TWI704211B - Organic electroluminescent devices and material thereof - Google Patents

Abstract

A material of the organic electroluminescent devices is provided. The material is a luminescent material and comprises a structure represented by Formula (I):

(I) wherein L is substituted or unsubstituted benzene, n is 0 or 1, Ar is selected from

、

、

、

、

、

or

Description

Organic electroluminescence device and its material

The present invention relates to an organic electroluminescence device and its materials, and in particular to a novel material that can be used in the electron transport layer and/or hole blocking layer of the organic electroluminescence device.

Organic light-emitting diodes (OLEDs) are light-emitting elements manufactured using the principle of organic electroluminescence (OEL). The principle of light emission means that under a certain electric field, the electron holes pass through the Hole Transport Layer (HTL) and the Electron Transport Layer (ETL) respectively, and then enter an organic substance with light-emitting characteristics (organic Luminescent layer). When electrons and holes recombine in this light-emitting layer, they will first form an "exciton", and then release the energy to return to the ground state, and the released energy will have Part of it is released in the form of light of different colors to make the OLED emit light.

。但Alq ₃的三重態能階過低(T ₁≒2.0 eV)，發光層內的三重態能量容易轉移至電子傳輸層上，導致淬息(quenching)現象產生，使得磷光元件效率偏低。 At present, the commonly used electron transport layer material in OLED devices is tris(8-hydroxyquinoline) aluminum (Alq ₃ )

. However, the triplet energy level of Alq ₃ is too low (T ₁ ≒2.0 eV), and the triplet energy in the light-emitting layer is easily transferred to the electron transport layer, resulting in quenching phenomenon and low efficiency of the phosphorescent element.

In order to reduce the quenching phenomenon, some phosphorescent system OLED elements will add BAlq as a barrier layer to use its higher triplet energy level (T ₁ ≒2.3eV) to reduce the quenching phenomenon, but there will still be a small part The triplet energy is transferred to the electron transport layer. In addition, with this approach, a layer of structure needs to be added during component production, which increases complexity and cost.

Therefore, the development of electron transport layer materials with higher triplet energy levels is the goal of relevant manufacturers.

The present invention provides a material for an organic electroluminescence device, the compound structure and product characteristics of which are different from those of the prior art, which is a novel invention.

(I) According to an embodiment of the present invention, a material for an organic electroluminescence device is provided. This material has the structure shown in the following chemical formula (I):

(I)

、

、

、

、

、

或

，R為甲基、乙基、經取代或未取代的苯、或經取代或未取代的萘。 In formula (I), L is substituted or unsubstituted benzene, n is 0 or 1, and Ar is

,

,

,

,

,

or

, R is methyl, ethyl, substituted or unsubstituted benzene, or substituted or unsubstituted naphthalene.

ET1 ET2 ET3

ET4 ET5 ET6

ET7 ET8 ET9

ET10 ET11 ET12

ET13 ET14 ET15

ET16 ET17 ET18

ET19 ET20 ET21

及

。 ET22 ET23 ET24 In one embodiment, the material of formula (I) is a compound represented by any one of the following chemical formulas:

ET1 ET2 ET3

ET4 ET5 ET6

ET7 ET8 ET9

ET10 ET11 ET12

ET13 ET14 ET15

ET16 ET17 ET18

ET19 ET20 ET21

and

. ET22 ET23 ET24

In one embodiment, the above-mentioned material is used as the electron transport layer of the organic electroluminescence device.

In one embodiment, the above-mentioned material is a hole blocking layer of an organic electroluminescence device.

In one embodiment, the above-mentioned material is a phosphorescent hybrid host material of an organic electroluminescent device.

According to another embodiment of the present invention, an organic electroluminescent device is provided, which includes a layered structure arranged in the following order: a transparent substrate, an anode layer, a hole transport layer, a light emitting layer, an electron transport layer, and a cathode layer. The organic electroluminescence device is characterized in that the electron transport layer contains the above-mentioned materials.

In one embodiment, a hole injection layer is further included between the anode layer and the hole transport layer of the organic electroluminescence device.

In one embodiment, the organic electroluminescence device further includes an electron injection layer between the electron transport layer and the cathode layer.

In one embodiment, the organic electroluminescent device further includes a hole blocking layer between the electron transport layer and the light emitting layer.

