Organic semiconductors are a promising alternative to inorganic counterparts for a variety of electronic devices, including organic photovoltaics and field effect transistors, as they are able to be solution-processed and the potential for roll-to-roll processing allows for a lower cost option. The crux of the effort to develop these technologies has been synthesizing new materials and engineering more efficient devices. Computational chemistry has also made important discoveries into the predictive models used to understand fundamental properties of these semiconductors. Marrying these efforts has the promise of leading to a better understanding of what is needed to achieve higher performing organic electronics.

This dissertation focuses on the incorporation of computational techniques into synthetic efforts of novel molecular semiconductors for organic photovoltaics and better understanding fundamental properties of organic semiconductors. Chapter one focuses on the development of four novel molecular designs to improve the efficiency through the incorporation of a weak donor unit and discusses the calculated and experimentally derived optoelectronic properties as well as the incorporation of the most promising molecules into solution-processed photovoltaic devices. Chapter two discusses the computational design and evaluation of molecular architectures incorporating two chromophores that absorb separate regions of the visible spectrum and the synthetic efforts of one new semiconductor for photovoltaic applications. Chapter three centers on the computational evaluation of intramolecular forces of heteroatoms in heterocyclic units used in relevant donor-acceptor molecular semiconductors and how these forces dictate the planarity and conformational preference. Chapter four outlines our effort to understand how the regioregularity of polymers affects the intramolecular reorganization through a computational evaluation of single oligomer chains for properties affecting charge mobilities in organic field effect transistors.