Green light-emitting organic electroluminescence device

Abstract

To provide an organic electroluminescent device that emits green light with a narrow half-width and CIEx and CIEy color coordinates that are close to the specifications defined by DCPI3 and BT2020.SOLUTION: In an organic electroluminescence element, an emitting layer has a host material, a phosphorescent material, and an emitter, and the lowest excited singlet energy level S1 and the lowest excited triplet energy level T1 of each material satisfy a predetermined relationship.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an organic electroluminescent device comprising an emitting layer B comprising a host material, a phosphorescent material and an emitter material, which exhibits a narrow (represented by a small full width at half maximum (FWHM)) green emission at an emission maximum between 500 and 560 nm. The present invention also relates to a method for producing green light by the organic electroluminescent device according to the present invention. [Background technology]

[0002] Organic electroluminescent devices, including one or more organic-based light-emitting layers, such as organic light-emitting diodes (OLEDs), light-emitting electrochemical cells (LECs) and light-emitting transistors, are becoming increasingly important. In particular, OLEDs are promising elements for electronic products such as screens, displays and lighting devices. In contrast to most electroluminescent devices that are essentially based on inorganic materials, organic electroluminescent devices based on organic materials can usually be produced in flexible and particularly thin layers. OLED-based screens and displays already available today have excellent efficiency and long life, or excellent color purity and long life, but do not have all three properties of excellent efficiency, long life and excellent color purity.

[0003] The color purity or color point of an OLED is generally given by CIEx and CIEy coordinates, while the color gamut for next generation displays is given by so-called BT-2020 and DCPI3 values. In general, to obtain such color coordinates, it is necessary to modify the cavity and adjust the color coordinates. To target such color gamut while achieving high efficiency in the top light-emitting element, a narrow emission spectrum is required in the bottom light-emitting element.

[0004] State-of-the-art phosphorescent emitters exhibit relatively broad emission, which is reflected in the broad emission of phosphorescent-based OLEDs (PHOLEDs) with emission spectral full width at half maximum (FWHM) of greater than 0.25 eV. The broad emission spectrum of PHOLEDs in the bottom emitter leads to high losses of outcoupling efficiency for top emitter structures while targeting the BT-2020 and DCPI tri-color regions. Summary of the Invention [Problem to be solved by the invention]

[0005] Recently, some fluorescent emitters, or thermally activated-delayed-fluorescence (TAF), which exhibit somewhat narrower emission spectra, have been developed. TADF (Transparent Electron Doped Fluorescence) emitters have been developed, which exhibit an emission spectrum FWHM of 0.25 eV or less and are therefore more suitable for achieving the BT-2020 and DCPI tri-color ranges. However, such fluorescent and TADF emitters generally exhibit low efficiency due to low lifetimes due to exciton-polaron or exciton-exciton annihilation, as well as decreasing efficiency at higher luminances (i.e., OLED roll-off behavior). [Means for solving the problem]

[0006] Surprisingly, it has been found that the light-emitting layer of the organic electroluminescent device, which comprises a host material, a phosphorescent material and an emitter material, emits green light with a small full width at half maximum (FWHM), and the organic electroluminescent device has excellent lifetime and quantum efficiency and emits green light. The primary emission of an organic electroluminescent device originates from the small FWHM emitter material. Effect of the Invention

[0007] Such organic electroluminescent devices produce green emission with small FWHM and CIEx and CIEy color coordinates close to the specifications defined by DCPI3 and BT2020. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Therefore, according to one aspect of the present invention, there is provided an organic electroluminescent device comprising a light-emitting layer B, (i) The lowest excited singlet state energy level S1 P and the lowest excited triplet state energy level T1 P and has energy E HOMO (H P ) with the highest occupied molecular orbital HOMO (H P ), and energy E LUMO (H P ) with the lowest unoccupied orbital LUMO(H P ) a host material H P and, (ii) The lowest excited singlet state energy level S1 E and the lowest excited triplet state energy level T1 E and has energy E HOMO (E E ) with the highest occupied molecular orbital HOMO (E E ), and energy E LUMO (E E ) with the lowest unoccupied orbital LUMO (E E ) Phosphorescent material E B and, (iii) The lowest excited singlet state energy level S1 S and the lowest excited triplet state energy level T1 S and has energy E HOMO (E S ) with the highest occupied molecular orbital HOMO (E S ), and energy E LUMO (E S ) with the lowest unoccupied orbital LUMO (E S ) with a small full width at half maximum (FWHM) emitter S B and The phosphorescent material E BThe smaller the half-width emitter energy, the smaller the half-width S B and the small half-width emitter S B emits light having a maximum emission of 500 nm to 560 nm, There is provided an organic electroluminescence element to which the relationships represented by the following formulas (1) to (4) are applied: T1 E >S1 S Formula (1) T1 P >T1 S Formula (2) T1 P >T1 E Formula (3) T1 P >S1 E Equation (4).

[0009] According to one embodiment, the phosphorescent material E B The lowest excited triplet state energy of the small half-width emitter S B The lowest excited singlet state energy of the host material H P The lowest excited triplet state energy of the small half-width emitter S B The lowest excited triplet state energy of the host material H P The lowest excited triplet state energy of the phosphorescent material E B The lowest excited triplet state energy of the host material H P The lowest excited triplet state energy of the phosphorescent material E B It can also be higher than the lowest excited singlet state energy of In one embodiment, a small FWHM emitter S B can have an emission spectrum exhibiting a full width at half maximum (FWHM) of approximately 0.25 eV (ie, ≦0.25 eV) or less.

[0010] In one embodiment, an emission spectrum having a full width at half maximum (FWHM) of approximately 0.25 eV or less is observable for fluorescent emitters and thermally activated delayed fluorescent emitters. In one embodiment, an emission spectrum having a full width at half maximum (FWHM) of approximately 0.25 eV or less is not observed for phosphorescent emitters. In one embodiment, the small FWHM emitter S B is phosphorescent material E B The emission spectrum may have a full width at half maximum (FWHM) smaller than the FWHM of the emission spectrum of B ) <FWHM(E B ).

[0011] In one embodiment, the organic electroluminescence element has a wavelength of 500 nm to 560 nm. Maximum emission λ max (D) can be represented.

[0012] In one embodiment, the organic electroluminescent device has a maximum emission λ of 510 nm to 550 nm. max (D) can be represented.

[0013] In one embodiment, a small FWHM emitter S B can emit light having a maximum emission of 510 nm to 550 nm.

[0014] In one embodiment, the light-emitting layer B of the organic electroluminescent device has a lowest excited singlet state energy level S1 N , the lowest excited triplet state energy level T1 N , Energy E HOMO (H N ) with the highest occupied molecular orbital HOMO (H N ), and energy E LUMO (H N ) with the lowest unoccupied orbital LUMO(H N ) a host material H N may further include The relationships represented by the following equations (2N), (3N) and (4N) are applied: T1 N >T1S Formula (2N) T1 N >T1 E Formula (3N) T1 N >S1 E Formula (4N) The relationships expressed by the following equations (5) to (11) apply: E LUMO (H P )>E LUMO (S B ) Formula (5) E LUMO (H P )>E LUMO (E B ) Formula (6) E HOMO (H P ) <E HOMO (S B ) Formula (7) E HOMO (H P ) <E HOMO (E B ) Formula (8) E LUMO (H N ) <E LUMO (S B ) Formula (9) E LUMO (H N ) <E LUMO (E B ) Formula (10) E HOMO (H N ) <E HOMO (S B ) Formula (11) E HOMO (H N ) <E HOMO (E B ) Equation (12).

[0015] According to the invention, the host material H N The lowest excited triplet state energy of the small half-width emitter S B The lowest excited triplet state energy of the host material H N The lowest excited triplet state energy of the phosphorescent material E BThe lowest excited triplet state energy of the host material H N The lowest excited triplet state energy of the phosphorescent material E B The lowest excited singlet state energy may be higher than that of the lowest excited singlet state energy of the

[0016] In addition, the host material H P The lowest unoccupied molecular orbital (LUMO) energy of the small half-width emitter S B The lowest unoccupied molecular orbital (LUMO) energy of the host material H P The lowest unoccupied molecular orbital (LUMO) energy of the phosphorescent material E B The lowest unoccupied molecular orbital (LUMO) energy of the aryl group may be higher than that of the aryl group.

[0017] Host material H P The highest occupied molecular orbital (HOMO) energy of the small half-width emitter S B The highest occupied molecular orbital (HOMO) energy of the host material H P The highest occupied molecular orbital (HOMO) energy of the phosphorescent material E B The highest occupied molecular orbital (HOMO) energy of the compound may be lower than that of the compound.

[0018] In addition, the host material H N The lowest unoccupied molecular orbital (LUMO) energy of the small half-width emitter S B The lowest unoccupied molecular orbital (LUMO) energy of the host material H N The lowest unoccupied molecular orbital (LUMO) energy of the phosphorescent material E B The lowest unoccupied molecular orbital (LUMO) energy of the aryl group may be lower than that of the aryl group.

[0019] Host material H N The highest occupied molecular orbital (HOMO) energy of the small half-width emitter S B The highest occupied molecular orbital (HOMO) energy of the host material H N The highest occupied track The HOMO energy of the phosphorescent material E B The highest occupied molecular orbital (HOMO) energy of the compound may be lower than that of the compound.

