阅读说明：本技术 一种具有高空穴迁移率的pled聚合物及其制备方法 (PLED polymer with high hole mobility and preparation method thereof ) 是由 冯旗 于 2020-06-15 设计创作，主要内容包括：本发明属有机发光显示领域,特别涉及一种具有高空穴迁移率的PLED聚合物及其制备方法。本发明提供了一种具有高空穴迁移率的PLED聚合物,其结构如式(I)所示。本发明还提供了一种具有高空穴迁移率的PLED聚合物的制备方法,包括将式(II)所示化合物和2,2’-(9,9-二辛基-9H-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。本发明提供的一种具有高空穴迁移率的PLED聚合物及其制备方法,解决了现有的PLED器件空穴迁移率较低的技术问题。(The invention belongs to the field of organic light-emitting display, and particularly relates to a PLED polymer with high hole mobility and a preparation method thereof. The invention provides a PLED polymer with high hole mobility, which has a structure shown in a formula (I). The invention also provides a preparation method of the PLED polymer with high hole mobility, which comprises the step of carrying out Suzuki coupling reaction on the compound shown in the formula (II) and 2,2' - (9, 9-dioctyl-9H-fluorene-2, 7-diyl) bis (4,4,5, 5-tetramethyl-1, 3, 2-dioxaborane) to prepare the polymer shown in the formula (I). The PLED polymer with high hole mobility and the preparation method thereof provided by the invention solve the technical problem of low hole mobility of the existing PLED device.)

1. A PLED polymer with high hole mobility, characterized in that the structure is shown in formula (I):

wherein n is 500-.

2. A preparation method of a PLED polymer with high hole mobility is characterized by comprising the steps of carrying out Suzuki coupling reaction on a compound shown as a formula (II) and 2,2' - (9, 9-dioctyl-9H-fluorene-2, 7-diyl) bis (4,4,5, 5-tetramethyl-1, 3, 2-dioxaborane) to prepare a polymer shown as a formula (I),

3. the method for preparing a PLED polymer with high hole mobility according to claim 2, wherein the time of the Suzuki coupling reaction is 12 to 48 hours.

4. The method for preparing a PLED polymer with high hole mobility according to claim 2 wherein the temperature of the Suzuki coupling reaction in step 1 is 100 ℃.

5. The method for preparing a PLED polymer with high hole mobility according to claim 2, wherein the compound represented by the formula (II) is prepared by the following steps:

step 1: carrying out bromination reaction on 4,4' -diiodobiphenyl to generate 2-bromo-4, 4' -diiodo-1, 1' -biphenyl;

step 2: carrying out nucleophilic substitution reaction on the 2-bromo-4, 4 '-diiodo-1, 1' -biphenyl and 3, 6-dioctylcarbazole to generate a compound shown as a formula (III):

and step 3: carrying out nucleophilic substitution reaction on the compound shown in the formula (III) and 2, 7-dibromo spiro [ fluorene-9, 2' -oxirane ] to generate a compound shown in a formula (IV),

and 4, step 4: and (3) carrying out a coupling reaction on the compound shown in the formula (IV) and 1, 4-dioxane to generate a compound shown in a formula (II).

6. The method for preparing a PLED polymer with high hole mobility according to claim 2 wherein the 2,2' - (9, 9-dioctyl-9H-fluorene-2, 7-diyl) bis (4,4,5, 5-tetramethyl-1, 3, 2-dioxaborane) is prepared by the following steps:

step 1: 2, 7-dibromo-fluorene is subjected to electrophilic substitution reaction to generate 2, 7-dibromo-9, 9-dioctyl-fluorene;

step 2: and carrying out nucleophilic substitution reaction on the 2, 7-dibromo-9, 9-dioctyl-fluorene and bis pinacol borate to generate 2,2' - (9, 9-dioctyl-9H-fluorene-2, 7-diyl) bis (4,4,5, 5-tetramethyl-1, 3, 2-dioxaborane).

Technical Field

The invention belongs to the field of organic light-emitting display, and particularly relates to a PLED polymer with high hole mobility and a preparation method thereof.

