LIGHT-EMITTING ELEMENT, DISPLAY DEVICE, ELECTRONIC APPARATUS, AND LIGHTING DEVICE

• Main Authors: SEO TETSUSHI, HAMADA TAKAO
• Format: Patent
• Language: English; Japanese
• Published: 02.02.2017
• Subjects: ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY

PROBLEM TO BE SOLVED: To provide a light-emitting element having high luminous efficiency.SOLUTION: The light-emitting element includes a first organic compound, a second organic compound, and a guest material. A LUMO level of the first organic compound is lower than a LUMO level of the second organic compound. A HOMO level of the first organic compound is lower than a HOMO level of the second organic compound. A LUMO level of the guest material is lower than the LUMO level of the first organic compound, and a HOMO level of the guest material is lower than the HOMO level of the second organic compound. An energy difference between the LUMO level and the HOMO level of the guest material is larger than an energy difference between the LUMO level of the first organic compound and the HOMO level of the second organic compound. The guest material has a function of converting triplet excitation energy into luminescence. A combination of the first organic compound and the second organic compound forms an exciplex.SELECTED DRAWING: Figure 2 【課題】発光効率の高い発光素子を提供する。【解決手段】第１の有機化合物と、第２の有機化合物と、ゲスト材料と、を有する発光素子である。第１の有機化合物のＬＵＭＯ準位は、第２の有機化合物のＬＵＭＯ準位より低く、第１の有機化合物のＨＯＭＯ準位は、第２の有機化合物のＨＯＭＯ準位より低い。ゲスト材料のＬＵＭＯ準位は、第１の有機化合物のＬＵＭＯ準位より低く、ゲスト材料のＨＯＭＯ準位は、第２の有機化合物のＨＯＭＯ準位より低い。ゲスト材料のＬＵＭＯ準位とＨＯＭＯ準位とのエネルギー差は、第１の有機化合物のＬＵＭＯ準位と、第２の有機化合物のＨＯＭＯ準位と、のエネルギー差より大きい。ゲスト材料は、三重項励起エネルギーを発光に変換することができる機能を有する。第１の有機化合物と、第２の有機化合物と、が励起錯体を形成する組み合わせである。【選択図】図２