Wettability control with self-assembler patterning for printed electronics

We investigated the lyophobic/lyophilic patterning method of self-assembled monolayers (SAMs) as gate dielectrics for printable electronics. Lyophobic/lyophilic patterning has been previously shown to damage the substrate surface. Therefore, it is mainly used for electrodes, but not semiconductors. We reduced the damage by partially removing the alkyl chains of the lyophobic SAM with oxygen plasma or vacuum ultraviolet treatment and replacing them with lyophilic molecules. This lyophilic area was formed in a room-temperature process, and we obtained a solution-processed organic transistor with a mobility of 2 x 10(-2) cm(2) V-1 s(-1) at 2.5 V operation. The transistor retained 54% of its mobility without the SAM replacement. By integrating a p-type transistor prepared in the same way, we achieved 2 V operation of an organic inverter and ring oscillator with gain of 30 and oscillation frequency of 3.1 Hz. (C) 2019 The Japan Society of Applied Physics