[0020] In one embodiment, the relationship represented by at least one of the following formulas (2E) and (3E), as well as the relationship represented by formula (1E), are applicable: E LUMO (H N )-E HOMO (H P )>T1 E Formula (1E) E LUMO (H P )-E LUMO (H N )≧0.2eV Formula (2E) E HOMO (H P )-E HOMO (H N )≧0.2eV Equation (3E).

[0021] Host material H N The lowest unoccupied molecular orbital (LUMO) energy of the host material H P The difference between the highest occupied molecular orbital (HOMO) energy of the phosphorescent material E B The lowest excited triplet state energy may be greater than the lowest excited triplet state energy of

[0022] Host material H P The highest occupied molecular orbital (HOMO) energy of the host material H N The HOMO energy may be at least 0.20 eV higher than the HOMO energy of E HOMO (H P ) is E HOMO (H N ) may be at least 0.20 eV more negative.

[0023] H N LUMO and H P The energy difference between the HOMO and H N HOMO and H P The energy difference between the HOMO and the LUMO (H N )-E HOMO (H P )>E HOMO (H P )E HOMO (H NIn one embodiment, the host material H P The HOMO energy of the host material H N The HOMO energy of the cation exchange group is preferably greater than 0.20 eV, more preferably greater than 0.25 eV, or even more preferably greater than 0.30 eV.

[0024] Typically, the host material H P The HOMO energy of the host material H N The HOMO energy of the compound is less than 4.0 eV, preferably less than 3.0 eV, more preferably less than 2.0 eV, or even less than 1.0 eV higher than the HOMO energy of the compound.

[0025] Alternatively, the host material H P The lowest unoccupied molecular orbital (LUMO) energy of the host material H N The LUMO energy may be at least 0.20 eV higher than the LUMO energy of E LUMO (H P ) is E LUMO (H N ) may be at least 0.20 eV more negative than H. N LUMO and H P The energy difference between the HOMO and H N LUMO and H P The energy difference between the LUMO of LUMO (H N )-E HOMO (H P )>E LUMO (H P )-E LUMO (H N In one embodiment, the host material H P The LUMO energy of the host material H N The LUMO energy of the host material H is more than 0.20 eV, preferably more than 0.25 eV, or more preferably more than 0.30 eV higher. P The LUMO energy of the host material H N The LUMO energy of the compound is less than 4.0 eV, preferably less than 3.0 eV, more preferably less than 2.0 eV, or even less than 1.0 eV higher than the LUMO energy of the compound.

[0026] Surprisingly, the main contributions to the emission band of the optoelectronic device according to the invention are i) E B From S B and ii) sufficient energy transfer to the host material H P and H N From E B and / or S. B S, which represents sufficient energy transfer to B It was found to be due to the release of

[0027] In one embodiment, the host material H P The highest occupied molecular orbital (HOMO) energy of the host material H N and the HOMO energy of the host material H P The lowest unoccupied molecular orbital (LUMO) energy of the host material H N The LUMO energy may be at least 0.20 eV higher than the LUMO energy of

[0028] In one embodiment, the host material H P The HOMO energy of the host material H N HO The HMO energy is 0.20 eV or more, preferably 0.25 eV or more, or more preferably 0.30 eV or more higher than the HMO energy of the host material. P The LUMO energy of the host material H N is greater than the LUMO energy of 0.20 eV, preferably greater than 0.25 eV, or more preferably greater than 0.30 eV.

[0029] In one embodiment, H P and H N can form an exciplex. Those skilled in the art will appreciate that H P and H N In addition to the method of selecting pairs of H and the requirements for the HOMO and / or LUMO energy levels described above, P and H NSelection criteria such as low stereoscopic shielding are known.

[0030] In one embodiment, H P can be selected from the group consisting of the following compounds or a mixture of two or more of the following compounds:

[0031] [ka]

[0032] [ka]

[0033] [ka]

[0034] [ka]

[0035] [ka]

[0036] In one embodiment, H N can be selected from the group consisting of the following compounds or a mixture of two or more of the following compounds:

[0037] [ka]

[0038] [ka]

[0039] In one embodiment, H P and HN forms an exciplex;H P and S B does not form an exciplex;H N and S B does not form an exciplex, and E B and S B does not form an exciplex.

[0040] In one embodiment, H P and H N forms an exciplex;H P and E B does not form an exciplex;H N and E B does not form an exciplex;H P and S B does not form an exciplex;H N and S B does not form an exciplex, and E B and S B does not form an exciplex.

[0041] H P and E B Exciplex formation of H N and E B Exciplex formation of H P and S B Exciplex formation of H N and S B exciplex formation; or E B and S B Exciplex formation.

[0042] In one embodiment, H N may be free of any phosphine oxide groups, in particular H N is not bis[2-(diphenylphosphino)phenyl]etheroxide (DPEPO).

[0043] As used herein, the terms organic electroluminescent device and optoelectronic light emitting device refer to a device that is P , phosphorescent material EB and small FWHM emitter S B The light-emitting layer B may be understood in the broadest sense as any device comprising a light-emitting layer B comprising:

[0044] An organic electroluminescent device can be understood in the broadest sense as any device based on organic materials suitable for emitting light in the visible or near ultraviolet (UV) range, i.e. in the wavelength range of 380 to 800 nm. Preferably, the organic electroluminescent device is capable of emitting light in the visible range, i.e. in the wavelength range of 400 to 800 nm.

[0045] In one embodiment, the organic electroluminescent device may be a device selected from the group consisting of an organic light emitting diode (OLED), a light emitting electrochemical cell (LEC), and a light emitting transistor.

[0046] Particularly preferably, the organic electroluminescent element may be an organic light emitting diode (OLED). Optionally, the organic electroluminescent element is entirely opaque, semi-transparent or (essentially) transparent.

[0047] The term "layer" as used in the context of the present invention is preferably a body having a broadly planar shape.

[0048] The light-emitting layer B may preferably have a thickness of 1 mm or less, more preferably 0.1 mm or less, even more preferably 10 μm or less, even more preferably 1 μm or less, and particularly preferably 0.1 μm or less.

[0049] In one embodiment, a small full width at half maximum (FWHM) emitter S Bmay be an organic material. According to the present invention, an organic emitter or an organic material can mean that the emitter or material is (mainly) composed of hydrogen (H), carbon (C), nitrogen (N), boron (B), silicon (Si), and optionally fluorine (F), optionally bromine (Br) and optionally oxygen (O). Particularly preferably, the organic emitter or organic material does not contain any transition metals.

[0050] In one embodiment, a small full width at half maximum (FWHM) emitter S B may be an organic TADF material. In one embodiment, the small FWHM emitter S B may be an organic emitter.

[0051] Compound H P , compound H N , emitter E B and emitter S B may be included in the organic electroluminescent device in any amount and in any proportion.

[0052] In one embodiment, in the organic electroluminescent device of the present invention, the light-emitting layer B comprises, by weight, an emitter E B From compound H P It may contain even more.

[0053] In one embodiment, in the organic electroluminescent device of the present invention, the light-emitting layer B comprises, by weight, an emitter E B From compound H N It may contain even more.

[0054] In one embodiment, in the organic electroluminescent device of the present invention, the light-emitting layer B contains, by weight, an emitter S B More TADF materials B It may contain even more.

[0055] H N In one embodiment in which the above is optional, in the organic electroluminescence device of the present invention, the light-emitting layer B is (i) 10 to 84% by weight of a host compound H P and, (ii) 0 to 84% by weight of a host compound H N and, (iii) 5 to 15% by weight of phosphorescent material E B and, (iv) 1 to 10 wt. % small FWHM emitter S B and selectively (v) 0-72% by weight of one or more solvents (or may comprise (i), (ii), (iii), (iv) and optionally (v)).

[0056] H N In one embodiment in which the above is optional, in the organic electroluminescence device of the present invention, the light-emitting layer B is (i) 22 to 70% by weight of a host compound H P and, (ii) 0 to 70% by weight of a host compound H N and, (iii) 5 to 10% by weight of phosphorescent material E B and, (iv) 1 to 5% by weight of emitter S B and selectively (v) 0-72% by weight of one or more solvents (or may comprise (i), (ii), (iii), (iv) and optionally (v)).

[0057] H N In one embodiment in which (i) 10 to 30% by weight of a host compound H P and, (ii) 40 to 74% by weight of a host compound H N and, (iii) 15 to 30% by weight of phosphorescent material E B and, (iv) 1-5 wt. % small FWHM emitter S B and selectively (v) 0-34% by weight of one or more solvents (or may comprise (i), (ii), (iii), (iv) and optionally (v)).

[0058] H N In one embodiment in which (i) 40 to 74% by weight of a host compound H N and, (ii) 10 to 30% by weight of a host compound H P and, (iii) 15 to 30% by weight of phosphorescent material E B and, (iv) 1-5 wt. % small FWHM emitter S B and selectively (v) 0-34% by weight of one or more solvents (or may comprise (i), (ii), (iii), (iv) and optionally (v)).

