Organic compound and application thereof

Abstract

Provided are an organic compound and use thereof. The organic compound has a structure shown in Formula I. Through molecular structure design, the organic compound is endowed with suitable HOMO and LUMO energy levels, which is conducive to matching energy levels of compounds in adjacent layers and achieving efficient exciton recombination. The organic compound has small overlap of HOMO/LUMO energy level, high singlet energy level E.sub.S, high triplet energy level E.sub.T and small energy level difference E.sub.ST, which is conducive to reverse intersystem crossing and achieving higher luminescence efficiency. The organic compound molecule has high stability and low stacking degree, which is conducive to reducing concentration quenching and has excellent thermal and film stability. The organic compound is suitable as TADF materials, which is use for OLED devices, conducive to preparing OLED devices, can improve luminescence efficiency and stability of devices, reduce turn-on voltage and extend lifetime of devices.

Claims

1. An organic compound having a structure represented by Formula I: ##STR00059## wherein X is selected from O, S, NR.sub.3, CR.sub.4R.sub.5 or SiR.sub.6R.sub.7; wherein Y is C or Si; wherein L is selected from any one of a single bond, substituted or unsubstituted C6-C30 arylene or substituted or unsubstituted C3-C30 heteroarylene; wherein Z is selected from any one of substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C6-C30 arylamine, or substituted or unsubstituted C6-C30 heteroarylamine; wherein R.sub.1, R.sub.2, R.sub.1 and R.sub.2 are each independently selected from any one of deuterium, halogen, cyano, substituted or unsubstituted C1-C30 linear or branched alkyl, substituted or unsubstituted C3-C30 cycloalkyl, C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C6-C30 arylamine, or substituted or unsubstituted C6-C30 heteroarylamine; wherein R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 are each independently selected from any one of hydrogen, deuterium, substituted or unsubstituted C1-C30 linear or branched alkyl, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl; wherein n.sub.1, n.sub.2 and n.sub.3 are each independently selected from an integer from 0 to 4; and wherein n.sub.4 is selected from an integer from 0 to 3.

2. The organic compound according to claim 1, wherein the substituted substituents in L, Z, R.sub.1, R.sub.2, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 are each independently selected from at least one of deuterium, halogen, cyano, unsubstituted or halogenated C1-C10 linear or branched alkyl, C3-C10 cycloalkyl, unsubstituted or halogenated C1-C10 alkoxy, C6-C20 aryl, C2-C20 heteroaryl, or C6-C20 arylamine.

3. The organic compound according to claim 1, wherein L is selected from a single bond, any one of the following groups, or any one of the following groups substituted with a substituent: ##STR00060## wherein the dashed line represents a linkage site of the group; and wherein the substituents are each independently selected from at least one of deuterium, C1-C10 linear or branched alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C6-C20 aryl, C2-C20 heteroaryl, or C6-C20 arylamine.

4. The organic compound according to claim 1, wherein Z is selected from any one of the following groups, or any one of the following groups substituted with a substituent: ##STR00061## wherein the dashed line represents a linkage site of the group; and wherein the substituents are selected from at least one of deuterium, halogen, cyano, unsubstituted or halogenated C1-C10 linear or branched alkyl, C3-C10 cycloalkyl, unsubstituted or halogenated C1-C10 alkoxy, C6-C20 aryl, C2-C20 heteroaryl, or C6-C20 arylamine.

5. The organic compound according to claim 1, wherein Z is selected from any one of the following groups: ##STR00062## wherein the dashed line represents a linkage site of the group; wherein U.sub.1 and U.sub.2 are each independently selected from O, S, NR.sub.14, CR.sub.15R.sub.16 or SiR.sub.17R.sub.18; wherein R.sub.11 and R.sub.12 are each independently selected from any one of deuterium, halogen, cyano, unsubstituted or halogenated C1-C1 linear or branched alkyl, C3-C10 cycloalkyl, unsubstituted or halogenated C1-C10 alkoxy, C6-C20 aryl, C2-C20 heteroaryl, or C6-C20 arylamine; wherein R.sub.13, R.sub.14, R.sub.15, R.sub.16, R.sub.17 and R.sub.18 are each independently selected from any one of hydrogen, deuterium, halogen, cyano, unsubstituted or halogenated C1-C10 linear or branched alkyl, C3-C10 cycloalkyl, unsubstituted or halogenated C1-C10 alkoxy, C6-C20 aryl, C2-C20 heteroaryl, or C6-C20 arylamine; wherein R.sub.15 and R.sub.16 are not linked or linked by a chemical bond to form a ring, and R.sub.17 and R.sub.18 are not linked or linked by a chemical bond to form a ring; wherein m.sub.1 and m.sub.3 are each independently selected from an integer from 0 to 4; wherein m.sub.2 is selected from an integer from 0 to 3; and wherein m.sub.4 is selected from an integer from 0 to 2.

6. The organic compound according to claim 5, wherein Z is selected from any one of the following groups, or any one of the following groups substituted with a substituent: ##STR00063## ##STR00064## wherein the dashed line represents a linkage site of the group; and wherein the substituents are selected from at least one of deuterium, C1-C10 linear or branched alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C6-C20 aryl, C2-C20 heteroaryl, or C6-C20 arylamine.

7. The organic compound according to claim 1, wherein R.sub.1, R.sub.2, R.sub.1 and R.sub.2 are each independently selected from any one of deuterium, halogen, cyano, C1-C10 linear or branched alkyl, C1-C10 alkoxy, substituted or unsubstituted C6-C20 aryl, substituted or unsubstituted C3-C20 heteroaryl, substituted or unsubstituted C6-C20 arylamine or substituted or unsubstituted C6-C20 heteroarylamine; and wherein the substituted substituents in R.sub.1, R.sub.2, R.sub.1 and R.sub.2 are each independently selected from at least one of deuterium, C1-C10 linear or branched alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C6-C20 aryl, C2-C20 heteroaryl, or C6-C20 arylamine.

8. The organic compound according to claim 7, wherein R.sub.1, R.sub.2, R.sub.1 and R.sub.2 are each independently selected from any one of the following groups: ##STR00065## ##STR00066## wherein the dashed line represents a linkage site of the group.

