Electro-photoluminescence in organics

We report a successful observation of the electro-photoluminescence (EL-PL) in thin, exciplex emitting, organic, solid films. The increasing electric field applied to injecting electrodes tends to reduce the total light emission because of the dissociation of emissive exciplex states and their precursors, and, at the same time, the radiative recombination of injected holes and electrons enhances the output of the electroluminescence (EL), the process that suppresses the total luminescence quenching. Increasing bulk concentration of the charge leads the EL output to exceed the PL component, a negative quenching (enhancement of the total emission) is observed.