Exploration of a Cellulose-Based Biocompatible Gate Dielectric for Low-Voltage Organic Transistors

Abstract

In this work, a cellulose-based biocompatible high-k dielectric cyanoethyl cellulose (CEC) is comprehensively explored for demonstration of low-voltage organic transistors. The organic field-effect transistor (OFET) devices fabricated using a blend of TIPS-Pentacene and polystyrene to create the active semiconductor layer exhibited excellent p-channel transistor behavior with maximum and average process transconductance values of ~ 9.0, and ~ 6.0 nF/V.s respectively, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</sub> / <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</sub> of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , and average threshold voltage of -0.4 (±0.1) V suitable for sub-5V operation. Moreover, very high electrical stability was achieved from these devices through bias-stress, and repeatability measurements. The device operation was still maintained after 6 months in normal ambient indicating a high shelf life. Finally, there was a minimal variation in performance upon annealing the devices up to 60 °C, indicating high reliability in harsh environmental operating conditions. Our results confirm that CEC can be a potential gate dielectric for organic and biodegradable electronics which is essential for sustainability.