Nanopatterning of 2D Materials by High-performance Pigment Molecules

abstract

English

Interface between an organic semiconductor and an inorganic substrate is crucial for functionality of many devices. Organic high-performance pigments, molecules such as diketopyrrolopyrroles (DPP) or epindolidiones used in this study, have a significant advantage of the facile synthesis and easy chemical modification, which resulted in their widespread use. The electronic properties can be engineered by the synthesis to match necessary requirements for the corresponding electronic devices. As a model system we study sub-monolayer amounts of deposited organic molecules on two-dimensional (2D) metal layer grown on a silicon substrate. Under clean conditions of ultra-high vacuum we study the interactions between the molecules and the substrate using scanning tunneling microscopy (STM) which allows the atomic-scale imaging. The 2D metal layers prepared on Si crystals often exhibit exotic properties due to strong correlation effects, such as the 2D superconductivity or spin splitting of electronic states. Our goal is further tuning of these exotic properties by means of self-ordered structures of organic molecules. Organic molecules are widely used as building blocks in plethora of spontaneously growing periodic superstructures on well-defined surfaces. Several types of intermolecular interactions can be involved. We have found that optimum bonding strategy when using 2D metal layers as substrates is to utilize double hydrogen bonds, as allowed by DPP or epindolidiones used in this study. Importantly, by modifying the side groups of the molecules we can change electronic properties of the system. Based mostly on STM observation and density functional theory calculations, we will demonstrate our success in preparation of perfectly ordered 1D rows of the pigment molecules. We will show effect of side groups as well as of the substrate. For future, the presented approach offers a way to modify topology of electrons confined within the 2D layer.

self-assembly; scanning tunneling microscopy; metal-passivated silicon surface; high-performance pigments

Kocán, P.; Sobotík, P.; Cigánek, M.; Ošťádal, I.; Krajčovič, J.

12. 9. 2024

Vysoké učení technické v Brně, Fakulta chemická

Brno, Česká republika

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https://www.fch.vut.cz/chl/konference/program/bookofabstracts-pdf-p269547