AUTHOR=Subramanian Arunprabaharan , Azimi Mona , Leong Cheng Yee , Lee Siew Ling , Santato Clara , Cicoira Fabio 

TITLE=Solution-Processed Titanium Dioxide Ion-Gated Transistors and Their Application for pH Sensing

JOURNAL=Frontiers in Electronics

VOLUME=3

YEAR=2022

URL=https://www.frontiersin.org/journals/electronics/articles/10.3389/felec.2022.813535

DOI=10.3389/felec.2022.813535

ISSN=2673-5857

ABSTRACT=<p>Titanium dioxide (TiO<sub>2</sub>) is an abundant metal oxide, widely used in food industry, cosmetics, medicine, water treatment and electronic devices. TiO<sub>2</sub> is of interest for next-generation indium-free thin-film transistors and ion-gated transistors due to its tunable optoelectronic properties, ambient stability, and solution processability. In this work, we fabricated TiO<sub>2</sub> films using a wet chemical approach and demonstrated their transistor behavior with room temperature ionic liquids and aqueous electrolytes. In addition, we demonstrated the pH sensing behavior of the TiO<sub>2</sub> IGTs with a sensitivity of ∼48 mV/pH. Furthermore, we demonstrated a low temperature (120°C), solution processed TiO<sub>2</sub>-based IGTs on flexible polyethylene terephthalate (PET) substrates, which were stable under moderate tensile bending.</p>