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Highly transparent (>85 %) and conductive (1.086×10−3 Ω cm) zinc oxide thin films have been deposited from specifically selected precursors allowing us to establish a direct correlation between their molecular structure and the optoelectronic properties of the deposited films. Mono‐ligated ethyl zinc compounds of varying steric bulk: [EtZn(OC(Me)CH(Me)N(iPr))]2 (1), [EtZn(OC(OEt)CH(Me)N(iPr))]2 (2) and [EtZn(OC(OEt)CH(CH3)N(Dipp))]2 (3) were compared with the related bis‐ligated zinc complexes [Zn(OC(Me)CH(Me)N(iPr))2] (4), [Zn(OC(OEt)CH(Me)N(iPr))2] (5) and [Zn(OC(OEt)CH(Me)N(Dipp))2] (6). In all cases bulkier ligands resulted in poorer electronic properties of deposited films, whilst all mono‐ligated compounds were shown as superior precursors. All complexes were characterised by 1H and 13C{1H} NMR and elemental analysis, with the structure of 6 determined by single crystal X‐ray diffraction. Zinc oxide films were deposited from single and dual source (with methanol) reactions of these precursors, and analysed via XRD, XPS and EDX. Optoelectronic properties were investigated through UV/vis spectroscopy and Hall effect measurements, and morphology was examined via SEM. Tauc plots from UV/vis data indicated that Film A showed the lowest band gap of 3.31 eV. Varying the elemental composition of the precursors led to changes in the elemental composition of the resultant films, as well as changes in their structural and optoelectronic properties. Using this approach of precursor design, we have been able to tune single source precursors towards zinc oxide to deposit films with specific properties. [ABSTRACT FROM AUTHOR]

Amidoenoate (AME = {ethyl-3-(R-amido)but-2-enoate}) complexes of aluminium and gallium, of the type: [AlCl2(AMER)] R = iPr (1-Al); [AlCl(AMER)2] R = iPr (2-Al), Dip (3-Al); [GaCl2(AMER)] R = iPr (1-Ga) and [GaCl(AMER)2] R = iPr (2-Ga), Dip (3-Ga), have been synthesised (iPr = isopropyl, Dip = 2,6-diisopropylphenyl). The coordination chemistry of these complexes has been studied in relation to precursor suitability. Investigations into the reactivity of the aluminium and gallium amidoenoate complexes involved reactions with hydride sources including alkali metal hydride salts, alkylsilanes, and magnesium hydride species and magnesium(I) dimers. The isolation of alkyl metal amidoenoate precursors including an aluminium hydride amidoenoate, [AlH(AMEDip)2] (4-Al) and dimethyl gallium amidoenoates [GaMe2(AMEDip)] (4-Ga), [GaMe2(AMEiPr)] (5-Ga) concluded the synthetic studies. A selection of the isolated complexes were used as precursors for aerosol assisted chemical vapour deposition (AACVD) at 500 °C. Thin films of either amorphous Al2O3 or Ga2O3 were deposited and subsequently annealed at 1000 °C to improve the materials' crystallinity. The films were characterised by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), UV-visible (UV-vis) spectroscopy and energy dispersive X-ray analysis (EDXA). [ABSTRACT FROM AUTHOR]

The developments in inkjet printing technology and the printed electronics industry in the past two decades have provided cost-effective, environmentfriendly, and reliable alternates to traditional methods of fabricating electrical devices. However, most commercial metallic inks require high sintering temperatures to form desired functional patterns, which limits the applications of printed electronics in scenarios that require electrical devices on thermally sensitive substrates, like biomaterials or bio-synthetic composite materials. This study provides the synthetic route of a novel silver-based metal organic decomposition (MOD) ink which is used to form highly conductive silver films on the thermally sensitive skin-inspired silk/epoxy composite substrates by directly inkjet printing with accurate pattern control, whilst self-decomposing and sintering at room temperature. The fabricated silver patterns on the thermally sensitive silk/epoxy composite substrate are highly conductive with conductivity of 4.65 × 104 S m-1. These silver patterns also show impressive malleability as bulk silver films, which can be further developed into motion sensors for wearable devices or medical applications. Our strategy provides a general platform for electronic functionalization without temperature constraints. The particle-free, reactive silver-precursor, and lower sintering temperature of the ink also widen the choices of substrates, as exemplified herein with outstanding printing quality and high electrical conductivity (1.20 × 106 S m-1) also achieve on paper. [ABSTRACT FROM AUTHOR]

