Advances in heterochromophoric perylene bisimide self-assemblies towards supramolecular electronics

Perylene bisimide (PBI) dyes are the quintessential and most well-studied class of dyes for designing biomimetic light harvesting (LH) self-assembled systems owing to their exceptional photophysical features such as excellent absorption, high molar extinction coefficient and high fluorescence quantum yield, thermal robustness, high charge carrier mobilities, and efficient exciton diffusion properties in their assemblies. Although excellent reviews spanning many aspects of PBI dyes and their applications are available in the literature, none of these to date have focused on heterochromophoric PBI assemblies in solution and their applications in electronics. To bridge the gap, this review focuses on heterochromophoric PBI dye self-assemblies, their optical properties in solution, morphological aspects and applications in solar light harvesting and charge and energy transfer, and their eventual integration in supramolecular electronic devices. The PBI heterochromophoric assemblies have been categorized into two major categories, namely, (i) covalent heterochromophoric self-assemblies and (ii) heterochromophoric PBI systems assembled via non-covalent interactions such as π-π stacking, hydrogen bonding, charge transfer interactions or co-assembly of PBIs with other chromophores and scaffolds. The detailed structural intricacies, photophysical properties in the solution phase, and morphologies of these assemblies are discussed followed by their established supramolecular electronic applications and future potential in the frontier areas of materials science.