ORGANIC EL ELEMENT AND ORGANIC EL DISPLAY DEVICE HAVING THE ORGANIC EL ELEMENT

• Main Authors: NOGUCHI SATOSHI, TAKAHASHI HISAMITSU
• Format: Patent
• Language: English; Japanese
• Published: 16.08.2023
• Subjects: ADVERTISING; CRYPTOGRAPHY; DISPLAY; DISPLAYING; EDUCATION; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; LABELS OR NAME-PLATES; PHYSICS; SEALS; SIGNS

To provide an organic EL element which can improve the light-emitting efficiency and an organic EL display device having the organic EL element.SOLUTION: An organic EL element includes: a first electrode; an organic light-emitting layer located on the first electrode; and a second electrode located on the organic light-emitting layer. The organic light-emitting layer comprises: a fluorescence dopant; a first host indicating the hole transport property; a second host indicating the electron transport property; and a third host. The triplet excitation energy level T1 of the third host is lower than the triplet excitation energy level TD1 of the fluorescence dopant, the triplet excitation energy level TH1 of the first host and the triplet excitation energy level TH2 of the second host. The deactivation rate of the triplet exciton in the third host is faster than the deactivation rate of the triplet exciton in the fluorescence dopant.SELECTED DRAWING: Figure 2 【課題】発光効率を向上可能な有機ＥＬ素子及び当該有機ＥＬ素子を備える有機ＥＬ表示装置を提供する。【解決手段】有機ＥＬ素子は、第１電極と、第１電極上に位置する有機発光層と、有機発光層上に位置する第２電極と、を備える。有機発光層は、蛍光ドーパントと、ホール輸送性を示す第１ホストと、電子輸送性を示す第２ホストと、第３ホストとを含み、第３ホストの三重項励起エネルギー準位Ｔ１は、蛍光ドーパントの三重項励起エネルギー準位ＴＤ１、第１ホストの三重項励起エネルギー準位ＴＨ１、及び第２ホストの三重項励起エネルギー準位ＴＨ２よりも低く、第３ホストにおける三重項励起子の失活速度は、蛍光ドーパントにおける三重項励起子の失活速度よりも速い。【選択図】図２