Spectral Features and Parameters of Some 1H-Pyrazolo[3,4-b]quinoxaline Derivative Dye Chromophores

ABSTRACT The role of ground state dipole moments of a dye chromophore on the principal features of the light-emitting diodes in the single-layered architecture ITO/PEDOT:PSS/pyrazoloquinoxaline (PQX):PVK/Ca/Al is explored for the first time. The ground state dipole moments of a chromophore determine excitonic carrier kinetics and their annihilation. It was established that the pyrazoloquinoxaline dye chromophores possessing lower dipole moments substantially favor larger electroluminescent efficiency. Parameters of the electroluminescence and current–voltage features are compared with the photoluminescence and absorption characteristics. The UV-Vis spectral absorption, photoluminescence, and current–voltage dependencies indicate a principal possibility to operate by charge kinetics at the almost fixed values of the Highest Occupied Molecular (HOMO) energy levels with respect to the basic ITO hole injector electrodes. Also, a separate role may be played by polaronic effects. We have shown a principal possi...