Passivation of organic light-emitting diodes with aluminum oxide thin films grown by plasma-enhanced atomic layer deposition

摘要

The passivation of organic light-emitting diodes (OLEDs) with Al_(2)O_(3) films containing small amounts of N (Al_(2)O_(3):N) was investigated by plasma-enhanced atomic layer deposition using a direct rf plasma with a short pulse time. Luminance—voltage and current density—voltage curves of an OLED passivated with a 300 nm Al_(2)O_(3):N film at 60℃ remained unchanged compared to those of nonpassivated OLED and 96% of the initial luminance were maintained even after operating for 850 h at 14 mA/cm~(2). The lifetime of an OLED with an 80℃ Al_(2)O_(3):N film was 650 h, 6.2 times longer than that of a nonpassivated sample, although the luminance—voltage characteristics of the OLED were altered to a considerable extent.