For organic photovoltaics (OPVs), the class of solar cells that are composed of mixtures of organic conjugated molecules, the 'fundamental processes that give rise to photocurrent generation involve the dynamics of excitons (i.e., Coulombically bound electron-hole pairs). At the molecular level, properties of the electronic structure such as excited state energy levels or electronic polarization depend sensitively on nuclear configuration. Therefore, the material properties that directly involve electronic degrees of freedom can exhibit complex morphological dependence. In the case of OPVs, which unlike their inorganic counterparts (e.g. Si-based solar cells) are typically disordered on the molecular length scale, the static and dynamic properties of excitons are dominated by heterogeneities. The community lacks a general description of the connection between molecular morphology, excitonic properties, and overall device efficiency and as a result the search for more efficient OPV materials is currently driven by trial-and-error. We seek to use molecular simulation in order to generate an improved understanding of the interplay between the dynamics of excitons and molecular disorder.
展开▼
