A blue light-emitting host composition, an organic electroluminescent device and a display device comprising the same

Abstract

The application discloses a blue light-emitting host composition, an organic electroluminescent device containing the same and a display device. The blue light-emitting host composition contains at least a first host compound, a second host compound and a third host compound; the structure of the first host compound is shown in formula I, the structure of the second host compound is shown in formula II, and the structure of the third host compound is shown in formula I or formula II. The melting point of the blue light-emitting host composition is lower than that of each single compound. The blue light-emitting host composition is evaporated to form a host composition film under continuous working conditions and different evaporation rates. The mass proportion of the blue light-emitting host composition in the film after final evaporation is relatively constant and is slightly different from the initial premixing proportion, thereby avoiding the problem that the actual evaporation component proportion is greatly different from the initial set premixing proportion, and the device performance is reduced.I, II.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of OLEDs, and specifically comprises a blue light-emitting host composition, an organic electroluminescent device comprising the same, and a display device. BACKGROUND

[0002] As a promising semiconductor light-emitting technology, organic electroluminescent devices (OLEDs) have made remarkable progress in recent years in terms of material science, device structure, performance optimization, and industrial application. How to further improve the comprehensive performance of blue organic electroluminescent devices is a hot research topic.

[0003] The existing pre-mixed double-host blue fluorescent light-emitting device has significant advantages. The double-host materials achieve good carrier balance through optimized energy level matching, which not only reduces the driving voltage and improves the luminous efficiency, but also effectively suppresses the efficiency roll-off. Currently, in the preparation of pre-mixed double-host blue fluorescent light-emitting devices, two host materials are usually pre-mixed in a preset mass ratio before evaporation, and then evaporated in one evaporation source. However, in the evaporation process, the two host components in the pre-mixed material do not evaporate in the pre-mixed ratio, resulting in a large difference between the actual evaporation film layer ratio of the two host materials and the initial preset ratio, which further leads to a decrease in the lifetime, and needs to be further optimized. Moreover, the ratio of the two host materials at different evaporation speeds is also difficult to maintain constant, which leads to fluctuations in device performance when the evaporation speed changes, poor stability, and greatly affects the production of devices under continuous working conditions. SUMMARY

[0004] In view of the above problems existing in the prior art, the application provides a blue light-emitting host composition and an organic electroluminescent device comprising the same.

[0005] To achieve the above purpose, the technical solution adopted by the application comprises:

[0006] The first aspect of the application provides a blue light-emitting host composition, which comprises at least a first host compound, a second host compound, and a third host compound; the structure of the first host compound is shown in formula I, the structure of the second host compound is shown in formula II, and the structure of the third host compound is shown in formula I or formula II; the first host compound, the second host compound, and the third host compound are not the same as each other;

[0007] I, II;

[0008] wherein Ar1, Ar2are each independently selected from any one or a combination of two of deuterated or non-deuterated aryl group having 6 to 30 carbon atoms, deuterated or non-deuterated condensed ring aryl group having 10 to 30 carbon atoms;

[0009] Ar3is selected from any one or a combination of two of deuterated or non-deuterated aryl group having 6 to 30 carbon atoms, deuterated or non-deuterated condensed ring aryl group having 10 to 30 carbon atoms;

[0010] Ar4is selected from any one or a combination of two of deuterated or non-deuterated heterocyclic group having 5 to 30 carbon atoms containing oxygen atom, deuterated or non-deuterated condensed ring heterocyclic group having 5 to 30 carbon atoms containing oxygen atom;

[0011] L1, L2, L3, L4are each independently selected from any one of single bond, deuterated or non-deuterated aryl group having 6 to 30 carbon atoms;

[0012] The mass percentage of any one of the blue light-emitting host compounds in the blue light-emitting host composition is between 10 and 80 wt%.

[0013] Further, Ar1, Ar2are each independently selected from any one or a combination of two of deuterated or non-deuterated aryl group having 6 to 20 carbon atoms, deuterated or non-deuterated condensed ring aryl group having 10 to 20 carbon atoms.

[0014] Further, Ar3is selected from any one or a combination of two of deuterated or non-deuterated aryl group having 6 to 20 carbon atoms, deuterated or non-deuterated condensed ring aryl group having 10 to 20 carbon atoms.

[0015] Further, Ar4is selected from any one or a combination of two of deuterated or non-deuterated heterocyclic group having 5 to 20 carbon atoms containing oxygen atom, deuterated or non-deuterated condensed ring heterocyclic group having 5 to 20 carbon atoms containing oxygen atom.

