OLED display device with long service life and preparation method and application thereof

Abstract

Compared with the prior art, the long-life OLED display device and the preparation method and application thereof have the advantages that the nitrogen-containing heterocyclic compound DT is used and can be bonded with free halogen to form a complex, so that the free halogen is stabilized, a complex molecular group is formed, the degree of freedom of molecules is reduced, and the service life of the OLED display device is prolonged. And free halogen in the chamber is reduced. DT is evaporated into a device, due to the fact that the Lewis base and halogen atoms in the compound have strong halogen bonds, a large amount of halogen is limited outside a light-emitting layer under the electromigration effect due to the complexing effect, the probability of re-dissociation is greatly reduced due to the existence of a complex, and the situation that the halogen enters the light-emitting layer to directly damage the service life is prevented.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of OLED display devices, and particularly relates to a long-life OLED display device and a preparation method and application thereof. BACKGROUND

[0002] Organic light emitting diode (OLED) is a new generation of display technology, which has the display characteristics of self-emission, fast response and the like, and is applied to various display terminal fields. The Micro-OLED technology applied in the micro display field also makes people pay attention to another application method of OLED. Since the brightness of Micro-OLED is relatively high and the light emitting efficiency is relatively low, the heat is seriously accumulated, which seriously affects the life performance of the device. At the same time, there is a significant difference in the life of different light colors, and improving the life of blue and green is of great significance to improve the overall life and make up for the short life, and improve the long-term color deviation of the product device.

[0003] The halogen in the material is one of the substances that have been proved to have an important influence on the life, but the halogen is mainly involved in each reaction in the role of a coupling reaction catalyst in the synthesis of organic materials, such as [PdCl2(PPh3)2], [PtCl2(PPh3)2], AgBF4, FeCl3, etc. are widely used and contain halogen catalysts. The amount of catalyst used is proportional to the reactants, and since an excess is required, it is unavoidable that the product will reach the final OLED refining material. In addition, IrCl3 (iridium chloride) and PtCl4 (platinum chloride) are also used as precursors in the synthesis of light-doped materials to finally synthesize light-doped materials. Similarly, the synthesis path also introduces halogen Cl. In addition, other coupling reactions such as Suzuki coupling are also based on halogenated materials as raw materials, so a certain amount of halogen will also be left in the product. The halogen in the above synthesis reactions will eventually be left in the evaporation material, thereby affecting the characteristics of the final product device.

[0004] When the device is prepared by the evaporation method, the following methods can be used to improve the life in the process direction, such as improving the vacuum level of the chamber, chamber baking treatment, reducing the material evaporation temperature, reducing the exhaust (Outgasing) during material evaporation, etc. Such physical methods mainly reduce the water and oxygen in the chamber, and such molecules with small structures are easily pumped out under vacuum. However, the disadvantage of this method is that it can only target small molecules, so it has no targeting for improving the life performance, such as being unable to respond strongly to halogen substances.

[0005] In summary, the prior art cannot effectively reduce the content of halogen in the material during the preparation of the OLED device by the evaporation method, and the halogen in the material is in a free state in the chamber, and the free path is high under vacuum and high temperature, which is extremely easy to migrate to the substrate. SUMMARY

[0006] The present application aims to provide a long-life OLED display device and its preparation method, first by evaporating DT material before and after evaporating key film layers in the chamber, efficiently removing and stabilizing released halogen in the evaporation process, preventing halogen from ionizing and damaging the chamber atmosphere under vacuum and high temperature in the chamber, and avoiding final deposition on the substrate to reduce the service life of the OLED device.

[0007] The present application also aims to provide a long-life OLED display device for OLED display devices.

[0008] The present application provides a long-life OLED display device and its preparation method, including the following steps:

[0009] Evaporate DT material before and after evaporating the light-emitting layer.

[0010] The DT material is a nitrogen-containing heterocyclic compound;

[0011] Preferably, the structure of the DT material is:

[0012]

[0013] In the structure:

[0014] X is selected from carbon, nitrogen or oxygen; n is selected from 0 or 1;

[0015] Y is selected from carbon, nitrogen or oxygen; n1 is selected from an integer between 0 and 5;

[0016] One of the nitrogen-containing five-membered ring or six-membered ring heterocyclic aromatic or aliphatic ring amine, n2 = 1, 2 or 3;

[0017] R1, R2 are independently selected from any one of hydrogen, deuterium, C1-C20 substituted or unsubstituted hydrocarbon group, C1-C20 substituted or unsubstituted alkoxy; m is selected from an integer between 1 and 4, and if X is carbon, m can be selected from 1-4, X is nitrogen, m can be selected from 1-3, X is oxygen, m can be selected from 1-2;

