Chitosan-Based Substrates for Flexible, Printable and Sustainable Organic Electronic Devices

Organic electronic devices are increasingly linked to energy generation, storage, and transduction mechanisms that emphasize ecological and sustainable principles. Consequently, device fabrication must align with these goals to minimize carbon footprints throughout the manufacturing process and product lifecycle. Chitosan, a biopolymer derived from the chemical processing of chitin found in crustacean shells and fish, offers notable advantages, including unique chemical properties, accessibility, low cost, and biodegradability. When combined with polysulfone, it provides enhanced durability and mechanical stability, enabling improved processability. This study explores the use of membranes synthesized from these materials as potential thermoplastic substrate replacements in the organic electronic device. We present two examples: the first device is an organic photovoltaic that exhibits rectifier diode characteristics, with a short-circuit current of 1.1 mA/cm² and an open-circuit voltage of 0.45 V under illumination. The second device is a vapor sensor demonstrating ammonia sensing activity, achieving 4% efficiency. The membranes were fabricated using the casting method and slot-die printing technology and were characterized by their mechanical and optical properties under different solvent exposures and temperature conditions. In both membranes, a thin film of PEDOT:PSS was used as an electrical conductor in two different chitosan-based substrates for organic devices.