EP0498979A1
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EP
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Organic electroluminescent device
Assignee: Toshiba Corp
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Filing: 1991-02-13
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Granted: —
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Expires: 2011-02-13
Abstract
Abstract An organic electroluminescent device is constituted by first and second electrodes (6, 2) opposing each other and a multilayered body having a plurality of organic films (5, 4, 3) sandwiched between the electrodes and including an electroluminescent layer. A donor impurity is doped in a first organic film in contact with the first electrode (6), and an acceptor impurity is doped in a second organic film (3) in contact with the second electrode (2). A third organic film (4) sandwiched between the first and second organic films (5, 3) serves as an electroluminescent layer. A material having a band gap narrower than those of the first and second organic films (5, 3) is selected as a material of the third organic film (4) so as to confine carriers. No impurity is doped in the third organic film (4).
Inventors
- 👤 Syun C/O Intellectual Property Division Egusa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 06:01
CPC Classifications
H; H05; H05B; H05B33/00; H05B33/12; H05B33/14; H10; H10K; H10K50/00; H10K50/10; H10K50/11; H10K50/14; H10K50/15; H10K50/155; H10K50/16; H10K50/165; H10K71/00; H10K71/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
122 words
An organic electroluminescent device comprising first and second electrodes (6, 2) opposing each other and a multilayered body constituted by a plurality of organic films sandwiched between said first and second electrodes (6, 2), characterized in that said multilayered body includes: a first organic film (5) formed in contact with said first electrode (6) and doped with a donor impurity; a second organic film (3) formed in contact with said second electrode (2) and doped with an acceptor impurity; and a third organic film (4) sandwiched between said first and second organic films (5, 3), serving as an electroluminescent layer, having a band gap narrower than those of said first and second organic films (5, 3), and not doped with an impurity.
Claim 2
Dependent Claim
206 words
An organic electroluminescent device according to claim 1, characterized in that assuming that a work function of said first electrode (6) is E M1 , a work function of said second electrode (2) is E M2 , energy differences of a lower end of a conduction band, a Fermi level, and an upper end of a valence band of said first organic film (5) from a vacuum level are E C1 , E₁, E V1 , respectively, energy differences of a lower end of a conduction band, a Fermi level, and an upper end of a valence band of said second organic film (3) from a vacuum level are E C2 , E₂, and E V2 , respectively, and energy differences of a lower end of a conduction band, a Fermi level, and an upper end of a valence band of said third organic film (4) from a vacuum level are E C3 , E₃, E V3 , respectively, E M1 < E₁, E M1 - E C1 < 0.5 eV E₂ < E M2 , E V2 - E M2 < 0.5 eV E C1 > E C2 E V1 > E C2 E C3 > E C2 E V1 > E V3 are satisfied.
Claim 3
Dependent Claim
40 words
An organic electroluminescent device according to claim 2, characterized in that said first, second, and third organic films (5, 3, 4) satisfy relations of: E C3 > E C1 > E C2 E V1 > E V2 > E V3
Claim 4
Dependent Claim
45 words
An organic electroluminescent device according to claim 2, characterized in that said first, second, and third organic films (5, 3, 4) satisfy relations of: E V2 ≃ E V3 E C1 > E C3 E C1 - E C3 < E V1 - E V3
Claim 5
Dependent Claim
45 words
An organic electroluminescent device according to claim 2, characterized in that said first, second, and third organic films (5, 3, 4) satisfy relations of: E C1 ≃ E C3 E V2 < E V3 E C3 - E C2 > E V3 - E V2
Claim 6
Dependent Claim
52 words
An organic electroluminescent device according to claim 2, characterized in that an impurity to be doped in said first organic film (5) is an inorganic or organic material which satisfies a relation of: I P - E C1 < eV assuming that an ionization energy of said impurity is I P .
Claim 7
Dependent Claim
52 words
An organic electroluminescent device according to claim 2, characterized in that an impurity to be doped in said second organic film (3) is an inorganic or organic material which satisfies a relation of: E V2 - E A < 1eV assuming that an electron affinity of said impurity is E A .
Claim 8
Dependent Claim
92 words
An organic electroluminescent device comprising first and second electrodes (15, 12) opposing each other and a multilayered body constituted by a plurality of organic films sandwiched between said electrodes, characterized in that said multilayered body includes a first organic film (14) formed in contact with said first electrode (15), not doped with an impurity, and serving as an electroluminescent layer, and a second organic film (13) formed in contact with said second electrode (12), forming a blocking contact with respect to said first organic film (14), and doped with an acceptor impurity.
Claim 9
Dependent Claim
78 words
An organic electroluminescent device according to claim 8, characterized in that an impurity to be doped in said second organic film (13) is an inorganic or organic material which satisfies a relation of: E V2 - E A < 1 eV assuming that an electron affinity of said impurity is E A and an energy difference of an upper end of a valence band of said second organic film (13) from a vacuum level is E V2 .
Claim 10
Dependent Claim
92 words
An organic electroluminescent device comprising first and second electrodes (15, 12) opposing each other and a multilayered body constituted by a plurality of organic films sandwiched between said electrodes, characterized in that said multilayered body includes a first organic film (14) formed in contact with said first electrode (15) and doped with a donor impurity, and a second organic film (13) formed in contact with said second electrode (12), forming a blocking contact with respect to said first organic film (14), not doped with an impurity, and serving as an electroluminescent layer.
Claim 11
Dependent Claim
77 words
An organic electroluminescent device according to claim 10, characterized in that an impurity to be doped in said first organic film (14) is an inorganic or organic material which satisfies a relation of: I P - E C1 < 1eV assuming that an ionization energy of said impurity is I P and an energy difference of a lower end of a conduction band of said first organic film (14) from a vacuum level is E C1 .
References Cited (Backward Citations)
EP0120673A2
Cited
EP0390551A2
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