[0059] In one embodiment, the phosphorescent material E B has a maximum emission in the range of 500–540 nm (polymethyl methacrylate (PMMA), λ max PMMA (E B In one embodiment, the phosphorescent material E B has a maximum emission λ in the range of 490-530 nm. max PMMA (E B ) can be represented as

[0060] Phosphorescent Materials Phosphorescent materials utilize the intramolecular spin-orbit interaction (heavy atom effect) induced by metal atoms to obtain light emission from triplets. Examples of such phosphorescent materials may include compounds represented by the general formula EI:

[0061] [ka] EI

[0062] In the formula EI, M is selected from the group consisting of Ir, Pt, Au, Eu, Ru, Re, Ag, and Cu; n is an integer from 1 to 3, X and Y are each independently a monoanionic bidentate ligand. Examples of compounds represented by formula EI may include compounds represented by general formula E-II or E-III below.

[0063] [ka] E-II

[0064] [ka] E-III

[0065] In formulas E-II and E-III, X' is an aromatic ring carbon (C) bonded to M, and Y' is a complex containing nitrogen (N) coordinated to M to form a ring. X' and Y' can be bonded, and X' and Y' can form a new ring. In formula E-III, Z is a bidentate ligand with two oxygens (O). In formulas E-II and E-III, M is a high From the viewpoints of efficiency and long life, Ir is preferable.

[0066] In the formulas E-II and E-III, the aromatic ring X′ is, for example, C 6 -C 30 Aryl group, C 6 -C 16 Aryl groups, preferably C 6 -C 12 Aryl groups, more preferably C 6 -C 10 aryl group, said X′ in each case being one or more substituents R E can be selectively replaced by

[0067] In the formulas E-II and E-III, Y′ is, for example, C 2 -C 30 Heteroaryl groups, C 2 -C 25 Heteroaryl groups, preferably C 2 -C 20 Heteroaryl groups, more preferably C 2 -C 15 Heteroaryl groups, particularly preferably C 2 -C 10 is a heteroaryl group, said Y′ being in each case a substituent R E Y′ can also be, for example, one or more substituents R E C selectively replaceable 1 -C 5 It is also a heteroaryl group.

[0068] In the formulas E-II and E-III, the bidentate ligand Z having two oxygens (O) can be, for example, a C 2 -C 30 Bidentate ligand, C with two oxygens 2 -C 25 Bidentate ligands, preferably C with two oxygens 2 -C 20 Bidentate ligands, more preferably C with two oxygens 2 -C 15 Bidentate ligands, particularly preferably C with two oxygen atoms 2 -C 10 is a bidentate ligand, said Z being in each case one or more substituents R E Z can also be optionally substituted with, for example, one or more substituents R E C with two oxygen atoms selectively replaceable 2 -C 5 It is also a bidentate ligand.

[0069] R E are hydrogen, deuterium, and N(R 5E ) 2 , OR 5E , S.R. 5E , Si(R 5E ) 3 , C.F. 3 , CN, halogen, One or more substituents R 5E C selectively replaceable 1 -C 40 an alkyl group, wherein one or more non-adjacent CH 2 The group is R 5E C=CR 5E , C≡C, Si(R 5E ) 2 , Ge(R 5E ) 2 , Sn(R 5E ) 2 , C=O, C=S, C=Se, C=NR 5E , P(=O)(R 5E ), SO, SO 2 , N.R. 5E , O, S or CONR 5E C replaced by 1 -C 40 Alkyl groups; One or more substituents R 5E C selectively replaceable 1 -C 40 A thioalkoxy group, wherein one or more non-adjacent CH 2 The group is R 5E C=CR 5E , C≡C, Si(R 5E ) 2 , Ge(R 5E ) 2 , Sn(R 5E ) 2 , C=O, C=S, C=Se, C=NR 5E , P(=O)(R 5E ), SO, SO 2 , N.R. 5E , O, S or CONR 5E C replaced by 1 -C 40 Thioalkoxy groups; and One or more substituents R 5E C selectively replaceable 6 -C 60 an aryl group; one or more substituents R 5EC selectively replaceable 3 -C 57 heteroaryl groups;

[0070] R 5E are hydrogen, deuterium, and N(R 6E ) 2 , OR 6E , S.R. 6E , Si(R 6E ) 3 , C.F. 3 ,C.N.,F. One or more substituents R 6E C selectively replaceable 1 -C 40 an alkyl group, wherein one or more non-adjacent CH 2 The group is R 6E C=CR 6E , C≡C, Si(R 6E ) 2 , Ge(R 6E ) 2 , Sn(R 6E ) 2 , C=O, C=S, C=Se, C=NR 6E , P(=O)(R 6E ), SO, SO 2 , N.R. 6E , O, S or CONR 6E C replaced by 1 -C 40 Alkyl groups; One or more substituents R 6E C selectively replaceable 6 -C 60 Aryl groups; and One or more substituents R 6E C selectively replaceable 3 -C 57 heteroaryl groups;

[0071] R 6E are in each case hydrogen, deuterium, OPh, and CF 3 ,C.N.,F. One or more hydrogen atoms may be optionally, independently of one another, deuterium, CN, CF 3 or C replaceable with F1 -C 5 Alkyl groups; One or more hydrogen atoms may be optionally, independently of one another, deuterium, CN, CF 3 or C replaceable with F 1 -C 5 Alkoxy groups; One or more hydrogen atoms may be optionally, independently of one another, deuterium, CN, CF 3 or C replaceable with F 1 -C 5 Thioalkoxy groups; At least one C 1 -C 5 C that can be selectively substituted with alkyl groups 6 -C 18 Aryl groups; At least one C 1 -C 5 C that can be selectively substituted with alkyl groups 3 -C 17 Heteroaryl groups; N(C 6 -C 18 Aryl group) 2 ; N(C 3 -C 17 Heteroaryl group 2 and N(C 3 -C 17 Heteroaryl group)(C 6 -C 18 aryl groups).

[0072] Substituent R E , R 5E or R 6E may optionally, independently of one another, be one or more substituents R E , R 5E , R 6E and / or together with X', Y' and Z form a monocyclic or polycyclic, aliphatic, aromatic, heteroaromatic and / or benzo-fused ring system. It is possible.

[0073] An example of a compound represented by formula E-II is Ir(ppy).3 , Ir(ppy) 2 (acac), Ir(mppy) 3 , Ir(PPy) 2 (m-bppy) and BtpIr(acac), Ir(btp) 2 (acac), Ir(2-phq) 3 , Hex-Ir(phq) 3 , Ir(fbi) 2 (acac), fac-tris(2-(3-p-xylyl)phenyl)pyridine iridium(III), Eu(dbm) 3 (Phen), Ir(piq) 3 , Ir(piq) 2 (acac), Ir(Fiq) 2 (acac), Ir(Flq) 2 (acac), Ru(dtb-bpy) 3 2(PF6), Ir(2-phq) 3 , Ir(BT) 2 (acac), Ir(DMP) 3 , Ir(Mpq) 3 , Ir(phq) 2 tpy, fac-Ir(ppy) 2 Pc, Ir(dp)PQ 2 , Ir(Dpm)(Piq) 2 , Hex-Ir(piq) 2 (acac), Hex-Ir(piq) 3 , Ir(dmpq) 3 , Ir(dmpq) 2 (acac), FPQIrpic, etc.

[0074] Other examples of the compound represented by chemical formula E-II include compounds represented by the following chemical formulas E-II-1 to E-II-11, in which "Me" represents a methyl group.

[0075] [ka]

[0076] [ka]

[0077] Other examples of the compound represented by chemical formula E-III include compounds represented by the following chemical formulas E-III-1 to E-III-6, in which "Me" represents a methyl group.

[0078] [ka]

[0079] Also, US-A 2003 / 017361, US-A 2004 / 262576, WO and iridium complexes as described in US-A 2010 / 027583, US-A 2019 / 245153, US-A 2013 / 119354 and / or US-A 2019 / 233451. In view of the high efficiency of phosphorescent materials, Ir(ppy) is used for green emission. 3 and Hex-Ir(ppy) 3 is available.

[0080] Small FWHM emitter material Small FWHM emitter S B can have an emission spectrum exhibiting a full width at half maximum (FWHM) of approximately 0.25 eV or less (ie, ≦0.25 eV).

[0081] Small FWHM emitter S B can be selected to exhibit an emission having a full width at half maximum (FWHM) in PMMA of less than 0.25 eV, preferably less than 0.20 eV, and more preferably less than 0.15 eV.

[0082] In one embodiment, a small FWHM emitter S B can be selected from the group consisting of fluorescent emitters and thermally activated delayed fluorescent emitters.

[0083] As used herein, the terms "fluorescent material" and "fluorescent emitter" are understood to be interchangeable.

[0084] According to the present invention, in the fluorescent material, ΔE ST The value is also 0.4 eV or more. As used herein, the terms "TADF material" and "TADF emitter" are understood to be interchangeable.

[0085] According to the present invention, in the TADF material, ΔE corresponds to the energy difference between the lowest excited singlet state (S1) and the lowest excited triplet state (T1). ST The value is less than 0.4 eV, preferably less than 0.3 eV, more preferably less than 0.2 eV, even more preferably less than 0.1 eV, or even more preferably less than 0.05 eV.

