Reversible Photoquenching of Luminescence in Conjugated Polymers

Photoluminescence in thin films of poly(p-phenylene vinylene) derivatives is studied using a two-beam excitation technique. It is demonstrated that excited state absorption leads to the reversible quenching of steady state luminescence. Measurements of ultrafast exciton dynamics show that this quenching is due to exciton depletion by photogenerated metastable quenching centers.