A clear complementary relationship between photoluminescent (PL) and electroluminescent (EL) images was observed for organic light-emitting diodes (OLEDs) based on poly(phenylenevinylene) (PPV) and dye-doped PPV So-called 'black spots' (dark circular regions observed on the active area of running OLEDs) become bright ones, when the photoluminescence of the same area is excited. A very small thickness of the active layer (ca. 10 nm) was the crucial point to observe this anticorrelation between EL and PL. A substantial increase of the PL yield ('anti-burning' effect) was observed after strong light exposure (ca. 10 mJ/cm(2)) of the polymer covered by an aluminium layer. The same light exposure without aluminium protection resulted in complete photobleaching of the polymer. The presence of a thin insulating layer between the polymer and aluminium was proposed to be responsible for these effects. This layer prevents electron injection and PL quenching due to exciton dissociation at the metal-polymer interface. The former effect leads to black spots in the EL image, the latter one gives rise to bright spots on the PL image situated on the same places. The intermediate layer can be also induced by light exposure. A very efficient energy transfer from the polymer to the dye and to the J-aggregates of the dye was demonstrated in PPV/dye composite films.