[0086] According to the present invention, ΔE corresponds to the energy difference between the lowest excited singlet state (S1) and the lowest excited triplet state (T1). ST Materials with a value of 0.4 eV are also TADF materials.

[0087] In one embodiment, a small FWHM emitter S B is also an organic green fluorescent emitter.

[0088] Small FWHM emitter S B A device in which the emitter is boron (B)-containing In one embodiment, a small FWHM emitter S B is also a green boron-containing emitter. Small FWHM emitter S B Examples of green boron compounds include compounds represented by the general chemical formula BI below: [ka] ··BI

[0089] B is boron; Ar 1 , Ar 2 , Ar 3are, independently of one another, selected in each occurrence from the group consisting of aromatic rings and heteroaromatic rings; Ar 1 , Ar 2 , Ar 3 can optionally be linked together to form a ring. The Ar of general chemical formula BI 1 , Ar 2 , Ar 3 Such an aromatic ring is, for example, an aryl ring having 6 to 30 carbon atoms, preferably an aryl ring having 6 to 16 carbon atoms, more preferably an aryl ring having 6 to 12 carbon atoms, and particularly preferably an aryl ring having 6 to 10 carbon atoms.

[0090] General chemical formula BI Ar 1 , Ar 2 , Ar 3 Specific examples of such aromatic rings include a benzene ring, which is also a monocyclic ring; a biphenyl ring, which is also a bicyclic ring; a naphthalene ring, which is also a fused bicyclic ring; a terphenyl ring, which is also a tricyclic ring (m-terphenyl, o-terphenyl or p-terphenyl); an acenaphthylene ring, a fluorene ring, a phenalene ring and a phenanthrene ring, which are fused tricyclic rings; a triphenylene ring, a pyrene ring and a naphthacene ring, which are fused tetracyclic rings; and a perylene ring and a pentacene ring, which are fused pentacyclic rings.

[0091] The Ar of general chemical formula BI 1 , Ar 2 , Ar 3 The heteroaromatic ring is, for example, a heteroaryl ring having 2 to 30 carbon atoms, and the heteroaryl ring is a heteroaryl ring having 2 to 25 carbon atoms, preferably a heteroaryl ring having 2 to 20 carbon atoms, more preferably a heteroaryl ring having 2 to 15 carbon atoms, and particularly preferably a heteroaryl ring having 2 to 10 carbon atoms. 1 , Ar 2 , Ar 3 The heteroaromatic ring as described above is also a heterocycle containing, for example, 1 to 5 heteroatoms selected from oxygen, sulfur and nitrogen as ring-constituting atoms in addition to carbon.

[0092] General chemical formula BI Ar 1 , Ar 2 , Ar 3 Examples of the heteroaromatic ring include a pyrrole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, a triazole ring, a tetrazole ring, a pyrazole ring, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, an indole ring, an isoindole ring, a 1H-indazole ring, a benzimidazole ring, a benzo Examples of such rings include an oxazole ring, a benzothiazole ring, a 1H-benzotriazole ring, a quinoline ring, an isoquinoline ring, a cinnoline ring, a quinazoline ring, a quinoxaline ring, a phthalazine ring, a naphthyridine ring, a purine ring, a pteridine ring, a carbazole ring, an acridine ring, a phenoxathiin ring, a phenoxazine ring, a phenothiazine ring, a phenazine ring, an indolizine ring, a furan ring, a benzofuran ring, an isobenzofuran ring, a dibenzofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a furazan ring, an oxadiazole ring, and a thianthrene ring.

[0093] General chemical formula BI Ar 1 , Ar 2 , Ar 3 In the aforementioned aromatic or heteroaromatic rings, such as a can be replaced by R a are, independently of one another, in each case hydrogen, deuterium, N(R 5 ) 2 , OR 5 , S.R. 5 , Si(R 5 ) 3 , C.F. 3 , CN, halogen, One or more substituents R 5 C selectively replaceable 1 -C 40 an alkyl group, wherein one or more non-adjacent CH 2 The group is R 5 C=CR 5, C≡C, Si(R 5 ) 2 , Ge(R 5 ) 2 , Sn(R 5 ) 2 , C=O, C=S, C=Se, C=NR 5 , P(=O)(R 5 ), SO, SO 2 , N.R. 5 , O, S or CONR 5 C replaced by 1 -C 40 Alkyl groups; One or more substituents R 5 C selectively replaceable 1 -C 40 A thioalkoxy group, wherein one or more non-adjacent CH 2 The group is R 5 C=CR 5 , C≡C, Si(R 5 ) 2 , Ge(R 5 ) 2 , Sn(R 5 ) 2 , C=O, C=S, C=Se, C=NR 5 , P(=O)(R 5 ), SO, SO 2 , N.R. 5 , O, S or CONR 5 C replaced by 1 -C 40 Thioalkoxy groups; and One or more substituents R 5 C selectively replaceable 6 -C 60 an aryl group; one or more substituents R 5 C selectively replaceable 3 -C 57 heteroaryl groups;

[0094] R 5 are, independently of one another, in each case hydrogen, deuterium, N(R 6 ) 2 , OR 6 , S.R. 6 , Si(R 6 ) 3, C.F. 3 ,C.N.,F. One or more substituents R 6 C selectively replaceable 1 -C 40 an alkyl group, wherein one or more non-adjacent CH 2 The group is R 6 C=CR 6 , C≡C, Si(R 6 ) 2 , Ge(R 6 ) 2 , Sn(R 6 ) 2 , C=O, C=S, C=Se, C=NR 6 , P(=O)(R 6 ), SO, SO 2 , N.R. 6 , O, S or CONR 6 C replaced by 1 -C 40 Alkyl groups; One or more substituents R 6 C selectively replaceable 6 -C 60 an aryl group; and one or more substituents R 6 C selectively replaceable 3 -C 57 heteroaryl groups;

[0095] R 6 are, independently of one another, in each case hydrogen, deuterium, OPh, CF 3 ,C.N.,F. One or more hydrogen atoms may be optionally, independently of one another, deuterium, CN, CF 3 or C replaceable with F 1 -C 5 Alkyl groups; One or more hydrogen atoms may be optionally, independently of one another, deuterium, CN, CF 3 or C replaceable with F 1 -C 5 Alkoxy groups; One or more hydrogen atoms may be optionally, independently of one another, deuterium, CN, CF 3 or C replaceable with F 1 -C 5Thioalkoxy groups; At least one C 1 -C 5 C that can be selectively substituted with alkyl groups 6 -C 18 Aryl groups; At least one C 1 -C 5 C that can be selectively substituted with alkyl groups 3 -C 17 Heteroaryl groups; N(C 6 -C 18 Aryl group) 2 ;N(C 3 -C 17 Heteroaryl group 2 , and N( C 3 -C 17 Heteroaryl group)(C 6 -C 18 aryl groups).

[0096] Examples of compounds represented by chemical formula BI include compounds represented by the following general chemical formulas B-II, B-III, and B-IV.

[0097] [ka] B-II

[0098] [ka] B-III

[0099] [ka] B-IV

[0100] Here, Y 1 , Y 2 , Y 3are, in each case independently of one another, NR′, O, C(R′) 2 , S or Si(R′) 2 wherein each R′ is independently selected from the group consisting of: One or more substituents R 6S C selectively substituted with 1 -C 5 Alkyl groups; One or more substituents R 6S C selectively substituted with 6 -C 60 Aryl groups; and One or more substituents R 6S C selectively substituted with 3 -C 57 heteroaryl groups; R 6S are, independently of one another, in each case hydrogen, deuterium, OPh, CF 3 ,C.N.,F. Optionally, one or more hydrogen atoms may be independently selected from deuterium, CN, CF 3 Or place it in F Interchangeable C 1 -C 5 Alkyl groups; Optionally, one or more hydrogen atoms may be independently selected from deuterium, CN, CF 3 or C replaceable with F 1 -C 5 Alkoxy groups; Optionally, one or more hydrogen atoms may be independently selected from deuterium, CN, CF 3 or C replaceable with F 1 -C 5 Thioalkoxy groups; Optionally, one or more hydrogen atoms may be independently selected from deuterium, CN, CF 3 or C replaceable with F 2 -C 5 Alkenyl groups; Optionally, one or more hydrogen atoms may be independently selected from deuterium, CN, CF 3 or C replaceable with F 2 -C 5 Alkynyl groups; At least one C 1 -C5 C that can be selectively substituted with alkyl groups 6 -C 18 Aryl groups; At least one C 1 -C 5 C that can be selectively substituted with alkyl groups 3 -C 17 Heteroaryl groups; N(C 6 -C 18 Aryl group) 2 , N(C 3 -C 17 Heteroaryl group 2 ; and N(C 3 -C 17 Heteroaryl group)(C 6 -C 18 aryl groups).

[0101] Substituent R a , R 5 , R 6 , R′ or R 6S may optionally, independently of one another, be one or more substituents R a , R 5 , R 6 , R′ or R 6S and / or an aromatic or heteroaromatic ring Ar 1 , Ar 2 and Ar 3 Together with the aryl group, they can form monocyclic or polycyclic, aliphatic, aromatic, heteroaromatic and / or benzene-fused rings.

