  Inspired by experimental observations related to electrolyte-gated
transistors (EGTs) where non-ideals behaviors are shown and not described by
just one theoretical model, we proposed a charge carriers transport model able
to describe the typical modes of operation profiles as well as some non-ideals
ones from electrolyte-gated field effect transistors (EGOFETs) and organic
electrochemical transistors (OECTs). Our analysis include the effect of 2D or
3D percolation transport (PT) and also the influence of a shallow exponential
traps distribution on the transport. Under these considerations, a non-constant
accumulation layer thickness along the channel can be formed. Such dependence
was included into our model in the effective mobility parameter dependent on
the accumulation thickness. 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 protuberance/lump appears. Other analyzed phenomenon was the
non-linear behavior for low drain voltage range in the output curve, even when
considering an ohmic contact. According to this proposed model, this curve
behavior is attributed to the traps distribution profile into the semiconductor
and the very thin accumulation layer thickness close to the injection contact.
It was also possible to analyze the conditions when the linear field effect
mobility is higher or lower than the saturation one. Finally, EGOFET and OECT
experimental data were successfully fitted with this model showing its
versatility.
