Conjugated polymers are at the origin of the new era of organic electronics and optoelectronics, with applications ranging from light-emitting diodes (LEDs), light-emitting field-effect transistors, field-effect transistors (FETs) and photovoltaic devices, to name the most relevant. Besides our ability to tune their properties by molecular engineering, the fact they can be processed from solution is originating new technological platforms for devices fabrication. This property creates new problems such as the need of new patterning techniques and how to deal with sequential polymer layer deposition (as one may destroy the soluble underlying layer).
In the last years, we have been investigating the use of polyfluorenes bearing oxetane side groups, which can undergo acid-catalysed polymerisation, leading to network formation. This ability has been used to fabricate FETs and multi-layer LEDs. More recently we have been addressing the use of phase separation to obtain films with submicron-structured surfaces, which are being explored in photovoltaic devices. As an alternative approach to prepare patterned structures from such materials, scanning near-field optical lithography has also been used.
In this presentation, we will provide an overview of these materials properties and prospects for new developments.