A Comparative Study on Printable Solid Electrolytes toward Ultrahigh Current and Environmentally Stable Thin Film Transistors

Printed oxide thin film transistors (TFTs) have outperformed their organic counterparts in the recent past; printable solid electrolytic insulators have also emerged as a suitable alternative to oxide dielectrics. In the present study, multiple composite solid polymer electrolytes (CSPEs) and an easy-to-formulate ion gel are fabricated and characterized for their double-layer capacitance (C-DL) values and the quality of electrostatic coupling. In the next step, alongside printed In2O3 as the semiconductor channel, the performance of the solid electrolytes is evaluated using printed top-gate TFTs. The semiconductor ink formulation and the device architecture are optimized to ensure unsurpassed device performance. In effect, unprecedented transistor performance is observed for all the three electrolytic insulators, with drive currents >10 mA and linear mobility >100 cm(2) V-1 s(-1); a rigorous discussion on the reliability factors and the merit/demerit of the linear versus saturation mobility values suggests reporting of only the linear mobility, henceforth. Next, the lifetime studies on the electrolyte-gated TFTs have shown superior environmental stability of the CSPE-gated devices. The present study not only provides a recipe to formulate a set of high-performance electrolytic gate insulators, but also offers a method to fabricate high-current power transistors, using the standard printing techniques.