indicates the stabilized CT states with more dendritic moieties than tBuCz2pTRZ and tBuCz2mTRZ. Nondoped solution-processed OLEDs using a simple device configuration (Figure ) without exciton barrier layers and containing only the dendrimers in the emissive layer exhibited the EQEmax of 18.5%, 19.9% and 28.7% for tBuCz2pTRZ, tBuCz2mTRZ and tBuCz2m2pTRZ, respectively. The performance of the device with tBuCz2m2pTRZ represents a step change in the efficiency of the nondoped solution-processed OLEDs.