Theoretical insights on pyrene end-capped thiophenes/furans and their suitability towards optoelectronic applications.

Organic semiconductors are attractive candidates for the development of flexible and efficient optoelectronic devices. In this work, we have studied the pyrene end-capped thiophene derivatives with different number of oligomeric rings and substituted with their oxygen analogue furan. Results indicate that the molecular planarity varies with the substitution of furan rings and the number of rings play a role on optoelectronic property of the systems. All the systems have shown ambipolar behavior, but the high charge barrier in the case of electrons could limit the device performance. Further, in photovoltaic analysis the increment in oligomeric ring has substantially reduces the open circuit voltage and the fill factor. However, the introduction of furan has improved the overall light harvesting efficiency. With the proper choice of material and device engineering the shorter systems can be considered for photovoltaics, where as the longer derivatives can be considered for light emitting device applications. [Display omitted] • Pyrene end-capped oligothiophenes were substituted with oligofurans and investigated for optoelectronic applications. • Planarity analysis indicate furan substituted molecules are more planar than that of the thiophene systems. • The planarity varies with respect to the number of thiophene/furan rings. • Both oligothiophenes and oligofurans shows ambipolar behavior but furan substitution tends to favor the hole transfer. • Results indicate shorter systems are suitable for photovoltaics and longer systems are preferable for light emitting device applications. [ABSTRACT FROM AUTHOR]