Blue and white OLEDs with highly stereoregular polymers

Organic light emitting diodes (OLEDs) are fabricated using two novel polymers, isotactic and syndiotactic poly(N-pentenyl-carbazole) (i-PPK and s-PPK), as emitting layers. The electroluminescence spectra of the devices are analyzed in comparison with the photoluminescence spectra of polymer films and are related to their microstructure properties. Blue light emitting diodes are obtained, except for the i-PPK based multilayer OLED, which emits white light due to three contributions (electroplex fluorescence, excimer phosphorescence and electromer emission). The results show that the polymer tacticity strongly affects the photoconductive properties of the devices.