| 초록 |
We report on Ge-doped In2O3 (IGO) films prepared by co-sputtering GeO2 and In2O3 targets for anode of phosphorescent organic light emitting diodes. At optimized annealing condition, the IGO film exhibited a low sheet resistance of 14.0 Ohm/square, a high optical transmittance of 86.9%, and a work function of 5.2 eV, comparable to conventional Sn-doped In2O3 (ITO) films. Due to the higher Lewis acid strength of the Ge4+ ion (3.06) than that of Sn3+(1.62), the IGO film showed higher transparency in the near infra-red and higher carrier mobility of 39.16 cm2/V-s than the ITO films. POLEDs fabricated on IGO anodes showed identical current density-voltage-luminance curves and efficiencies to POLED with ITO electrodes. A bulk heterojunction OPV with the optimized IGO anode exhibited a good cell performance. |