[0016] Further, L1, L2, L3, L4are each independently selected from any one of single bond, deuterated or non-deuterated aryl group having 6 to 20 carbon atoms.

[0017] Further, the mass percentage of any one of the blue light-emitting host compounds in the blue light-emitting host composition is between 10 and 75 wt%.

[0018] Further, the mass percentage of any one of the blue light-emitting host compounds in the blue light-emitting host composition is between 10 and 70 wt%.

[0019] Further, the mass percentage of any one of the blue light-emitting host compounds in the blue light-emitting host composition is between 10 and 65 wt%.

[0020] Further, the mass ratio of any one compound in the blue light-emitting host composition is between 10-60 wt%.

[0021] Further, the mass ratio of the sum of the compounds selected from Formula I in the blue light-emitting host composition is not less than 10 wt% of the mass of the blue light-emitting host composition.

[0022] Further, the mass ratio of the sum of the compounds selected from Formula I in the blue light-emitting host composition is not less than 20 wt% of the mass of the blue light-emitting host composition.

[0023] Further, the mass ratio of the sum of the compounds selected from Formula I in the blue light-emitting host composition is not less than 30 wt% of the mass of the blue light-emitting host composition.

[0024] Further, the mass ratio of the sum of the compounds selected from Formula I in the blue light-emitting host composition is not less than 40 wt% of the mass of the blue light-emitting host composition.

[0025] Further, the mass ratio of the sum of the compounds selected from Formula II in the blue light-emitting host composition is not less than 10 wt% of the mass of the blue light-emitting host composition.

[0026] Further, the mass ratio of the sum of the compounds selected from Formula II in the blue light-emitting host composition is not less than 20 wt% of the mass of the blue light-emitting host composition.

[0027] Further, the mass ratio of the sum of the compounds selected from Formula II in the blue light-emitting host composition is not less than 30 wt% of the mass of the blue light-emitting host composition.

[0028] Further, the mass ratio of the sum of the compounds selected from Formula II in the blue light-emitting host composition is not less than 40 wt% of the mass of the blue light-emitting host composition.

[0029] In combination with the first aspect, the ratio of the sum of the compounds selected from Formula I to the sum of the compounds selected from Formula II in the blue light-emitting host composition is 1:9-9:1.

[0030] Further, the ratio of the sum of the compounds selected from Formula I to the sum of the compounds selected from Formula II in the blue light-emitting host composition is 2:8-8:2.

[0031] Further, the ratio of the sum of the compounds selected from Formula I to the sum of the compounds selected from Formula II in the blue light-emitting host composition is 3:7-7:3.

[0032] Further, the ratio of the total mass of the compound selected from Formula I to the total mass of the compound selected from Formula II in the blue light-emitting host composition is 4:6~6:4.

[0033] Further, the heterocyclic group containing an oxygen atom is preferably exemplified by furyl and the like;

[0034] The fused ring heterocyclic group containing an oxygen atom is preferably exemplified by dibenzofuranyl, naphthobenzofuranyl, benzo[4,5-BCD]furanyl and the like.

[0035] In combination with the first aspect, Ar1, Ar2are each independently selected from any one or a combination of two of deuterated or non-deuterated phenyl, deuterated or non-deuterated biphenyl, deuterated or non-deuterated naphthyl, deuterated or non-deuterated phenanthryl;

[0036] Ar3is selected from any one or a combination of two of deuterated or non-deuterated phenyl, deuterated or non-deuterated biphenyl, deuterated or non-deuterated naphthyl;

[0037] Ar4is selected from any one of , , , , and any hydrogen in Ar4may be replaced by deuterium;

[0038] L1, L2, L3, L4are each independently selected from any one of a single bond, deuterated or non-deuterated phenyl, deuterated or non-deuterated biphenyl;

[0039] When the third host compound is selected from the structure shown in Formula I, the mass ratio of the first host compound, the second host compound and the third host compound in the blue light-emitting host composition is 0.1~6:0.5~7:1;

[0040] When the third host compound is selected from the structure shown in Formula II, the mass ratio of the first host compound, the second host compound and the third host compound in the blue light-emitting host composition is 0.5~7:0.1~6:1.

[0041] In combination with the first aspect, the difference between the molecular weights of any two compounds among the first host compound, the second host compound and the third host compound is within 100, i.e. the difference between the molecular weights of the first host compound and the second host compound is within 100, the difference between the molecular weights of the first host compound and the third host compound is within 100, and the difference between the molecular weights of the second host compound and the third host compound is within 100.

[0042] In combination with the first aspect, when the first host compound, the second host compound and the third host compound are deuterated compounds, the deuteration rate of each deuterated site in the structure is >5%.

