Organic electroluminescent device and a display device comprising the organic electroluminescent device

An organic electroluminescent device comprising an anode layer, a cathode layer, a first emission layer, a second emission layer, a hole injection layer, an electron injection layer, a first electron transport layer, and a first charge generation layer,

• wherein
• the first charge generation layer is arranged between the first emission layer and the second emission layer,
• the electron injection layer is arranged adjacent to the cathode layer;
• the first charge generation layer comprises a first n-type charge generation layer and a first p-type charge generation layer,
• the first n-type charge generation layer is arranged closer to the anode layer than the first p-type charge generation layer,
• the first electron transport layer is arranged between the first emission layer and the first charge generation layer,
• the first electron transport layer is arranged in direct contact with the first n-type charge generation layer,
• wherein
• the hole injection layer comprises a first organic p-dopant and first hole transport matrix compound,
• wherein the first organic p-dopant comprises at least three CN groups, and wherein the first organic p-dopant has a molecular weight of ≥400 g/mol, and wherein the first organic p-dopant has a LUMO energy level of less than −5.10 eV;
• the first electron transport layer comprises an electron transport compound comprising a six-member heteroaromatic ring comprising at least two nitrogen ring atoms and wherein the first electron transport layer is:
• essentially free of a compound selected from the group comprising a 8-hydroxyquinolinolato-lithium complex;
• or
• comprises ≥0 wt.-% to ≤1 wt.-% of a compound selected from the group comprising a 8-hydroxyquinolinolato-lithium complex,
• wherein the wt.-% of the components is based on the total weight of the first electron transport layer;
• the first n-type charge generation layer comprises an electron transport matrix compound comprising a heteroaromatic ring comprising at least one nitrogen ring atom, and a metal dopant;
• the first p-type charge generation layer comprises a second organic p-dopant and a second hole transport matrix compound;
• wherein the second organic p-dopant comprises at least four CN groups, and wherein the second organic p-dopant has a molecular weight of ≥400 g/mol and a LUMO energy level of less than −4.80 eV;
• wherein the first hole transport matrix compound and the second hole transport matrix compound are selected the same or different from the group comprising an arylamine compound, diarylamine compound, triarylamine compound, a compound of formula (Ia) or a compound of formula (Ib):
• wherein:
• T1, T2, T3, T4 and T5 are independently selected from a single bond, phenylene, biphenylene, terphenylene or naphthenylene;
• T6 is phenylene, biphenylene, terphenylene or naphthenylene;
• Ar1, Ar2, Ar3, Ar4 and Ar5 are independently selected from substituted or unsubstituted C6 to C20 aryl, or substituted or unsubstituted C3 to C20 heteroarylene, substituted or unsubstituted biphenylene, substituted or unsubstituted fluorene, substituted 9-fluorene, substituted 9,9-fluorene, substituted or unsubstituted naphthalene, substituted or unsubstituted anthracene, substituted or unsubstituted phenanthrene, substituted or unsubstituted pyrene, substituted or unsubstituted perylene, substituted or unsubstituted triphenylene, substituted or unsubstituted tetracene, substituted or unsubstituted tetraphene, substituted or unsubstituted dibenzofurane, substituted or unsubstituted dibenzothiophene, substituted or unsubstituted xanthene, substituted or unsubstituted carbazole, substituted 9-phenylcarbazole, substituted or unsubstituted azepine, substituted or unsubstituted dibenzo[b,f]azepine, substituted or unsubstituted 9,9′-spirobi[fluorene], substituted or unsubstituted spiro[fluorene-9,9′-xanthene], or a substituted or unsubstituted aromatic fused ring system comprising at least three substituted or unsubstituted aromatic rings selected from the group comprising substituted or unsubstituted non-hetero, substituted or unsubstituted hetero 5-member rings, substituted or unsubstituted 6-member rings and/or substituted or unsubstituted 7-member rings, substituted or unsubstituted fluorene, or a fused ring system comprising 2 to 6 substituted or unsubstituted 5- to 7-member rings and the rings are selected from the group comprising (i) unsaturated 5- to 7-member ring of a heterocycle, (ii) 5- to 6-member of an aromatic heterocycle, (iii) unsaturated 5- to 7-member ring of a non-heterocycle, (iv) 6-member ring of an aromatic non-heterocycle;
• wherein the substituents of Ar1, Ar2, Ar3, Ar4 and Ar5 are selected the same or different from the group comprising H, D, F, C(═O)R′1, CN, Si(R′1)3, P(═O)(R′1)2, OR′1, S(═O)R′1, S(═O)2R′1, substituted or unsubstituted straight-chain alkyl having 1 to 20 carbon atoms, substituted or unsubstituted branched alkyl having 1 to 20 carbon atoms, substituted or unsubstituted cyclic alkyl having 3 to 20 carbon atoms, substituted or unsubstituted alkenyl or alkynyl groups having 2 to 20 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 20 carbon atoms, substituted or unsubstituted aromatic ring systems having 6 to 40 aromatic ring atoms, and substituted or unsubstituted heteroaromatic ring systems having 5 to 40 aromatic ring atoms, unsubstituted C6 to C18 aryl, unsubstituted C3 to C18 heteroaryl, a fused ring system comprising 2 to 6 unsubstituted 5- to 7-member rings and the rings are selected from the group comprising unsaturated 5- to 7-member ring of a heterocycle, 5- to 6-member of an aromatic heterocycle, unsaturated 5- to 7-member ring of a non-heterocycle, and 6-member ring of an aromatic non-heterocycle,
• wherein R′1 is selected from H, D, straight-chain alkyl having 1 to 6 carbon atoms, branched alkyl having 1 to 6 carbon atoms, cyclic alkyl having 3 to 6 carbon atoms, alkenyl or alkynyl groups having 2 to 6 carbon atoms, C6 to C18 aryl or C3 to C18 heteroaryl;
• wherein
• the LUMO energy level of the first organic p-dopant is further away from vacuum level than the LUMO energy level of the second organic p-dopant;
• and
• wherein
• the electron injection layer comprises Ytterbium.