Chalcogenoarene semiconductors: new ideas from old materials

Abstract

There are certain aspects of the electronic and packing behavior of planar aromatic molecules containing exocyclic chalcogen atoms (i.e., sulfur, selenium, tellurium) which need considerable re-enlightenment. This class of semiconductors was once regarded as next-generation π-donors for applications in charge-transfer complexes. With the advent of new device technologies such as light-emitting diodes, solar cells, and organic transistors, the interest in charge-transfer complexes eventually tapered off. However, significant progress in the use of this class of materials in modern organic devices has been reported over the last five years. In this article, we review the exocyclic arenes with chalcogen atoms in peri-positions, summarize synthetic routes to these compounds and take a close look at their basic properties. Particular emphasis is placed upon their packing arrangements and the effect of exocyclic chalcogen atoms on the crystal packing motifs. Selected example applications from this class of materials in different fields will be highlighted. As a final note, we provide a prediction for their use in mainstream applications such as energy and fundamental charge transport/generation.