Optoelectronic features of Y-shaped push–pull molecules based on imidazole

The paper involves organic light-emitting diodes fabricated with application of Y-shaped push–pull imidazole derivatives (chromophores) blended with poly(N-vinylcarbazole) as an organic active materials. The absorbance, photoluminescence and electroluminescence spectra of chromophores as well as electroluminescence–voltage, current– voltage and electroluminescence–voltage of the manufactured devices are presented. All investigated imidazole derivatives dissolved in tetrahydrofuran exhibited strong luminescence. The investigated organic light-emitting diodes exhibit red-shift in the main spectral maxima from 520 to 598 nm for photoluminescence and from 535 to 590 nm for electroluminescence depending on the type of imidazole derivative used. The electroluminescence spectra also proved to be very stable over the luminance range from 700 to 1600 cd/m², which is the luminance used for typical lighting applications.