Organic light-emitting device and apparatus including the same

An organic light-emitting device comprising:

• a first electrode;
• a second electrode;
• and
• an organic layer disposed between the first electrode and the second electrode, the organic layer comprising a first emission layer, a second emission layer disposed between the first emission layer and the second electrode, and at least one auxiliary layer, wherein the at least one auxiliary layer comprises an optional first auxiliary layer having a first host disposed between the first electrode and the first emission layer and directly contacting the first emission layer, a second auxiliary layer having a second host disposed between the second emission layer and the second electrode and directly contacting the second emission layer, and a third auxiliary layer comprising either a first host or a second host disposed between the first emission layer and the second emission layer;
• wherein the organic layer further comprises a hole transport region disposed between the first electrode and the first emission layer or the first auxiliary layer and directly contacting the first electrode, and an electron transport region disposed between the second emission layer or the second auxiliary layer and the second electrode and directly contacting the second electrode,
• wherein the hole transport region comprises a hole transport layer and the electron transport region comprises an electron transport layer and an electron injection layer,
• wherein the electron transport layer comprises a first electron transport layer and a second electron transport layer,
• the first emission layer comprises a first host, a second host, and a first dopant and emits blue light;
• and
• the second emission layer comprises a first host, a second host, and a second dopant and emits blue light;
• wherein:
• the first hosts included in the first emission layer, the second emission layer, and the at least one auxiliary layer comprise a compound of Formula 1-1 and are identical to or different from each other,
• when the third auxiliary layer comprises a first host, a first host included in the third auxiliary layer and a first host included in the first emission layer are identical to or different from each other, and a first host included in the third auxiliary layer and a first host included in the second emission layer are identical to or different from each other;
• and
• when the third auxiliary layer comprises a second host, a second host included in the third auxiliary layer and a second host included in the first emission layer are identical to or different from each other, and a second host included in the third auxiliary layer and a second host included in the second emission layer are identical to or different from each other:
• wherein, in Formula 1-1,
• A11 and A12 are each, independently from one another, benzene, naphthalene, anthracene, phenanthrene, fluoranthene, triphenylene, pyrene, chrysene, indene, fluorene, spiro-bifluorene, benzofluorene, dibenzofluorene, carbazole, benzocarbazole, dibenzocarbazole, dibenzofuran, or a dibenzothiophene;
• R11 and R12 are each, independently from one another, hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C1-C60 alkyl group, a C2-C60 alkenyl group, a C2-C60 alkynyl group, a C1-C60 alkoxy group, a C3-C10 cycloalkyl group, a C1-C10 heterocycloalkyl group, a C3-C10 cycloalkenyl group, a C1-C10 heterocycloalkenyl group, —Si(Q1)(Q2)(Q3), —N(Q1)(Q2), or —B(Q1)(Q2);
• c11 to c12 are each, independently from one another, an integer from 1 to 8;
• L11 is a single bond or a r electron-deficient nitrogen-free cyclic group;
• a π electron-deficient nitrogen-free cyclic group substituted with at least one, independently from one another, deuterium, a cyano group, a C1-C60 alkyl group, a C1-C60 alkoxy group, and a π electron-deficient nitrogen-free cyclic group;
• a11 is an integer from 1 to 3;
• Ar11 is:
• a π electron-deficient nitrogen-free cyclic group;
• a π electron-deficient nitrogen-free cyclic group substituted with at least one of deuterium, a cyano group, a C1-C60 alkyl group, a C1-C60 alkoxy group, and a π electron-deficient nitrogen-free cyclic group;
• or
• —Si(Q1)(Q2)(Q3) or —N(Q1)(Q2);
• and
• b11 is an integer from 1 to 5;
• wherein Q1 to Q3 are each, independently from one another, hydrogen, deuterium, a C1-C60 alkyl group, a C2-C60 alkenyl group, a C2-C60 alkynyl group, a C1-C60 alkoxy group, a r electron-deficient nitrogen-free cyclic group, a biphenyl group, or a terphenyl group, and
• the second hosts included in the first emission layer, the second emission layer and the at least one auxiliary layer comprise at least one of an electron transport host and a bipolar host and are identical to or different from each other;
• the first dopant and the second dopant, each comprise, independently from one another, at least one of a phosphorescent organometallic compound and a thermally activated delayed fluorescence (“TADF”) compound satisfying Equation 1 below, and the first dopant and the second dopant are different from each other:
• ΔEST=S1−T1≤0.3 eV <Equation 1>
• wherein, in Equation 1, S1 is a lowest excitation singlet energy level (eV) of the TADF compound, and T1 is a lowest excitation triplet energy level (eV) of the TADF compound.