[0102] In one embodiment, the compounds represented by formula BI include compounds represented by formulas B-III-1, B-III-2, B-III-3, B-IV-1, B-IV-2, and B-IV-3.

[0103] [ka] B-III-1

[0104] [ka] B-III-2

[0105] [ka] B-III-3

[0106] [ka] B-IV-1

[0107] [ka] B-IV-2

[0108] [ka] B-IV-3

[0109] wherein the aforementioned structures can be optionally substituted with one or more substituents which optionally form additional rings.

[0110] In one embodiment, a small FWHM emitter S B comprises or consists of a polycyclic aromatic compound.

[0111] In one embodiment of the present invention, a small FWHM emitter S Bis also a near-range-charge-transfer (NRCT) emitter. According to the present invention, the NRCT emitter exhibits a delayed component in the time-resolved photoluminescence spectrum and exhibits a short-range HOMO-LUMO separation as described in Hatakeyama et al. (Advanced Materials, 2016, 28(14):2777-2781, DOI:10.1002 / adma.201505491). In one embodiment, the NRCT emitter is also a TADF material.

[0112] Examples of compounds represented by formula B-III-I include the following structures:

[0113] [ka]

[0114] [ka]

[0115] [ka]

[0116] [ka]

[0117] In one embodiment, a small FWHM emitter S B is also a green boron-containing NRCT emitter selected from the group:

[0118] [ka]

[0119] Those skilled in the art will appreciate that the organic electroluminescent device of the present invention typically includes an emitting layer B. Preferably, the organic electroluminescent device includes at least one of the following layers: at least one emitting layer B, at least one anode layer A, and at least one cathode layer C.

[0120] Preferably, the anode layer A comprises at least one component selected from the group consisting of indium tin oxide, indium zinc oxide, PbO, SnO, graphite, doped silicon, doped germanium, doped GaAs, doped polyaniline, doped polypyrrole, doped polythiophene, and mixtures of two or more thereof.

[0121] Preferably, the cathode layer C comprises at least one component selected from the group consisting of Al, Au, Ag, Pt, Cu, Zn, Ni, Fe, Pb, In, W, Pd, LiF, Ca, Ba, Mg, and mixtures or alloys of two or more thereof.

[0122] Preferably, the light-emitting layer B is located between the anode layer A and the cathode layer C. Thus, the general setup ABC is preferred. It does not of course exclude the presence of one or more optional additional layers. Said additional layers can be present on each of the A, B and / or C faces.

[0123] In one embodiment, the organic electroluminescent device comprises at least the following layers: A) an anode layer A comprising at least one component selected from the group consisting of indium tin oxide, indium zinc oxide, PbO, SnO, graphite, doped silicon, doped germanium, doped GaAs, doped polyaniline, doped polypyrrole, doped polythiophene, and mixtures of two or more thereof; B) light-emitting layer B; and C) A cathode layer C comprising at least one component selected from the group consisting of Al, Au, Ag, Pt, Cu, Zn, Ni, Fe, Pb, In, W, Pd, LiF, Ca, Ba, Mg and mixtures or alloys of two or more thereof.

[0124] The light-emitting layer B may be located between the anode layer A and the cathode layer C.

[0125] In one embodiment, when the organic electroluminescent device is an OLED, the organic electroluminescent device optionally includes the following layer structure: A) an anode layer A illustratively comprising indium tin oxide (ITO); HTL) Hole transport layer HTL; B) a light-emitting layer B according to the present invention, as described herein; ETL) electron transport layer ETL; and C) A cathode layer illustratively comprising Al, Ca and / or Mg. Preferably, the layer order here is A-HTL-B-ETL-C.

[0126] The organic electroluminescent device may also optionally include one or more protective layers to protect the organic electroluminescent device from damaging exposure to harmful substances in the environment including, for example, moisture, vapors and / or gases.

[0127] Preferably, the anode layer A is located on the surface of a substrate. The substrate may be made of any material or composition of materials. Most often, a glass slide is used as the substrate. Alternatively, a thin metal layer (e.g., copper, gold, silver or aluminum film) or a plastic film or plastic slide may be used, which may allow a higher level of flexibility. The anode layer A is made of a material that allows obtaining an almost (essentially) transparent film. Since at least one of the two electrodes must be (essentially) transparent to allow light emission from the OLED, one of the anode layer A or the cathode layer C is transparent. Preferably, the anode layer A is rich in or made of a transparent conductive oxide (TCO).

[0128] Such anode layers A illustratively include indium tin oxide, aluminum zinc oxide, fluorine doped tin oxide, indium zinc oxide, PbO, SnO, zirconium oxide, molybdenum oxide, vanadium oxide, tungsten oxide, graphite, doped Si, doped Ge, doped GaAs, doped polyaniline, doped polypyrrole, and / or doped polythiophene.

[0129] Particularly preferably, the anode layer A is (essentially) made of indium tin oxide (ITO) (e.g., (InO 3 ) 0.9 (SnO 2 ) 0.1 The roughness of the anode layer A due to the transparent conductive oxide (TCO) is also mitigated by using a hole injection layer (HIL). The HIL also facilitates the injection of similar charge carriers (e.g., holes) in that the transport of similar charge carriers from the TCO to the hole transport layer (HTL) is facilitated. The hole injection layer (HIL) can be made of poly-3,4-ethylenedioxythiophene (PEDOT), polystyrenesulfonic acid (PSS), MoO 2 , V 2 O5 , CuPC or CuI, and in particular mixtures of PEDOT and PSS. The hole injection layer (HIL) can also prevent diffusion of metals from the anode layer A into the hole transport layer (HTL). For example, the HIL can be poly-3,4-ethylenedioxythiophene:polystyrenesulfonate (PEDOT:PSS), poly-3,4-ethylenedioxythiophene (PEDOT), 4,4',4"-tris[phenyl(m-tolyl)amino]triphenylamine (mMTDATA), 2,2′,7,7′-tetrakis(n,n-diphenylamino)-9,9′-spirobifluorene (Spiro-TAD), N1,N1′-(biphenyl-4,4′-diyl)bis(N1-phenyl-N4,N4-di-m-tolylbenzene-1,4-diamine (DNTPD), N,N′-bis(1-naphthalenyl)-N,N′-bis -phenyl-(1,1′-biphenyl)-4,4′-diamine (NPB), N,N′-diphenyl-N,N′-di-[4-(N,N-diphenylamino)phenyl]benzidine (NPNPB), N,N,N′,N′-tetrakis(4-methoxyphenyl)benzidine (MeO-TPD), 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN) and / or N,N′-diphenyl-N,N′-bis-(1-naphthyl)-9,9′-spirobifluorene-2,7-diamine (Spiro-NPD).

[0130] Adjacent to the anode layer A or the hole injection layer (HIL), typically, a hole transport layer (HTL) is located. Any hole transport compound can be used here. Illustratively, electron-rich heteroaromatic compounds, such as triarylamines and / or carbazoles, are also used as hole transport compounds. The HTL can reduce the energy barrier between the anode layer A and the light-emitting layer B (which plays the role of the light-emitting layer (EML)). The hole transport layer (HTL) is also an electron blocking layer (EBL). Preferably, the hole transport compound has a relatively high energy level of the triplet state T1. For example, the hole transport layer (HTL) may be made of tris(4-carbazolyl-9-ylphenyl)amine (TCTA), poly(4-butylphenyl-diphenylamine) (poly-TPD), poly(4-butylphenyl-diphenylamine) ([alpha]-NPD), 4,4′-cyclohexylidene-bis[N,N-bis(4-methylphenyl)benzeneamine] (TAPC), 4,4′,4″-triphenylamine ... The HTL may also include star-shaped heterocycles such as bis[2-naphthyl(phenyl)-amino]triphenylamine (2-TNATA), Spiro-TAD, DNTPD, NPB, NPNPB, MeO-TPD, HAT-CN and / or 9,9′-diphenyl-6-(9-phenyl-9H-carbazol-3-yl)-9H,9′H-3,3′-bicarbazole (TrisPcz). The HTL may also include a p-doped layer composed of an inorganic or organic dopant in an organic hole-transporting matrix. As the inorganic dopant, for example, a transition metal oxide such as vanadium oxide, molybdenum oxide or tungsten oxide may be used. As the organic dopant, for example, tetrafluorotetracyanoquinodimethane (F4-TCNQ), copper-pentafluorobenzoic acid (Cu(I)pFBz) or a transition metal complex may be used.

[0131] For example, EBLs include 1,3-bis(carbazol-9-yl)benzene (mCP), 9,9′-bis([1,1′-biphenyl]-3-yl)-3,3′-bi-9H-carbazole (CAS 1352040-89-1); TCTA, 2-TNATA, 3,3-di( 9H-carbazol-9-yl)biphenyl (mCBP), 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, 9-[3-(dibenzothiophen-2-yl)phenyl]-9H-carbazole, 9-[3,5-bis(2-dibenzofuranyl)phenyl]-9H-carbazole, 9-[3,5-biphenyl bis(2-dibenzothiophenyl)phenyl]-9H-carbazole, tris-Pcz, 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi), 3′,5′-di-(N-carbazolyl)-[1,1′-biphenyl]-2-carbonitrile (DCPBN; CAS 1918991-70-4), 3-(N-carbazolyl)-N-phenylcarbazo Some contain NCNPC and / or N,N'-dicarbazolyl-1,4-dimethylbenzene (DCB).

