Electronic structures and impurity segregation around extended defects in pentacene films: first-principles study

摘要

Extended defects such as grain boundaries (GBs) promote serious damage for carrier transport in organic molecular solids. In this work, we studied electronic structures of specific examples of stacking-fault (SF) and GB defects in pentacene films by the first-principles calculation. We found that the SF decreases the carrier transfer for hole carriers, while it works as a scattering potential for electron carriers. In the case of the present GB, we showed that the band offset appears at the GB, reflecting the difference in molecular density and configuration across the GB. Moreover, we showed that the present GB works as a sink of impurity atoms and traps carriers.