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Three organotin carboxylate species stabilized by the same ligands, but varying in size and structure, were studied to elucidate the effects of the structure on reactivity in the context of direct-...

Thin films made from transparent conducting oxide (TCO) nanocrystals are promising alternatives to traditional vacuum-sputtered films. However, the material properties of nanocrystal-derived thin f...

Metal-oxide thin films find many uses in (opto)electronic and renewable energy technologies. Their deposition by solution methods aims to reduce manufacturing costs relative to vacuum deposition while achieving comparable electronic properties. Solution deposition on temperature-sensitive substrates (e.g., plastics), however, remains difficult due to the need to produce dense films with minimal thermal input. Here, we investigate combustion thin-film deposition, which has been proposed to produce high-quality metal-oxide films with little externally applied heat, thereby enabling low-temperature fabrication. We compare chemical composition, chemical structure, and evolved species from reactions of several metal nitrate [In(NO3)3, Y(NO3)3, and Mg(NO3)2] and fuel additive (acetylacetone and glycine) mixtures in bulk and thin-film forms. We observe combustion in bulk materials but not in films. It appears acetylacetone is removed from the films before the nitrates, whereas glycine persists in the film beyond...

We describe a process to produce aqueous precursor solutions of the flat-Al13 hydroxo cluster (Al13(μ3-OH)6(μ2-OH)18(H2O)24(NO3)15) via stoichiometric dissolution of bulk Al(OH)3(s) in HNO3(aq). We highlight its facility by demonstrating high yields and large-scale synthesis. X-ray diffraction confirms formation of a single-phase product, and Raman spectra show characteristic O-Al-O vibrational modes, both techniques confirming the identity of the flat-Al13 cluster in the bulk. 27Al NMR spectroscopy and dynamic light scattering also confirm the presence of the cluster in aqueous solution. We show the as-prepared solution produces smooth and continuous thin films via spin-coating. In capacitors, the films exhibit low leakage currents (near 10 nA/cm2) and dielectric constants expected for amorphous Al2O3. Because the precursor preparation requires no postsynthesis purification, it is readily scalable to large volumes.

Solid-state 71Ga and 69Ga NMR was used to probe the structure of the hydroxo-aquo cluster, [Ga13(μ3-OH)6(μ2-OH)18(H2O)24](NO3)15, envisioned as a solution-processable material for thin film electronics. This species, termed Ga13, is made up of three types of 6-coordinate gallium sites, with bridging OH groups and H2O species decorating the outer edges. Solid-state NMR at two magnetic fields (13.9 and 21.1 T) of these quadrupolar nuclei, in conjunction with modeling, demonstrates that these sites are best represented as distorted octahedra, exhibiting a wide range of distinct quadrupolar couplings and asymmetry parameters. This information is critical for analyses of the local coordination environment for gallium in related gallium-oxide films, and this work adds to the growing body of evidence that gallium solid-state NMR is a useful tool for structural analyses.

Solution deposition is a scalable method to fabricate transparent conducting and semiconducting oxide films that could enable low-cost large-area optoelectronic devices, including solar cells and electrochromic windows. However, high temperatures (>500 °C) are typically required to remove excess counterions and ligands from solution-deposited films. We report the synthesis of reactive F-modified tin(II) hydroxide nitrate nanoscale cluster precursors from the controlled dissolution of SnO and SnF2 in minimal nitric acid (∼1.6 mol HNO3 per mol Sn). After spin-casting to form films, heating at temperatures < 100 °C consumes the nitrate counterions likely by oxidation of the tin(II) precursor to form amorphous F:SnO2. The optical, electrical, structural, and morphological properties of F-doped and undoped SnO2 thin films are reported as a function of annealing temperature on both glass and polyimide (Kapton) substrates. Electron microscopy and X-ray reflectivity results show that the films are uniform and cra...