Longevity of plastic-based organic light-emitting devices by means of protective oils as passivation layer

For the encapsulation of plastic-based organic light-emitting devices (OLEDs), an inert oil as a liquid passivation layer is applied on the periphery of the device. The electroluminescence (EL) and rate of degradation of such devices are examined to compare the electrical and emissive properties of the devices before and after forming the inert liquid passivation layer. The presence of the liquid layer firmly prevents the occurrence and growth of dark spots and enhances the lifetime of the devices in air. Driven at 27.45 mA/cm2 (Lo~1780 cd/m2), a driving lifetime of 195.0 h is achieved, which is affected by the type of inert oil used.