In one embodiment, the hole blocking layer includes the aforementioned material.

In one embodiment, the anode layer and the cathode layer of the organic electroluminescence device are respectively in contact with an external power source to form electrical paths.

In detail, the novel structural material of the present invention is easier to prepare and purify than traditional electron transport layer materials, and has a higher triplet energy level, which can reduce the occurrence of quenching. The organic electroluminescent device using this material as the electron transport layer has higher phosphorescence efficiency than the organic electroluminescent device using the conventional electron transport layer material.

(I) The present invention provides a material for an organic electroluminescence device, which has the structure shown in the following chemical formula (I):

(I)

、

、

、

、

、

或

，R為甲基、乙基、經取代或未取代的苯、或經取代或未取代的萘。 In formula (I), L is substituted or unsubstituted benzene, n is 0 or 1,

,

,

,

,

,

or

, R is methyl, ethyl, substituted or unsubstituted benzene, or substituted or unsubstituted naphthalene.

As used herein, "substituted" benzene or naphthalene means that the bondable position on benzene or naphthalene is replaced by more than one methyl group. For example, since -L- already includes left and right bonding positions, it can be benzene substituted with 1 to 4 methyl groups. Since -R includes only one bonding position, it can be benzene substituted with 1 to 5 methyl groups, or naphthalene substituted with 1 to 7 methyl groups.

表示L可鍵結在

4個位置其中之一；

表示R可位於

5個位置其中之一；

表示R可位於

3個位置其中之一。 In the Ar structure, the substituents marked with a wavy line ﹏ indicate the connection position of Ar and L. The substituent inserted into the center of the ring and across multiple rings means that the substituent can be located at any bondable position on the rings. for example,

Indicates that L can be bonded to

One of 4 positions;

Indicates that R can be located

One of 5 positions;

Indicates that R can be located

One of 3 positions.

方案 2 ：兩步 Suzuki coupling 偶聯反應

The material of formula (I) can be obtained, for example, by the following synthesis method: Scheme 1 : Single-step Suzuki coupling reaction

Scheme 2 : Two-step Suzuki coupling reaction

The above scheme uses a single-step or two-step Suzuki coupling reaction for synthesis, and the reaction time is short and the preparation is easy, and the by-products are less generated, and the purification difficulty is low.

Hereinafter, several application examples are used to illustrate each step of the above reaction. However, it should be particularly noted that the proportions and types of the added components of the compounds in the examples are for demonstration purposes only, and are not intended to limit the present invention. Example 1 : Synthesis of Intermediate Sub 1

(Sub2-X) 30.7g 4-chlorobenzo[4,5]furo[3,2-D]pyrimidine, 31.6g 3-bromophenylboronic acid, 8.7g tetrakis(triphenylphosphine) palladium, and 41.5 g Potassium carbonate, place it under a nitrogen system, add 450ml tetrahydrofuran/150ml deionized water, stir to dissolve and then heat to reflux for reaction for 3 hours. After cooling, the organic layer was extracted and separated, and the aqueous layer was extracted twice with 300 ml of ethyl acetate, and the organic layers were combined and concentrated. The mixed solvent was recrystallized with tetrahydrofuran/methanol, filtered to obtain a white solid, and dried to obtain 34 g of intermediate Sub 1 finished product, with a yield of 71%. Example 2 : Synthesis of Intermediate Sub 2-1 Intermediate Sub 2-X can be synthesized through the following reaction route (starter B)

(Sub2-X)

Take Sub 2-1 as an example:

Sub 2-5 Place 38.3g of 2-(tribromophenyl)triphenylene in a 1L three-necked flask, place it under a nitrogen system, add 400ml of tetrahydrofuran, stir to dissolve and then cool to -85℃, drop in 48ml (2.5M) n-butyllithium, After stirring for 30 minutes, 19.0 g of triethyl borate was dropped, and the temperature was gradually increased and stirred for 16 hours. Add 300ml of hydrochloric acid (1N) aqueous solution and stir for 1 hour at room temperature, extract with ethyl acetate, collect the organic layer and concentrate, add 500ml of n-hexane to force out the solid, filter to obtain a white solid, dry to obtain Sub 2-1 31g, The rate is 90%. Example 3 : Synthesis of Intermediate Sub 2-5