[0018] In the structure The nitrogen-containing five-membered ring or six-membered ring heterocyclic aromatic or aliphatic ring amine group can be selected from one of the following general formula (1), general formula (2), general formula (3), general formula (4), general formula (5), general formula (6), general formula (7):

[0019] General formula (1):

[0020] General formula (2):

[0021] General Formula (3):

[0022] General Formula (4):

[0023] General Formula (5):

[0024] General Formula (6):

[0025] General Formula (7):

[0026] wherein R1, R2 are independent of each other, and are defined as the same as the foregoing description; that is, R1, R2 are independently selected from any one of hydrogen, deuterium, C1-C20 substituted or unsubstituted hydrocarbyl, C1-C20 substituted or unsubstituted alkoxy.

[0027] Preferably, The structure of the DT material represented by General Formula (2) is any one of the following structural formulas:

[0028] DT1-1:

[0029] DT1-2:

[0030] DT1-3:

[0031] DT1-4:

[0032] DT2-1:

[0033] DT2-2:

[0034] DT3-1:

[0035] DT3-2:

[0036] DT3-3:

[0037] DT4-1:

[0038] DT4-2:

[0039] DT4-3:

[0040] DT4-4:

[0041] DT4-5:

[0042] DT4-6:

[0043] Further, the evaporation DT material can be uniformly attached to the inner wall of the chamber, and the evaporation DT material is evaporated to the chamber before the evaporation of the light-emitting layer to the substrate in the chamber, so that the process of pre-evaporation is carried out to improve the atmosphere in the chamber and realize the dehalogenization treatment.

[0044] The evaporation DT material is used with a baffle during the evaporation of the DT material, and the DT material is not deposited on the substrate due to the blocking of the baffle before the evaporation of the substrate, and the thickness of the DT material layer on the substrate is 0 nm; the evaporation DT material is evaporated for 30 min.

[0045] Alternatively, the baffle is not used during the evaporation of the DT material, and the DT material is not only attached to the inner wall of the chamber, but also forms a DT material layer on the substrate, and the thickness of the DT material layer is 0-1000 nm, and the thickness is not 0 nm; preferably, the evaporation time is controlled within 30 min.

[0046] Further, the evaporation DT material is used with a baffle during the evaporation of the DT material, and the DT material is not deposited on the substrate due to the blocking of the baffle before the evaporation of the substrate, and the thickness of the DT material layer on the substrate is 0 nm; the evaporation DT material is evaporated for 30 min; then the baffle is not used, and the evaporation of the DT material is continued, the evaporation DT material is evaporated for 30 min; the DT material is not only attached to the inner wall of the chamber, but also forms a DT material layer on the substrate, and the thickness of the DT material layer is 0-1000 nm, and the thickness is not 0 nm.

[0047] The application provides a long-life OLED display device prepared by the above method.

[0048] The application provides an application of the long-life OLED display device to an OLED display device.

[0049] The inventors found that halogen evaporated into the device exists as free ions or complexes, which can migrate at high current density, reach the light-emitting layer and affect the device characteristics. The stabilization of halogen is mainly achieved by halogen bond, which is a non-covalent interaction between halogen atoms (Lewis acid) and neutral or negatively charged Lewis bases. As a kind of intermolecular interaction parallel to hydrogen bond, halogen bond has a wide range of applications in many fields such as molecular recognition, chiral resolution, crystal engineering and supramolecular assembly. The bond energy of C-X bond combined with Lewis base is about 5-180 KJ / mol, and the bond length is about 1-3 angstrom; compared with the range of hydrogen bond energy, it has obvious advantages in molecular recognition. The present application uses halogen bond to remove and stabilize the halogen released during the evaporation of the material by intermolecular complexation.

[0050] The present application mainly provides a process method of evaporating a special DT material before and after the key film layer of the chamber, which fixes the halogen suspended in the chamber during preparation by complexation of halogen bond, so that the halogen deposited and suspended in the chamber wall is stabilized, and the influence of the adverse atmosphere on the service life of the device is reduced. Such DT material can be deposited in front and back of the light-emitting layer of the device in a relatively thin thickness during device preparation, and the probability of halogen entering the light-emitting layer can be reduced without affecting the energy level and electron mobility, so as to improve the service life of the OLED device. The structure of such DT material is a kind of organic Lewis base containing nitrogen heterocycle or oxygen heterocycle, the molecule of the material has more electron donor units, and contains a plurality of pyridine, imidazole, piperidine, pyrimidine or pyrazine units, and the basicity is further adjusted and improved by adding electron-donating groups. Hydrocarbon groups are added to adjust the molecular weight and film-forming property, so that the material has good adaptability in the device.

