title: Soluble Metal Oxo Alkoxide Inks with Advanced Rheological Properties for Inkjet-Printed Thin-Film Transistors.
abstract: Semiconductor inks containing an indium-based oxo alkoxide precursor material were optimized regarding rheology requirements for a commercial 10 pL inkjet printhead. The rheological stability is evaluated by measuring the dynamic viscosity of the formulations for 12 h with a constant shear rate stress under ambient conditions. It is believed that the observed superior stability of the inks is the result of effectively suppressing the hydrolysis and condensation reaction between the metal oxo alkoxide precursor complex and atmospheric water. This can be attributed to a strong precursor coordination and the resulting reduction in ligand exchange dynamics of the solvent tetrahydrofurfuryl alcohol which is used as the main solvent in the formulations. It is also shown that with a proper selection of cosolvents, having high polar Hansen solubility parameter values, the inks drop formation properties and wettability can be fine-tuned by maintaining the inks rheological stability. Good drop jetting performance without satellite formation and high drop velocities of 8.25 m/s were found with the support of dimensionless numbers and printability windows. By printing single 10 pL ink dots onto short channel indium-tin-oxide electrodes, In2O3calcination at 350 °C and a solution-processed back-channel protection, high average saturation mobility of approximately 10 cm2/(V s) are demonstrated in a bottom-contact coplanar thin-film transistor device structure.
authors.affiliation: Evonik Resource Efficiency GmbH, Electronic Solutions, 45772 Marl, Germany.|Institute of Technology for Nanostructures and CENIDE, University of Duisburg-Essen , 47057 Duisburg, Germany.
authors.forename: Sebastian
authors.identifier: http://orcid.org/0000-0003-1446-9064
authors.initials: S
authors.lastname: Meyer
authors.affiliation: Evonik Resource Efficiency GmbH, Electronic Solutions, 45772 Marl, Germany.
authors.forename: Duy Vu
authors.initials: DV
authors.lastname: Pham
authors.affiliation: Evonik Resource Efficiency GmbH, Electronic Solutions, 45772 Marl, Germany.
authors.forename: Sonja
authors.initials: S
authors.lastname: Merkulov
authors.affiliation: Evonik Resource Efficiency GmbH, Electronic Solutions, 45772 Marl, Germany.
authors.forename: Dennis
authors.initials: D
authors.lastname: Weber
authors.affiliation: Evonik Resource Efficiency GmbH, Electronic Solutions, 45772 Marl, Germany.
authors.forename: Alexey
authors.initials: A
authors.lastname: Merkulov
authors.affiliation: Institute of Technology for Nanostructures and CENIDE, University of Duisburg-Essen , 47057 Duisburg, Germany.
authors.forename: Niels
authors.initials: N
authors.lastname: Benson
authors.affiliation: Institute of Technology for Nanostructures and CENIDE, University of Duisburg-Essen , 47057 Duisburg, Germany.
authors.forename: Roland
authors.initials: R
authors.lastname: Schmechel
keywords: inkjet-printing; printability window; rheological stability; soluble metal oxo alkoxides; thin-film transistors