9. The organic compound according to claim 1, wherein R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 are each independently selected from any one of C1-C10 linear or branched alkyl, substituted or unsubstituted C6-C20 aryl, or substituted or unsubstituted C3-C20 heteroaryl; and wherein the substituted substituents are each independently selected from at least one of deuterium, C1-C10 linear or branched alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C6-C20 aryl, C2-C20 heteroaryl or C6-C20 arylamine.

10. The organic compound according to claim 9, wherein R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 are each independently selected from any one of methyl, phenyl, biphenyl, terphenyl, naphthyl or pyridyl.

11. The organic compound according to claim 1, wherein n.sub.1, n.sub.2, n.sub.3 and n.sub.4 are each independently 0, 1 or 2.

12. The organic compound according to claim 1, wherein the organic compound is selected from any one of the following Compound M1 to Compound M140: ##STR00067## ##STR00068## ##STR00069## ##STR00070## ##STR00071## ##STR00072## ##STR00073## ##STR00074## ##STR00075## ##STR00076## ##STR00077## ##STR00078## ##STR00079## ##STR00080## ##STR00081## ##STR00082##

13. An organic light-emitting diode (OLED) device, comprising an anode, a cathode and an organic thin film disposed between the anode and the cathode, wherein the organic thin film comprises the organic compound according to claim 1.

14. The OLED device according to claim 13, wherein the organic thin film comprises a light-emitting layer, wherein the light-emitting layer comprises the organic compound.

15. The OLED device according to claim 14, wherein the organic compound is used as a guest material of the light-emitting layer.

16. A display panel, comprising the OLED device according to claim 13.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The FIGURE is a structure diagram of an OLED device according to an embodiment of the present disclosure.

REFERENCE LIST

(2) 1 substrate 2 anode 3 hole injection layer 4 hole transport layer electron blocking layer 6 light-emitting layer 7 hole blocking layer 8 electron transport layer 9 electron injection layer 10 cathode

DETAILED DESCRIPTION

(3) Technical solutions of the present disclosure are further described below through the embodiments. Those skilled in the art are to understand that the embodiments described herein are merely used for understanding the present disclosure and are not to be construed as specific limitations to the present disclosure.

(4) A first aspect of the present disclosure is to provide an organic compound having a structure represented by Formula I:

(5) ##STR00002##

(6) In Formula I, X is selected from O, S, NR.sub.3, CR.sub.4R.sub.5 or SiR.sub.6R.sub.7.

(7) In Formula I, Y is C or Si.

(8) In Formula I, L is selected from any one of a single bond, substituted or unsubstituted C6-C30 arylene, or substituted or unsubstituted C3-C30 heteroarylene. When L is the single bond, it means that the group Z is linked to a B atom by the single bond.

(9) In Formula I, Z is selected from any one of substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C6-C30 arylamine, or substituted or unsubstituted C6-C30 heteroarylamine.

(10) In Formula I, R.sub.1, R.sub.2, R.sub.1 and R.sub.2 are each independently selected from any one of deuterium, halogen, cyano, substituted or unsubstituted C1-C30 linear or branched alkyl, substituted or unsubstituted C3-C30 cycloalkyl, C1-C30 alkoxy, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C6-C30 arylamine, or substituted or unsubstituted C6-C30 heteroarylamine.

(11) R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 are each independently selected from any one of hydrogen, deuterium, substituted or unsubstituted C1-C30 linear or branched alkyl, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl.

(12) In Formula I, n.sub.1, n.sub.2, n.sub.3 and n.sub.4 each represent the number of groups, wherein n.sub.1, n.sub.2 and n.sub.3 are each independently selected from an integer from 0 to 4, for example, may be 0, 1, 2, 3 or 4, and n.sub.4 is selected from an integer from 0 to 3, for example, may be 0, 1, 2 or 3.

(13) When n.sub.12, multiple (at least two) R.sub.1 are the same group or different groups; the same is true for n.sub.2, n.sub.3 and n.sub.4, which is not repeated here.

(14) The organic compound provided by the present disclosure has a structure represented by Formula I and is a boron-containing aromatic compound. Through a design of a molecular structure, the organic compound has a suitable HOMO energy level and LUMO energy level, which is conducive to matching energy levels of compounds in adjacent layers and achieving efficient exciton recombination. The molecular structure of the compound is relatively twisted so that the organic compound has a relatively small overlap between the HOMO energy and the LUMO energy level and a relatively small energy level difference E.sub.ST between a singlet state and a triplet state (E.sub.ST0.30 eV, which may be as low as 0.05-0.3 eV), which achieves efficient reverse intersystem crossing (RISC) so that more triplet excitons cross to the singlet state to emit fluorescence and higher luminescence efficiency is achieved. Moreover, B-containing units of the organic compound are joined to form a spiro ring, which not only improves molecular stability but also reduces a degree of stacking between molecules, which is conducive to reducing concentration quenching. The organic compound is applicable to an OLED device as a TADF material, is suitable for use as a material of a light-emitting layer, and has excellent thermal stability and film stability. Therefore, the organic compound is conducive to preparing the OLED device so that the device is more stable during operation. Moreover, the organic compound significantly improves luminescence efficiency of the device, reduces a turn-on voltage and energy consumption and extends a lifetime of the device.

(15) In the present disclosure, C6-C30 may each independently be C6, C8, C9, C10, C12, C13, C14, C15, C16, C18, C20, C22, C24, C26, C28 or the like.

(16) C3-C30 may each independently be C3, C4, C5, C6, C8, C9, C10, C12, C13, C14, C15, C16, C18, C20, C22, C24, C26, C28 or the like.

(17) C1-C30 may each independently be C2, C3, C4, C5, C6, C8, C9, C10, C12, C13, C14, C15, C16, C18, C20, C22, C24, C26, C28 or the like.

(18) In the present disclosure, halogen includes fluorine, chlorine, bromine or iodine. The same description hereafter has the same meaning.

