Water-based 2-dimensional anatase TiO2 inks for printed diodes and transistors

2-Dimensional (2D) materials are attracting strong interest in printed electronics because of their unique properties and easy processability, enabling the fabrication of devices with low cost and mass scalable methods such as inkjet printing. For the fabrication of fully printed devices, it is of fundamental importance to develop a printable dielectric ink, providing good insulation and the ability to withstand large electric fields. Hexagonal boron nitride (h-BN) is typically used as a dielectric in printed devices. However, the h-BN film thickness is usually above 1 mu m, hence limiting the use of h-BN in low-voltage applications. Furthermore, the h-BN ink is composed of nanosheets with broad lateral size and thickness distributions, due to the use of liquid-phase exfoliation (LPE). In this work, we investigate anatase TiO2 nanosheets (TiO2-NS), produced by a mass scalable bottom-up approach. We formulate the TiO2-NS into a water-based and printable solvent and demonstrate the use of the material with sub-micron thickness in printed diodes and transistors, hence validating the strong potential of TiO2-NS as a dielectric for printed electronics.

Automated summary

2D materials have unique properties and easy processability, making them attractive for printed electronics. Hexagonal boron nitride (h-BN) is commonly used as a dielectric in printed devices, but its limitations in low-voltage applications have led to the exploration of anatase TiO2 nanosheets (TiO2-NS) as a printable dielectric ink. In this work, water-based and printable solvent formulations of TiO2-NS are demonstrated to have sub-micron thickness and can be used in printed diodes and transistors, showcasing their potential for printed electronics.