In-situ grazing incidence wide-angle x-ray scattering as a function of time is used to explore the dynamics of bulk heterojunction (BHJ) active layers. A small percentage of solvent additive induces nucleation of polymeric crystallites, increases the orientational order of the crystallites, and allows further nucleation for a period of time greater than 40 minutes. These observations are absent when the BHJ blend is cast from pure chlorobenzene.In the second part, we will examine a new class of small molecules with modular features that can be used to fine tune the optical absorption to match the solar spectrum, molecular orbital energies that are appropriate to achieve excellent power conversion efficiencies and topological attributes for controlling phase separation and film forming behavior. Using very small quantities of solvent additives, which control the crystallite size of the donor domains, it is possible to attain power conversion efficiencies of 6.7 %.

Design, synthesis, and processing of narrow band gap organic semiconductors for solar cell fabrication

243rd National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.