(19) In the present disclosure, the term aryl includes monocyclic aryl or polycyclic aryl (for example, a ring formed by fusing two, three, four, five or the like benzene rings) and illustratively includes, but is not limited to, phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, spirobifluorenyl, anthryl, indenyl, phenanthryl, pyrenyl, acenaphthenyl, triphenylene, chrysenyl, acenaphthylenyl, perylenyl or the like. The same description hereafter has the same meaning.

(20) A heteroatom in the term heteroaryl includes O, S, N, P, B, Si or the like. Heteroaryl includes monocyclic heteroaryl or polycyclic heteroaryl (a ring formed by fusing heteroaryl to at least one aromatic group) and illustratively includes, but is not limited to, pyridyl, pyrazinyl, pyrimidyl, pyridazinyl, triazinyl, quinolinyl, isoquinolinyl, quinoxalinyl, quinazolinyl, acridinyl, phenanthrolinyl, benzofuranyl, benzothienyl, dibenzofuranyl, dibenzothienyl, carbazolyl and derivative groups thereof (N-phenylcarbazolyl, N-pyridylcarbazolyl, N-naphthylcarbazolyl, benzocarbazolyl, dibenzocarbazolyl, indolocarbazolyl, azacarbazolyl or the like), furanyl, thienyl, pyrrolyl, phenothiazinyl, phenoxazinyl, hydroacridinyl, silaspirobifluorenyl or the like. The same description hereafter has the same meaning.

(21) The term arylene is a divalent group based on the aforementioned aryl; and the term heteroarylene is a divalent group based on the aforementioned heteroaryl. Specific examples are not repeated.

(22) The term arylamine refers to a monovalent group formed through substitution of at least one hydrogen in amino (NH.sub.2) by the aforementioned aryl and illustratively includes, but is not limited to, phenylamino, biphenylamino, naphthylamino or the like.

(23) The term heteroarylamine refers to a monovalent group formed through substitution of at least one hydrogen in amino (NH.sub.2) by the aforementioned heteroaryl and illustratively includes, but is not limited to, pyridylamino, pyrazinylamino, pyrimidylamino or the like.

(24) In an embodiment, the substituted substituents in L, Z, R.sub.1, R.sub.2, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 are each independently selected from at least one of deuterium, halogen, cyano, unsubstituted or halogenated C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) linear or branched alkyl, C3-C10 (for example, C3, C4, C5, C6, C7, C8, C9 or the like) cycloalkyl, unsubstituted or halogenated C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) alkoxy, C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) aryl, C2-C20 (for example, C2, C3, C4, C5, C6, C8, C10, C12, C14, C16, C18 or the like) heteroaryl, or C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) arylamine.

(25) In an embodiment, L is selected from a single bond, any one of the following groups or any one of the following groups substituted with a substituent:

(26) ##STR00003##

(27) wherein the dashed line represents a linkage site of the group.

(28) The substituents are each independently selected from at least one of deuterium, C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) linear or branched alkyl, C3-C10 (for example, C3, C4, C5, C6, C7, C8, C9 or the like) cycloalkyl, C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) alkoxy, C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) aryl, C2-C20 (for example, C2, C3, C4, C5, C6, C8, C10, C12, C14, C16, C18 or the like) heteroaryl, or C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) arylamine.

(29) In an embodiment, Z is selected from any one of the following groups or any one of the following groups substituted with a substituent:

(30) ##STR00004##

(31) wherein the dashed line represents a linkage site of the group.

(32) The substituents are selected from at least one of deuterium, halogen, cyano, unsubstituted or halogenated C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) linear or branched alkyl, C3-C10 (for example, C3, C4, C5, C6, C7, C8, C9 or the like) cycloalkyl, unsubstituted or halogenated C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) alkoxy, C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) aryl, C2-C20 (for example, C2, C3, C4, C5, C6, C8, C10, C12, C14, C16, C18 or the like) heteroaryl, or C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) arylamine.

(33) In an embodiment, Z is selected from any one of the following groups:

(34) ##STR00005## ##STR00006##

(35) wherein the dashed line represents a linkage site of the group.

(36) U.sub.1 and U.sub.2 are each independently selected from O, S, NR.sub.14, CR.sub.15R.sub.16 or SiR.sub.17R.sub.18.

(37) R.sub.11 and R.sub.12 are each independently selected from any one of deuterium, halogen, cyano, unsubstituted or halogenated C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) linear or branched alkyl, C3-C10 (for example, C3, C4, C5, C6, C7, C8, C9 or the like) cycloalkyl, unsubstituted or halogenated C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) alkoxy, C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) aryl, C2-C20 (for example, C2, C3, C4, C5, C6, C8, C10, C12, C14, C16, C18 or the like) heteroaryl, or C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) arylamine.

(38) R.sub.13, R.sub.14, R.sub.15, R.sub.16, R.sub.17 and R.sub.18 are each independently selected from any one of hydrogen, deuterium, halogen, cyano, unsubstituted or halogenated C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) linear or branched alkyl, C3-C10 (for example, C3, C4, C5, C6, C7, C8, C9 or the like) cycloalkyl, unsubstituted or halogenated C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) alkoxy, C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) aryl, C2-C20 (for example, C2, C3, C4, C5, C6, C8, C10, C12, C14, C16, C18 or the like) heteroaryl, or C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) arylamine.

(39) R.sub.15 and R.sub.16 are not linked or linked by a chemical bond to form a ring, and R.sub.17 and R.sub.18 are not linked or linked by a chemical bond to form a ring.

(40) m.sub.1 and m.sub.3 are each independently selected from an integer from 0 to 4, for example, may be 0, 1, 2, 3 or 4.

(41) m.sub.2 is selected from an integer from 0 to 3, for example, may be 0, 1, 2 or 3.

(42) m.sub.4 is selected from an integer from 0 to 2, for example, may be 0, 1 or 2.

(43) In an embodiment, Z is selected from any one of the following groups or any one of the following groups substituted with a substituent:

(44) ##STR00007## ##STR00008##

(45) wherein the dashed line represents a linkage site of the group.

