Selenophene Electronics

Substituting individual heavier (or lighter) atoms would appear to be an extremely straightforward method of controlling the optoelectronic properties of π‐conjugated molecules that has minimal impact on solid‐state materials properties, yet things are never as they appear. Selenophenes are a distinct class of material separate from thiophenes. Their HOMOLUMO gap is often narrow, which is attractive for photonic applications. Intermolecular SeSe interactions increase ordering on a molecular scale and lead to distinct solid‐state organization, which often leads to excellent charge‐transport properties. The crystallization of selenophene is distinct from thiophenes, and thus, composites of selenophenes and other organic materials have distinct nano‐ and microscale morphologies. Some of the best organic optoelectronic devices use selenophene‐containing materials, yet early results were less encouraging. The most recent syntheses, structure determination, and electronic device properties of π‐conjugated selenophene‐based materials are reviewed. Significantly more work is justified and this review sets the stage for those studies.