Single molecule spectroscopic studies of organic rectifiers composed of pyrene and perylenebisimide

► Molecular rectifier properties vary at the single molecule level. ► The presence of pyrene affects perylenebisimide's fluorescence stability. ► Embedding in polymer thin film stabilizes perylenebisimide's fluorescence. ► Unique dipole emission patterns reveal molecular orientation in polymer thin film. ► Pyrene acts as a structure directing group for the orientation of perylene within the polymer thin films.