Organic EL element for multi-color emission
AssigneeDenso Corporation
InventorsHarumi Suzuki, Tetsuya Kato
Life of this patent
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Abstract
An organic EL element includes a luminescent layer containing an organic compound and sandwiched between an anode and a cathode. The luminescent layer is composed of a hole-transporting luminescent layer and an electron-transporting luminescent layer. Both luminescent layers emit light simultaneously. Each of the hole-transporting luminescent layer and the electron-transporting luminescent layer includes two or more kinds of fluorescent materials so that the emission spectrum from the hole-transporting luminescent layer 4a substantially confirms the emission spectrum from of the electron-transporting luminescent layer.
Claims13
An organic EL element comprising:
- an anode;
- a cathode;
- and
- an organic luminescent layer located between the anode and the cathode, the organic luminescent layer including:
- a hole-transporting luminescent layer that includes a hole-transporting base material doped with a first fluorescent material, which includes at least two different fluorescent substances, such that the hole-transporting layer emits a spectrum of mixed light, wherein the hole-transporting layer is provided with a supply of holes;
- and
- an electron-transporting luminescent layer that includes an electron-transporting base material doped with a second fluorescent material, which includes at least two different fluorescent substances, such that the electron-transporting material emits a spectrum of mixed light, wherein the electron-transporting layer is provided with a supply of electrons, and wherein the spectrum of the electron-transporting layer is substantially the same as the spectrum of the hole-transporting layer even if the supply of holes and the supply of electrons become unbalanced, such that the EL has substantially constant chromaticity,
- and wherein the hole-transporting luminescent layer directly contacts the electron-transporting luminescent layer, and the fluorescent peak wavelengths of the hole-transporting luminescent layer and the electron-transporting luminescent layer under a solid state are in a range of 380 nm to less than 510 nm.
An organic EL element comprising:
- an anode;
- a cathode;
- a hole-transporting luminescent layer located between the anode and the cathode, wherein the hole-transporting layer is made of a hole-transporting base material doped with a first fluorescent material, which includes at least two different fluorescent substances, such that the hole-transporting layer emits light in a first mixed-color when holes and electrons are supplied by the anode and the cathode;
- and
- an electron-transporting luminescent layer located between the anode and the cathode, wherein the electron-transporting layer is made of an electron-transporting base material doped with a second fluorescent material, which includes at least two different fluorescent substances, such that the electron-transporting material emits light in a second mixed-color when the holes and electrons are supplied, wherein chromaticity coordinates of light emitted from the layers change in accordance with changes in a balance of the supply of holes and electrons, and the variation in either one of an X chromaticity coordinate and a Y chromaticity coordinate is equal to or less than 0.03 despite changes in the balance of the supply of holes and electrons,
- and wherein the hole-transporting luminescent layer directly contacts the electron-transporting luminescent layer, and the fluorescent peak wavelengths of the hole-transporting luminescent layer and the electron-transporting luminescent layer under a solid state are in a range of 380 nm to less than 510 nm.
Dependencies are inferred from the claim text.