Sub 2-5

Sub 2-10 Following the synthesis procedure in Example 2 Intermediate Sub 2-1, the 2-(tribromophenyl)triphenylene was changed to 34.9g of 2-phenyl-1-(3-bromophenyl)benzimidazole, and it was collected by filtration. A white solid was obtained and dried to obtain Sub 2-5 27g, with a yield of 88%. Example 4 : Synthesis of Intermediate Sub 2-10

Sub 2-10

Following the synthesis procedure in Example 2 Intermediate Sub 2-1, the 2-(tribromophenyl)triphenylene was changed to 30.1g 1-(4-bromophenyl)-2-ethyl-1H-benzo[ D] Imidazole, filtered to obtain white solid, dried to obtain Sub 2-10 22g, yield 83%.

According to the above description, the same synthesis method as in the synthesis of Sub 2-1 in Example 2 can be used to change the type of the starting material B to synthesize the following various intermediates Sub 2-X, as shown in Table 1:

2

3  

Sub 2-3 （可購得） 4  

Sub 2-4 （可購得） 5

Sub 2-5 6  

Sub 2-6 （可購得） 7

Sub 2-7 8

Sub 2-8 9

Sub 2-9 10

Sub 2-10 *列出CAS No.之化合物，表示其可以在市面上購得，可節省合成時間 實施例 5 ：中間體 Sub 3-1 之合成 :

起始物C             起始物D Table 1 Preparation of Sub 2-X Starter B Obtained Intermediate (Sub 2-X) 1

2

3

Sub 2-3 (available for purchase) 4

Sub 2-4 (available for purchase) 5

Sub 2-5 6

Sub 2-6 (available for purchase) 7

Sub 2-7 8

Sub 2-8 9

Sub 2-9 10

Sub 2-10 * CAS No. of the compounds listed, which may represent are commercially available, can save time Synthesis Example 5: Synthesis of Intermediate Sub 3-1 of:

Starter C Starter D

Place 26.5g 2-chlorodibenzoquinoxaline, 21.1g 3-bromophenylboronic acid, 5.8g tetrakis(triphenylphosphine) palladium, and 27.7g potassium carbonate in a 1L three-necked flask under nitrogen system and add 300ml tetrahydrofuran/100ml deionized water, stir to dissolve and react under reflux for 3 hours. After cooling, filter the solid. Use 300ml ethyl acetate to rinse the solid, 300ml tetrahydrofuran to rinse the solid to obtain a pale yellow solid. Dry to obtain Sub 3-1 product 32g, the yield was 81%. Example 6 : Synthesis of Intermediate Sub 3-3

Following the synthesis procedure of the intermediate Sub 3-1 in Example 5, the 2-chlorodibenzoquinoxaline was changed to 24.1g 2-chloro-4-phenylquinazoline to prepare 30g of Sub 3-3. The yield was 81%. Example 7 : Synthesis of Intermediate Sub 3-5

Following the synthesis procedure of Intermediate Sub 3-1 in Example 5, replacing 2-chlorodibenzoquinoxaline with 29.1g 2-chloro-4-phenylbenzo[h]quinazoline to prepare Sub 3 -3 34g finished product, yield 83%. Example 8 : Synthesis of Intermediate Sub4-1

A 0.5L three-necked flask was placed with 19.3g 2-(3-bromophenyl) dibenzoquinoxaline, 15.2g pinacol diborate, 1.8g [1,1'-bis(diphenylphosphine) Ferrocene] palladium dichloride, and 12.2g potassium acetate, placed under a nitrogen system, add 250ml tetrahydrofuran, stir to dissolve and then heat to reflux for 9 hours. After cooling, add 200ml of deionized water and stir to extract and separate the organic layer. The aqueous layer was extracted once with 100 ml of ethyl acetate, and the organic layers were combined and concentrated. Then, the solid was washed with 300 ml of n-hexane, filtered to obtain a brown solid, and dried to obtain 17 g of Sub 4-1 finished product with a yield of 78%. Example 9 : Synthesis of Intermediate Sub 4-3

Following the synthesis procedure of the intermediate Sub 4-1 in Example 8, the 2-(3-bromophenyl)dibenzoquinoxaline was changed to 18.1g 2-(3-bromophenyl)dibenzoquinoxaline , 15g of Sub 4-3 finished product can be prepared, and the yield is 74%. Example 10 : Synthesis of Intermediate Sub 4-5

Following the synthesis procedure of the intermediate Sub 4-1 in Example 8, the 2-(3-bromophenyl)dibenzoquinoxaline was changed to 20.5g 2-(3-bromophenyl)-4-phenylbenzene With [h]quinazoline, 16g of Sub 4-5 can be prepared with a yield of 71%.