The field of printed electronics strives for lower processing temperatures to move toward flexible substrates that have vast potential: from wearable medical devices to animal tagging. Typically, ink formulations are optimized using mass screening and elimination of failures; as such, there are no comprehensive studies on the fundamental chemistry at play. Herein, findings which describe the steric link to decomposition profile: combining density functional theory, crystallography, thermal decomposition, mass spectrometry, and inkjet printing, are reported. Through the reaction of copper(II) formate with excess alkanolamines of varying steric bulk, tris‐co‐ordinated copper precursor ions: "[CuL3]," each with a formate counter‐ion (1–3) are isolated and their thermal decomposition mass spectrometry profiles are collected to assess their suitability for use in inks (I1–3). Spin coating and inkjet printing of I1,2 provides an easily up‐scalable method toward the deposition of highly conductive copper device interconnects (ρ = 4.7–5.3 × 10−7 Ω m; ≈30% bulk) onto paper and polyimide substrates and forms functioning circuits that can power light‐emitting diodes. The connection among ligand bulk, coordination number, and improved decomposition profile supports fundamental understanding which will direct future design. [ABSTRACT FROM AUTHOR]

Precursor design is the crucial step in tailoring the deposition profile towards a multitude of functional materials. Most commercially available aluminium oxide precursors require high processing temperatures (>500 °C). Herein, we report the tuning of the decomposition profile (200–350 °C) of a range of octahedrally coordinated tris(β‐ketoiminate) aluminium complexes of the type [Al(MeCN(R)CHC=OMe)3], by varying the R substituents in the ligands. The complexes are derived from the reaction of trimethylamine alane (TMAA) and a series of N‐substituted β‐ketoiminate ligands (R‐acnacH, R=Me, Et, iPr, Ph) with varying R‐substituents sizes. When the more sterically encumbered ligand (R=Mes) was used, the Al atom became five‐coordinate, therefore representing the threshold to octahedral coordination around the metal in these type of compounds, which, consequently, lead to a change of decomposition profile. The resulting compounds have been characterised by NMR spectroscopy, mass spectrometry, elemental analysis and single crystal X‐ray diffraction. [Al(MeCN(Me)CHC=OMe)3] has been used as a single source precursor for the deposition of Al2O3. Thin films were deposited via aerosol assisted chemical vapour deposition (AACVD), with toluene as the solvent, and were analysed using SEM, EDX and XPS. [ABSTRACT FROM AUTHOR]

Silver (Ag) amidinate metal organic decomposition precursors of the type: [Ag2((ArN)2C(H))2] (Ar = 2,6-dimethylphenyl (1), 2,6-diethylphenyl (2) and 2,6-diisopropylphenyl (3)) have been used for the first time in the deposition of Ag films on glass with multiple functionalities with potential application in optical/biological sensors or for use in electronic circuitry. Precursors 1–3 were isolated from the reaction of silver acetate with the appropriate ligand in a 1:2 stoichiometry and were characterized by 1H and 13C{1H} NMR, thermal gravimetric analysis and single crystal X-ray diffraction for 2. Single-layer depositions at 200 °C on glass substrates via spin coating produced transparent (>90% transmittance) coatings, with well-defined Ag nanoparticles. Multi-layer depositions at 200 °C on glass had a metallic lustre and were found to be conductive (ρ = 0.916–1.83 × 10−6 Ωm). All films were strongly adhered and displayed excellent coverage of the substrate. Ag films deposited from 1 to 3 were analysed by grazing incidence X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive X-ray analysis and scanning electron microscopy, with optical properties determined by UV-Vis spectroscopy. [ABSTRACT FROM AUTHOR]