Permissions for Reuse

Full figure

Fig. 1. (Color online) Schematic structures of blue PHOLEDs with separately or stepwise doping profile in the EML and proposed energy level scheme for the device under zero applied bias. First citation in article

Full figure

Fig. 2. (Color online) Comparison of uniformly (device A) and separately doped (devices B–D) device performances. (a) Electroluminescence spectra at 10  mA/cm² Inset: EQE vs voltage. (b) Current-voltage-luminescence (I-V-L) characteristics. First citation in article

Full figure

Fig. 3. (Color online) Comparison of uniformly (4%, 7%, and 10 %) and stepwise doped (device E: x=4%, 7%, and 13%) device performances. (a) Current-voltage (I-V) characteristics. Inset: EQE vs voltage. (b) Power efficiency vs luminance. First citation in article