Bright organic electroluminescent devices with double-layer cathode

Electroluminescent devices were fabricated using a diamine derivative and tris (8-quinolinolato) aluminum (III) complex as the hole transport layer and the emitting layer, respectively. The glass substrate/anode/hole transport layer/emitting layer/cathode cells structure was employed. The anode was indium-tin-oxide (ITO) transparent electrode, and the cathode was a double layer consisting of first layer of Mg or Li and the second layer of Ag. Intense bright green emission with luminance of 40400 cd/m/sup 2/ was achieved at 18-V with a current density of 330 mA/cm/sup 2/ for the cell with the Al complex doped with 1 mol.% of coumarin 6 and Li/Ag as the cathode.<
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