According to the above description, the same synthesis method as the synthesis of Sub 3-1 and Sub 4-1 in Example 5 and Example 8 can be used to change the types of starting materials C and D to synthesize the following intermediates Sub 4-X , Organize the following table 2:

2

3

4

5

6

實施例 11 ：電子傳輸層材料 ET1 之合成

Table 2 Preparation of Sub4-X Starter C Starter D Sub 3-X Sub 4-X 1

2

3

4

5

6

Example 11 : Synthesis of electron transport layer material ET1

Put 6.5g Sub 1, 7.7g Sub 2-1, and 5.5g potassium carbonate in a 250ml three-necked flask under nitrogen system, add 90ml toluene/30ml deionized water/3ml ethanol, stir to dissolve and then add 1.1g four Palladium (triphenylphosphine) was heated and refluxed for 4 hours. After cooling, methanol was added, the solid was separated out and the solid was collected, and toluene was recrystallized three times, and a bright white solid was obtained by filtration, and dried to obtain 8 g of ET1 finished product with a purity of 99% and a yield of 75%. Under the pressure of 10 ^-3 Torr, heat ET1 at 300°C for sublimation. Collect the sublimated solids to obtain ET1 with a purity of 99.5%, weigh 7g, and yield 88%.

¹ H NMR (400MHz, CDCl ₃ ): δ9.29(s, 1H), δ8.94(d, 2H), 8.77-8.60(m, 6H), δ8.30(d, 1H), δ8.14( s, 1H), δ7.98(d, 1H), δ7.93(d, 1H), δ7.89-7.59(m, 10H), δ7.52(t, 1H)

MS (m/z): [M ⁺ ] calcd. C ₄₀ H ₂₄ N ₂ O for, 548; found, 548 Example 12 : Synthesis of electron transport layer material ET3

Following the synthesis procedure of ET1 in Example 11, replacing Sub 1 with 4.1 g of starting material A, after purification, 7.5 g of finished ET3 can be prepared with a yield of 80%. After sublimation, ET3 with a purity of 99.5% was obtained, weighing 6.1g, and the yield was 81%.

¹ H NMR (400MHz, CDCl ₃ ): δ9.31(s, 1H), δ9.03(s, 1H), 8.97(d, 1H), δ8.83-8.60(m, 6H), δ8.30( d, 1H), δ8.01(t, 2H), δ7.81-7.63(m, 7H), δ7.52(t, 1H)

MS (m/z): [M ⁺ ] calcd. C ₃₄ H ₂₀ N ₂ O for, 472; found, 472 Example 13 : Synthesis of electron transport layer material ET5

Following the synthesis procedure of ET1 in Example 11, Sub 2-1 was changed to 6.9g Sub 2-4. After purification, 7.1g of finished ET5 could be prepared with a yield of 70%. After sublimation, ET5 with a purity of 99.5% was obtained, weighing 5.8g, and the yield was 81%.

¹ H NMR (400MHz, CDCl ₃ ): δ9.26(s, 1H), δ8.81(s, 1H), 8.59(d, 1H), δ8.29(d, 1H), δ7.91(d, 1H), δ7.79(d, 1H), δ7.77-7.25(m, 16H).

MS (m/z): [M ⁺ ] calcd. C ₃₅ H ₂₂ N ₄ O for, 514; found, 514 Example 14 : Synthesis of electron transport layer material ET14

Following the synthesis procedure of ET1 in Example 11, replacing Sub 2-1 with 5.9 g sub 2-10, after purification, 6.8 g of finished ET14 can be prepared with a yield of 73%. After sublimation, ET14 with a purity of 99.5% was obtained, weighing 5.3g, and the yield was 78%.

