We introduce novel atomic/molecular layer deposition (ALD/MLD) processes for the fabrication of crystalline inorganic-organic coordination network thin films with a number of different metal and organic constituents.[1-3] All the deposition processes fulfill the basic principles of ALD/MLD-type growth including the sequential self-saturated gas-surface reactions and atomic/molecular-level control of the film thickness. To develop these processes, we systematically investigated different aromatic polycarboxylates as the organic precursor and different inorganic precursors based on the most electropositive elements, that is, the s-block metals and lanthanides. As a result, well-behaving ALD/MLD processes were developed for a number of s-block metal based coordination network materials known from bulk samples in literature, and also several novel crystalline thin-film materials were discovered that had not been reported before in bulk form. The stability of the films in heat and humidity treatments were systematically studied to verify that some of the films reversibly absorb/desorb water molecules forming well-defined crystalline water-derivative phases. Our work thus underlines the strength of the ALD/MLD technique in discovering new exciting coordination network thin-film materials.
1. Nisula, M. & Karppinen, M. Atomic/Molecular Layer Deposition of Lithium Terephthalate Thin Films as High Rate Capability Li-Ion Battery Anodes. Nano Lett. 16, 1276–1281 (2016).
2. Ahvenniemi, E. & Karppinen, M. In Situ Atomic/Molecular Layer-by-Layer Deposition of Inorganic–Organic Coordination Network Thin Films from Gaseous Precursors. Chem. Mater. 28, 6260–6265 (2016).
3. Penttinen, J., Nisula, M. & Karppinen, M. Atomic/Molecular Layer Deposition of s-Block Metal Carboxylate Coordination Network Thin Films. Chem. - A Eur. J. 23, 18225–18231 (2017).