Organic light-emitting device

An organic light-emitting device comprising:

• a first electrode;
• a second electrode facing the first electrode;
• and an organic layer between the first electrode and the second electrode,
• wherein the organic layer comprises an emission layer,
• the emission layer comprises a first compound, a second compound, and a fluorescent dopant,
• the first compound, the second compound, and the fluorescent dopant are different from one another,
• a total weight of the first compound and the second compound is greater than a weight of the fluorescent dopant,
• wherein
• the first compound and the second compound satisfy at least one of Equation 1 to Equation 5, or the first compound, the second compound, and the fluorescent dopant satisfy at least one of Equation 6 to 11:
• |S1(H1)−2×T1(H2)|≤0.15 eV Equation 1
• T1(H1)>T1(H2) Equation 2
• T1(H1)>T2(H2) Equation 3
• |HOMO(H1)|<|HOMO(H2)| Equation 4
• |LUMO(H1)|<|LUMO(H2)| Equation 5
• S1(H2)>S1(FD) Equation 6
• T1(H2)>T1(FD) Equation 7
• |HOMO(H2)|>|HOMO(FD)| Equation 8
• |LUMO(H2)|>|LUMO(FD)| Equation 9
• |HOMO(H1)|>|HOMO(FD)| Equation 10
• |LUMO(H1)|<|LUMO(FD)| Equation 11
• wherein, in Equations 1 to 11,
• S1(H1) represents an S1 singlet energy level (electron volts, eV) of the first compound,
• S1(H2) represents an S1 singlet energy level (eV) of the second compound,
• S1(FD) represents an S1 singlet energy level (eV) of the fluorescent dopant,
• T1(H1) represents a T1 triplet energy level (eV) of the first compound,
• T1(H2) represents a T1 triplet energy level (eV) of the second compound,
• T1(FD) represents a T1 triplet energy level (eV) of the fluorescent dopant,
• T2(H2) represents a T2 triplet energy level (eV) of the second compound, and
• |HOMO(H1)| represents an absolute value of the highest occupied molecular orbital (HOMO) energy level (eV) of the first compound,
• |HOMO(H2)| represents an absolute value of the HOMO energy level (eV) of the second compound,
• |HOMO(FD)| represents an absolute value of the HOMO energy level (eV) of the fluorescent dopant,
• |LUMO(H1)| represents an absolute value of the lowest unoccupied molecular orbital (LUMO) energy level (eV) of the first compound,
• |LUMO(H2)| represents an absolute value of the LUMO energy level (eV) of the second compound,
• |LUMO(FD)| represents an absolute value of the LUMO energy level (eV) of the fluorescent dopant, and
• S1(H1), S1(H2), S1(FD), T1(H1), T1(H2), T1(FD), T2(H2), HOMO(H1), HOMO(H2), HOMO(FD), LUMO(H1), LUMO(H2) and LUMO(FD) are each be obtained using a density functional theory (DFT) that is a quantum chemistry computational method based on the 6-311+G(d,p) basis set, and
• the first compound may be a compound represented by Formula 1:
• wherein, in Formula 1, Ar1 is a group represented by Formula 2A,
• in Formula 1, Ar2 is a group represented by Formula 2B,
• in Formula 2B, ring A1 is a dibenzofuran group or a dibenzothiophene group,
• in Formulae 1, 2A, and 2B, R1 to R3, R11, and R12 are each independently:
• hydrogen, deuterium, a C1-C20 alkyl group, a C1-C20 alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a carbazolyl group, a pyridinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, or a dibenzosilolyl group;
• a C1-C20 alkyl group or a C1-C20 alkoxy group, each substituted with at least one deuterium;
• or
• a phenyl group, a biphenyl group, a terphenyl group, a carbazolyl group, a pyridinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, or a dibenzosilolyl group, each substituted with at least one deuterium, a C1-C20 alkyl group, a C1-C20 alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a carbazolyl group, a pyridinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, or any combination thereof,
• in Formulae 1 and 2A, a1 and a3 are each independently an integer from 0 to 3, when a1 is 2 or greater, at least two R1(s) are identical to or different from each other, and when a3 is 2 or greater, at least two R3(s) are identical to or different from each other,
• in Formulae 1 and 2B, a2 and a12 are each independently an integer from 0 to 4, when a2 is 2 or greater, at least two R2(s) are identical to or different from each other, and when a12 is 2 or greater, at least two R12(s) are identical to or different from each other,
• in Formula 2B, a11 is an integer from 0 to 6, and when a11 is 2 or greater, at least two R11(s) are identical to or different from each other,
• in Formula 2A, R4 is:
• a phenyl group, a biphenyl group, or a terphenyl group;
• a phenyl group, a biphenyl group, or a terphenyl group, each substituted with deuterium, a C1-C20 alkyl group, a C1-C20 alkoxy group, or any combination thereof,
• in Formula 2A, a4 is an integer from 1 to 4, and when a4 is 2 or greater, at least two R4(s) are identical to or different from each other, and
• in Formula 2A, R5 is:
• hydrogen, deuterium, a C1-C20 alkyl group, or a C1-C20 alkoxy group;
• or
• a C1-C20 alkyl group or a C1-C20 alkoxy group, each substituted with at least one deuterium,
• wherein, in Formulae 2A and 2B, * indicates a binding site to an adjacent atom.