¹ H NMR (400MHz, CDCl ₃ ): δ9.27(s, 1H), δ8.79(s, 1H), 8.54(d, 1H), δ8.22(d, 1H), δ7.91-7.81( m, 2H), δ7.77-7.25(m, 11H), δ2.91(m, 2H), δ1.36(t, 3H).

MS (m/z): [M ⁺ ] calcd. C ₃₁ H ₂₂ N ₄ O for, 466; found, 466 Example 15 : Synthesis of electron transport layer material ET16

Following the synthesis procedure of ET1 in Example 11, Sub 2-1 was changed to 9.5 g sub 4-1, and the reaction was carried out for 16 hours. The ET16 material has extremely poor solubility in solvents. The reactants are filtered solid and refluxed with 200ml of tetrahydrofuran for 1 hour 3 times. After filtering again, 8g of finished ET16 can be obtained with a yield of 72%. After sublimation, ET16 with a purity of 99.5% was obtained, weighing 6g, and the yield was 75%.

MS (m/z): [M ⁺ ] calcd. C ₃₈ H ₂₂ N ₄ O for, 550; found, 550 Example 16 : Synthesis of electron transport layer material ET19

Following the synthesis procedure of ET1 in Example 11, Sub 2-1 was changed to 8.9g sub 4-3, and the reaction was carried out for 16 hours. After purification, 7g of finished ET19 can be prepared with a yield of 70%. After sublimation, ET19 with a purity of 99.5% was obtained, weighing 5.5g, and the yield was 78%.

¹ H NMR (400MHz, CDCl ₃ ): δ9.27(s, 1H), δ9.05(s, 1H), 8.95(s, 1H), δ8.72(d, 1H), δ8.58(d, 1H), δ8.28(d, 1H), δ8.18(d, 1H), δ8.11(d, 1H), δ7.97-7.81(m, 5H), δ7.73-7.44(m, 9H ).

MS (m/z): [M ⁺ ] calcd. C ₃₆ H ₂₂ N ₄ O for, 526; found, 525 Example 17 : Synthesis of electron transport layer material ET22

Following the synthesis procedure of ET1 in Example 11, Sub 2-1 was changed to 10.1g sub 4-5, and the reaction was carried out for 16 hours. After purification, 8.5g of finished ET22 can be prepared with a yield of 74%. After sublimation, ET22 with a purity of 99.5% was obtained, weighing 6.6g, and the yield was 78%.

¹ H NMR (400MHz, CDCl ₃ ): δ9.28(s, 1H), δ9.07(s, 1H), 8.93(s, 1H), δ8.82-8.76(m, 2H), δ8.60( d, 1H), δ8.31-8.12(m, 4H), δ8.01-7.91(m, 5H), δ7.76-7.52(m, 9H).

MS (m/z): [M ⁺ ] calcd. C ₄₀ H ₂₄ N ₄ O for, 576; found, 576 Example 18 : Measurement of triplet energy levels

For the electron transport layer materials synthesized in the above Examples 11-17, the triplet energy levels (T ₁ ) were calculated through low-temperature phosphorescence emission spectroscopy (phosphorescence), and the results are listed in Table 3 below:

Table 3 The triplet energy levels of the materials of the examples and comparative examples Triplet energy level (T ₁ ) ET1 2.70 eV ET3 2.76 eV ET5 2.72 eV ET14 2.75 eV ET16 2.50 eV ET19 2.57 eV ET22 2.52 eV Alq ₃ (comparative example) 2.0 eV

It can be seen from Table 3 that the triplet energy level (T ₁ ) of the material of the present invention is higher than the commonly used electron transport layer material Alq ₃ , and has a higher triplet energy level, which is suitable for use in the electron transport layer of phosphorescent elements and/ Or hole barrier.

