Organic light emitting element and organic light emitting device
View Patent ↗The present invention relates to an organic light emitting element and an organic light emitting device including the same. An impurity layer close to an electrode is doped with a small amount, and an impurity layer for a p-n junction is doped with a large amount, such that a high current may flow under a low voltage.
1. An organic light emitting element, comprising:
a first electrode;
a first impurity layer of a first conductive type contacting the first electrode;
a first light emission layer contacting the first impurity layer;
a second impurity layer of a second conductive type contacting the first light emission layer;
a third impurity layer of the first conductive type directly contacting the second impurity layer;
a second light emission layer contacting the third impurity layer;
a fourth impurity layer of the second conductive type contacting the second light emission layer; and
a second electrode contacting the fourth impurity layer,
wherein an amount of an impurity doped in the second and third impurity layers is larger than an amount of an impurity doped in the first and fourth impurity layers.
2. The organic light emitting element of claim 1 , wherein
the amount of the impurity is determined with reference to a value of a weight percent (wt %).
3. The organic light emitting element of claim 2 , wherein
the first impurity layer and the fourth impurity layer are doped with the impurity at less than 10 wt %, and the second impurity layer and the third impurity layer are doped with the impurity at more than 18 wt %.
4. The organic light emitting element of claim 1 , wherein:
the first light emission layer and the second light emission layer each comprise at least two sub-emission layers that emit light of different colors; and
a combination of the light emitted from the at least two sub-emission layers in the first light emission layer and the second light emission layer is white.
5. The organic light emitting element of claim 1 , wherein
the first light emission layer and the second light emission layer emit light of the same primary color.
6. The organic light emitting element of claim 1 , wherein
the first impurity layer and the third impurity layer are p-type hole injection layers.
7. The organic light emitting element of claim 6 , wherein
the first impurity layer and the third impurity layer are doped by a dopant of one among vanadium pentoxide (V 2 O 5 ), tungsten oxide (WO 3 ), molybdenum oxide (MoO 2 ), and tetrafluoro-tetracyano-p-quinodimethane (F4-TCNQ) to one material of NPB, triphenylamine, and an amine series.
8. The organic light emitting element of claim 1 , wherein
the second impurity layer and the fourth impurity layer are n-type electron injection layers.
9. The organic light emitting element of claim 8 , wherein
the second impurity layer and the fourth impurity layer are doped by a dopant of one of an alkali metal and an alkali earth metal to one of an oxadiazole series and aluminum tris(8-hydroxyquinoline) (Alq3) series.
10. The organic light emitting element of claim 1 , wherein
the first electrode comprises a pixel electrode comprising indium zinc oxide or indium tin oxide, and the second electrode comprises a common electrode comprising aluminum.
11. An organic light emitting element, comprising:
a first electrode;
a second electrode facing the first electrode; and
at least two emission members disposed between the first electrode and the second electrode,
wherein the at least two emission members each comprise a p-type impurity layer, an n-type impurity layer, and an emission layer,
the p-type impurity layer of a first emission member and the n-type impurity layer of a second emission member directly contact each other to form a p-n junction,
the p-type impurity layer of the second emission member and the n-type impurity layer of the first emission member are disposed respectively closest to the first electrode and the second electrode, and
an amount of the impurity in the p-type impurity layer of the first emission member and the n-type impurity layer of the second emission member is larger than an amount of the impurity in the p-type impurity layer of the second emission member and the n-type impurity layer of the first emission member.
12. The organic light emitting element of claim 11 , wherein
the impurity is doped at less than 10 wt % in the p-type impurity layer of the second emission member and the n-type impurity layer of the first emission member, and the impurity is doped at more than 18 wt % in the p-type impurity layer of the first emission member and the n-type impurity layer of the second emission member.