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.