Laser printing of polythiophene for organic electronics

We report on the development of hybrid organic/inorganic thin-film transistors using regioregular poly-3-hexylthiophene (P3HT) semiconductor material deposited by means of the solid-phase Laser Induced Forward Transfer (LIFT) technique. P3HT pixels were LIFT-printed onto Au/Ti source and drain electrodes formed on silicon dioxide/p+-type Si substrate. Deposition of the P3HT pixels was investigated as a function of the laser fluence using donor substrates with and without a dynamic release layer. Device electrical characterization reveals efficient field-effect action of the bottom gate on the organic channel. The transfer IDS-VGS characteristics exhibit well-defined sub-threshold, linear and saturation regimes designating LIFT as a promising technique for hybrid organic/inorganic transistor technology.

Research highlights▶ This method resulted in laterally well-resolved square deposits, without any observed damage on their surface even in the absence of a dynamic release layer and therefore avoids the risk of contamination. ▶ The electrical characterization of Al/P3HT/Al devices indicated that a space-charge-limited-current mechanism dominates the conductivity of bulk P3HT. ▶ An analysis of bottom-contact P3HT TFTs behavior showed that functioning P3HT TFTs could be fabricated with LIFT technique.