Green electrolyte-based organic electronic devices

Electrolyte is an essential component to most organic electronics devices. Traditional electrolyte materials are based on solutions of inorganic salt in common organic solvents. However, it is recognized that the use of organic solvents has severe implications on the environment and waste management, safety hazard caused by high volatility and flammability, as well as human and eco-toxicity issues. In recent years, these major concerns have driven the academic and industrial communities to consider more environmentally friendly or “green” solvents. This chapter presents a perspective on the current progress and advances in the field of green electrolytes for organic electronics devices. We provide a critic analysis of the main families of green electrolytes including aqueous electrolytes, hydrogels, ionic liquids and ion-gels, deep eutectic solvents, and green polymer electrolytes. Each of these alternative solvents have its own strengths and limitations, which are discussed in light of recent literature. The key organic electrochemical devices that will be included in this section comprise organic electrochemical transistors, light emitting electrochemical cells, and organic batteries. Finally, this chapter emphasizes how the use of green solvents is expanding the field of application of organic electronics to bioelectronic applications such as organic sensors for health monitoring and electrophysiological sensing devices.