Organic electroluminescence cells based on thin films deposited by ultraviolet laser ablation

Organic thin films of copper-phthalocyanine (CuPc) and aluminum tris-8-hydroxyquinline (Alq₃) were fabricated via KrF laser ablation. In spite of poor crystallinity exhibited in the reconstructed organic films, the CuPc film still works as a hole-transport layer in electroluminescence cells based on the CuPc and Alq₃ layers. Electroluminescence at ∼500 nm was obtained with a low initiation voltage of ∼12 V. There is no significant difference in electroluminescence performance for devices fabricated via laser ablation and thermal evaporation. Emission at ∼600 nm caused by energy transfer from Alq₃ to 4-(Dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM) is also observed from a DCM-doped Alq₃ emission layer.