阅读说明：本技术 一种绿光有机电致发光材料及其制备方法 (Green light organic electroluminescent material and preparation method thereof ) 是由 李彪 于 2020-06-15 设计创作，主要内容包括：本发明属光电显示器件技术领域,具体涉及一种绿光有机电致发光材料及其制备方法。本发明提供了一种绿光有机电致发光材料,其结构如式(I)所示：其中,R为氢原子、碳原子数1-20的直链或者支链烷基,x的取值为0-1,聚合度n的取值为1-500。本发明还提供了一种绿光有机电致发光材料的制备方法,包括：将2’,7’-二溴-1,2,7,8-四辛基-9,9’-螺双[芴],2,2’-(2’,7’-二溴-9,9’-螺双[芴]-2,7-二基)双(9-乙基-9H-咔唑)和2,2’-(1’,2’,7’,8’-四辛基-9,9’-螺双[芴]-2,7-二基)双(4,4,5,5-四甲基-1,3,2-二氧杂硼烷)通过Suzuki偶联反应制得式(I)所示聚合物。本发明提供的一种绿光有机电致发光材料及其制备方法,解决了现有的绿光金属铱配合物易猝灭且在高亮度下效率严重下降的技术问题。(The invention belongs to the technical field of photoelectric display devices, and particularly relates to a green light organic electroluminescent material and a preparation method thereof. The invention provides a green light organic electroluminescent material, which has a structure shown in a formula (I): wherein, R is a hydrogen atom, a straight chain or branched chain alkyl with 1-20 carbon atoms, x takes the value of 0-1, and the polymerization degree n takes the value of 1-500. The invention also provides a preparation method of the green light organic electroluminescent material, which comprises the following steps: 2',7' -dibromo-1, 2,7, 8-tetraoctyl-9, 9' -spirobi [ fluorene ], 2,2' - (2', 7' -dibromo-9, 9' -spirobi [ fluorene ] -2, 7-diyl) bis (9-ethyl-9H-carbazole) and 2,2' - (1',2',7',8' -tetraoctyl-9, 9' -spirobi [ fluorene ] -2, 7-diyl) bis (4,4,5, 5-tetramethyl-1, 3, 2-dioxaborane) are subjected to Suzuki coupling reaction to prepare the polymer shown in the formula (I). The invention provides a green light organic electroluminescent material and a preparation method thereof, which solve the technical problems that the existing green light metal iridium complex is easy to quench and the efficiency is seriously reduced under high brightness.)

1. A green organic electroluminescent material is characterized in that the structure is shown as formula (I):

wherein, R is a hydrogen atom, a straight chain or branched chain alkyl with 1-20 carbon atoms, x takes the value of 0-1, and the polymerization degree n takes the value of 1-500.

2. The green organic electroluminescent material according to claim 1, wherein x is 0.1 to 0.3.

3. A preparation method of a green organic electroluminescent material is characterized by comprising the following steps: 2',7' -dibromo-1, 2,7, 8-tetraoctyl-9, 9' -spirobi [ fluorene ], 2,2' - (2', 7' -dibromo-9, 9' -spirobi [ fluorene ] -2, 7-diyl) bis (9-ethyl-9H-carbazole) and 2,2' - (1',2',7',8' -tetraoctyl-9, 9' -spirobi [ fluorene ] -2, 7-diyl) bis (4,4,5, 5-tetramethyl-1, 3, 2-dioxaborane) are subjected to Suzuki coupling reaction to prepare the polymer shown in the formula (I).

4. The method for preparing a green organic electroluminescent material according to claim 2, wherein the temperature of the Suzuki coupling reaction is 80 ℃.

5. The method for preparing a green organic electroluminescent material according to claim 2, wherein the time of the Suzuki coupling reaction is 30 hours.

Technical Field

The invention belongs to the technical field of photoelectric display devices, and particularly relates to a green light organic electroluminescent material and a preparation method thereof.

Background

In recent years, with the rapid development of intelligent mobile communication devices and the internet, the demand for information display technology is increasing. Organic electroluminescent devices (OLEDs) have been produced in response to the trend of the times, and have become a new generation of information display technology. Due to the characteristics of self-luminescence, low energy consumption, wide viewing angle, high brightness, flexible display, fast response time, simple device manufacturing process and the like, OLEDs have good application value in the daily flat panel display technology and solid state lighting. Due to the above characteristics, OLEDs have been the focus of research by researchers. To do in order toThe device can obtain full-color display, and red light, green light and blue light materials with excellent performance generally must be obtained at the same time. The existing green light materials mostly adopt green light metal iridium complexes. Jayaraman et al synthesized four iridium complexes based on phenylbenzimidazole, and all of the devices showed efficient green emission with maximum luminance up to 130301cdm^-2. However, the iridium complexes described above also have some problems such as: the phenomenon of quenching by solid state aggregation and the corresponding device operation suffer from severe efficiency degradation problems, especially at high brightness.

Therefore, the existing green-emitting metal iridium complex is easy to quench and has a serious efficiency reduction at high brightness, which is a technical problem to be solved by those skilled in the art.

Disclosure of Invention

The invention provides a green-light organic electroluminescent material and a preparation method thereof, and solves the technical problems that the existing green-light metal iridium complex is easy to quench and the efficiency is seriously reduced under high brightness.

The invention provides a green light organic electroluminescent material, which has a structure shown in a formula (I):

wherein, R is a hydrogen atom, a straight chain or branched chain alkyl with 1-20 carbon atoms, x takes the value of 0-1, and the polymerization degree n takes the value of 1-500.

Preferably, x is 0.1-0.3.

The invention also provides a preparation method of the green light organic electroluminescent material, which comprises the following steps: 2',7' -dibromo-1, 2,7, 8-tetraoctyl-9, 9' -spirobi [ fluorene ], 2,2' - (2', 7' -dibromo-9, 9' -spirobi [ fluorene ] -2, 7-diyl) bis (9-ethyl-9H-carbazole) and 2,2' - (1',2',7',8' -tetraoctyl-9, 9' -spirobi [ fluorene ] -2, 7-diyl) bis (4,4,5, 5-tetramethyl-1, 3, 2-dioxaborane) are subjected to Suzuki coupling reaction to prepare the polymer shown in the formula (I).

Preferably, the temperature of the Suzuki coupling reaction is 80 ℃.

Preferably, the time of the Suzuki coupling reaction is 30 h.

Compared with the prior art, the invention has the following advantages and beneficial effects:

prepared by the inventionThe PL spectrum of the polymer has a maximum peak value at about 525nm, which indicates that the polymer realizes green light emission, and no obvious red shift is found in the spectrum, indicating that the spectrum stability of the polymer is strong. The maximum lumen efficiency and the maximum external quantum efficiency of a device prepared by the polymer are respectively 12.5cd/A, and the maximum brightness also reaches 41200cd/m^2，And can maintain higher current efficiency at higher brightness.

Drawings

FIG. 1 is an EL/PL spectrum in a toluene solution of a polymer prepared in example 12 of the present invention;

FIG. 2 is an EL/PL spectrum in a toluene solution of a polymer prepared in example 13 of the present invention;

FIG. 3 is an EL/PL spectrum in a toluene solution of a polymer prepared in example 14 of the present invention;

FIG. 4 is a graph of luminance versus operating voltage for polymers prepared in examples 12-14 of the present invention.

Detailed Description

The present invention will be described in further detail with reference to specific examples, which are not intended to limit the present invention in any manner. Reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.