[0132] For host compounds, the energies of the first excited triplet state T1 are measured from the onset of the time-gated emission spectrum at 77 K, typically with a delay time of 1 ms and an integration time of 1 ms, measured in a film of polymethyl methacrylate (PMMA) containing 10 wt % of the host, unless otherwise stated.

[0133] For small full width at half maximum (FWHM) emitters, the energy of the first excited triplet state T1 is measured from the onset of a time-gated emission spectrum at 77 K, typically with a delay time of 1 ms and an integration time of 1 ms, measured in a film of PMMA containing 1 wt. % emitter, unless otherwise stated.

[0134] For phosphorescent compounds, the energy of the first excited triplet state T1 is measured from the onset of the time-gated emission spectrum at room temperature, typically with a delay time of 1 ms and an integration time of 1 ms, measured in a film of PMMA containing 10 wt. % emitter, unless otherwise stated.

[0135] Orbitals and excited state energies can also be determined by experimental methods known to those skilled in the art. Experimentally, the highest occupied molecular orbital E HOMO The energies of the lowest unoccupied orbital E are also determined by methods well known to those skilled in the art from cyclic voltammetry measurements with an accuracy of 0.1 eV. LUMO The energy of E HOMO +E gap E is calculated by gap is determined as follows:

[0136] For host compounds, unless otherwise stated, the emission onset for a film with a 10 wt % host of PMMA corresponds to the energy of the first excited singlet state S1, E gap Used as.

[0137] For small full width at half maximum (FWHM) emitters, unless otherwise stated, the emission onset of a film with 1 wt. % small full width at half maximum (FWHM) emitter in PMMA corresponds to the energy of the first excited singlet state S1, E gap Used as.

[0138] For organic phosphorescent emitters, unless otherwise stated, the emission onset for a film with a 10 wt % host of PMMA corresponds to the energy of the first excited singlet state S1, E gap Used as.

[0139] Any electron transporter can be used in the electron transport layer (ETL). Illustratively, electron-deficient compounds such as benzimidazole, pyridine, triazole, oxadiazole (e.g., 1,3,4-oxadiazole), phosphine oxide and sulfone can be used. Illustratively, the electron transporter ETM can also be a star-shaped heterocycle such as 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl (TPBi). The ETM is illustratively 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (NBphen), aluminum-tris(8-hydroxyquinoline) (Alq3), diphenyl-4-triphenylsilylphenyl-phosphine oxide (TSPO1), 2,7-di(2,2′-bipyridin-5-yl)triphenyl (BPyTP2), dibenzo[b,d]thiophen-2-yltriphenylsilane (Sif87), dibenzo[b,d]thiophen-2-yl)diphenylsilane (Sif88), 1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene (BmPyPhB) and / or 4,4′-bis-[2-(4,6-diphenyl-1,3,5-triazinyl)]-1,1′-biphenyl (BTB). Optionally, the electron transport layer is also doped with a material such as 8-hydroxyquinolinolatritium (Liq). Optionally, a second electron transport layer can be located between the electron transport layer and the cathode layer C. The electron transport layer (ETL) can also block holes. Alternatively, a hole blocking layer (HBL) is introduced.

[0140] [ka] The HBL may include, for example, HBM1.

[0141] 2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline = bathocuproine (BCP), bis(8-hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum (BAlq), 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (NBphen), aluminum-tris(8-hydroxyquinoline) (Alq3), diphenyl-4-triphenylsilylphenyl-phosphine oxide (TSPO1), 2,4,6-tris(biphenyl-3-yl)-1,3,5-triazine (T2T), 2, These may also include 4,6-tris(triphenyl-3-yl)-1,3,5-triazine (T3T), 2,4,6-tris(9,9′-spirobifluoren-2-yl)-1,3,5-triazine (TST), 2,4-diphenyl-6-(3′-triphenylsilylphenyl)-1,3,5-triazine (DTST), 2,8-bis(4,6-diphenyl-1,3,5-triazinyl)dibenzofuran (DTDBF) and / or 1,3,5-tris(N-carbazolyl)benzene / 1,3,5-tris(carbazol-9-yl)benzene (TCB / TCP).

[0142] Adjacent to the electron transport layer (ETL) may be a cathode layer C. For example, the cathode layer C may comprise or consist of a metal (e.g. Al, Au, Ag, Pt, Cu, Zn, Ni, Fe, Pb, LiF, Ca, Ba, Mg, In, W or Pd) or a metal alloy. For practical reasons, the cathode layer C may also consist of an (essentially) opaque metal such as Mg, Ca or Al. Alternatively, or in addition, the cathode layer C may also comprise graphite and / or carbon nanotubes (CNTs). Alternatively, the cathode layer C may also consist of nanoscale silver wires.

[0143] The OLED may optionally further include a protective layer between the electron transport layer (ETL) D and the cathode layer C (also designated as the electron injection layer (EIL)). The protective layer may be any of lithium fluoride, cesium fluoride, silver, 8-hydroxyquinolinolatolithium (Liq), Li 2 O, BaF2 , MgO and / or NaF.

[0144] As used herein, unless more specifically defined in a particular context, the hue designations of emitted and / or absorbed light are as follows: Purple: >380~420nm wavelength range; Deep blue: wavelength range >420~475nm; Sky blue: wavelength range >475~500nm; Green: >500~560nm wavelength range; Yellow: >560~580nm wavelength range; Orange: >580~620nm wavelength range; Red: Wavelength range of >620~800nm. Unless otherwise stated, for small FWHM emitters, such hues are 1 wt. Maximum emission λ of PMMA film with % emitters max PMMA For phosphorescent and host materials, such hues are expressed as the maximum emission λ of the PMMA film, which is 10%, unless otherwise stated. max PMMA Represents.

[0145] Thus, for example, a deep blue emitter has a maximum emission λ in the range of 420-475 nm. max PMMA The sky blue emitter has a maximum emission λ in the range of 475-500 nm. max PMMA and the green emitter has a maximum emission λ in the range of 500-560 nm. max PMMA and the red emitter has a maximum emission λ in the range of 620-800 nm. max PMMA has.

[0146] Thus, one embodiment of the present invention provides: i) 1000 cd / m 2ii) an OLED exhibiting an external quantum efficiency of more than 10%, preferably more than 13%, more preferably more than 15%, even more preferably more than 18%, or even more than 20% at constant current density J 0 =15mA / cm 2 The present invention relates to OLEDs exhibiting LT95 values ​​of greater than 100 hours, preferably greater than 200 hours, more preferably greater than 400 hours, even more preferably greater than 750 hours, or even more preferably greater than 1000 hours.

[0147] One embodiment of the present invention relates to an OLED that emits light with a clear color point.According to the present invention, the OLED can emit light with a narrow emission band (small full width at half maximum (FWHM)).In one embodiment, the OLED according to the present invention can emit light with the FWHM of the main emission peak being less than 0.25eV, preferably less than 0.20eV, more preferably less than 0.15eV, or even less than 0.13eV.

[0148] One embodiment of the present invention relates to an OLED that emits light having CIEx and CIEy close to the CIEx (=0.170) and CIEy (=0.797) color coordinates of primary green (CIEx=0.170 and CIEy=0.797) defined by ITU-R Recommendation BT.2020 (Rec.2020), which is suitable for use in UHD (Ultra High Definition) displays such as UHD-TVs. In this context, the term "close" refers to the range of CIEx and CIEy coordinates provided at the end of this paragraph. While in commercial applications, top-emitting (top electrode is transparent) devices are typically used, the test devices used throughout the present invention represent bottom-emitting devices (bottom electrode and substrate are transparent). Thus, a further aspect of the present invention relates to an OLED whose bottom emission exhibits CIEx colour coordinates of 0.15 to 0.45, preferably 0.15 to 0.35, more preferably 0.15 to 0.30, even more preferably 0.15 to 0.25 or even more preferably 0.15 to 0.20, and / or CIEy colour coordinates of 0.60 to 0.92, preferably 0.65 to 0.90, more preferably 0.70 to 0.88, even more preferably 0.75 to 0.86 or even more preferably 0.79 to 0.84.

[0149] One embodiment of the present invention relates to an OLED that emits light having CIEx and CIEy close to the CIEx (=0.265) and CIEy (=0.65) color coordinates of primary green (CIEx=0.265 and CIEy=0.65) defined by DCIP3. The term "close" in this context refers to the range of CIEx and CIEy coordinates provided at the end of this paragraph. In commercial applications, typically top-emitting (top electrode is transparent) devices are used, while the test devices used throughout the present invention represent bottom-emitting devices (bottom electrode and substrate are transparent). Thus, one embodiment of the present invention relates to an OLED in which the bottom-emitting exhibits CIEx color coordinates i) between 0.2 and 0.45, preferably between 0.2 and 0.35, more preferably between 0.2 and 0.30, even more preferably between 0.24 and 0.28, or even more preferably between 0.25 and 0.27, and / or ii) between 0.60 and 0.80. The present invention relates to OLEDs exhibiting a CIEy colour coordinate of 0.9, preferably 0.6 to 0.8, more preferably 0.60 to 0.70, even more preferably 0.62 to 0.68, or even more preferably 0.64 to 0.66.

