Metal Organic Frameworks-Based Optical Thin Films

Abstract

Metal-organic frameworks (MOFs) are organic-inorganic hybrid materials with ordered pore structures assembled by metal centers and organic ligands through coordination bonds, but conventionally they are mostly in powder form. In recent years, metal-organic framework films have received increasing attention due to their potential applications in nanotechnology and nanodevices. The intrinsic ultrahigh porosity of MOFs may lead to a low refractive index of MOF materials. In addition, over 70,000 types of MOFs exist, and their properties can be tuned through the adoption of different metal motifs, organic ligands, or crystal morphologies. These characteristics make MOFs a potential new generation of optical thin film materials. In this chapter, the fabrication methods of MOF thin films, the optical properties of MOF optical thin films, and their application in optical sensors were described.

A Real‐Time LSPR‐Based Study of Metal‐Organic Framework (MOF) Growth

“…According to the calculation of the effective refractive index, [29] it is possible that the deposited MOF layer has a lower RI than water and decreases the RI of the entire sensorically active layer. The RI of a thin MOF layer depends on the compactness of the layer and on the deposition technique and may well be lower than the RI of water [2] . However, the AFM images do not substantiate the presence of MOF material on the sample surface.…”

“…Metal-Organic Framework materials (MOF) are innovative hybrid structures that can offer great potential for various applications, such as gas storage, sensing, photothermal or catalysis. [1][2][3][4][5] These inorganic-organic hybrid materials consist of metal centers (secondary building units, SBU) which are connected by multifunctional organic molecules (linkers). [6] More than 100 000 different crystal structures are accessible using different metals and linker molecules.…”

Cobalt-Doped ZIF-8 Nanoparticle-Decorated Fiber Optic Sensor for Copper Ion Detection

“…Moreover, MOF films can be deposited on a substrate by a variety of standard physical and chemical deposition techniques. 20 Heavy metal ions interact with MOFs based on ion exchange, diffusion, chelation, strong coordination bonds, and/or weak interactions such as electrostatic attractions, hydrogen bonding, and Van der Waals forces. 21 These interactions manifest changes in their structural, chemical, and optical properties, owing to a complex interplay of their properties.…”

“…Of these, MOFs, a well-established class of porous nano/microstructures, offer a larger surface area, high adsorption capacity, high porosity, and excellent stability for sensing applications. Moreover, MOF films can be deposited on a substrate by a variety of standard physical and chemical deposition techniques . Heavy metal ions interact with MOFs based on ion exchange, diffusion, chelation, strong coordination bonds, and/or weak interactions such as electrostatic attractions, hydrogen bonding, and Van der Waals forces .…”

Low and ultralow RI materials

“…An example process flow for a Back Side Illumination (BSI) CMOS image sensor (CIS) is shown in Figure 1. In this work, we report on spin coated films utilizing UiO-66-type MOF-based materials 8 that can achieve refractive indexes of below 1.25 at 550 nm wavelength. These films can be formulated in fab friendly solvents, such as mixtures of propylene glycol monomethyl ether (PGME) and cosolvents.…”