Background

An organic electroluminescent device (PLED) is a light emitting element which is self-luminous, high-brightness, and full-color, and a phenomenon that electrons and holes are recombined to emit light in an organic light emitting layer under the action of an applied electric field to generate current light emission. The organic electroluminescent device has: the power consumption is low under low direct current voltage; the luminous brightness is high, and the efficiency is high; the luminous color is wide; the response speed is high; thin display parts and the like. Therefore, organic electroluminescence is one of the most competitive technologies in the field of flat panel displays in the future. In order to improve the stability of the PLED device and reduce power consumption, the selection of a suitable hole injection material is a key point of research. In recent years, inorganic compounds such as vanadium oxide, tungsten oxide and molybdenum oxide are tried to be used as a hole injection layer, and although the HOMO energy level of the materials is low and the open-circuit voltage of the materials can be close to 1.0V, the low hole mobility limits the short-circuit current of the device and influences the final electroluminescent efficiency of the PLED device.

Semiconductor photoelectricity, volume 25, No. 3, page 191, 2004, discloses a device in which an ITO electrode, a metal electrode, and a polymer film therebetween are sandwiched, and the polymer film adopts a blended layer of a polymer and other small molecule light-emitting materials, so as to improve the hole mobility of a PLED stacked device. However, in the process of manufacturing the device, the metal electrode film such as Al on the polymer functional layer needs to be formed by vacuum thermal evaporation. The vacuum evaporation metal electrode needs high-vacuum-degree vacuum equipment, so that the preparation method is complicated, the cost is high, and the hole mobility is low.

Therefore, the low hole mobility of the conventional PLED device is a technical problem to be solved by those skilled in the art.

Disclosure of Invention

It is an object of the present invention to provide a PLED polymer with high hole mobility.

It is another object of the present invention to provide a method for preparing a PLED polymer having high hole mobility.

The purpose of the invention is realized by the following scheme:

the invention provides a PLED polymer with high hole mobility, which has a structure shown in a formula (I):

wherein n is 500-.

The invention also provides a preparation method of the PLED polymer with high hole mobility, which comprises the following steps of carrying out Suzuki coupling reaction on a compound shown as a formula (II) and 2,2' - (9, 9-dioctyl-9H-fluorene-2, 7-diyl) bis (4,4,5, 5-tetramethyl-1, 3, 2-dioxaborane) to prepare a polymer shown as a formula (I):

preferably, the time of the Suzuki coupling reaction is 12-48 h.

Preferably, the temperature of the Suzuki coupling reaction in the step 1 is 100 ℃.

Preferably, the compound represented by the formula (II) is prepared by the following steps:

step 1: carrying out bromination reaction on 4,4' -diiodobiphenyl to generate 2-bromo-4, 4' -diiodo-1, 1' -biphenyl;

step 2: carrying out nucleophilic substitution reaction on the 2-bromo-4, 4 '-diiodo-1, 1' -biphenyl and 3, 6-dioctylcarbazole to generate the compound shown in the formula (III)

And step 3: carrying out nucleophilic substitution reaction on the compound shown in the formula (III) and 2, 7-dibromo spiro [ fluorene-9, 2' -ethylene oxide ] to generate a compound shown in a formula (IV):

and 4, step 4: and (3) carrying out a coupling reaction on the compound shown in the formula (IV) and 1, 4-dioxane to generate a compound shown in a formula (II).

Preferably, the 2,2' - (9, 9-dioctyl-9H-fluorene-2, 7-diyl) bis (4,4,5, 5-tetramethyl-1, 3, 2-dioxaborane) is prepared by the following steps:

step 1: 2, 7-dibromo-fluorene is subjected to electrophilic substitution reaction to generate 2, 7-dibromo-9, 9-dioctyl-fluorene;

step 2: and carrying out nucleophilic substitution reaction on the 2, 7-dibromo-9, 9-dioctyl-fluorene and bis pinacol borate to generate 2,2' - (9, 9-dioctyl-9H-fluorene-2, 7-diyl) bis (4,4,5, 5-tetramethyl-1, 3, 2-dioxaborane).

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

when the PLED polymer prepared by the embodiment of the invention is used as a single-hole device, the effective voltage of the PLED polymer prepared by the invention is higher than that of a PFO device along with the increase of current density, and the effective voltage of the PLED polymer is higher than that of the PFO deviceThe highest effective voltage reaches 7.56x10^-5cm²The higher the effective voltage of a single-hole device, the higher the hole transport efficiency.

In addition, the HOMO energy levels of the PLED polymer prepared by the invention are measured to be-5.38, -5.40, -5.39 and-5.39 eV respectively. And the LUMO energy levels are-3.39, -3.34, -3.35 and-3.36 eV respectively, and the low HOMO energy level and the high LUMO energy level can provide enough driving force for the effective separation of excitons in the PLED device, so that the hole mobility of the PLED device is greatly improved.

Drawings

FIG. 1 is a current density-effective voltage curve of PLED polymer having high hole mobility prepared by example 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.