Efficiency of the Switching Process in Organic Electrochemical Transistors.

Entirely screen printed organic electrochemical transistors (OECTs) based on poly(3,4-ethylenedioxithiophene) poly(styrenesulfonate) ( PEDOT: PSS) and a polymer electrolyte are investigated in view of a correlation between the electrical charge consumed during switching and the volume of PEDOT: PSS in the transistor channel. An understanding of the relation between charge consumption and the amount of electrochemically active PEDOT is essential for the design of high performance transistors and for providing a deeper insight into the fundamentals of the electrochemical switching process in OECTs. It turned out that a precise control of the width of the PEDOT: PSS source-drain line is imperative for maximizing both the on-current and the on/off current ratio of lateral OECTs.