[0051] Compared with the prior art, the present application uses nitrogen-containing heterocyclic compound DT, which can bond with free halogen to form a complex, thereby stabilizing the free halogen, forming a complex molecular group, reducing the molecular freedom, and reducing the free halogen inside the chamber. The DT is evaporated into the device, and due to the strong halogen bond between the Lewis base in the compound and the halogen atom, the complexation makes the halogen under the action of electric migration be largely limited outside the light-emitting layer, and the existence of the complex greatly reduces the probability of re-dissociation, thereby preventing the halogen from entering the light-emitting layer and directly damaging the service life. BRIEF DESCRIPTION OF DRAWINGS

[0052] Figure 1 Process flow chart for long-life device preparation method;

[0053] Figure 2 OLED device structure schematic diagram of device A completed in Example 1;

[0054] Figure 3The finished OLED device structure schematic diagram for the device C of Example 2 is prepared;

[0055] Figure 4 The J-V graph for the device property test of Examples 1 and 2 is prepared;

[0056] Figure 5 The EL Spectra graph for the device property test of Examples 1 and 2 is prepared;

[0057] Figure 6 The lifetime curve graph for the device property test of Examples 1 and 2 is prepared;

[0058] In the figure, 201-anode, 202-hole injection layer, 203-hole transport layer, 204-electron blocking layer, 205-emitting layer, 206-hole blocking layer, 207-electron transport layer, 208-electron injection layer, 209-cathode, 210-DT material layer. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0060] The test materials and reagents used in the following embodiments, unless otherwise specified, can be obtained from commercial channels.

[0061] The specific techniques or conditions not mentioned in the embodiments can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0062] The general preparation structure includes anode, hole injection layer HIL, hole transport layer HTL, electron blocking layer EBL, emitting layer EML, hole blocking layer HBL, electron transport layer ETL, electron injection layer EIL and cathode. The preparation is carried out by using the dehalogenation method of the DT material of the present application, and the schematic diagram is shown in Figure 1.

[0063] The present application provides a preparation method of a long-life OLED display device, comprising the following steps:

[0064] 1) On the substrate or base, an anode 201 is deposited by magnetron sputtering or thermal evaporation, and ITO is commonly used, and on which a hole injection layer 202, a hole transport layer 203 and an electron blocking layer 204 are sequentially deposited, respectively, wherein the hole injection layer material is commonly used in the art, including but not limited to the following: m-MTDATA, TDATA, 2-TNANA, F4TCNQ, HATCN, etc. or its doping; the hole transport layer material includes but is not limited to NPB, TPD, TAPC and other commercial materials; the structural formula of TDATA is as follows:

[0065] The structural formula of m-MTDATA is as follows:

[0066] The structural formula of 2-TNANA is as follows:

[0067] The structural formula of F4TCNQ is as follows:

[0068] The structural formula of NPB is as follows:

[0069] The structural formula of TPD is as follows:

[0070] 2) Before preparing the light-emitting layer 205, the chamber is subjected to dehalogen treatment, and the DT material is evaporated, and the evaporation time is controlled within 30 min, the material can be uniformly attached to the inner wall of the chamber, and due to the blocking of the evaporation substrate baffle, the DT material is not deposited on the electron blocking layer 204, and the evaporation thickness is 0 nm;

[0071] Alternatively, step 2) is: before preparing the light-emitting layer 205, the chamber is subjected to dehalogen treatment, and no baffle is used, and the DT material is evaporated on the substrate prepared in step 1), that is, the DT material layer 210 is obtained on the electron blocking layer 204, the evaporation thickness ranges from 0 to 1000 nm (the thickness is not taken as 0), and the evaporation time is controlled within 30 min, and the DT material can be uniformly attached to the inner wall of the chamber;

[0072] Further alternatively, step 2) is: first, before preparing the light-emitting layer 205, the chamber is subjected to dehalogen treatment, and the DT material is not deposited on the electron blocking layer 204 by using the blocking of the baffle, and the evaporation time is controlled within 30 min, and the material can be uniformly attached to the inner wall of the chamber; then the baffle is removed, and the DT material is evaporated, so that the material can be uniformly attached to the inner wall of the chamber, and the DT material is evaporated on the substrate prepared in step 1), that is, the DT material layer 210 is obtained on the electron blocking layer 204, and the evaporation thickness ranges from 0 to 1000 nm (the thickness is not taken as 0), and the evaporation time is controlled within 30 min.