(46) The substituents are selected from at least one of deuterium, C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) linear or branched alkyl, C3-C10 (for example, C3, C4, C5, C6, C7, C8, C9 or the like) cycloalkyl, C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) alkoxy, C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) aryl, C2-C20 (for example, C2, C3, C4, C5, C6, C8, C10, C12, C14, C16, C18 or the like) heteroaryl, or C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) arylamine.

(47) In an embodiment, R.sub.1, R.sub.2, R.sub.1 and R.sub.2 are each independently selected from anyone of deuterium, halogen, cyano, C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) linear or branched alkyl, C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) alkoxy, substituted or unsubstituted C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) aryl, substituted or unsubstituted C3-C20 (for example, C3, C4, C5, C6, C8, C10, C12, C14, C16, C18 or the like) heteroaryl, substituted or unsubstituted C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) arylamine, or substituted or unsubstituted C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) heteroarylamine.

(48) The substituted substituents in R.sub.1, R.sub.2, R.sub.1 and R.sub.2 are each independently selected from at least one of deuterium, C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) linear or branched alkyl, C3-C10 (for example, C3, C4, C5, C6, C7, C8, C9 or the like) cycloalkyl, C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) alkoxy, C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) aryl, C2-C20 (for example, C2, C3, C4, C5, C6, C8, C10, C12, C14, C16, C18 or the like) heteroaryl, or C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) arylamine.

(49) In an embodiment, R.sub.1, R.sub.2, R.sub.1 and R.sub.2 are each independently selected from any one of the following groups:

(50) ##STR00009## ##STR00010##

(51) wherein the dashed line represents a linkage site of the group.

(52) In an embodiment, at least one (for example, one, two or three) of Z, R.sub.1 or R.sub.2 is an electron-donating group.

(53) In a preferred embodiment of the present disclosure, the organic compound has a D-A type molecular structure, where D represents an electron donor and A represents an electron acceptor. A B-containing spiro structure in the organic compound has an electron withdrawing property and collaborates, as A in the molecular structure, with a specific electron-donating group (at least one of Z, R.sub.1 or R.sub.2) which serves as D. The formed D-A type structural framework is more conducive to achieving excellent TADF characteristics so that the organic compound has higher luminescence efficiency.

(54) In the present disclosure, the electron-donating group refers to a group capable of increasing an electron cloud density on a benzene ring and illustratively includes, but is not limited to, carbazolyl and derivative groups thereof (N-phenylcarbazolyl, N-pyridylcarbazolyl, N-naphthylcarbazolyl, benzocarbazolyl, dibenzocarbazolyl, indolocarbazolyl, azacarbazolyl or the like), phenothiazinyl, phenoxazinyl, hydroacridinyl, diphenylamino, phenylpyridylamino or the like.

(55) In an embodiment, Z is the electron-donating group.

(56) In an embodiment, at least one (one or two) of R.sub.1 or R.sub.2 is the electron-donating group.

(57) In an embodiment, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 are each independently selected from any one of C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) linear or branched alkyl, substituted or unsubstituted C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) aryl, or substituted or unsubstituted C3-C20 (for example, C3, C4, C5, C6, C8, C10, C12, C14, C16, C18 or the like) heteroaryl.

(58) The substituted substituents are each independently selected from at least one of deuterium, C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) linear or branched alkyl, C3-C10 (for example, C3, C4, C5, C6, C7, C8, C9 or the like) cycloalkyl, C1-C10 (for example, C1, C2, C3, C4, C5, C6, C7, C8, C9 or the like) alkoxy, C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) aryl, C2-C20 (for example, C2, C3, C4, C5, C6, C8, C10, C12, C14, C16, C18 or the like) heteroaryl, or C6-C20 (for example, C6, C9, C10, C12, C14, C16, C18 or the like) arylamine.

(59) In an embodiment, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 are each independently selected from any one of methyl, phenyl, biphenyl, terphenyl, naphthyl or pyridyl.

(60) In an embodiment, n.sub.1, n.sub.2, n.sub.3 and n.sub.4 are each independently 0, 1 or 2.

(61) In a specific embodiment, the organic compound is selected from any one of the following Compound M1 to Compound M140:

(62) ##STR00011## ##STR00012## ##STR00013## ##STR00014## ##STR00015## ##STR00016## ##STR00017## ##STR00018## ##STR00019## ##STR00020## ##STR00021## ##STR00022## ##STR00023## ##STR00024## ##STR00025## ##STR00026##

(63) A second aspect of the present disclosure is to provide an OLED device. The OLED device includes an anode, a cathode and an organic thin film disposed between the anode and the cathode, where the organic thin film includes at least one of the organic compounds according to the first aspect.

(64) In an embodiment, the organic thin film includes a light-emitting layer. The light-emitting layer includes at least one of the organic compounds according to the first aspect.

(65) In an embodiment, the organic compound is used as a host material or a guest material of the light-emitting layer.

(66) In an embodiment, the organic compound is used as the guest material of the light-emitting layer.

(67) In an embodiment, an anode material of the OLED device may be a metal, a metal oxide or a conductive polymer. The metal includes copper, gold, silver, iron, chromium, nickel, manganese, palladium, platinum or the like and alloys thereof. The metal oxide includes indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide, indium gallium zinc oxide (IGZO) or the like. The conductive polymer includes polyaniline, polypyrrole, poly (3-methylthiophene) or the like. In addition to the above materials that facilitate hole injection and combinations thereof, the anode material further includes known materials suitable for use as the anode.

(68) A cathode material of the OLED device may be a metal or a multilayer metal material.

(69) The metal includes aluminum, magnesium, silver, indium, tin, titanium or the like and alloys thereof. The multilayer metal material includes LiF/Al, LiO.sub.2/Al, BaF.sub.2/Al or the like. In addition to the above materials that facilitate electron injection and combinations thereof, the cathode material further includes known materials suitable for use as the cathode.

(70) The organic thin film of the OLED device includes at least one light-emitting layer (EML) and any one or a combination of at least two of an electron transport layer (ETL), a hole transport layer (HTL), a hole injection layer (HIL), an electron blocking layer (EBL), a hole blocking layer (HBL) and an electron injection layer (EIL) disposed on both sides of the light-emitting layer. A capping layer (CPL) may also be optionally disposed on the cathode of the OLED device (on a side of the cathode facing away from the anode).

