Carboxymethyl Cellulose as a Sustainable Dielectric Material for Organic Field-Effect Transistors

The exploration and development of sustainable materials in electronics are essential for reducing the environmental impact of electronic waste. Additionally, there is an increasing need for simplified fabrication methods that eliminate the use of hazardous substances. Biopolymers have recently emerged as promising alternatives, offering flexibility, biodegradability, lightweight properties, and versatility in achieving diverse electrical characteristics. In this work, we study a commercially available water-soluble cellulose derivative, carboxymethyl cellulose, as a dielectric layer for electronic devices. We report on its film fabrication, dielectric characterization, and implementation in p- and n-type organic field-effect transistors. The cellulose films showed high optical transparency, very low surface roughness, and a 4-fold increase in capacitance per unit area compared to our reference dielectric polymer, poly(methyl-methacrylate). When integrated as a dielectric film into the transistor platform, carboxymethyl cellulose enabled operation below |10 V|, representing a 7-fold reduction in threshold voltage. These findings provide insight into the enormous potential of carboxymethyl cellulose for developing more sustainable and environmentally friendly electronic devices through a highly scalable, low-cost, and simple fabrication process.