Ultrafast photoluminescence spectroscopy of exciton-exciton annihilation in oligoaniline films with nanoscale ordering
Résumé
The exciton dynamics and optical characteristics of blue-emitting N,N'-diphenyl-1,4-phenylene-diamine oligoaniline films have been determined. Transient photoluminescence experiments are consistent with internal quantum yields of 5.3% and 10.1% measured for oriented and nonoriented films, respectively. The data indicate a drastic dependence on nanoscale ordering which promotes photoluminescence quenching, a large annihilation rate, and fast exciton diffusion. Therefore, the emission properties can be controlled by the textural morphologies of the layers.