Organic light emitting device
AssigneeCanon Kabushiki Kaisha
InventorSeishi Miura
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Abstract
An organic light emitting device has a light emitting layer and an electron injecting and transporting layer which are sandwiched between a pair of electrodes formed of an anode and a cathode. The electron injection dopant material is doped into an electron transporting material in such a manner that concentration of the dopant becomes low, high, and low in the regions of the electron injecting and transporting layer in the stated order from the light emitting layer side in the film thickness direction. Further, in the region brought into contact with the cathode of the electron injecting and transporting layer, the concentration of the dopant is preferably set high. The organic light emitting device improves drive durability and high light extraction efficiency.
Claims5
An organic light emitting device comprising:
- an anode and a cathode which are opposed to each other;
- a light emitting layer formed between the anode and the cathode;
- an electron injecting and transporting layer formed between the cathode and the light emitting layer and brought into contact with the cathode and the light emitting layer, wherein:
- the electron injecting and transporting layer contains an electron transporting material and cesium carbonate as an electron injection dopant material and has a first region, a second region, and a third region in the stated order from the light emitting layer side which differ from one another in concentration of an electron injection dopant material;
- and
- the concentration of the electron injection dopant material in the second region is higher than the concentrations of the electron injection dopant material in the first region and the third region.
Dependencies are inferred from the claim text.