(71) In a specific embodiment, as shown in the FIGURE which is a structure diagram of the OLED device, the OLED device includes a substrate 1 and an anode 2, a hole injection layer 3, a hole transport layer 4, an electron blocking layer 5, a light-emitting layer 6, a hole blocking layer 7, an electron transport layer 8, an electron injection layer 9 and a cathode 10 which are stacked on the substrate 1 in sequence. An arrow represents a direction of light emission. The light-emitting layer 6 includes at least one of the organic compounds according to the first aspect.

(72) The OLED device may be prepared by the following method: forming the anode on a transparent or opaque smooth substrate, forming an organic thin layer on the anode, and forming the cathode on the organic thin layer. The organic thin layer may be formed by a known film formation method such as evaporation deposition, sputtering, spin coating, impregnation and ion plating.

(73) A third aspect of the present disclosure is to provide a display panel. The display panel includes the OLED device according to the second aspect.

(74) In an embodiment, the organic compound having a structure represented by Formula I and provided by the present disclosure may be prepared by one of the following synthesis routes one to four: (1) when Y is C, route one is as follows:

(75) ##STR00027## (2) when Y is C, route two is as follows:

(76) ##STR00028## (3) when Y is Si, route three is as follows:

(77) ##STR00029## (4) when Y is Si, route four is as follows:

(78) ##STR00030##

(79) In the above synthesis routes, X, L, Z, R.sub.1, R.sub.2, R.sub.1, R.sub.2, n.sub.1, n.sub.2, n.sub.3 and n.sub.4 are limited within the same range as in Formula I. Moreover, the groups such as R.sub.1 and R.sub.2 may be introduced into the organic compound by using a raw material containing corresponding substituents (as shown above) or by reacting halogen on a skeletal structure with

(80) ##STR00031##

Example 1

(81) Organic Compound M1 has the following structure:

(82) ##STR00032##

(83) A method for preparing Organic Compound M1 includes the steps below.

(84) ##STR00033##

(85) Compound A01 (30 mmol) was added to a three-necked flask and dissolved in tetrahydrofuran (200 mL) through stirring. Under nitrogen protection, the solution was cooled to 78 C. Then a 2 M solution of n-butyllithium (n-BuLi) (15 mL) was slowly added dropwise and then the system was stirred for 0.5 h. Then a solution of Compound B01 (30 mmol) in tetrahydrofuran (THF) was added dropwise to the reaction solution. After dropping, the reaction solution was warmed to room temperature and stirred for 2 h. A saturated solution of ammonium chloride was added to quench the reaction, water was added and layers were separated, and an organic phase was concentrated to obtain an oily substance. A mixture of acetic acid (100 mL) and HCl (20 mL) was added to the oily substance, and the system was stirred and refluxed for 12 h. The reaction solution was cooled, added with saturated salt solution, and extracted with dichloromethane to obtain the organic phase. The organic phase was washed three times with water, evaporated to remove the solvent. The residue was recrystallized from dichloromethane/petroleum ether to obtain Compound M01-1.

(86) ##STR00034##

(87) In a 250 mL round-bottom flask, M01-1 (10 mmol), C01 (12 mmol) and Na.sub.2CO.sub.3 (80 mmol) were separately added to the solvent of toluene/absolute ethyl alcohol (EtOH)/H.sub.2O (75/25/50, mL) to form a mixed solution. Then tetrakis(triphenylphosphine)palladium (Pd(PPh.sub.3).sub.4) (0.48 mmol) was added to the above mixed solution and the system was refluxed for 20 h in a nitrogen atmosphere to obtain an intermediate. The intermediate was cooled to room temperature, added to water, filtered through a Celite pad, extracted with dichloromethane, washed with water, dried over anhydrous magnesium sulfate, filtered and evaporated. The crude product was purified through silica gel column chromatography to obtain the target product M1.

(88) Results of an elemental analysis of Organic Compound M1 (molecular formula C.sub.49H.sub.31B.sub.2NO): theoretical values: C 87.66, H 4.65, B 3.22, N 2.09, O 2.38; measured values: C 87.66, H 4.65, B 3.22, N 2.09, O 2.38. A relative molecular mass obtained through liquid chromatography-mass spectrometry: theoretical value: 671.26; measured value: 671.28.

Example 2

(89) Organic Compound M19 has the following structure:

(90) ##STR00035##

(91) A method for preparing Organic Compound M19 includes the following step:

(92) ##STR00036##

(93) In a 250 mL round-bottom flask, M01-1 (10 mmol), C19 (12 mmol) and Na.sub.2CO.sub.3 (80 mmol) were separately added to the solvent of toluene/EtOH/H.sub.2O (75/25/50, mL) to form a mixed solution. Then Pd(PPh.sub.3).sub.4 (0.48 mmol) was added to the above mixed solution and the system was refluxed for 20 h in a nitrogen atmosphere to obtain an intermediate. The intermediate was cooled to room temperature, added to water, filtered through a Celite pad, extracted with dichloromethane, washed with water, dried over anhydrous magnesium sulfate, filtered and evaporated. The crude product was purified through silica gel column chromatography to obtain the target product M19.

(94) Results of an elemental analysis of Organic Compound M19 (molecular formula C.sub.55H.sub.35B.sub.2NO): theoretical values: C 88.37, H 4.72, B 2.89, N 1.87, O 2.14; measured values: C 88.37, H 4.72, B 2.89, N 1.87, O 2.14. A relative molecular mass obtained through liquid chromatography-mass spectrometry: theoretical value: 747.29; measured value: 747.28.

Example 3

(95) Organic Compound M39 has the following structure:

(96) ##STR00037##

(97) A method for preparing Organic Compound M39 includes the steps below.

(98) ##STR00038##

(99) B39 (50 mmol) was dissolved in THF (250 mL), A39 (50 mmol) was dissolved in THF (750 mL), and the solution of B39 was added dropwise to the solution of A39. The obtained mixture was stirred for 16 h at room temperature. After the solvent was removed in vacuum, the residue was dissolved in dichloromethane (250 mL), washed three times with distilled water (200 mL) and dried over sodium sulfate. An organic phase was evaporated, and the residue was recrystallized five times from dioxane to obtain Compound M39-1.

