METAL-INDUCED PHOTOLUMINESCENCE QUENCHING OF A PHENYLENE VINYLENE OLIGOMER AND ITS RECOVERY

Metal/polymer interfaces play an important role in polymeric light emi tting diodes (LEDs). In typical organic light-emitting devices, metall ic electrodes are used to inject charged carriers into the organic ele ctroluminescent (EL) medium. However, what other effects the metals ha ve on the organic medium is not well known. In this work, we report se vere photoluminescence (PL) quenching of organic thin films comprising of one of the most useful materials, namely 1,4-bis[4-(3,5-di-tert-bu tylstyryl)styryl]benzene (4PV), upon sub-monolayer deposition of Al, A g, and Ca in an ultra high vacuum environment. The severity of the lum inescence quenching may greatly affect the EL device performance. Gap states at the Ca/4PV interface are shown to be responsible for the PL quenching. The oxidation of Ca resulted in the removal of the gap stat es and the recovery of the quenched PL.