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US 2025/0040336 A1Published application
Light-Emitting Device, Light-Emitting Apparatus, Electronic Device, and Lighting Device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorSatoshi SEO
Life of this patent
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Abstract
To provide a light-emitting device not only including a light-emitting layer in which energy is efficiently transferred from a host material to a guest material but also having high reliability. The light-emitting device not only includes a light-emitting layer in which the T1 levels and the S1 levels of a host material and a guest material fall within certain ranges so that energy can be efficiently transferred from the host material to the guest material and but also has improved reliability.
Claims18
A light-emitting device comprising:
- a light-emitting layer between a pair of electrodes,
- wherein the light-emitting layer comprises a first organic compound, a second organic compound, and a phosphorescent substance,
- wherein a T1 level (TD(edge)) and a T1 level (TH(edge)) satisfy Formula (1):
- 0.07
- eV
- ≤
- T
- H
-
- (
- edge
- )
- -
- T
- D
-
- (
- edge
- )
- ≤
- 0.27
- eV
- ,
- (
- 1
- )
- wherein a difference between an S1 level (S′H(edge)) and the T1 level (TH(edge)) satisfies Formula (2):
- 0.2
- eV
- ≤
- S
- H
-
- (
- edge
- )
- ′
- -
- T
- H
-
- (
- edge
- )
- ≤
- 0.408
- eV
- ,
- (
- 2
- )
- wherein the T1 level (TH(edge)) represents the lower of T1 levels derived from emission edges on a short wavelength side of phosphorescent spectra of the first organic compound and the second organic compound,
- wherein the T1 level (TD(edge)) represents a T1 level derived from an absorption edge of an absorption spectrum of the phosphorescent substance, and
- wherein the S1 level (S′H(edge)) represents an S1 level derived from an emission edge on a short wavelength side of a fluorescent spectrum of a mixed material of the first organic compound and the second organic compound.
51 more elements
A light-emitting device comprising:
- a light-emitting layer between a pair of electrodes,
- wherein the light-emitting layer comprises a first organic compound, a second organic compound, and a phosphorescent substance,
- wherein a T1 level (TD(edge)) and a T1 level (TH(edge)) satisfy Formula (1):
- 0.07
- eV
- ≤
- T
- H
-
- (
- edge
- )
- -
- T
- D
-
- (
- edge
- )
- ≤
- 0.17
- eV
- ,
- (
- 1
- )
- wherein a difference between an S1 level (S′H(edge)) and the T1 level (TH(edge)) satisfies Formula (2):
- 0.2
- eV
- ≤
- S
- H
-
- (
- edge
- )
- ′
- -
- T
- H
-
- (
- edge
- )
- ≤
- 0.408
- eV
- ,
- (
- 2
- )
- wherein the T1 level (TH(edge)) represents the lower of T1 levels derived from emission edges on a short wavelength side of phosphorescent spectra of the first organic compound and the second organic compound,
- wherein the T1 level (TD(edge)) represents a T1 level derived from an absorption edge of an absorption spectrum of the phosphorescent substance, and
- wherein the S1 level (S′H(edge)) represents an S1 level derived from an emission edge on a short wavelength side of a fluorescent spectrum of a mixed material of the first organic compound and the second organic compound.
51 more elements
Dependencies are inferred from the claim text.