Solution Atomic Layer Deposition of Smooth, Continuous, Crystalline Metal–Organic Framework Thin Films

• Published in: Chemistry of materials Vol. 34; no. 22; pp. 9836 - 9843
• Main Authors: Barr, Maïssa K. S., Nadiri, Soheila, Chen, Dong-Hui, Weidler, Peter G., Bochmann, Sebastian, Baumgart, Helmut, Bachmann, Julien, Redel, Engelbert
• Format: Journal Article
• Language: English
• Published: American Chemical Society 22.11.2022
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/acs.chemmater.2c01102

For the first time, a procedure has been established for the growth of surface-anchored metal–organic framework (SURMOF) copper­(II) benzene-1,4-dicarboxylate (Cu-BDC) thin films of thickness control with single molecule accuracy. For this, we exploit the novel method solution atomic layer deposition (sALD). The sALD growth rate has been determined at 4.5 Å per cycle. The compact and dense SURMOF films grown at room temperature by sALD possess a vastly superior film thickness uniformity than those deposited by conventional solution-based techniques, such as dipping and spraying while featuring clear crystallinity from 100 nm thickness. The highly controlled layer-by-layer growth mechanism of sALD proves crucial to prevent unwanted side reactions such as Ostwald ripening or detrimental island growth, ensuring continuous Cu-BDC film coverage. This successful demonstration of sALD-grown compact continuous Cu-BDC SURMOF films is a paradigm change and provides a key advancement enabling a multitude of applications that require continuous and ultrathin coatings while maintaining tight film thickness specifications, which were previously unattainable with conventional solution-based growth methods.