Title: | Fast Dynamic Synthesis of MIL-68(In) Thin Films in High Optical Quality for Optical Cavity Sensing |
Author(s): | Monjezi BH; Okur S; Limbach R; Chandresh A; Sen K; Hashem T; Schwotzer M; Wondraczek L; Woll C; Knebel A; |
Address: | "Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz Platz 1, 76344 Eggenstein-Leopoldshafen, Germany. Otto Schott Institute of Materials Research, Friedrich Schiller University Jena, Fraunhoferstrasse 6, 07743 Jena, Germany" |
ISSN/ISBN: | 1936-086X (Electronic) 1936-0851 (Linking) |
Abstract: | "Fabrication of metal-organic framework (MOF) thin films rigidly anchored on suitable substrates is a crucial prerequisite for the integration of these porous hybrid materials into electronic and optical devices. Thus, far, the structural variety for MOF thin films available through layer-by-layer deposition was limited, as the preparation of those surface-anchored metal-organic frameworks (SURMOFs) has several requirements: mild conditions, low temperatures, day-long reaction times, and nonaggressive solvents. We herein present a fast method for the preparation of the MIL SURMOF on Au-surfaces under rather harsh conditions: Using a dynamic layer-by-layer synthesis for MIL-68(In), thin films of adjustable thickness between 50 and 2000 nm could be deposited within only 60 min. The MIL-68(In) thin film growth was monitored in situ using a quartz crystal microbalance. In-plane X-ray diffraction revealed oriented MIL-68(In) growth with the pore-channels of this interesting MOF aligned parallel to the support. Scanning electron microscopy data demonstrated an extraordinarily low roughness of the MIL-68(In) thin films. Mechanical properties and lateral homogeneity of the layer were probed through nanoindentation. These thin films showed extremely high optical quality. By applying a poly(methyl methacrylate) layer and further depositing an Au-mirror to the top, a MOF optical cavity was fabricated that can be used as a Fabry-Perot interferometer. The MIL-68(In)-based cavity showed a series of sharp resonances in the ultraviolet-visible regime. Changes in the refractive index of MIL-68(In) caused by exposure to volatile compounds led to pronounced position shifts of the resonances. Thus, these cavities are well suited to be used as optical read-out sensors" |
Keywords: | MOF Gas Sensor Metal-Organic Frameworks Optical Quality SURMOF Resonating Cavity Thin Film Deposition; |
Notes: | "PubMed-not-MEDLINEMonjezi, Bahram Hosseini Okur, Salih Limbach, Rene Chandresh, Abhinav Sen, Kaushik Hashem, Tawheed Schwotzer, Matthias Wondraczek, Lothar Woll, Christof Knebel, Alexander eng 2023/03/07 ACS Nano. 2023 Mar 28; 17(6):6121-6130. doi: 10.1021/acsnano.3c01558. Epub 2023 Mar 6" |