Decomposable Flexible Organic Transistors with a Cellulose-Based Gate Dielectric and Substrate for Biodegradable Electronics

Abstract

In this work, decomposable and combustible flexible organic transistors with a cellulose-based dielectric and substrate were demonstrated in an effort to produce biodegradable systems for eco-sustainable electronics. High-k cyanoethyl cellulose (CEC) was explored as a suitable gate dielectric candidate for enhancing the biodegradability of flexible devices fabricated on a paper substrate. The fabricated flexible biodegradable transistors exhibited high performance for -5 V operation with excellent saturation in the output characteristics along with remarkable environmental, operational, electromechanical, and thermal stability. Upon thermal annealing, the performance of the devices did not degrade till the temperature of 60 °C, indicating their suitability for practical operating environments. Moreover, the devices exhibited decent stability upon exposure to very high humidity. Most importantly, these devices were decomposed in water-rich soil in 19 days due to the microorganisms present in soil, confirming the excellent biodegradability, which is highly essential for eco-sustainable electronics. Moreover, the combustion of the devices in fire, one of the quickest methods for degradation, led to a significant reduction in mass of more than 75%, leaving ashes primarily consisting of the remains of Ag bottom-gate and Au source/drain electrodes. Our results on the demonstration of flexible devices with full decomposability in soil and high combustibility can be a significant step toward the preparation of fully biodegradable flexible electronics to minimize the effects of e-waste on environment and soil.

Keywords: biodegradable; decomposable; eco-friendly; organic transistor; paper electronics.