Stability of 8-hydroxyquinoline aluminum films encapsulated by a single Al2O3 barrier deposited by low temperature atomic layer deposition

100 nm thick 8‐AlQ3 films deposited onto silicon wafers have been encapsulated by mean of low temperature atomic layer deposition of Al2O3 (20 nm). Investigation of the film evolution under storage test as harsh as 65 °C/85% RH has been investigated up to ~ 1000 h and no severe degradation could be noticed. The results have been compared to raw AlQ3 films which deteriorate far faster in the same conditions. For that purpose, fluorescence measurements and atomic force microscopy have been used to monitor the film evolution while transmission electron microscopy has been used to image the interface between AlQ3 and Al2O3. This concept of bilayer AlQ3/Al2O3 barrier films has finally been tested as an encapsulation barrier onto an organic light-emitting diode.

► Thin Al2O3 films have been deposited by atomic layer deposition onto organic films.
► AlQ3/Al2O3-encapsulated organic light-emitting diodes show long-term stability.
► Unencapsulated reference AlQ3 films degrade much faster.