Poly(N-vinylcarbazole) doped with a pyrazoloquinoline dye:: A deep blue light-emitting composite for light-emitting diode applications -: art. no. 024505

We investigated the spectral properties of light-emitting diodes based on a deep blue-emitting pyrazoloquinoline dye doped into a poly(N-vinylcarbazole)-based matrix. Even though the electroluminescence (EL) of the host is redshifted and broadened with respect to the emission of the dye, the EL spectrum becomes fully dominated by the dye emission at concentrations of ca. 2 wt %. This is attributed to a competition of exciplex formation on the matrix and exciton formation on the dye. (c) 2006 American Institute of Physics.