阅读说明：本技术 化合物、显示面板和显示装置 (Compound, display panel and display device ) 是由 张磊 高威 牛晶华 刘营 邓东阳 李杨 肖文静 匡立莲 于 2020-07-31 设计创作，主要内容包括：本发明属于OLED技术领域并提供了用作电子传输材料的化合物,其具有化学式1所示的结构,其中,X<Sub>1</Sub>、X<Sub>2</Sub>、X<Sub>3</Sub>、X<Sub>4</Sub>、X<Sub>5</Sub>和X<Sub>6</Sub>各自独立地选自C原子或N原子；R<Sub>1</Sub>和R<Sub>2</Sub>各自独立地选自氢原子、取代或未取代的C6-C60芳基、取代或未取代的C4-C60杂芳基、取代或未取代的C10-C60稠芳基、C8-C30稠杂芳基。本发明的化合物具有合适的HOMO和LUMO值,可以有效提高电子传输能力。本发明的化合物具有高的电子迁移率,优异的热稳定性和薄膜稳定性,有利于提升发光效率。本发明还提供一种显示面板和显示装置。(The present invention belongs to the technical field of OLED and provides a compound used as an electron transport material, which has a structure shown in chemical formula 1, wherein X 1 、X 2 、X 3 、X 4 、X 5 And X 6 Each independently selected from a C atom or a N atom; r 1 And R 2 Each independently selected from a hydrogen atom, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C4-C60 heteroaryl group, a substituted or unsubstituted C10-C60 fused aryl group, and a C8-C30 fused heteroaryl group. The compound of the invention has proper HOMO and LUMO values, and can effectively improve the electron transport capacity. The compound provided by the invention has high electron mobility, excellent thermal stability and film stability, and is beneficial to improving the luminous efficiency. The invention also provides a display panel and a display device.)

1. A compound having the general structure shown in formula 1:

wherein, X₁、X₂、X₃、X₄、X₅And X₆Each independently selected from a C atom or a N atom;

R₁and R₂Each independently selected from hydrogen atom, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C4-C60 heteroaryl, substitutedOr unsubstituted C10-C60 fused aryl, C8-C30 fused heteroaryl.

2. The compound of claim 1, wherein X is₁、X₂And X₃At least one of them being an N atom, and X₄、X₅And X₆At least one of which is an N atom.

3. A compound according to any one of claims 1 or 2, wherein R is₁And R₂Each independently selected from the group consisting of:

wherein Cy is present or absent; when Cy is present, Cy is selected from an aromatic ring or aromatic fused ring;

n is selected from 0, 1 or 2;

# denotes the ligation site.

4. A compound of claim 3, wherein R is₁And R₂Each independently selected from any one of the following groups:

# denotes the ligation site.

5. A compound according to any one of claims 1 or 2, wherein R is₁And R₂Each independently selected from the group consisting of:

x is selected from O, S, N-R₀₁Or C (R)₀₂R₀₃)；

Wherein R is₀、R₀₁、R₀₂And R₀₃Each independently selected from a hydrogen atom, a C1-C6 alkyl group, a C1-C6 alkoxy group, a C6-C12 aryl group;

m is selected from 0, 1 or 2;

# denotes the ligation site.

6. A compound of claim 5, wherein R is₁And R₂Each independently selected from any one of the following groups:

r₁、r₂、r₃、r₄and r₅Each independently selected from a hydrogen atom, a C1-C6 alkyl group, a C1-C6 alkoxy group, a C6-C12 aryl group;

m is selected from the number 0, 1 or 2;

# denotes the ligation site.

7. A compound according to any one of claims 1 or 2, wherein R is₁And R₂Each independently selected from any one of the following groups:

wherein, Y, Z₁、Z₂Each independently selected from O, S, N-R₇Or C (R)₀₄R₀₅)；

X₇、X₈、X₉、X₁₀、X₁₁Each independently is selected from C or N atoms;

R₆、R₇、R₀₄and R₀₅Independently selected from hydrogen atom, C1-C6 alkyl, C1-C6 alkoxy, C6-C12 aryl;

p is selected from the number 0, 1 or 2;

# denotes the ligation site.

8. According to claim 7The compound of (1), wherein R is₁And R₂Each independently selected from any one of the following groups:

r₈selected from hydrogen atom, C1-C6 alkyl, C1-C6 alkoxy, C6-C12 aryl;

# denotes the ligation site.

9. The compound of claim 1, wherein the compound is selected from one of the following compounds:

10. a display panel comprising an organic light emitting device, wherein the organic light emitting device comprises an anode, a cathode, an electron transport layer and a light emitting layer disposed between the anode and the cathode in an opposing relationship, wherein the material of the electron transport layer comprises one or more compounds of any one of claims 1 to 9.

