Effect of thermal annealing on an emissive layer containing a blend of a small molecule and polymer as host for application in OLEDs.

In order to improve the performance of OLEDs, a host-guest mixture was used as an emissive layer. To have better host properties, a mixture of different materials with suitable properties can also be used as a host. In this study, we used a mixture of a polymer and a small molecule as the host and studied the effect of thermal annealing on the emissive layer properties by using Ir(ppy) as the emitter.