Suppressing degradation of ITO electrode for electroluminescence device by transparent MoO3 barrier layer

The degradation of Indium tin oxide (ITO), a widely used electrode in optoelectronic devices, reduces the reliability of devices and even results in the irreversible failure of devices. Herein, irreversible failure of Er-doped npn light-emitting devices is observed below the breakdown field strength, which originates from the migration of metal ions from the ITO electrode under high electric fields. By inserting a MoO 3 barrier into Er-doped npn devices, the migration of metal ions from the ITO electrode is effectively suppressed to prevent contamination of the luminescent layer, thereby improving the operational stability and doubling the optical power density. The blocking effect of the MoO 3 layer on the electromigration of metal ions comes from the elimination of grain boundaries as fast diffusion paths, as well as the spontaneous interface reaction between the MoO 3 layer and ITO electrode to form an interface with residual positive charges, which generates Coulombic repulsion on metal ions.