[0043] Further, formula I is selected from one of the following structures:

[0044]

[0045]

[0046]

[0047] ;

[0048] wherein Dn represents n hydrogens are replaced by deuterium, n is a positive integer, and has a value of 1 to the maximum deuteration number.

[0049] For example, any hydrogen in the above structures can be replaced by deuterium, such as For example, any hydrogen in the above structures can be replaced by deuterium, such as

[0050] In combination with the first aspect, formula II is selected from one of the following structures:

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059] ​​​​​

[0060]

[0061]

[0062]

[0063]

[0064] ;

[0065] wherein Dn represents n hydrogens are replaced by deuterium, n is a positive integer, and has a value from 1 to the maximum number of deuterium substitutions.

[0066] Further, the blue light emitting host composition is selected from any one of the following:

[0067] Composition 1:

[0068]

[0069] Composition 2:

[0070]

[0071] Composition 3:

[0072]

[0073] Composition 4:

[0074]

[0075] Composition 5:

[0076]

[0077] Composition 6:

[0078]

[0079] Composition 7:

[0080]

[0081] Composition 8:

[0082]

[0083] Composition 9:

[0084]

[0085] Composition 10:

[0086]

[0087] Composition 11:

[0088]

[0089] Composition 12:

[0090]

[0091] Composition 13:

[0092]

[0093] Composition 14:

[0094]

[0095] Composition 15:

[0096]

[0097] Composition 16:

[0098]

[0099] Composition 17:

[0100]

[0101] Composition 18:

[0102]

[0103] Composition 19:

[0104]

[0105] Composition 20:

[0106]

[0107] Composition 21:

[0108]

[0109] Composition 22:

[0110]

[0111] Composition 23:

[0112]

[0113] Composition 24:

[0114]

[0115] Composition 25:

[0116]

[0117] Composition 26:

[0118]

[0119] Composition 27:

[0120]

[0121] Composition 28:

[0122]

[0123] Composition 29:

[0124] ;

[0125] The compound A-1 to compound A-29 in each composition is a first host compound, the compound B-1 to compound B-29 is a second host compound, and the compound C-1 to compound C-29 is a third host compound.

[0126] A second aspect of the present application provides an organic electroluminescence device, comprising an anode, a hole transport zone, a light-emitting layer, an electron transport zone, and a cathode which are sequentially arranged on a substrate; wherein the light-emitting layer comprises the blue light-emitting host composition as described above.

[0127] Further, the light-emitting layer comprises a host material and a guest material, wherein the host material comprises the blue light-emitting host composition as described above.

[0128] A third aspect of the present application provides a display device comprising the organic electroluminescence device as described above.

[0129] Advantages of the present application:

[0130] The blue light-emitting host composition disclosed in the present application comprises at least three different compounds, i.e. a first host compound, a second host compound and a third host compound, by combining the composition defined in the present application within the mass ratio range defined in the present application, to form a blue light-emitting host composition, the melting point of the composition is lower than the melting point of each single compound; the blue light-emitting host composition provided in the present application is evaporated to form a host composition film under continuous working conditions and different evaporation rates, the mass ratio of the blue light-emitting host composition provided in the present application in the film after final evaporation is relatively constant, and the difference with the initial premixed ratio is small. The blue light-emitting host composition provided in the present application is applied to a blue organic electroluminescent device as a host material of a light-emitting layer, the blue light-emitting host composition provided in the present application can not only significantly reduce the driving voltage of the device, but also significantly prolong the service life of the device, and under continuous working conditions, the voltage efficiency and the service life of the organic electroluminescent device prepared from the blue light-emitting host composition provided in the present application are relatively stable, which indicates that the blue light-emitting host composition provided in the present application is more likely to obtain an organic electroluminescent device with excellent and stable performance. BRIEF DESCRIPTION OF DRAWINGS

[0131] Figure 1 It is a schematic diagram of the structure of the organic electroluminescent device of the present application, wherein 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a hole transport layer, 5 is a light-emitting auxiliary layer, 6 is a light-emitting layer, 7 is a hole blocking layer, 8 is an electron transport layer, 9 is an electron injection layer, 10 is a cathode, and 11 is a cover layer.

[0132] Figure 2 It is a DSC curve of compound A-1.

[0133] Figure 3 It is a DSC curve of compound B-1.

[0134] Figure 4 It is a DSC curve of compound C-1.

[0135] Figure 5 It is a DSC curve of the composition mixed by compound A-1, B-1 and C-1 in a mass ratio of 2:5:3.

