US 11,944,010 B2
Organic electroluminescent device
Hajime Nakanotani, Fukuoka (JP); Chihaya Adachi, Fukuoka (JP); Takahiro Higuchi, Fukuoka (JP); and Taro Furukawa, Fukuoka (JP)
Assigned to KYULUX, INC., Fukuoka (JP)
Filed by KYULUX, INC., Fukuoka (JP)
Filed on Jun. 29, 2022, as Appl. No. 17/809,786.
Application 17/809,786 is a division of application No. 17/071,719, filed on Oct. 15, 2020, granted, now 11,450,817.
Application 17/071,719 is a division of application No. 14/911,761, granted, now 10,862,047, issued on Dec. 8, 2020, previously published as PCT/JP2014/071373, filed on Aug. 13, 2014.
Claims priority of application No. 2013-168587 (JP), filed on Aug. 14, 2013; and application No. 2014-038472 (JP), filed on Feb. 28, 2014.
Prior Publication US 2022/0344598 A1, Oct. 27, 2022
Int. Cl. H10K 85/60 (2023.01); C09K 11/06 (2006.01); H10K 50/11 (2023.01); H10K 50/12 (2023.01); H10K 85/30 (2023.01); H10K 101/10 (2023.01); H10K 101/30 (2023.01)
CPC H10K 85/6572 (2023.02) [C09K 11/06 (2013.01); H10K 50/11 (2023.02); H10K 50/121 (2023.02); H10K 85/622 (2023.02); H10K 85/654 (2023.02); H10K 85/656 (2023.02); H10K 85/657 (2023.02); C09K 2211/1011 (2013.01); C09K 2211/1014 (2013.01); C09K 2211/1033 (2013.01); C09K 2211/1044 (2013.01); C09K 2211/1074 (2013.01); C09K 2211/1077 (2013.01); C09K 2211/186 (2013.01); H10K 85/324 (2023.02); H10K 85/631 (2023.02); H10K 2101/10 (2023.02); H10K 2101/30 (2023.02)] 18 Claims
OG exemplary drawing
 
1. An organic electroluminescent device comprising an anode, a cathode, and at least one organic layer including a light emitting layer between the anode and the cathode,
the light emitting layer containing a first organic compound, a second organic compound, and at least one third organic compound that satisfy the following expression (A), the second organic compound being a delayed fluorescent material consisting of the atoms selected from H, D, C, N, O, and S having an energy difference ΔEST between a lowest singlet excited state and a lowest triplet excited state at 77K of 0.3 eV or less, the third organic compound being a light emitting material, and the third organic compound is excited to the singlet excited state by accepting energy from the second organic compound in the singlet excited state:
ES1(A)>ES1(B)>ES1(C)  (A)
wherein ES1 (A) represents a lowest singlet excitation energy level of the first organic compound; ES1 (B) represents a lowest singlet excitation energy level of the second organic compound; and ES1 (C) represents a lowest singlet excitation energy level of the third organic compound.