(100) ##STR00039##

(101) In a 250 mL round-bottom flask, M39-1 (10 mmol), C01 (12 mmol) and Na.sub.2CO.sub.3 (80 mmol) were separately added to the solvent of toluene/EtOH/H.sub.2O (75/25/50, mL) to form a mixed solution. Then Pd(PPh.sub.3).sub.4 (0.48 mmol) was added to the above mixed solution and the system was refluxed for 20 h in a nitrogen atmosphere to obtain an intermediate. The intermediate was cooled to room temperature, added to water, filtered through a Celite pad, extracted with dichloromethane, washed with water, dried over anhydrous magnesium sulfate, filtered and evaporated. The crude product was purified through silica gel column chromatography to obtain the target product M39.

(102) Results of an elemental analysis of Organic Compound M39 (molecular formula C.sub.48H.sub.31B.sub.2NOSi): theoretical values: C 83.86, H 4.55, B 3.15, N 2.04, O 2.33, Si 4.09; measured values: C 83.86, H 4.55, B 3.15, N 2.04, O 2.33, Si 4.09. A relative molecular mass obtained through liquid chromatography-mass spectrometry: theoretical value: 687.24; measured value: 687.25.

Example 4

(103) Organic Compound M40 has the following structure:

(104) ##STR00040##

(105) A method for preparing Organic Compound M40 includes the steps below.

(106) ##STR00041##

(107) Compound A40 (30 mmol) was added to a three-necked flask and dissolved in tetrahydrofuran (200 mL) through stirring. Under nitrogen protection, the solution was cooled to 78 C. Then a 2 M solution of n-BuLi (15 mL) was slowly added dropwise and then the system was stirred for 0.5 h. Then a solution of Compound B01 (30 mmol) in tetrahydrofuran was added dropwise to the reaction solution. After dropping, the reaction solution was warmed to room temperature and stirred for 2 h. A saturated solution of ammonium chloride was added to quench the reaction, water was added and layers were separated, and an organic phase was concentrated to obtain an oily substance. A mixture of acetic acid (100 mL) and HCl (20 mL) was added to the oily substance, and the system was stirred and refluxed for 12 h. The reaction solution was cooled, added with saturated salt solution, and extracted with dichloromethane to obtain the organic phase. The organic phase was washed three times with water, evaporated to remove the solvent. The residue was recrystallized from dichloromethane/petroleum ether to obtain Compound M40-1.

(108) ##STR00042##

(109) In a 250 mL round-bottom flask, M40-1 (10 mmol), C01 (12 mmol) and Na.sub.2CO.sub.3 (80 mmol) were separately added to the solvent of toluene/EtOH/H.sub.2O (75/25/50, mL) to form a mixed solution. Then Pd(PPh.sub.3).sub.4 (0.48 mmol) was added to the above mixed solution and the system was refluxed for 20 h in a nitrogen atmosphere to obtain an intermediate. The intermediate was cooled to room temperature, added to water, filtered through a Celite pad, extracted with dichloromethane, washed with water, dried over anhydrous magnesium sulfate, filtered and evaporated. The crude product was purified through silica gel column chromatography to obtain the target product M40.

(110) Results of an elemental analysis of Organic Compound M40 (molecular formula C.sub.55H.sub.36B.sub.2N.sub.2): theoretical values: C 88.49, H 4.86, B 2.90, N 3.75; measured values: C 88.49, H 4.86, B 2.90, N 3.75. A relative molecular mass obtained through liquid chromatography-mass spectrometry: theoretical value: 746.31; measured value: 746.30.

Example 5

(111) Organic Compound M41 has the following structure:

(112) ##STR00043##

(113) A method for preparing Organic Compound M41 includes the steps below.

(114) ##STR00044##

(115) This step differs from step (1) in Example 3 only in that A39 was replaced with A41 in an equimolar amount, and other raw materials and process parameters were the same so that Compound M41-1 was obtained.

(116) ##STR00045##

(117) This step differs from step (2) in Example 3 only in that M39-1 was replaced with M41-1 in an equimolar amount, and other raw materials and process parameters were the same so that the target product M41 was obtained.

(118) Results of an elemental analysis of Organic Compound M41 (molecular formula C.sub.54H.sub.36B.sub.2N.sub.2Si): theoretical values: C 85.05, H 4.76, B 2.84, N 3.67, Si 3.68; measured values: C 85.05, H 4.76, B 2.84, N 3.67, Si 3.68. A relative molecular mass obtained through liquid chromatography-mass spectrometry: theoretical value: 762.28; measured value: 762.30.

Example 6

(119) Organic Compound M43 has the following structure:

(120) ##STR00046##

(121) A method for preparing Organic Compound M43 includes the following step:

(122) ##STR00047##

(123) This step differs from step (2) in Example 5 only in that C01 was replaced with C43 in an equimolar amount, and other raw materials and process parameters were the same so that the target product M43 was obtained.

(124) Results of an elemental analysis of Organic Compound M43 (molecular formula C.sub.52H.sub.34B.sub.2N.sub.4Si): theoretical values: C 81.69, H 4.48, B 2.83, N 7.33, Si 3.67; measured values: C 81.69, H 4.48, B 2.83, N 7.33, Si 3.67. A relative molecular mass obtained through liquid chromatography-mass spectrometry: theoretical value: 764.27; measured value: 764.30.

Example 7

(125) Organic Compound M44 has the following structure:

(126) ##STR00048##

(127) A method for preparing Organic Compound M44 differs from Example 1 only in that C01 in step (2) was replaced with C44

(128) ##STR00049##
in an equimolar amount, and other raw materials and process parameters were the same so that the target product M44 was obtained.

(129) Results of an elemental analysis of Organic Compound M44 (molecular formula C.sub.55H.sub.37B.sub.2NO): theoretical values: C 88.14, H 4.98, B 2.88, N 1.87, O 2.13; measured values: C 88.14, H 4.98, B 2.88, N 1.87, O 2.13. A relative molecular mass obtained through liquid chromatography-mass spectrometry: theoretical value: 749.31; measured value: 749.32.