[0136] Figure 6 It is a DSC curve of the composition mixed by compound A-1 and B-1 in a mass ratio of 5:5. DETAILED DESCRIPTION

[0137] In order to more clearly understand the content of the present application, the embodiments will be described in detail in combination with the drawings.

[0138] The compounds of the present application are suitable for use in light-emitting elements, display panels, and electronic devices, and in particular, in organic electroluminescent devices. The electronic devices described herein are devices comprising at least one layer of an organic compound, which can also comprise layers of inorganic materials or be formed entirely of inorganic materials. The electronic devices are preferably organic electroluminescent devices (OLEDs), organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), organic dye-sensitized solar cells (O-DSSCs), organic optical detectors, organic photoreceptors, organic field-quench devices (O-FQDs), light-emitting electrochemical cells (LECs), organic laser diodes (O-lasers), and organic plasmonic devices. The electronic devices are preferably organic electroluminescent devices (OLEDs). A schematic structural diagram of an exemplary organic electroluminescent device is shown in Figure 1

[0139] Experimental Section

[0140] For a more clear understanding of the present application, the polycyclic compound, the preparation method of the compound, and the light-emitting properties of the device will be explained in detail with reference to the examples. Various chemical reactions can be applied to the synthesis method of the compound of one embodiment of the present application. However, it should be noted that the synthesis method of the compound of one embodiment of the present application is not limited to the synthesis methods described below. Unless otherwise specified, the following synthesis is performed in anhydrous solvents under a protective gas atmosphere. Solvents and reagents can be purchased from conventional reagent suppliers.

[0141] The compounds used in the following compositions can be purchased and synthesized by oneself.

[0142] Composition Example 1

[0143] This example provides a blue light-emitting host composition consisting of compound A-1, compound B-1, and compound C-1, the mass ratio of each compound being as shown in Table 1:

[0144] .

[0145] Composition Example 2

[0146] This example provides a blue light-emitting host composition consisting of compound A-2, compound B-2, and compound C-2, the mass ratio of each compound being as shown in Table 1:

[0147] ​.

[0148] Composition Example 3

[0149] This example provides a blue light-emitting host composition consisting of compound A-3, compound B-3, and compound C-3, the mass ratio of each compound being as shown in Table 1:

[0150] .

[0151] Composition Example 4

[0152] This example provides a blue light-emitting host composition consisting of compound A-4, compound B-4, and compound C-4, the mass ratio of each compound being as shown in Table 1:

[0153] .

[0154] Composition Example 5

[0155] This example provides a blue light-emitting host composition consisting of compound A-5, compound B-5, and compound C-5, the mass ratio of each compound being as shown in Table 1:

[0156] .

[0157] Composition Example 6

[0158] This example provides a blue light-emitting host composition consisting of compound A-6, compound B-6, and compound C-6, the mass ratio of each compound being as shown in Table 1:

[0159] .

[0160] Composition Example 7

[0161] This example provides a blue light-emitting host composition consisting of compound A-7, compound B-7, and compound C-7, the mass ratio of each compound being as shown in Table 1:

[0162] .

[0163] Composition Example 8

[0164] The present embodiment provides a blue light-emitting host composition consisting of compound A-8, compound B-8 and compound C-8, the mass ratio of each compound being as shown in Table 1:

[0165] .

[0166] Composition Example 9

[0167] The present embodiment provides a blue light-emitting host composition consisting of compound A-9, compound B-9 and compound C-9, the mass ratio of each compound being as shown in Table 1:

[0168] .

[0169] Composition Example 10

[0170] The present embodiment provides a blue light-emitting host composition consisting of compound A-10, compound B-10 and compound C-10, the mass ratio of each compound being as shown in Table 1:

[0171] .

[0172] Composition Example 11

[0173] The present embodiment provides a blue light-emitting host composition consisting of compound A-11, compound B-11 and compound C-11, the mass ratio of each compound being as shown in Table 1:

[0174] .

[0175] Composition Example 12

[0176] The present embodiment provides a blue light-emitting host composition consisting of compound A-12, compound B-12 and compound C-12, the mass ratio of each compound being as shown in Table 1:

[0177] .

[0178] Composition Example 13

[0179] The present embodiment provides a blue light-emitting host composition consisting of compound A-13, compound B-13 and compound C-13, the mass ratio of each compound being as shown in Table 1:

[0180] .

[0181] Composition Example 14

[0182] This example provides a blue light-emitting host composition consisting of compound A-14, compound B-14, and compound C-14, the mass ratio of each compound being as shown in Table 1:

[0183] .

