Effect of electric field on the electrical properties of a self-assembled perylene bisimide.

A functionalised perylene bisimide forms two different self-assembled structures in water depending on the solution pH. Structure 1 (formed at pH 6.2) consists of a fibrous structure, whilst structure 2 (formed at pH 9.4) consists of disordered aggregates. Despite being formed from the same molecule, structure 1 shows higher stability under illumination and electric field than structure 2, demonstrating that the nature of the self-assembled aggregate is critical in devices. Interestingly, both structures show p-type behaviour.