The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 17, 2025
Filed:
Mar. 08, 2024
Semiconductor Energy Laboratory Co., Ltd., Kanagawa-ken, JP;
Abstract
A light-emitting device with high emission efficiency and reliability is provided. The light-emitting device includes a fluorescent light-emitting layer and a phosphorescent light-emitting layer. A host material used in the fluorescent light-emitting layer has a function of converting triplet excitation energy into light emission and a guest material used in the fluorescent light-emitting layer emits fluorescence. The guest material has a molecular structure including a luminophore and a protecting group, and one molecule of the guest material includes five or more protecting groups. The introduction of the protecting groups into the molecule inhibits transfer of triplet excitation energy from the host material to the guest material by the Dexter mechanism. An alkyl group or a branched-chain alkyl group is used as the protecting group. The longest wavelength absorption band in the absorption spectrum of the guest material in the phosphorescent light-emitting layer has an overlap with the emission spectrum of the host material in the phosphorescent light-emitting layer.