[0184] Composition Example 15

[0185] This example provides a blue light-emitting host composition consisting of compound A-15, compound B-15, and compound C-15, the mass ratio of each compound being as shown in Table 1:

[0186] .

[0187] Composition Example 16

[0188] This example provides a blue light-emitting host composition consisting of compound A-16, compound B-16, and compound C-16, the mass ratio of each compound being as shown in Table 1:

[0189] .

[0190] Composition Example 17

[0191] This example provides a blue light-emitting host composition consisting of compound A-17, compound B-17, and compound C-17, the mass ratio of each compound being as shown in Table 1:

[0192] .

[0193] Composition Example 18

[0194] This example provides a blue light-emitting host composition consisting of compound A-18, compound B-18, and compound C-18, the mass ratio of each compound being as shown in Table 1:

[0195] .

[0196] Composition Example 19

[0197] This example provides a blue light-emitting host composition consisting of compound A-19, compound B-19, and compound C-19, the mass ratio of each compound being as shown in Table 1:

[0198] .

[0199] Composition Example 20

[0200] This example provides a blue light-emitting host composition consisting of compound A-20, compound B-20, and compound C-20, the mass ratio of each compound being as shown in Table 1:

[0201] .

[0202] Composition Example 21

[0203] This example provides a blue light-emitting host composition consisting of compound A-21, compound B-21, and compound C-21, the mass ratio of each compound being as shown in Table 1:

[0204] .

[0205] Composition Example 22

[0206] This example provides a blue light-emitting host composition consisting of compound A-22, compound B-22, and compound C-22, the mass ratio of each compound being as shown in Table 1:

[0207] .

[0208] Composition Example 23

[0209] This example provides a blue light-emitting host composition consisting of compound A-23, compound B-23, and compound C-23, the mass ratio of each compound being as shown in Table 1:

[0210] .

[0211] Composition Example 24

[0212] This example provides a blue light-emitting host composition consisting of compound A-24, compound B-24, and compound C-24, the mass ratio of each compound being as shown in Table 1:

[0213] .

[0214] Composition Example 25

[0215] This example provides a blue light-emitting host composition consisting of compound A-25, compound B-25, and compound C-25, the mass ratio of each compound being as shown in Table 1:

[0216] .

[0217] Composition Example 26

[0218] This example provides a blue light-emitting host composition consisting of compound A-26, compound B-26, and compound C-27, the mass ratio of each compound being as shown in Table 1:

[0219] .

[0220] Composition Example 28

[0221] This example provides a blue light-emitting host composition consisting of compound A-28, compound B-28, and compound C-28, the mass ratio of each compound being as shown in Table 1:

[0222] .

[0223] Composition Example 29

[0224] This example provides a blue light-emitting host composition consisting of compound A-29, compound B-29, and compound C-29, the mass ratio of each compound being as shown in Table 1:

[0225] .

[0226] Table 1

[0227]

[0228] Note: The mass ratio of each compound in Table 1 refers to the mass ratio of each host compound in the corresponding blue light emitting host composition.

[0229] Manufacture and characterization of OLED

[0230] Device embodiment

[0231] The organic electroluminescent device provided by the application comprises an anode, a hole transport zone, a light emitting layer, an electron transport zone and a cathode which are sequentially arranged on a substrate.

[0232] Further, the hole transport zone comprises a hole injection layer, a hole transport layer and a light emitting auxiliary layer; and the electron transport zone comprises an electron transport layer and an electron injection layer.

[0233] Further, the light emitting layer is composed of a host material and a guest material, and the light emitting layer host material can be composed of one kind of molecular material or multiple kinds of molecular materials.

[0234] The composition provided by the application can be used in the light emitting layer of the organic electroluminescent device.

[0235] The anode in the embodiment adopts an anode material commonly used in the art, such as ITO, Ag or a multilayer structure thereof. The hole injection layer adopts a hole injection material commonly used in the art, and is doped with F4TCNQ, HATCN, NDP-9 and the like. The hole transport layer adopts a hole transport material commonly used in the art. The light emitting layer adopts the host and guest material composition provided by the application. The electron transport layer adopts an electron transport material commonly used in the art. The electron injection layer adopts an electron injection material commonly used in the art, such as LiQ, LiF, Yb and the like. The cathode adopts a material commonly used in the art, such as metal Al, Ag or a metal mixture (Ag-doped Mg, Ag-doped Ca and the like).

