Coulomb effect induced intrinsic degradation in OLED

Abstract Intrinsic degradation in 100 nm AlQ 3 OLED device with strong luminescence was observed while nearly no degradation in 50 nm AlQ 3 device with weak luminescence was observed for the same operation time. Based on the EL and PL measurements, it was suggested that penetration of AlQ 3 molecules into NPB layer resulted in the increase of electron leakage current, and thus significant loss of current efficiency. A plausible Coulomb effect induced intrinsic degradation mechanism was therefore proposed to explain the experimental results.