Hole injection material, hole injection layer comprising same, and OLED display panel

Abstract

The invention relates to a hole injection material. The hole injection material comprises a compound having a structure represented by formula (I); and in the formula (I), R1, R2, R3, R4, R5, R6, R7 and R8 are respectively independently selected from an electron withdrawing group, the hydrogen atom and a non-electron withdrawing group, and at least one of the R1, R2, R3, R4, R5, R6, R7 and R8 is the electron withdrawing group. The hole injection material has a cross-conjugated structure, and is grafted with the electron-withdrawing group, and the electron-withdrawing group cooperates with thecross-conjugated system to expand an electron receiving area to a large range and make a large number of electrons jump to the LUMO energy level of a doped material from the HOMO energy level of a hole transport material, so that many free holes are formed in the hole transport material, thereby the conductivity of a device is improved; and the hole injection material has good non-planar characteristics, so the a crystallization effect is prevented, and the light extraction efficiency of the device is improved.

Description

technical field

[0001] The invention belongs to the field of preparation of organic light-emitting diodes, and in particular relates to a hole injection material, a hole injection layer containing it, an OLED display panel and electronic equipment. Background technique

[0002] An OLED display is a display made of organic light-emitting diodes. Due to its self-illumination, high contrast ratio, thin thickness, fast response speed, flexible panel, and simple structure, it is considered to be the next generation of flat-panel display technology. The structure of OLED devices is generally: cathode (Cathode) / electron injection layer (EIL) / electron transport layer (ETL) / light emitting layer (EML) / hole transport layer (HTL) / hole injection layer (HIL) / anode ( Anode). Energy level matching is very important for organic electroluminescent devices. The general structure of OLED devices mostly uses ITO as the anode, but its work function is relatively high, and the energy...

Examples

preparation example 1

[0047] A hole-injecting material, the structure of which is The preparation method comprises the following steps:

[0048]

[0049] Add a-1 (163.88mg, 1mmol), Pd(OAc) to the reaction flask 2 (8.96 mg, 4% mmol) and 2-dicyclohexylphosphine-2,4,6-triisopropylbiphenyl (XPhos) (19.07 mg, 8% mmol). Then a-2 (1.84g, 5mmol) was added dropwise into the reaction flask, and stirring was continued at 60°C for 6h after completion. The reaction solution was concentrated and passed through a column to obtain a-3.

[0050] Characterization:

[0051] NMR: 13 H NMR: (1H, 27.5); (1H, 33.5); (8H, 117.2); (2H, 136.5); (4H, 165.3);

[0052] Mass spectrum: 332.06.

preparation example 2

[0054] A hole-injecting material, the structure of which is The preparation method comprises the following steps:

[0055]

[0056] Add b-1 (163.88mg, 1mmol), Pd(OAc) to the reaction flask 2 (8.96 mg, 4% mmol) and 2-dicyclohexylphosphine-2,4,6-triisopropylbiphenyl (XPhos) (19.07 mg, 8% mmol). Then b-2 (2.58g, 5mmol) was added dropwise into the reaction flask, and stirring was continued at 60°C for 6h after completion. The reaction solution was concentrated and passed through a column to obtain b-3.

[0057] Characterization:

[0058] NMR: 13 H NMR: (1H, 27.5); (1H, 37.5); (4H, 88.9); (4H, 110.5); (4H, 116.4); (4H, 116.5); (4H, 117.2); (4H, 140.5) ;(8H,144.7);(8H,149.7);

[0059] Mass spectrum: 926.05.

preparation example 3

[0061] A hole-injecting material, the structure of which is The preparation method comprises the following steps:

[0062]

[0063] Add c-1 (163.88mg, 1mmol), Pd(OAc) to the reaction flask 2 (8.96 mg, 4% mmol) and 2-dicyclohexylphosphine-2,4,6-triisopropylbiphenyl (XPhos) (19.07 mg, 8% mmol). Then b-2 (2.55g, 5mmol) was added dropwise into the reaction flask, and stirring was continued at 60°C for 6h after completion. The reaction solution was concentrated and passed through a column to obtain b-3.

