Gate-dependent modulation of rectification characteristics of organic electrochemical rectifiers

Abstract

Organic Electrochemical Rectifiers (OECRs), derived from Organic Electrochemical Transistors, are promising components for flexible electronics and bioelectronic circuits due to their tunable rectifying behavior. In this study, we investigate the effect of gate electrode material on the rectification performance of OECRs using platinum (Pt), silver (Ag), and copper (Cu) gates. Our results reveal that the gate electrode potential, established through electric double layer formation at the gate/electrolyte interface, significantly influences channel conductivity and sets the intrinsic potential difference between the OECR terminals. Devices with Pt and Ag gates exhibit clear diode-like rectification, while the Cu-gated device displays non-diode-like behavior. Spectro-electrochemical measurements and electrochemical impedance spectroscopy confirm that negative gate electrode potentials (Ag and Cu) induce hole depletion in the channel. Open-circuit potential measurements further reveal a nonlinear potential profile along the channel in the absence of external bias. These findings demonstrate that the intrinsic gate potential is a critical design parameter that governs electrochemical doping, potential distribution, and the overall rectification characteristics of OECRs.