11. A display device comprising the display panel of claim 10.

Technical Field

The invention belongs to the technical field of OLED, and particularly relates to a compound used as an electron transport material, a display panel comprising the compound and a display device comprising the compound.

Background

The electron transport material used in conventional electroluminescent devices is Alq3, but the electron mobility ratio of Alq3 is relatively low (approximately at l 0)^-6cm²Vs) such that electron transport and hole transport of the device are not balanced. With the commercialization and practicability of electroluminescent devices, electronic transmission materials having higher transmission efficiency and better usability are desired. In this field, researchers have done a great deal of exploratory work.

Most of the electron transport materials currently used in the market, such as batho-phenanthroline (BPhen), Bathocuproine (BCP) and TmPyPB, can substantially meet the market demand of organic electroluminescent panels, but their glass transition temperature is low, generally less than 85 ℃, and the generated joule heat during device operation can cause molecular degradation and change of molecular structure, resulting in low panel efficiency and poor thermal stability. Meanwhile, the molecular structures have high symmetry and are easy to crystallize after a long time. Once the electron transport material is crystallized, the intermolecular charge jump mechanism is different from the normal amorphous thin film mechanism, resulting in the decrease of electron transport performance, the imbalance of electron and hole mobility of the whole device, the great decrease of exciton formation efficiency, and the concentration of exciton formation at the interface of the electron transport layer and the light emitting layer, resulting in the serious decrease of device efficiency and lifetime.

Therefore, the design and development of the stable and efficient electron transport material with high electron mobility and high glass transition temperature are used for improving the luminous efficiency of the device and prolonging the service life of the device, and the design and development of the electron transport material have important practical application value.

Disclosure of Invention

In view of the above, the present invention provides a compound for use as an electron transport material, the compound having a general structure represented by chemical formula 1:

wherein, X₁、X₂、X₃、X₄、X₅And X₆Each independently selected from a C atom or a N atom;

R₁and R₂Each independently selected from a hydrogen atom, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C4-C60 heteroaryl group, a substituted or unsubstituted C10-C60 fused aryl group, and a C8-C30 fused heteroaryl group.

The invention provides an electron transport material which has appropriate HOMO and LUMO values and can effectively improve the electron transport capacity. The compound provided by the invention has high electron mobility, excellent thermal stability and film stability, and is beneficial to improving the luminous efficiency.

Drawings

FIG. 1 shows the general structure of the compounds of the present invention;

FIG. 2 is a schematic structural diagram of an OLED device provided by the present invention;

fig. 3 is a schematic diagram of a display device according to an embodiment of the present invention.

Detailed Description

The present invention is further illustrated by the following examples and comparative examples, which are intended to be illustrative only and are not to be construed as limiting the invention. The technical scheme of the invention is to be modified or replaced equivalently without departing from the scope of the technical scheme of the invention, and the technical scheme of the invention is covered by the protection scope of the invention.

An aspect of the present invention provides a compound for use as an electron transport material, the compound having a general structure represented by chemical formula 1:

wherein, X₁、X₂、X₃、X₄、X₅And X₆Each independently selected from a C atom or a N atom;

R₁and R₂Each independently selected from a hydrogen atom, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C4-C60 heteroaryl group, a substituted or unsubstituted C10-C60 fused aryl group, and a C8-C30 fused heteroaryl group.

The nitrogen heteroaryl and the sulfoxide group in the compound have good metal compound doping effect, can effectively perform doping action with a metal compound, are favorable for improving the electron injection and transmission performance of an electron transmission layer, and enhance the transmission rate of holes and electrons in a balancer device and the luminous efficiency of the device.

In the general structure shown in chemical formula 1, the dotted line indicates that the sulfone group and the two benzene rings connected to the two sides of the sulfone group can form a ring by a real single bond, or can indicate that the ring is not formed, that is, the dotted line indicates that the single bond connecting the benzene rings on the two sides of the sulfone group does not exist.

According to one embodiment of the compound of the present invention, the compound has a general structure shown in chemical formula 1-1:

according to one embodiment of the compounds of the present invention, X₁、X₂And X₃At least one of them being an N atom, and X₄、X₅And X₆At least one of which is an N atom. The compound in the scheme not only increases the sites for doping the metal compound, but also the electron accepting capability of the pure sulfoxide group is not enough to reach the LUMO energy level value required by an electron transport material, and the electron accepting capability of the compound provided by the invention is enhanced by the N atom. In addition, due to X₁、X₂And X₃At least one of them being an N atom, and X₄、X₅And X₆In which at least one is an N atom, X₁、X₂And X₃The ring is nitrogen heterocycle and X₄、X₅And X₆The ring is a nitrogen heterocyclic ring, and the SP3 hybridized carbon atom on the fluorenyl is connected to the ortho position of the nitrogen atom in the nitrogen heterocyclic ring, so that the structure is relatively simple and convenient to synthesize, and the electron accepting LUMO energy level of the invention is inclined toThe core is of an integral structure and is not too dispersed. In addition, the compound structure of the embodiment can also enhance the electron accepting capability of the material, does not weaken the peripheral HOMO group, and integrally enables the compound of the invention to have better carrier accepting and transmitting capability, thereby improving the luminous efficiency of the device.