Example 8

(130) Organic Compound M45 has the following structure:

(131) ##STR00050##

(132) A method for preparing Organic Compound M45 differs from Example 1 only in that C01 in step (2) was replaced with C45

(133) ##STR00051##
in an equimolar amount, and other raw materials and process parameters were the same so that the target product M45 was obtained.

(134) Results of an elemental analysis of Organic Compound M45 (molecular formula C.sub.59H.sub.39B.sub.2NO): theoretical values: C 88.63, H 4.92, B 2.70, N 1.75, O 2.00; measured values: C 88.63, H 4.92, B 2.70, N 1.75, O 2.0. A relative molecular mass obtained through liquid chromatography-mass spectrometry: theoretical value: 799.32; measured value: 799.34.

Example 9

(135) Organic Compound M117 has the following structure:

(136) ##STR00052##

(137) A method for preparing Organic Compound M117 includes the steps below.

(138) ##STR00053##

(139) Compound A01 (30 mmol) was added to a three-necked flask and dissolved in tetrahydrofuran (200 mL) through stirring. Under nitrogen protection, the solution was cooled to 78 C. Then a 2 M solution of n-BuLi (15 mL) was slowly added dropwise and then the system was stirred for 0.5 h. Then a solution of Compound B117 (30 mmol) in tetrahydrofuran was added dropwise to the reaction solution. After dropping, the reaction solution was warmed to room temperature and stirred for 2 h. A saturated solution of ammonium chloride was added to quench the reaction, water was added and layers were separated, and an organic phase was concentrated to obtain an oily substance. A mixture of acetic acid (100 mL) and HCl (20 mL) was added to the oily substance, and the system was stirred and refluxed for 12 h. The reaction solution was cooled, added with saturated salt solution, extracted with dichloromethane to obtain the organic phase. The organic phase was washed three times with water, evaporated to remove the solvent. The residue was recrystallized from dichloromethane/petroleum ether to obtain Compound M117-1.

(140) ##STR00054##

(141) In a 250 mL round-bottom flask, M117-1 (10 mmol), C117 (12 mmol) and Na.sub.2CO.sub.3 (80 mmol) were separately added to the solvent of toluene/EtOH/H.sub.2O (75/25/50, mL) to form a mixed solution. Then Pd(PPh.sub.3).sub.4 (0.48 mmol) was added to the above mixed solution and the system was refluxed for 20 h in a nitrogen atmosphere to obtain an intermediate. The intermediate was cooled to room temperature, added to water, filtered through a Celite pad, extracted with dichloromethane, washed with water, dried over anhydrous magnesium sulfate, filtered and evaporated. The crude product was purified through silica gel column chromatography to obtain the target product M117.

(142) Results of an elemental analysis of Organic Compound M117 (molecular formula C.sub.55H.sub.35B.sub.2NO): theoretical values: C 88.37, H 4.72, B 2.89, N 1.87, O 2.14; measured values: C 88.37, H 4.72, B 2.89, N 1.87, O 2.14. A relative molecular mass obtained through liquid chromatography-mass spectrometry: theoretical value: 749.29; measured value: 749.28.

Example 10

(143) Organic Compound M118 has the following structure:

(144) ##STR00055##

(145) A method for preparing Organic Compound M118 includes the following step:

(146) ##STR00056##

(147) Example 10 differs from Example 9 only in that C117 in step (2) was replaced with C118 in an equimolar amount, and other raw materials and process parameters were the same so that the target product M118 was obtained.

(148) Results of an elemental analysis of Organic Compound M118 (molecular formula C.sub.55H.sub.37B.sub.2NO): theoretical values: C 88.14, H 4.98, B 2.88, N 1.87, O 2.13; measured values: C 88.14, H 4.98, B 2.88, N 1.87, O 2.13. A relative molecular mass obtained through liquid chromatography-mass spectrometry: theoretical value: 749.31; measured value: 749.32.

(149) Simulated Calculations of Compounds

(150) By use of a density-functional theory (DFT), for the organic compounds provided by the present disclosure, the distribution of frontier molecular orbitals (HOMO and LUMO) was optimized and calculated by using a Gaussian 09 package (Gaussian Inc.) at a calculation level of B3LYP/6-31G(d). Moreover, a singlet energy level E.sub.S and a triplet energy level E.sub.T of a molecule of the compound were simulated and calculated based on a time-dependent density-functional theory (TD-DFT), and E.sub.ST was obtained. The results are shown in Table 1.

(151) TABLE-US-00001 TABLE 1 HOMO LUMO E.sub.S E.sub.T E.sub.ST Compound (eV) (eV) (eV) (eV) (eV) M1 1.78 5.30 2.929 2.7979 0.1311 M19 1.80 5.37 3.1961 2.9138 0.2823 M39 1.90 5.25 2.7294 2.6546 0.0748 M40 1.64 5.23 2.9228 2.6677 0.2551 M41 1.78 5.18 2.7651 2.5903 0.1748 M43 2.01 5.44 2.9793 2.6836 0.2957 M44 1.79 4.90 2.7764 2.7188 0.0576 M45 1.81 4.88 2.7139 2.4623 0.2516 M117 1.79 5.35 3.1535 2.8544 0.2991 M118 1.79 4.88 2.7264 2.5697 0.1567

(152) As can be seen from the results in Table 1, the organic compounds provided by the present disclosure each have a relatively suitable HOMO energy level and LUMO energy level, which is conducive to matching energy levels of compounds in adjacent layers and achieving efficient exciton recombination. Moreover, the organic compounds provided by the present disclosure each have a relatively high E.sub.S, a relatively high E.sub.T and a relatively small E.sub.ST (for example, E.sub.ST0.30 eV) and achieves a relatively small energy level difference between a singlet state and a triplet state, which is conducive to reverse intersystem crossing from the triplet energy level to the singlet energy level. The organic compounds are suitable for use as TADF materials to achieve higher luminescence efficiency.