[0236] The electrode preparation method and the deposition method of each functional layer in the embodiment are all conventional methods in the art, for example, vacuum thermal evaporation or inkjet printing, and will not be described here again. Only some process details in the preparation process and test methods are described as follows:

[0237] Device embodiment 1

[0238] The substrate used in the application is subjected to the following operations: after the ITO substrate is patterned to have a light emitting area with a size of 3mm×3mm, it is subjected to water / isopropanol ultrasonic treatment, UV / ozone irradiation and then 100℃ drying. After that, the ITO substrate is installed on a substrate support of a vacuum deposition device and the pressure is adjusted to make the vacuum rate 1×10 -7torr. Then, the following operations were performed: first, a hole injection layer was formed by vacuum depositing compound HT01 and compound PD01 (mass ratio of compound HT01 to compound PD01 was 97:3) at a thickness of 10 nm on the ITO layer (anode) of the substrate; second, a hole transport layer was formed by vacuum depositing compound HT01 at a thickness of 100 nm on the hole injection layer; third, a light-emitting auxiliary layer was formed by vacuum depositing compound BP01 at a thickness of 5 nm on the hole transport layer; fourth, a light-emitting layer was formed by vacuum depositing a mixture of the composition embodiment 1 provided by the present application and compound BD01 at a thickness of 20 nm on the light-emitting auxiliary layer, wherein the composition embodiment 1 served as a host material and compound BD01 served as a guest material, and the mass ratio of the composition embodiment 1 to the guest material was 98:2; fifth, a hole blocking layer was formed by vacuum depositing compound HB01 at a thickness of 5 nm on the light-emitting layer; sixth, an electron transport layer was formed by vacuum depositing compound ET01 and compound LiQ (mass ratio of compound ET01 to compound LiQ was 1:1) at a thickness of 30 nm on the hole blocking layer; seventh, an electron injection layer was formed by vacuum depositing Yb at a thickness of 1 nm on the electron transport layer; eighth, a cathode was formed by depositing Mg and Ag (mass ratio of Mg to Ag was 1:9) at a thickness of 15 nm on the electron injection layer; and ninth, a cover layer was formed by depositing compound CP01 at a thickness of 50 nm on the cathode. Finally, the substrate on which the deposition was completed was encapsulated, a coating device was used to perform a coating process on the cleaned cover plate with UV glue, the cover plate coated in this way was moved to a pressing section, the substrate on which the deposition was completed was placed on the upper end of the cover plate, and the substrate and the cover plate were laminated under the action of a laminating device, and at the same time, the UV glue was subjected to light curing, thereby preparing a top-emission organic electroluminescent device. The structure of the device is shown in Figure 1 .

[0239] In addition to the host and guest materials of the light-emitting layer, the molecular structural formulas of the materials of the other layers are as follows:

[0240]

[0241]

[0242]

[0243] Device embodiments 2-5

[0244] The organic electroluminescent devices were prepared by using the above method and taking the composition embodiments 2 to 5 provided by the present application as the host materials, thereby obtaining device embodiments 2-5.

[0245] Device comparative examples 1-3

[0246] The host compositions in Table 2 were made into organic electroluminescent devices by the above method, and the specific composition combinations are shown in Table 2, to obtain device comparative examples 1-3.

[0247] The OLED devices described above were tested by standard methods. To this end, the driving voltage, luminous efficiency of the organic electroluminescent device were determined at a current density of J = 10 mA / cm 2 2 The LT97 indicates that the luminous intensity of the prepared blue light device decreases to 97% of its initial value L0 after a time LT97 when the device is operated at a current density of J = 20 mA / cm

[0248] The test instruments and methods for testing the performance of the above-mentioned example, comparative example OLED devices are as follows:

[0249] The luminous efficiency C.E (cd / A) and color coordinates (CIEy) were tested using a spectral scanner PhotoResearch PR-635;

[0250] Current density and turn-on voltage: tested using a digital source meter Keithley 2400;

[0251] The luminous efficiency of the blue light device is greatly affected by the chromaticity, and the industry generally uses the BI value as the basis for the efficiency of the blue light device, and the BI (Blue index) is obtained by dividing the luminous efficiency C.E (cd / A) by the color coordinates (CIEy);

[0252] Lifetime test: silicon photovoltaic OLED device lifetime test system was used.

[0253] The performance test results of the above-mentioned devices are shown in Table 2.

[0254] Table 2 Blue light device performance test results

[0255]

[0256] Note: The mass ratio in Table 2 refers to the mass ratio of each host compound in the corresponding host composition.

[0257] As can be seen from the above data, the single host material device of device comparative example 3 has a high driving voltage and a short lifetime; compared with the single host device, the double host device of device comparative example 1 reduces the driving voltage of the device, but the efficiency and lifetime of the device are reduced, the double host device of device comparative example 2 prolongs the device lifetime to some extent, but the driving voltage and efficiency are not improved; and the device examples 1-5 provided by the present application can significantly reduce the driving voltage of the device and significantly prolong the lifetime of the device.