[0064] Characterization:

[0065] NMR: 13 H NMR: (1H, 27.5); (1H, 33.5); (4H, 107.7); (4H, 110.5); (4H, 117.2); (8H, 133.2); (4H, 138.5); (4H, 140.5) ;(8H,145.6);

[0066] Mass spectrum: 898.03.

technical field

[0001] The invention belongs to the field of preparation of organic light-emitting diodes, and in particular relates to a hole injection material, a hole injection layer containing it, an OLED display panel and electronic equipment. Background technique

[0002] An OLED display is a display made of organic light-emitting diodes. Due to its self-illumination, high contrast ratio, thin thickness, fast response speed, flexible panel, and simple structure, it is considered to be the next generation of flat-panel display technology. The structure of OLED devices is generally: cathode (Cathode) / electron injection layer (EIL) / electron transport layer (ETL) / light emitting layer (EML) / hole transport layer (HTL) / hole injection layer (HIL) / anode ( Anode). Energy level matching is very important for organic electroluminescent devices. The general structure of OLED devices mostly uses ITO as the anode, but its work function is relatively high, and the energy...

Examples

preparation example 1

[0047] A hole-injecting material, the structure of which is The preparation method comprises the following steps:

[0048]

[0049] Add a-1 (163.88mg, 1mmol), Pd(OAc) to the reaction flask 2 (8.96 mg, 4% mmol) and 2-dicyclohexylphosphine-2,4,6-triisopropylbiphenyl (XPhos) (19.07 mg, 8% mmol). Then a-2 (1.84g, 5mmol) was added dropwise into the reaction flask, and stirring was continued at 60°C for 6h after completion. The reaction solution was concentrated and passed through a column to obtain a-3.

[0050] Characterization:

[0051] NMR: 13 H NMR: (1H, 27.5); (1H, 33.5); (8H, 117.2); (2H, 136.5); (4H, 165.3);

[0052] Mass spectrum: 332.06.

preparation example 2

[0054] A hole-injecting material, the structure of which is The preparation method comprises the following steps:

[0055]

[0056] Add b-1 (163.88mg, 1mmol), Pd(OAc) to the reaction flask 2 (8.96 mg, 4% mmol) and 2-dicyclohexylphosphine-2,4,6-triisopropylbiphenyl (XPhos) (19.07 mg, 8% mmol). Then b-2 (2.58g, 5mmol) was added dropwise into the reaction flask, and stirring was continued at 60°C for 6h after completion. The reaction solution was concentrated and passed through a column to obtain b-3.

[0057] Characterization:

[0058] NMR: 13 H NMR: (1H, 27.5); (1H, 37.5); (4H, 88.9); (4H, 110.5); (4H, 116.4); (4H, 116.5); (4H, 117.2); (4H, 140.5) ;(8H,144.7);(8H,149.7);

[0059] Mass spectrum: 926.05.

preparation example 3

[0061] A hole-injecting material, the structure of which is The preparation method comprises the following steps:

[0062]

[0063] Add c-1 (163.88mg, 1mmol), Pd(OAc) to the reaction flask 2 (8.96 mg, 4% mmol) and 2-dicyclohexylphosphine-2,4,6-triisopropylbiphenyl (XPhos) (19.07 mg, 8% mmol). Then b-2 (2.55g, 5mmol) was added dropwise into the reaction flask, and stirring was continued at 60°C for 6h after completion. The reaction solution was concentrated and passed through a column to obtain b-3.

[0064] Characterization:

[0065] NMR: 13 H NMR: (1H, 27.5); (1H, 33.5); (4H, 107.7); (4H, 110.5); (4H, 117.2); (8H, 133.2); (4H, 138.5); (4H, 140.5) ;(8H,145.6);

[0066] Mass spectrum: 898.03.

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