Perylenes, Porphyrins, and Other Large Dye Molecules for Molecular Layer Deposition

Abstract

Molecular layer deposition (MLD) is an incredibly powerful and flexible tool for designing completely new materials with novel and unique properties. The low temperature layer‐by‐layer approach and the use of highly reactive reactants allows one to combine vastly different organic and inorganic species and construct nanostructures with subnanometer precision. If not limited by the volatility of the reactants involved, the possibilities will be endless. This is most notable for the organic building blocks where an overall low volatility severely limits the toolbox of large molecules with interesting optical and electrical properties such as red‐ox activity and optical conversion. In this work, different strategies for molecular design of large molecules are investigated that allow vaporization while still having the necessary reactivity for MLD growth. Using these strategies, film growth with perylene and porphyrin derivatives, both molecules well known for their functional and optical properties are successfully achieved. With this knowledge, there is an opening to include much larger and more complex organic molecules into the world of vapor phase chemistry.

Chemical Bonding and Crystal Structure Schemes in Atomic/Molecular Layer Deposited Fe-Terephthalate Thin Films

“…Common to all three of these techniques, ALD, ALD/MLD, and MLD, is that they can produce high-quality, pinhole-free, large-area homogeneous, and conformal thin films and coatings even on challenging substrates with atomic/molecular level precision but yet in an industry-feasible fashion. ,, These attractive attributes are derived from the self-terminating gas-surface reactions and the unique precursor feeding sequence in which the two (or more) different precursors are individually pulsed into the reactor chamber separated by an inert gas purge. Numerous ALD/MLD processes have been developed for, e.g., magnetic, − optical, − thermoelectric, , bioactive, , electrochemical, − and barrier/encapsulation − applications. Chemistry-wise, these materials cover most of the s-block and 3d transition metals, lanthanides, and some p-block and 4d and 5d transition metals, together with a variety of organic moieties from simple alkyls (e.g., ethylene glycol) to more complex aromatic molecules (e.g., azobenzene-4,4-dicarboxylic acid or 9,10-anthracenedicarboxylic acid), , and even natural organics (e.g., nucleobases or curcumin). , …”