[0258] Performance test of composition examples ​

[0259] To illustrate the advantage of the blue light-emitting host composition provided by the present application in the evaporation process, the melting point of the composition examples provided by the present application was measured, and the DSC curves of some host compounds and compositions are shown in FIG. 1. Figures 2 to 5 The measurement results are shown in Table 3.

[0260] Table 3

[0261]

[0262] Note: The melting point tester is NETZSCH DSC 3500, and the mass ratio of each host compound in the corresponding blue light-emitting host composition in Examples 1 to 5 is shown in Table 1.

[0263] From FIG. 1, it can be read that the melting point of compound A-1 is 282°C, the melting point of compound B-1 is 290°C, the melting point of compound C-1 is 282°C, and the melting point of the composition mixed from compounds A-1, B-1 and C-1 according to the proportion in Table 1 is 243°C. It can be seen that the melting point of the blue light-emitting host composition provided by the present application is lower than that of each single compound, and the lower melting point is conducive to the formation of an organic thin film by evaporation of the composition provided by the present application with constant component ratio. Figures 2 to 5

[0264] The composition used in Device Comparative Example 1, as can be seen from the figure, the comparative composition does not form a single phase change peak, and has no fixed single melting point. The lack of fixed single melting point may result in poor component constancy of the composition in the evaporation process. Figure 6 Host composition thin film component constancy test

[0265] To further illustrate the advantage of the blue light-emitting host composition provided by the present application, the host composition thin film was formed from the composition examples, and the component constancy of the thin film was tested. The host composition was premixed according to the premixing ratio (i.e. the mass ratio of each host compound in the corresponding host composition) in Table 4-1 to Table 4-3, and then the premixed host composition was formed into a thin film with a thickness of 2000Å at different evaporation rates. The above operation was repeated three times in succession (i.e. the same composition was continuously evaporated three times to form a thin film at the same premixing ratio), and the mass ratio of each compound in the three thin films formed was determined by high performance liquid chromatography analysis method, and the evaluation results are as follows:

[0266] Table 4-1

[0267]

[0268] Table 4-2

[0269]

[0270] ​

[0271] Table 4-3

[0272]

[0273] From the above table, it can be seen that at the deposition rates of 0.5 Å / s, 1 Å / s and 3 Å / s, respectively, compared with the comparative effect examples 1-1 to 1-9 composed of two-component mixed host materials, the mass proportions of each compound in the thin film after final deposition in the effect examples 1-1 to 2-9 composed of the blue light-emitting host composition provided by the application are relatively constant under continuous operation conditions, and the difference with the initial premixing proportion is small.

[0274] At the low deposition rate of 0.5 Å / s, the mass proportions of each compound in the thin film after final deposition of the comparative effect examples 1-1 to 1-3 are greatly different from the initial premixing proportion under continuous operation conditions, and the deposition component proportion does not have an adverse effect on the device performance according to the premixing proportion.

[0275] With the increase of the deposition rate, although the mass proportions of each compound in the thin film after final deposition of the comparative effect examples composed of two-component mixed host materials are closer to the initial premixing proportion, the mass proportions of each compound in the thin film after final deposition of the two-component mixed host materials under continuous operation conditions appear large fluctuations, and at the deposition rate of 3 Å / s, it can be seen that the fluctuations of the two-component mixed host materials of the comparative effect examples 1-7 to 1-9 are obviously increased, while the blue light-emitting host compositions of the effect examples 1-7 to 2-9 provided by the application maintain good process stability and component proportion constancy under different deposition rates, indicating that by using the blue light-emitting host composition provided by the application, good component proportion constancy can be maintained under different production processes and continuous operation conditions, while the comparative effect examples composed of two-component mixed host materials have large differences between the mass proportions of each compound in the thin film after final deposition and the initial premixing proportion under different deposition rates and continuous operation conditions, which is likely to result in that the deposited organic film layer components cannot be composed according to the premixing proportion, and the premixing advantage cannot be stably played.

[0276] Constantity test of device performance

[0277] According to the above process, the composition used in the comparative effect example 1-1 is continuously prepared into device comparative examples 1-1 to 1-3 under the same conditions, the blue light-emitting host composition of the effect example 1-1 of the application is continuously prepared into device examples 1-1 to 1-3 under the same conditions, and the device performance is tested under the same test conditions according to Table 2, and the results are shown in Table 5.

[0278] Table 5

[0279]

[0280] Note: The mass ratio in Table 5 refers to the mass ratio of each host compound in the corresponding host composition.

