Influence of Gate Voltage Operation on Effective Mobility of Electrolyte-Gated Organic Transistors

Abstract

Low-voltage operation has long been a beneficial characteristic of electrolyte-gated organic transistors (EGOTs) because of the high capacitance of the electrolyte dielectric layer. Operating below 3 V, several reported EGOTs have effective mobilities above 1 cm(2) V-1 s(-1) based on the recently introduced reliability factor for organic field-effect transistors (OFETs). In this study, we report on the influence of gate voltage operation on the effective mobilities of EGOTs using poly(3-hexylth-iophene) (P3HT) semiconductor and electrolyte dielectric operating at different gate voltages of -1, -1.5, and -2 V. Average field-effect mobilities (mu(FET)) of 2.35 +/- 0.41 (2.39 +/- 0.27), 3.74 +/- 0.33 (2.95 +/- 0.32), and 3.30 +/- 0.44 (2.81 +/- 0.38) cm(2) V-1 s(-1) are measured in the saturation (linear) regimes for devices operating at -1, -1.5 and -2 V, respectively. With a reliability factor of 74.9 +/- 2.8% (86.2 +/- 2.2%) in the saturation (linear) regime, devices at -1.5 V measured the highest average effective mobility (mu(eff)) of 2.79 +/- 0.22 (2.54 +/- 0.29) cm(2) V-1 s(-1) in the saturation (linear) regime due to efficient charge transport with minimal charge scattering. Our results highlight fundamental optimization techniques helpful for achieving optimal effects.