Atomic layer deposition (ALD) of high-quality inorganic thin films has been one of the cornerstones of microelectronics already for decades, while its counterpart for organic thin films, i.e. molecular layer deposition (MLD), remained nearly un-exploited for long. In recent years, the hybrid of these two techniques, i.e. ALD/MLD, has been strongly emerging. Since both ALD and MLD cycles are modular, they can be combined into any arbitrary precursor cycling pattern to grow elaborated superstructures with functional interfaces to introduce multiple and even mutually contradicting properties into a single material.
The combined ALD/MLD technique allows us to fabricate novel hybrid materials not readily accessible through any other fabrication route.1 These include exciting in-situ crystalline metal-organic framework (MOF) materials2 and inorganic-organic structures in which ultra-thin organic layers are introduced between nm-scale metal oxide layers to e.g. enhance mechanical flexibility, block phonon conduction, or bring photoactivity. In this presentation, I will briefly discuss exciting examples of properties/functionalities realized for these materials: (i) electroactive lithium-organic thin films for battery components,3,4 (ii) organic-component-sensitized lanthanide-organic films for flexible white-light emitting phosphors and upconverting layers for solar cells,5,6 (iii) ZnO-based oxide:organic superlattice coatings for textile-integrated thermoelectrics,7,8 and (iv) ε-Fe2O3:azobenzene superlattice films for flexible and photo-responsive room-temperature magnets.9,10
Multia & M. Karppinen, Atomic/molecular layer deposition for designer’s functional metal-organic materials, Adv. Mater. Interfaces 202200210 (2022).
Multia, D. Kravchenko, V. Rubio-Giménez, A.Philip, R. Ameloot & M. Karppinen, Nanoporous metal-organic framework thin films prepared directly from gaseous precursors by atomic and molecular layer deposition: implications for microelectronics, ACS Appl. Nano Mater.6, 827 (2023).
Madadi, J. Heiska, J. Multia & M. Karppinen, Atomic and molecular layer deposition of alkali metal based thin films, ACS Appl. Mater. Interfaces13, 56793-56811 (2021).
Multia, J. Heiska, A. Khayyami & M. Karppinen, Electrochemically active in-situ crystalline lithium-organic thin films by ALD/MLD, ACS Appl. Mater. Interfaces12, 41557 (2020).
Ghazy, M. Lastusaari & M. Karppinen, White-light emitting multi-lanthanide terephthalate thin films by atomic/molecular layer deposition, submitted (2023).
Ghazy, M. Safdar, M. Lastusaari, A. Aho, A. Tukiainen, H. Savin, M. Guina & M. Karppinen, Luminescent (Er,Ho)2O3 thin films by ALD to enhance the performance of silicon solar cells, Sol. Ener. Mater. Sol. Cells219, 110787 (2021).
Marin, R. Funahashi & M. Karppinen, Textile-integrated ZnO-based thermoelectric device using atomic layer deposition, Adv. Eng. Mater. 22, 2000535 (2020).
Ghiyasi, M. Milich, J. Tomko, P.E. Hopkins & M. Karppinen, Organic-component dependent thermal conductivity reduction in ALD/MLD grown ZnO:organic superlattice thin films, Appl. Phys. Lett. 118, 211903 (2021).
Jussila, A. Philip, J. Linden & M. Karppinen, High-quality magnetically hard ε-Fe2O3 thin films through ALD for room-temperature applications, Adv. Eng. Mater.25, 2201262 (2023).
Philip, Y. Zhou, G.C. Tewari, S. van Dijken & M. Karppinen, Optically controlled large-coercivity room-temperature thin-film magnets, J. Mater. Chem. C10, 294 (2022).
Maarit Karppinen received her doctor degree in inorganic chemistry from Helsinki University of Technology in 1993. After holding shorter-term teaching and research fellow positions in Finland, she accepted first a one-year visiting professorship and later in 2001 a regular associate professor chair in Japan at the Materials and Structures Laboratory, Tokyo Institute of Technology, where she brought the deep chemistry contribution to the strong multidisciplinary research group focusing on functional oxide materials. In 2006 she returned back to her Alma Mater as a full professor to combine her expertise in fundamental new-material research to the long traditions of the laboratory in leading ALD thin-film research.
In 2008 she became the head of the Chemistry Department; this leadership was then transformed to the newly established Aalto University, formed by merging Helsinki University of Technology with two other universities from the Helsinki area. For 2009-2013 she was also holding the prestigious Academy Professor position in Finland. Currently she is internationally renowned for her pioneering research on complex perovskite oxides and ALD/MLD fabricated inorganic-organic thin films; for this latter field she received her ERC Advanced grant in 2013, followed by two ERC Proof-of-Concept grants. Her group’s work is truly interdisciplinary, covering both the design and synthesis of new materials and their characterization for a variety of functionalities. She was nominated as a VIP Visiting International Professor at Ruhr-University Bochum in 2016, and Aalto Distinguished Professor in 2017.