In Situ Atomic/Molecular Layer-by-Layer Deposition of Inorganic-Organic Coordination Network Thin Films from Gaseous Precursors

Crystalline inorganic-organic coordination network materials possess a property palette highly attractive for a number of frontier applications. In many prospective applications of these materials, high-quality thin films would be required. Gas-phase thin-film techniques could potentially provide a number of advantages over the current liquid-phase techniques for depositing such state-of-the-art hybrid thin films. The strongly emerging atomic/molecular layer deposition (ALD/MLD) technique in particular enables the rational fabrication of inorganic-organic thin films in a digital atomic/molecular layer-by-layer manner through successive gas-to-surface reactions of inorganic and organic precursors, but the resultant films have been amorphous. Here, we demonstrate the in situ ALD/MLD growth of well-crystalline calcium terephthalate (Ca-TP) coordination network thin films in a wide deposition temperature range. We moreover investigate the water absorption/desorption characteristics of the films and report attractive mechanical properties for both the dry and water-intercalated films.