Virtual Design in Organic Electronics: Screening of a Large Set of 1,4-Bis(phenylethynyl)benzene Derivatives as Molecular Semiconductors

In this work, we have theoretically studied the electronic properties of a large series of 1,4-bis(phenylethynyl)benzene derivatives, with the chemical formula Y–C≡C–X–C≡C–Y, with X and Y being aromatic rings and chosen to act as donor and acceptor moieties. Employing state-of-the-art DFT calculations, we analyzed a set of relevant electronic properties related to the optoelectronic and semiconductor character of these systems, namely, molecular and energy levels, electron affinity, ionization potential, reorganization energy, and electronic coupling between neighboring molecules forming dimers, obtained after evaluation of binding energy landscapes. The latter energy magnitude is needed to disclose first the favored intermolecular interactions (i.e., the lowest binding energy) to concomitantly estimate next the charge transport rates. The systematic screening performed allowed us to anticipate the possible use of some of these derivatives as p-type, n-type, or even ambipolar organic molecular semiconductors.M.M. thanks the E2TP CYTEMA-SANTANDER program for financial support. Likewise, the authors are grateful for the project DIPUAB-16-GARZONRUIZ financed jointly by the “Diputación de Albacete” and the “Universidad de Castilla-La Mancha”