Vapour printing: patterning of the optical and electrical properties of organic semiconductors in one simple step

Abstract

We have exploited the effective and versatile concept of post-deposition treatment using vapour and added a new dimension, space, in order to form patterns of organic thin films with modified optical and electrical properties in a low cost and straightforward fashion. To achieve this feat, we developed a vapour printer which locally exposes an organic film to low concentrations of common organic solvents. This technique readily enables the generation of spatially resolved patterns through three different approaches: (i) local changes in molecular conformation; (ii) local changes in the degree of crystallinity; and (iii) local chemical reactions. In order to demonstrate the potential of vapour printing, we have fabricated a range of proof-of-concept optoelectronic devices, including integrated optical interferometers, photodiodes with position dependent response, organic solar cells and conducting wires.