It is particularly noted that although various electron transport layer materials and their synthesis methods are described in the foregoing Examples 11-17, the materials of the present invention are not limited thereto. According to the synthesis method of Example 11 above, a variety of different finished materials (code ET1-ET24) can be synthesized by using different starting materials and then through Suzuki coupling reaction. The combination can be shown in Table 4 below:

Table 4 Comparison of reactants and products of Suzuki coupling reaction # Reactant 1 Reactant 2 product 1 Sub1 Sub2-1 ET1 2 Sub1 Sub2-2 ET2 3 39876-88-5 Sub2-1 ET3 4 Sub1 Sub2-3 ET4 5 Sub1 Sub2-4 ET5 6 39876-88-5 Sub2-3 ET6 7 Sub1 Sub2-5 ET7 8 Sub1 Sub2-6 ET8 9 39876-88-5 Sub2-5 ET9 10 Sub1 Sub2-7 ET10 11 Sub1 Sub2-8 ET11 12 39876-88-5 Sub2-7 ET12 13 Sub1 Sub2-9 ET13 14 Sub1 Sub2-10 ET14 15 39876-88-5 Sub2-9 ET15 16 Sub1 Sub4-1 ET16 17 Sub1 Sub4-2 ET17 18 39876-88-5 Sub4-1 ET18 19 Sub1 Sub4-3 ET19 20 Sub1 Sub4-4 ET20 twenty one 39876-88-5 Sub4-3 ET21 twenty two Sub1 Sub4-5 ET22 twenty three Sub1 Sub4-6 ET23 twenty four 39876-88-5 Sub4-5 ET24 Example 19 Component test data 1

Please refer to FIG. 1, which shows the structure of the organic electroluminescence device 10 used in this embodiment. The organic electroluminescence device 10 of this embodiment is mainly prepared by vacuum evaporation, and includes a glass substrate 1, an ITO 2 (anode layer), a hole injection layer 3 (HIL), and a hole transport layer 4 ( hole transport layer (HTL), light-emitting layer 5 (host light-emitting material and guest light-emitting material), electron transport layer 6 (ETL), and cathode layer 7. The anode layer 2 and the cathode layer 7 are respectively in contact with an external power source to form electrical paths. This embodiment uses this device to test the characteristics of the organic electroluminescence device of the present invention.

In particular, in actual application, the organic electroluminescent device of the present invention is not limited to the above aspect, and the structure can be adjusted according to requirements. For example, an electron injection layer (EIL) can be designed between the electron transport layer 6 and the cathode layer 7, and a hole blocking layer can be designed between the electron transport layer and the light emitting layer, or the holes can be omitted. The injection layer 3 does not limit the structure of the organic electroluminescence device in the present invention.

The organic electroluminescence device of the present invention is characterized in that the electron transport layer material is the compound ET-X of formula (I), and the conventional electron transport material Alq _{3 is} used as a comparative example. In addition, the materials used in the other layers of the organic electroluminescent device of the embodiment and the comparative example are exactly the same, as detailed in Table 5 below: Table 5 Materials of each layer of the organic electroluminescent device structure material Substrate 1 glass Anode layer 2 Indium tin oxide ITO Hole Injection Layer (HIL) 3 CuPc 70nm Hole Transport Layer (HTL) 4 NPB 10nm Light emitting layer 5 Phosphorescent host material: CBP (4,4'-Bis(N-carbazolyl)-1,1'-biphenyl) Phosphorescent guest material: Ir(mphq) ₂ (acac) [(Bis(2-(3,5-dimethylphenyl) quinoline-C2,N')(acetylacetonato)iridium(III)] Electron Transport Layer (ETL) 6 ET-X & Alq ₃ 25nm Cathode layer 7 LiF 1nm, Al 150nm

This device is an orange-red light OLED, and the chemical structure of each material is as follows:

The test results of the organic electroluminescence device using the various materials of the embodiment of the present invention and the traditional material Alq ₃ as the electron transport layer material are shown in Table 6 below: Table 6 Characteristics of the organic electroluminescence device of the embodiment and the comparative example Example ETL Voltage (V) ELmax (nm) Current Efficiency* (cd/A) 1 ET1 6.7 617 nm 10.7 2 ET3 7.6 618 nm 10.2 4 ET5 6.8 617 nm 11.2 5 ET16 7.5 617 nm 10.3 6 ET19 7.5 618 nm 10.8 7 ET22 7.6 616 nm 11.0 Comparative example Alq3 8.4 616 nm 8.8 *Measured value under current density of 50mA/cm ²

