Light emitting diodes based on pyrazoloquinoline derivatives

Light emitting diodes based on pyrazoloquinoline derivatives were synthesized. Principal role of dye chromophore static dipole moment's values for the light emitting diodes possessing single layered architecture ITO/PVK:pyrazoloquinoline/Ca/Al is explored. It is established that pyrazoloquinoline dye chromophore with lower state dipole moments favor enhanced output electroluminescence. It may be caused by decrease of nonradiative recombination for the dyes with lower dipole moments. Parameters of the observed electroluminescence are compared with the photoluminescence, current-voltage features and parameters of the state, transitions and excited dipole moments of the dye chrmophore. The performed absorption, photoluminescent and carrier kinetics investigations of the chromophore indicate a principal possibility to operate by the carrier kinetics by variation of the value of their state dipole moments without a necessity of variation by energy positions of the HOMO/LUMO levels.