Impact of Al/Ti Electrodes on the Performance and Operational Stability of n-Channel Solution-Processed Solid-State Electrolyte-Gated Transistors: Applications in Reservoir Computing

The impact of Al/Ti electrodes on enhancing the performance and operational stability of n-channel organic electrolyte-gated transistors (OEGTs) is investigated. Utilizing Al/Ti electrodes as source and drain electrodes in diketopyrrolopyrrole (DPP)-based polymeric semiconductor OEGTs leads to a significant decrease in the charge injection barrier for electrons, resulting in improvement of all electrical parameters including on-current, mobility, on-off ratio, and threshold voltages. Furthermore, through a comparative analysis of transistors utilizing polymer insulators and solid electrolytes as gate dielectrics, the effect of alterations in the electrodes on the contact resistance of each device is examined. In comparison to OEGTs with Au electrodes, OEGTs with Al/Ti electrodes demonstrate higher operational stability following multiple cycling tests. Finally, the OEGTs produced in this study demonstrate reliable short-term memory characteristics, which are subsequently utilized for reservoir computing, achieving a high recognition accuracy of 94% for spoken digits.