General Model for Charge Carriers Transport in Electrolyte‐Gated Transistors

Abstract A charge carrier transport model able to describe the typical modes of operation and some non‐ideal ones from electrolyte‐gated field effect transistors and organic electrochemical transistors (OECTs) is proposed. The analysis include the effect of 2D or 3D percolation transport (PT) and the influence of a shallow exponential trap distribution on the transport. Under these considerations, a non‐constant accumulation layer thickness along the channel can be formed, resulting in a non‐constant effective mobility. The accumulation thickness can depict 2D or 3D PT or even a transition between them. This transition can produce a non‐ideal profile between the linear and saturation regimes in the output curve, region in which a lump appears. Other analyzed phenomenon is the non‐linear behavior for low drain voltage in the output curve, even considering an ohmic contact. This phenomenon is attributed to the traps distribution profile into the semiconductor and the thin accumulation layer thickness close to the injection contact. The conditions when the linear field effect mobility is higher or lower than the saturation one is also analyzed. Finally, electrolyte‐gated organic field effect transistors and OECT experimental data are successfully fitted with this model showing its versatility.