo 2D MoS$_2$ z organskimi molekulami, s poudarkom na vlogi topil v procesu. MoS$_2$ monolayer chemical vapor deposition 2D materials organic molecules drop-casting photoluminescence Raman spectroscopy atomic force microscopy surface modification solvent effects optoelectronic properties MoS$_2$ monoplast kemijska parna depozicija 2D materiali organske molekule kapljično litje fotoluminiscenca Ramanova spektroskopija mikroskopija za atomsko silo površinska modifikacija vplivi topil optoelektronske lastnosti true false false Angleški jezik Slovenski jezik Doktorsko delo/naloga 2026-02-02 09:32:08 2026-02-02 09:32:08 2026-02-04 13:20:48 0000-00-00 00:00:00 2025 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 159275 254939907 21170.pdf 21170.pdf 1 4FD41FF113F807EB6900718226436630 4f28fa49b7449b601717f93a2aaba438f4abe2bb04c4fabc92ab1b6af3426611 9c14dcbc-0011-11f1-a1ba-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=226966 Fakulteta za matematiko in fiziko 0 0 0