[0281] From the above table, it can be seen that the voltage efficiency and lifetime of the device embodiments 1-1 to 1-3 provided by the present application are more stable, and are all better than those of the device comparative examples. From Table 5, it can also be seen that the device performance of the device comparative examples 1-1 to 1-3 has obvious fluctuation, which may be due to the fact that the composition of the comparative examples 1-1 to 1-3 has no fixed melting point, resulting in poor constant of the composition during evaporation process, the mass ratio of each compound in the thin film after final evaporation is greatly different from the initial premixed ratio, which makes the device performance of the device comparative examples fluctuate greatly. However, the melting point of the blue light emitting host composition provided by the present application is lower than that of each single compound, and the lower melting point is conducive to the evaporation of the composition provided by the present application to form an organic thin film with constant component ratio. Therefore, the device performance of the device prepared under continuous working conditions is more stable, which shows that the present application is more suitable for commercial mass production.

[0282] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description, and it is impossible to enumerate all the embodiments here. Any obvious changes or variations derived from the technical solutions of the present application still fall within the protection scope of the present application.

Claims

1. A blue luminescent host composition, characterized in that, It comprises at least a first main compound, a second main compound, and a third main compound; the structure of the first main compound is shown in Formula I, the structure of the second main compound is shown in Formula II, and the structure of the third main compound is shown in Formula I or Formula II. The first main compound, the second main compound, and the third main compound are different from each other; AND, II; Ar1 and Ar2 are each independently selected from any one or any combination of two of the following: deuterated or non-deuterated phenyl, deuterated or non-deuterated biphenyl, deuterated or non-deuterated naphthyl, and deuterated or non-deuterated phenanthryl. Ar3 is selected from any one or any combination of two of the following: deuterated or non-deuterated phenyl, deuterated or non-deuterated biphenyl, deuterated or non-deuterated naphthyl. Ar4 is selected from , , , Any one of the hydrogen atoms in Ar4 can be replaced by deuterium; L1, L2, L3, and L4 are each independently selected from any one of single-bonded, deuterated or non-deuterated phenyl, or deuterated or non-deuterated biphenyl. When the third host compound is selected from the structure shown in Formula I, the mass ratio of the first host compound, the second host compound and the third host compound in the blue luminescent host composition is 0.1~6:0.5~7:1; When the third host compound is selected from the structure shown in Formula II, the mass ratio of the first host compound, the second host compound and the third host compound in the blue luminescent host composition is 0.5~7:0.1~6:1; The mass percentage of any one of the main compounds in the blue luminescent host composition is between 10 and 80 wt%. The difference in molecular weight between any two compounds in the first, second, and third main compounds is within 100; When the first, second, and third host compounds are deuterated compounds, the deuteration rate of each deuteration site in their structure is >5%.

2. The blue light-emitting host composition according to claim 1, characterized in that, Formula I is selected from one of the following structures: ； Where Dn represents n hydrogen atoms being replaced by deuterium, and n is a positive integer, ranging from 1 to the maximum deuterium algebra.

3. The blue luminescent host composition according to claim 1, characterized in that, Formula II is selected from one of the following structures: ； Where Dn represents n hydrogen atoms being replaced by deuterium, and n is a positive integer, ranging from 1 to the maximum deuterium algebra.

4. The blue luminescent host composition according to claim 1, characterized in that, The blue luminescent host composition is selected from any one of the following: Composition 1: Composition 2: Composition 3: Composition 4: Composition 5: Composition 6: Composition 7: Composition 8: Composition 9: Composition 10: Composition 11: Composition 12: Composition 13: Composition 14: Composition 15: Composition 16: Composition 17: Composition 18: Composition 19: Composition 20: Composition 21: Composition 22: Composition 23: Composition 24: Composition 25: Composition 26: Composition 27: Composition 28: Composition 29: ； In each composition, compounds A-1 to A-29 are the first main compounds, compounds B-1 to B-29 are the second main compounds, and compounds C-1 to C-29 are the third main compounds.

5. An organic electroluminescent device, characterized in that, It includes an anode, a hole transport region, a light-emitting layer, an electron transport region, and a cathode sequentially disposed on a substrate; wherein the light-emitting layer includes the blue light-emitting host composition as described in any one of claims 1 to 4.

6. The organic electroluminescent device according to claim 5, characterized in that, The light-emitting layer comprises a host material and a guest material, wherein the host material comprises the blue light-emitting host composition as described in any one of claims 1 to 4.

7. A display device, characterized in that, Including the organic electroluminescent device as described in claim 5 or 6.

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