Inverted organic light-emitting diodes with an electrochemically deposited zinc oxide electron injection layer

Electrical and optical properties of poly(dioctylfluorene-alt-benzothiadiazole) based inverted organic light-emitting diodes (iOLEDs) with electrochemically deposited ZnO electron-injecting layer (EIL) have been studied. The device characteristics of the iOLEDs fabricated in this work (8600 cd/m2, 1.5 cd/A at 6.0 V) are almost comparable to those of conventional iOLEDs with sputtered ZnO EIL, indicating that the electron injection properties of electrodeposited ZnO EIL are similar to those of sputtered ZnO EIL. Impedance spectroscopy reveals that the equivalent circuits of iOLEDs with electrochemically deposited ZnO EIL and with sputtered ZnO EIL are indistinguishable.