Organic Thin Film Transistors Incorporating Recessed Electrodes on Polymer Gate Dielectric

The solution-processed inverted co-planar organic thin film transistor (OTFT) incorporating recessed source-drain-gate and polymer gate dielectric is demonstrated to realize a fully recessed device. The impact of recessed electrodes on the contact resistance (
$R_{c}$
) and the mobility (
$\mu $
) is thoroughly investigated by comparing the performance of fully recessed devices, partially recessed (source-drain) devices and standard non-recessed devices. A reduction in
$R_{c}$
by two orders of magnitude and 3-fold increase in
$\mu $
to attain the values of
$60 k\Omega $
-
$cm$
(without any surface treatment) and
$1.5\times 10^{-2}cm^{2}/Vs$
respectively are achieved in a fully recessed device as compared to the standard non-recessed device.