(153) Several application examples of the organic compounds of the present disclosure applied to OLED devices are listed below.

Application Example 1

(154) A structure diagram of an OLED device is shown in the FIGURE. The OLED device includes a substrate 1, an anode 2, a hole injection layer 3, a hole transport layer 4, an electron blocking layer 5, a light-emitting layer 6, a hole blocking layer 7, an electron transport layer 8, an electron injection layer 9 and a cathode 10 which are stacked in sequence. An arrow in the FIGURE represents a direction of light emission.

(155) The OLED device is prepared through steps described below.

(156) (1) A glass substrate 1 with an indium tin oxide (ITO) anode 2 (with a thickness of 100 nm) was sonicated in isopropanol and deionized water for 30 min separately, and cleaned under ozone for about 10 min. The cleaned glass substrate 1 was installed onto a vacuum deposition device.

(157) (2) Compound a was deposited by means of vacuum evaporation on the ITO anode 2 as a hole injection layer 3 with a thickness of 10 nm.

(158) (3) Compound b was deposited by means of vacuum evaporation on the hole injection layer 3 as a hole transport layer 4 with a thickness of 40 nm.

(159) (4) Compound c was deposited by means of vacuum evaporation on the hole transport layer 4 as an electron blocking layer 5 with a thickness of 10 nm.

(160) (5) A light-emitting host compound d and Organic Compound M1 (a guest material) provided in Example 1 were co-deposited at a doping ratio of 10% (mass ratio) by means of vacuum evaporation on the electron blocking layer 5 as a light-emitting layer 6 with a thickness of 30 nm.

(161) (6) Compound e was deposited by means of vacuum evaporation on the light-emitting layer 6 as a hole blocking layer 7 with a thickness of 10 nm.

(162) (7) Compound f was deposited by means of vacuum evaporation on the hole blocking layer 7 as an electron transport layer 8 with a thickness of 30 nm.

(163) (8) Compound h (LiF) was deposited by means of vacuum evaporation on the electron transport layer 8 as an electron injection layer 9 with a thickness of 2 nm.

(164) (9) An aluminum electrode was deposited by means of vacuum evaporation on the electron injection layer 9 as a cathode 10 with a thickness of 100 nm so that the OLED device was obtained.

(165) The compounds used in the OLED device have the following structures:

(166) ##STR00057## ##STR00058##

Application Examples 2 to 13 and Comparative Example 1

(167) An OLED device in each of Application Examples 2 to 13 and Comparative Example 1 differs from that in Application Example 1 only in that Organic Compound M1 in step (5) was replaced with a respective compound shown in Table 2 in an equivalent amount, and other layer structures, materials and preparation methods were the same as those in Application Example 1.

(168) Performance Evaluation of OLED Devices

(169) Currents were measured using a Keithley 2365A digital nanovoltmeter at different voltages for the OLED devices and then divided by a light-emitting area so that the current densities of the OLED devices at different voltages were obtained. The luminance and radiant energy flux density of the OLED devices at different voltages were tested using a Konicaminolta CS-2000 spectrometer. According to the current densities and luminance of the OLED device at different voltages, a turn-on voltage and current efficiency (CE, Cd/A) at the same current density (10 mA/cm.sup.2) were obtained, where VON was a turn-on voltage under the luminance of 1 Cd/m.sup.2. A lifetime LT95 was obtained by measuring time taken for the OLED device to reach 95% of initial luminance (under a condition of 50 mA/cm.sup.2). The specific data are shown in Table 2.

(170) TABLE-US-00002 TABLE 2 OLED Guest Material of V.sub.ON CE LT95 Device Light-emitting Layer (V) (Cd/A) (h) Application M1 4.08 12.0 45 Example 1 Application M19 4.14 11.3 42 Example 2 Application M39 4.11 11.9 47 Example 3 Application M40 4.10 11.7 40 Example 4 Application M41 4.12 11.8 42 Example 5 Application M43 4.15 11.5 43 Example 6 Application M44 4.07 12.2 46 Example 7 Application M45 4.10 11.8 45 Example 8 Application M117 4.12 11.7 41 Example 9 Application M118 4.09 11.9 44 Example 10 Application M23 4.17 11.4 42 Example 11 Application M24 4.13 11.8 41 Example 12 Application M26 4.10 11.6 43 Example 13 Comparative Comparative 4.25 9.95 36 Example 1 Compound

(171) As can be seen from the test results in Table 2, the organic compounds provided by the present disclosure are applied to the OLED devices such that the devices each have a relatively low turn-on voltage, relatively high luminescence efficiency and a relatively long lifetime, for example, the working voltage 4.15 V, the current efficiency (CE)11.3 Cd/A and the lifetime LT9540 h. Compared with the device in the comparative example, the OLED device using the organic compound of the present disclosure has a reduced working voltage (turn-on voltage) and significantly improved luminescence efficiency. This may result from a relatively twisted structure of the organic compound of the present disclosure so that the organic compound has a relatively small overlap between the HOMO energy level and the LUMO energy level and a relatively small energy level difference E.sub.ST, which achieves efficient reverse intersystem crossing (RISC), causes more triplet excitons to cross to a singlet state for fluorescence emission, and achieves higher luminescence efficiency. Moreover, B-containing units of the organic compound of the present disclosure are joined to form a spiro ring, which improves molecular stability and the stability of the device. The joined spiro ring reduces a degree of stacking among molecules, which is conducive to reducing concentration quenching. The organic compound of the present disclosure has excellent thermal stability and film stability and is more stable when the OLED device is working. Therefore, the organic compound is conducive to preparing the OLED device and extending the lifetime of the OLED device.

(172) The applicant states that although the organic compound and the application thereof of the present disclosure are described through the preceding examples, the present disclosure is not limited to the preceding process steps, which means that the implementation of the present disclosure does not necessarily depend on the preceding process steps. Those skilled in the art are to understand that any improvements made to the present disclosure, equivalent substitutions of selected raw materials, additions of adjuvant ingredients, selections of specific manners or the like in the present disclosure all fall within the protection scope and the disclosure scope of the present disclosure.