[0150] The terms "aryl" and "aromatic" as used throughout this application are understood in the broadest sense as any monocyclic or polycyclic aromatic moiety. In one embodiment, the aryl residue is 6 ~C 18 It is also an aryl residue. In one embodiment, the aryl residue is C 6 ~C 14 Aryl residue, or C 6 ~C 10It is also an aryl residue. More specific definitions are provided in the paragraphs of each compound above. Unless otherwise indicated, aryl can also be optionally substituted by one or more substituents as further exemplified throughout this application. Thus, the term "arylene" refers to a divalent residue that possesses two attachment sites to other molecular structures and acts as a linker structure. As used throughout this application, the terms "heteroaryl" and "heteroaromatic" are understood in the broadest sense to refer to any monocyclic, bicyclic or polycyclic heteroaromatic moiety containing at least one heteroatom, particularly those having 1 to 3 heteroatoms per aromatic ring. In one embodiment, the heteroaryl residue is C 2 ~C 17 In one embodiment, the heteroaryl residue is C 2 ~C 13 Aryl residue, or C 2 ~C 13 It is also an aryl residue.

[0151] Exemplary heteroaromatic compounds include pyrrole, furan, thiophene, imidazole, oxazole, thiazole, triazole, pyrazole, pyridine, pyrazine, and pyrimidine. Unless otherwise indicated, heteroaryl can be optionally substituted with one or more substituents as further exemplified throughout this application. Thus, the term "heteroarylene" refers to a divalent residue that possesses two attachment sites to other molecular structures and acts as a linker structure.

[0152] Unless otherwise stated, percentages refer to percent by weight ((weight / weight), (w / w), wt.).

[0153] As used throughout this application, the term "alkyl" is understood in the broadest sense, both as a linear or branched alkyl residue. Preferred alkyl residues are those containing 1 to 15 carbon atoms. Illustratively, alkyl residues are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, and the like. Unless otherwise indicated, alkyl can also be optionally substituted by one or more substituents, which are further exemplified throughout this application. Thus, the term "alkylene" refers to a divalent residue that possesses two attachment sites to other molecular structures and acts as a linker structure. Unless otherwise indicated, the term "substituted" is understood in the broadest sense, as used herein, particularly in connection with aryl, arylene, heteroaryl, alkyl, and the like. Preferably, such substitution is at least one of C 1 -C 20 Alkyl group, C 7 -C 19 Alkaryl and C 6 -C 18 By "substituted" is meant a residue selected from the group consisting of aryl groups. Thus, preferably there are no charged moieties, and more preferably there are no functional groups present in such substitutions. It will be appreciated that hydrogen can be substituted for deuterium in each case.

[0154] Unless otherwise specified, any layer of the various embodiments may be deposited by any suitable method. In the context of the present invention, the layer, including the light-emitting layer B, may optionally also be produced by a liquid process (also referred to as a "film process", "fluid process", "solution process" or "solvent process"), which means that the components contained in each layer are applied to a part of the surface of the device in liquid form. Preferably, in the context of the present invention, the layer, including the light-emitting layer B, may also be produced by spin-coating. Thin and (essentially) homogeneous layers may be deposited by such methods well known to those skilled in the art. A layer having a uniform thickness is obtained.

[0155] Alternatively, in the context of the present invention, the layer comprising the emissive layer B can also be produced by other methods based on liquid processes, such as casting (e.g. drop casting) and rolling methods, as well as printing methods (e.g. inkjet printing, gravure printing, blade coating), which are optionally carried out in an inert atmosphere (e.g. nitrogen atmosphere).

[0156] In one embodiment, in the context of the present invention, the layers may also be produced by any other method known to those skilled in the art, including but not limited to vacuum processing methods known to those skilled in the art, such as deposition by thermal (cavity) evaporation, organic vapor phase deposition (OVPD) and organic vapor jet printing (OVJP).

[0157] When producing a layer by a liquid process, a solution containing the components of the layer (i.e., for the light-emitting layer B of the present invention, one or more host compounds H P and typically one or more phosphorescent materials E B , at least small full width at half maximum (FWHM) emitter S B and optionally one or more other host compounds H N ) may further comprise a volatile organic solvent, which is optionally one selected from the group consisting of tetrahydrofuran, dioxane, chlorobenzene, diethylene glycol diethyl ether, 2-(2-ethoxyethoxy)ethanol, gamma butyrolactone, N-methylpyrrolidinone, ethoxyethanol, xylene, toluene, anisole, phenetole, acetonitrile, tetrahydrothiophene, benzonitrile, pyridine, trihydrofuran, triarylamine, cyclohexanone, acetone, propylene carbonate, ethyl acetate, benzene, and propylene glycol monoethyl ether acetate (PGMEA). Also, a combination of two or more solvents may be used. After being applied in liquid form, the layer is subsequently dried and / or cured by any technique, illustratively at ambient conditions, elevated temperatures (e.g., about 50° C. or about 60° C.) or reduced pressure.

[0158] Alternatively, the organic electroluminescent element (e.g., an OLED) may be, for example, an essentially white organic electroluminescent element or a blue organic electroluminescent element. For example, the white organic electroluminescent element may contain at least one (deep) blue emitter compound as well as a green light (e.g., a phosphorescent material E B or small FWHM emitter S B ) and / or one or more emitter compounds that emit red light. Optionally, there can then be an energy transfer between two or more of the compounds described above.

[0159] The organic electroluminescent element may form a thin layer having a thickness of 5 mm or less, 2 mm or less, 1 mm or less, 0.5 mm or less, 0.25 mm or less, 100 μm or less, or 10 μm or less as a whole.

[0160] Organic electroluminescent devices (e.g., OLEDs) are small (e.g., 5 mm 2 Less than or equal to 1 mm 2 having a surface area of ​​0.5 to 20 cm 2 ) or large (e.g., 20 cm 2 The organic electroluminescent devices (e.g., OLEDs) according to the present invention can be used as large area lighting devices, as luminescent wallpapers, as luminescent window frames or glass, as luminescent labels, as luminescent posers or as flexible screens or flexible displays to selectively generate screens. Besides the general applications, the organic electroluminescent devices (e.g., OLEDs) can be used exemplarily as luminescent films, as "smart packaging" labels or as innovative design elements. They can also be used for cell detection and inspection (e.g., biolabeling).

[0161] One of the main purposes of an organic electroluminescent device is to produce light. Therefore, the present invention further relates to a method for producing light in a desired wavelength range, comprising the step of providing an organic electroluminescent device according to the present invention.

[0162] Thus, another aspect of the present invention is (i) providing an organic electroluminescent device according to the present invention; and (ii) A method for producing light in a desired wavelength range, comprising the step of applying an electric current to the organic electroluminescent device. Yet another aspect of the invention relates to a method of manufacturing an organic electroluminescent device by assembling the aforementioned elements. The invention also relates to a method of using the organic electroluminescent device to generate green light. EXAMPLES

[0163] The examples and claims further illustrate the invention. Cyclic voltammogram In dichloromethane or a suitable solvent and a suitable supporting electrolyte (e.g., 0.1 mol / l tetrabutylammonium hexafluorophosphate), -3 Cyclic voltammograms of solutions with concentrations of organic molecules in mol / l were measured. The measurements were carried out at room temperature and in a nitrogen atmosphere with a three-electrode assembly (working and counter electrodes: Pt wire, reference electrode: Pt wire) and with FeCp 2 / FeCp 2 + The HOMO data were corrected using peroxene as an internal standard relative to a saturated calomel electrode (SCE).

[0164] Density functional theory calculations The molecular structure was optimized using the BP86 function and the Resolution of Identity (RI) approach. The excitation energies were calculated with the Time-Dependent DFT (TD-DFT) method using the (BP86) optimized structure. The orbital energies and excited state energies were calculated with the B3LYP function. For numerical integration, the Def2-SVP basis set and m4-grid were used. The Turbomole program package was used for all calculations.

[0165] optical physical measurements Sample preparation: spin coating Equipment: Spin150, SPS euro The sample concentration, dissolved in an appropriate solvent, is 10 mg / ml. Program: 1) 3 sec at 400 U / min at 1000 U / s; 20 sec at 1000 U / min. 3) 10 sec at 4000 U / min at 1000 U / s. After coating, the film was dried at 70° C. for 1 min.

[0166] Photoluminescence spectroscopy and time-correlated single photon coefficient (TCSPC) Steady-state emission spectroscopy was recorded using a Model FluoroMax-4 (Horiba Scientific) equipped with a 150 W xenon-Arc lamp, excitation and emission monochromators, a Hamamatsu R928 photomultiplier tube, and time-correlated single-photon counting options. Standard correction fits were used to correct the emission and excitation spectra.

[0167] The excited state lifetimes are determined using the same system using the TCSPC method with an FM-2013 instrument and a Horiba Yvon TCSPC hub.

