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, InO calcination at 350 °C and a solution-processed back-channel protection, high average saturation mobility of approximately 10 cm/(V s) are demonstrated in a bottom-contact coplanar thin-film transistor device structure.

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Optimization of thin-fi lm transistors performance is usually accompanied by an increase of the process temperature. This work presents a method to raise the fi eld effect mobility by a factor of 3 without a change of the process parameters. The modifi cation involves a solution doping process where an ammine zinc complex is formed in the presence of metal ions of the 13 th group, namely gallium and indium. Morphological studies, including scanning electron microscopy and atomic force microscopy, reveal the difference among the resulting fi lms. Moreover, X-ray diffraction results show that the doping affects the preferred orientation of the zinc oxide crystals in the resulting fi lm. The electrical properties vary distinctly and are best for a solution doped with both gallium and indium. With a double-layer system the performance of this new precursor exceeds fi eld effect mobility values of 1 cm 2 V −1 s −1 after a maximum process temperature of 160 °C.

In this work, solution based metal-oxide TFT with BCE structure is successfully implemented in TFT-LCD production line. The well-known slot-die coating technology is used to deposit liquid phase semiconductor on Gen4.5 substrates. Finally, a 5.5 inch TFT LCD driven by solution metal oxide TFT was successfully demonstrated.