Light-Emitting Element, Light-Emitting Device, Electronic Appliance, and Lighting Device

    公开(公告)号:US20240023423A1

    公开(公告)日:2024-01-18

    申请号:US18216285

    申请日:2023-06-29

    CPC classification number: H10K85/342 H10K50/11 H10K50/13 H10K50/16 H10K85/622

    Abstract: A light-emitting element which includes a plurality of light-emitting layers between a pair of electrodes and has low driving voltage and high emission efficiency is provided. A light-emitting element including first to third light-emitting layers between a cathode and an anode is provided. The first light-emitting layer includes a first phosphorescent material and a first electron-transport material; the second light-emitting layer includes a second phosphorescent material and a second electron-transport material; the third light-emitting layer includes a fluorescent material and a third electron-transport material; the first to third light-emitting elements are provided in contact with an electron-transport layer positioned on a cathode side; and a triplet excitation energy level of a material included in the electron-transport layer is lower than triplet excitation energy levels of the first electron-transport material and the second electron-transport material.

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