[0168] Excitation light source: NanoLED 370 (wavelength: 371 nm, pulse duration: 1.1 ns) NanoLED 290 (wavelength: 294nm, pulse duration: <1ns) SpectraLED 310 (wavelength: 314nm) SpectraLED 355 (wavelength: 355nm) Data analysis (exponential fit) is performed using the software suite DataStation and DAS6 analysis software. The fit is determined using the chi-squared test.

[0169] Photoluminescence quantum yield measurement Photoluminescence quantum yield For the measurement of PL quantum yield (PLQY), an Absolute PL quantum yield measurement C9920-03G system (Hamamatsu Photonics) was used. The quantum yield and CIE coordinates were measured using the software U6039-05 version 3.6.0.

[0170] Emission maxima are given in nm, quantum yields Φ are given in %, and CIE coordinates are given as x,y values.

[0171] The PLQY is determined using the following protocol: 1) Quality assurance: Anthracene in ethanol (known concentration) is used as a standard. 2) Excitation wavelength: The absorption maximum of an organic molecule is measured and that wavelength is used to excite the molecule. 3) Measurement: The quantum yield is measured on a solution or film sample in a nitrogen atmosphere. The yield is calculated using the following formula:

[0172]

number

[0173] The above n photon indicates the number of photons, and Int indicates the intensity.

[0174] Production and characterization of organic electroluminescent devices Vacuum deposition methods also produce OLED devices containing the organic molecules according to the present invention. When a layer contains one or more compounds, the weight percentage of one or more compounds is given in %. The total weight percentage value is 100%, so when no value is specified, the percentage of the compound is the difference between the specified value and 100%.

[0175] OLEDs that are not fully optimized are characterized by their external quantum efficiency (%), which is dependent on intensity and current, calculated using the light detected by a photodiode by measuring the electroluminescence spectrum using standard methods.

[0176] The lifetime of an OLED device is extracted from the change in luminance while operating at a constant current density. The LT50 value corresponds to the time when the measured luminance has decreased to 50% of the initial luminance, similarly, LT80 corresponds to the point when the measured luminance has decreased to 80% of the initial luminance, and LT95 corresponds to the point when the measured luminance has decreased to 95% of the initial luminance at the next time point.

[0177] Accelerated lifetime measurements are performed (e.g. by applying increased current densities). 2 In the present invention, the LT80 value is determined using the following formula:

[0178]

number

[0179] Said L 0 denotes the initial luminance at the applied current density. Values ​​correspond to the average of multiple pixels (typically 2-8) and the standard deviation across the pixels is provided. The figure shows the data series for one OLED pixel.

[0180] Experimental Results [ka]

[0181] [ka]

[0182] [ka]

[0183] [ka]

[0184] [ka]

[0185] [ka]

[0186] [ka] HBM1 (Hole Blocking Material)

[0187] [Table 1]

[0188] Here, LUMO CV is the energy of the lowest unoccupied molecular orbital determined by the cyclic voltammogram. a The emission spectrum is Ir(ppy) in chloroform. 3 Recorded from solution. b The emission spectrum is B Recorded from a 0.001 mg / mL solution of -2.

[0189] [Table 2]

[0190] In order to evaluate the results of the present invention, comparative experiments were carried out with different compositions of the light-emitting layer (6). P and H N The ratio was kept constant in the comparative experiments.

[0191] [Table 3]

[0192] Here, mCBP is H P and host N1 is H N Used as Ir(ppy) 3 E B and emitter S1 is S B Percentages are percent by weight.

[0193] [Table 4]

[0194] [Table 5]

[0195] Here, mCBP is H P and host N1 is H N Used as Ir(ppy) 3 E B and emitter S1 is S B Percentages are percent by weight.

[0196] [Table 6]

[0197] [Table 7]

[0198] [Table 8]

[0199] [Table 9]

[0200] Here, mCBP is H P and host N1 is H N Used as Ir(ppy) 3 E B and emitter S2 is S B The percentage is used as Percent by weight.

[0201] [Table 10]

[0202] [Table 11]

[0203] Here, host P1 is H P and host N1 is H N Used as Ir(ppy) 3 E B and emitter S2 is S B Percentages are percent by weight.

[0204] [Table 12]

[0205] mCBP P Used as 7% Ir(ppy) 3 E B All H used as For the type elements, a relative lifetime increase of 16% (from 1.00 to 1.16) was observed for emitter S1, and a relative lifetime increase of 140% (from 1.00 to 2.40) for emitter S2. is observed. Meanwhile, the efficiency remained almost constant (approximately EQE=23%) and the FWHM decreased by 33% (from 0.30 eV to 0.20 eV) for emitter S1 and by 46% (from 0.30 eV to 0.16 eV) for emitter S2. For green applications, the color points improved to CIEx=0.26, CIEy=0.66 for emitter S1 and to CIEx=0.32, CIEy=0.65 for emitter S2. Host P1 is H P Used as 7% Ir(ppy) 3 E B All used as For H-type devices, a 10% relative lifetime increase (from 1.00 to 1.10) is observed for emitter S1 and a 60% relative lifetime increase (from 1.00 to 1.60) is observed for emitter S2, while the efficiency remains almost constant (approximately EQE=24%) and the FWHM decreases by 30% (from 0.30 to 0.21) for emitter S1 and by 45% (from 0.31 to 0.17) for emitter S2. For green applications, the color points are improved to CIEx=0.26, CIEy=0.66 for emitter S1 and CIEx=0.32, CIEy=0.65 for emitter S2.

[0206] Host P1 is H P Used as 10% Ir(ppy) 3 E B Used as a S2 to S B For all H-shaped elements used as , a relative lifetime increase of 44% (from 1.00 to 1.40) is observed, while the efficiency remains almost constant (approximately EQE=24%) and the FWHM decreases by 33% (from 0.30 to 0.21). For green applications, the color point is improved to CIEx=0.26, CIEy=0.66.

[0207] [Table 13] Here, host P2 is H P and host N2 is H N Used as E B -I is E B and emitter S2 is S B Percentages are percent by weight.

[0208] [Table 14]

[0209] Comparing P-type elements and H-type elements, host P1 is H P and host N2 is used as H N Used as 7%E B -I to E B and emitter S2 is used as S B Use as For the H-shaped device, a 59% relative lifetime extension (from 1.00 to 1.59) was observed, an efficiency improvement was observed (from 23.2% to 26.1%), the FWHM was reduced by 45% (from 0.29 eV to 0.16 eV), and the color point for green applications was achieved.

[0210] Relative lifetimes were determined for all device experiments based on the individual LT95 lifetimes measured at 1200 nits.

[0211] Results for emitter S3

[0212] JPEG2025029184000053.jpg7586 Emitter S3 (small FWHM emitter S B )

[0213] [Table 15]

[0214] Here, LUMO CVis the energy of the lowest unoccupied molecular orbital determined by the cyclic voltammogram.

[0215] [Table 16]

[0216] Here, host P1 is H P and host N1 is H N Used as Ir(ppy) 3 E B and emitter S3 is S B Percentages are percent by weight.

[0217] JPEG2025029184000056.jpg32135 Comparing P-type elements and H-type elements, host P1 is H P Used as 7%Ir(p py) 3 E B and emitter S3 is used as S B For the H-type device used as a , a relative lifetime extension of 34% (from 1.00 to 1.34) was observed, an improvement in efficiency was observed (from 23.2% to 24.7%), the FWHM was reduced by 42% (from 0.31 eV to 0.18 eV), and the color point for green applications was achieved.

[0218] Relative lifetimes were determined for all device experiments based on the individual LT95 lifetimes measured at 1200 nits.

Claims

[Claim 1] An organic electroluminescence element comprising a light-emitting layer B, (i) The lowest excited singlet state energy level S1 Ｐ and the lowest excited triplet state energy level T1 Ｐ With energy E ＨＯＭＯ (H Ｐ ) with the highest occupied molecular orbital HOMO (H Ｐ ), and energy E ＬＵＭＯ (H Ｐ ) with the lowest unoccupied orbital LUMO (H Ｐ ) a host material H Ｐ and, (ii) The lowest excited singlet state energy level S1 Ｅ and the lowest excited triplet state energy level T1 Ｅ With energy E ＨＯＭＯ (E Ｅ ) with the highest occupied molecular orbital HOMO (E Ｅ ), and energy E ＬＵＭＯ (E Ｅ ) with the lowest unoccupied orbital LUMO (E Ｅ ) Phosphorescent material E Ｂ and, (iii) lowest excited singlet state energy level S1 Ｓ and the lowest excited triplet state energy level T1 Ｓ With energy E ＨＯＭＯ (E Ｓ ) with the highest occupied molecular orbital HOMO (E Ｓ ), and energy E ＬＵＭＯ (E Ｓ ) with the lowest unoccupied orbital LUMO (E Ｓ ) a small full width at half maximum (FWHM) emitter S Ｂ and The phosphorescent material E Ｂ is the energy of the small half-width emitter S Ｂ , and the small half-width emitter S Ｂ emits light having an emission maximum between 500 nm and 560 nm; An organic electroluminescence element to which the relationships represented by the following formulas (1) to (4) apply: T1 Ｅ >S1 Ｓ Formula (1) T1 Ｐ >T1 Ｓ Formula (2) T1 Ｐ >T1 Ｅ Formula (3) T1 Ｐ >S1 Ｅ Formula (4).

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