Fabrication method for organic light emitting device and organic light emitting device fabricated by the same method
The present invention relates to a method for producing an organic light emitting device, comprising a step of sequentially forming on a substrate a first electrode formed of a metal, one or more organic material layers including a light emitting layer, and a second electrode, which comprises a step of forming a layer on the first electrode using a metal having the higher oxidation rate than the first electrode before forming the organic material layer, and to an organic light emitting device produced by the same.
1. A method to reduce or remove a native oxide on a cathode in an organic light emitting device, comprising:
forming on a substrate the cathode, the cathode comprising a first metal and the native oxide layer of the first metal,
forming a layer comprising a second metal directly in contact with the native oxide, by a vacuum thermal evaporation, on the native oxide layer of the first metal and introducing oxygen plasma, such that the second metal and the native oxide layer of the first metal react to form a metal oxide layer of the second metal on the cathode, wherein the second metal has a higher oxidation rate than the first metal, and
forming one or more organic material layers including a light emitting layer, and an anode on the metal oxide layer,
wherein first metal is selected from the group consisting of aluminum, molybdenum, chromium, magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, silver, tin, lead and an alloy thereof;
wherein the second metal is selected from the group consisting of calcium, magnesium, a calcium and silver mixture, a magnesium and silver mixture, and a calcium and magnesium mixture;
wherein the thickness of the metal oxide layer is 1 to 10 nm; and
wherein one of the organic material layers is an electron injecting layer in contact with the metal oxide layer.
2. The method according to claim 1 , wherein the organic light emitting device is of a top emission type or of a dual emission type.
3. The method according to claim 1 , wherein upon forming the layer comprising the second metal, the layer is selectively formed on the cathode by using a shadow mask.