In the first part of this manuscript, two OLED devices composed of Alq3:DCM–TPA organic material as doped emitting layer, have been simulated. In the first device, the reduced mobility property of this doped layer and in the second device, trapping effects of this dopant are considered. With comparison of the simulation results obtained for these devices, the approximated values of the traps concentration and Gaussian width of traps is obtained. In the second part, the OLED devices with considering of the NPB:Alq3 organic material as mixed host emitting layer have been simulated for obtaining optimal thickness of the emitting layer. In the final part, an OLED device composed of (NPB:Alq3):DCM–TPA organic material as mixed host-doped emitting layer has been simulated for studying the influence of DCM–TPA dopant on the performance of this device.