According to one embodiment of the compounds of the present invention, X₁、X₂And X₃At least one of them being an N atom, and X₄、X₅And X₆In which at least one is a N atom, R₁Or R₂At the ortho-position of the nitrogen atom.

According to one embodiment of the compound of the present invention, the structure of the compound is symmetrical. The symmetrical structure is not only beneficial to the synthesis of the compound, but also can enable the molecules of the compound to have better regularity, thereby being beneficial to the evaporation of the compound.

According to one embodiment of the compounds of the invention, R₁And R₂Each independently selected from the group consisting of:

wherein Cy is present or absent; when Cy is present, Cy is selected from an aromatic ring or aromatic fused ring;

n is selected from 0, 1 or 2;

# denotes the ligation site.

According to one embodiment of the compounds of the invention, R₁And R₂Each independently selected from the group consisting of:

wherein Cy is selected from benzene ring, naphthalene ring and phenanthrene ring.

According to one embodiment of the compounds of the invention, R₁And R₂Each independently selected from any one of the following groups:

# denotes the ligation site.

According to one embodiment of the compounds of the invention, R₁And R₂Each independently selected from the group consisting of:

x is selected from O, S, N-R₀₁Or C (R)₀₂R₀₃)；

Wherein R is₀、R₀₁、R₀₂And R₀₃Each independently selected from a hydrogen atom, a C1-C6 alkyl group, a C1-C6 alkoxy group, a C6-C12 aryl group;

m is selected from 0, 1 or 2;

# denotes the ligation site.

According to one embodiment of the compounds of the invention, R₁And R₂Each independently selected from any one of the following groups:

r₁、r₂、r₃、r₄and r₅Each independently selected from a hydrogen atom, a C1-C6 alkyl group, a C1-C6 alkoxy group, a C6-C12 aryl group;

m is selected from the number 0, 1 or 2;

# denotes the ligation site.

According to one embodiment of the compounds of the invention, R₁And R₂Each independently selected from any one of the following groups:

wherein, Y, Z₁、Z₂Each independently selected from O, S, N-R₇Or C (R₀₄R₀₅)；

X₇、X₈、X₉、X₁₀、X₁₁Each independently is selected from C or N atoms;

R₆、R₇、R₀₄and R₀₅Independently selected from hydrogen atom, C1-C6 alkyl, C1-C6 alkoxy, C6-C12 aryl;

p is selected from the number 0, 1 or 2;

# denotes the ligation site.

According to one embodiment of the compounds of the invention, R₁And R₂Each independently selected from any one of the following groups:

r₈selected from hydrogen atom, C1-C6 alkyl, C1-C6 alkoxy, C6-C12 aryl;

# denotes the ligation site.

According to one embodiment of the compound of the present invention, the compound is selected from one of the following compounds:

the invention also provides a display panel comprising an organic light-emitting device, wherein the organic light-emitting device comprises an anode and a cathode which are oppositely arranged, and an electron transport layer and a light-emitting layer which are positioned between the anode and the cathode, wherein the material of the electron transport layer comprises one or more of the compounds disclosed by the invention.

According to the display panel of the present invention, the electron injection layer includes the compound of the present invention and a doping metal. Preferably the doping metal is selected from one or more of the metals sodium, potassium, calcium, cesium and ytterbium. The doped metal can solve the problems of over high energy barrier of an interface between an electron transport layer and a cathode and low performance of the organic light-emitting display panel in the existing organic light-emitting display panel. By doping metal in the electron injection layer, the purposes of reducing the interface energy barrier between the electron transport layer and the cathode of the organic light-emitting display panel, improving the electron injection capability and improving the performance of the organic light-emitting display panel are achieved.

According to the display panel of the present invention, the organic light emitting device further includes one or more of a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, or an electron injection layer.

The luminescent performance of different devices requires reasonable matching of the luminescent functional layers. Thus, different organic light emitting functional layers may be selected according to different display requirements and selected compounds.

The present invention also exemplarily describes the synthesis of compounds a002, a016, a018, a029 and a 032.