The light-emitting range of the above-mentioned devices is about 617 nm (orange-red light wavelength range), which is an orange-red light OLED. It can be seen from Table 3 that the organic electroluminescence device using the electron transport layer material of the present invention has a higher luminous efficiency than the organic electroluminescence device using the traditional electron transport layer material Alq ₃ , which is increased by as much as 25%. In addition, the preparation methods of the above-mentioned materials are simple, easy to synthesize and purify, and have the potential for commercial application. Example 20 Component Test Data 2

The electron transport layer material of the present invention can be mixed with the electric transport layer HTL material in proportion to form a phosphorescent hybrid host material (co-host) to replace the existing host material (CBP). The following measures the properties of the organic electroluminescence device using the phosphorescent hybrid host material of the present invention. The materials and structure of the organic electroluminescence device are shown in Table 7 below, and the unlisted film structure is the same as the device test data 1 of Example 19.

Table 7 The characteristics of the organic electroluminescence device of the embodiment and the comparative example Example HOST ETL Turn-on Voltage (V) ELmax (nm) Current Efficiency* (cd/A) 4 CBP ET5 6.8 617 nm 11.2 6 CBP ET19 7.5 617 nm 10.8 7 CBP ET22 7.6 616 nm 11.0 9 NPB:ET5 (1:1) ET5 5.9 618 nm 14.2 10 NPB:ET19 (1:1) ET19 6.1 617 nm 13.7 11 NPB:ET22 (1:1) ET22 6.3 617 nm 13.5 *Measured value under current density of 50mA/cm ²

It can be seen from the above device test data that this electron transport layer material can improve the efficiency of the device, and when mixed with the hole transport material (HTL) in an appropriate ratio, it can be used as a phosphorescent hybrid host material (co-Host), which can be effective Improve component efficiency (up to 31%) and reduce the complexity of component production.

Although the present invention is described above with examples, these examples are not intended to limit the present invention. Those skilled in the art can make equivalent implementations or changes to these embodiments without departing from the technical spirit of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of the patent application attached thereafter.

1: Glass substrate 10: Organic electroluminescence device 2: ITO (anode layer) 3: Hole injection layer 4: Hole transport layer 5: Light emitting layer 6: Electron transport layer 7: Cathode layer

Figure 1 is a schematic diagram of the organic electroluminescence device of the present invention.

1: Glass substrate 10: Organic electroluminescence device 2: ITO (anode layer) 3: Hole injection layer 4: Hole transport layer 5: Light emitting layer 6: Electron transport layer 7: Cathode layer

Claims (11)

A material for an organic electroluminescence device, which has the structure shown in the following chemical formula (I):

(I); where L is substituted or unsubstituted benzene, n is 0 or 1, Ar is selected from

,

,

,

,

,

or

, R is methyl, ethyl, substituted or unsubstituted benzene or substituted or unsubstituted naphthalene. The material described in item 1 of the scope of patent application is a compound represented by any one of the following chemical formulas:

ET1 002 ET2 ET3 003

ET4 ET5 004 ET6

ET7 ET8 ET9

ET10 ET11 ET12

ET13 ET14 ET15

ET16 005 ET17 ET18 006

ET19 007 ET20 ET21

and

. ET22 ET23 ET24 The material described in item 1 or 2 of the scope of the patent application is used as the electron transport layer of the organic electroluminescence device. The material described in item 1 or 2 of the scope of patent application is used as a hole blocking layer for organic electroluminescence devices. The material described in item 1 or 2 of the scope of the patent application is used as the phosphorescent hybrid host material of the organic electroluminescent device. An organic electroluminescence device comprising a layered structure arranged in the following order: a transparent substrate, an anode layer, a hole transport layer, a light-emitting layer, an electron transport layer and a cathode layer; the organic electroluminescence device is characterized by: The electron transport layer contains the materials described in item 1 or 2 of the scope of patent application. According to the device described in claim 6, wherein the anode layer and the hole transport layer further include a hole injection layer. According to the device described in item 6 of the scope of patent application, an electron injection layer is further included between the electron transport layer and the cathode layer. According to the device described in item 6 of the scope of patent application, a hole blocking layer is further included between the electron transport layer and the light-emitting layer. The device described in item 9 of the scope of patent application, wherein the hole blocking layer comprises the material described in item 1 or 2 of the scope of patent application. The device described in item 6 of the scope of patent application, wherein the anode layer and the cathode layer are respectively in contact with an external power source to form an electrical path.

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