[0073] The conditions for evaporating the DT material are: vacuum degree 1.0E-7 torr, evaporation rate 0.1 A / s

[0074] The materials CBP and Ir complex used in the light-emitting layer are as follows:

[0075] The Ir complex is used as a dopant of the light-emitting layer, and the doping ratio is 3%.

[0076] The DT material is an organic compound, and its structural formula is as follows:

[0077]

[0078] In the structural formula:

[0079] X is selected from carbon, nitrogen or oxygen; n is selected from 0 or 1;

[0080] Y is selected from carbon, nitrogen or oxygen; n1 is selected from an integer between 0 and 5;

[0081] one of the heterocyclic aromatic or aliphatic amine groups represented as a nitrogen-containing five-membered ring or six-membered ring,

[0082] n2 = 1, 2 or 3;

[0083] R1, R2 are independently selected from any one of hydrogen, deuterium, C1-C20 substituted or unsubstituted hydrocarbon group, C1-C20 substituted or unsubstituted alkoxy group; m is selected from an integer between 1 and 4, and if X is carbon, m can be selected from 1-4, if X is nitrogen, m can be selected from 1-3, and if X is oxygen, m can be selected from 1-2;

[0084] In the structural formula The nitrogen-containing five-membered ring or six-membered ring heterocyclic aromatic or aliphatic amine group can be selected from one of the following general formula (1), general formula (2), general formula (3), general formula (4), general formula (5), general formula (6), general formula (7):

[0085] General formula (1):

[0086] General formula (2):

[0087] General formula (3):

[0088] General formula (4):

[0089] General formula (5):

[0090] General formula (6):

[0091] General formula (7):

[0092] wherein R1, R2 are independent of each other, and the specific definitions are the same as the foregoing description; that is, R1, R2 are independently selected from any one of hydrogen, deuterium, C1-C20 substituted or unsubstituted hydrocarbon group, C1-C20 substituted or unsubstituted alkoxy group.

[0093] Preferably, The structure of the DT material represented by general formula (2) is any one of the following structures:

[0094] DT1-1:

[0095] DT1-2:

[0096] DT1-3:

[0097] DT1-4:

[0098] DT2-1:

[0099] DT2-2:

[0100] DT3-1:

[0101] DT3-2:

[0102] DT3-3:

[0103] DT4-1:

[0104] DT4-2:

[0105] DT4-3:

[0106] DT4-4:

[0107] DT4-5:

[0108] DT4-6:

[0109] Among the compounds of the above structural formula, the small molecular weight DT1-1 has a melting point of 109-112℃ and an acidity coefficient (pKa) of 5.17; the large molecular weight DT4-6 has a melting point of 198℃ and an acidity coefficient (pKa) of 6.81±0.10 (Predicted), and is in the form of a powder-like solid with moderate melting point and stable properties and strong basicity, and can form halogen bond complex with halogen.

[0110] 3) Subsequently, the light-emitting layer 205 is evaporated, and after the evaporation of the light-emitting layer is completed, the evaporation of the DT material is continued, the evaporation chamber is used with a baffle, the evaporation time is controlled within 30 minutes, the material can be uniformly attached to the inner wall of the chamber, and due to the blocking of the baffle before the evaporation of the substrate, the DT material is not deposited on the light-emitting layer 205, and the evaporation thickness is 0 nm;

[0111] Alternatively, step 3) is: after the preparation of the light-emitting layer 205, the chamber is subjected to dehalogen treatment, and at the same time, no baffle is used, so as to evaporate the DT material on the substrate prepared in step 2), that is, to obtain the DT material layer 210 on the light-emitting layer 205, the evaporation thickness ranges from 0 to 1000 nm (the thickness is not taken as 0), and the evaporation time is controlled within 30 minutes, and the DT material can be uniformly attached to the inner wall of the chamber;

[0112] Further alternatively, step 3) is: first, after the preparation of the light-emitting layer 205, the chamber is subjected to dehalogen treatment, and the baffle is used to block the deposition of the DT material on the substrate, and the evaporation time is controlled within 30 minutes, and the material can be uniformly attached to the inner wall of the chamber; then, the baffle is removed, and the evaporation of the DT material is carried out, so as to uniformly attach the material to the inner wall of the chamber, and evaporate the DT material on the substrate prepared in step 2), that is, to obtain the DT material layer 210 on the light-emitting layer 205, the evaporation thickness ranges from 0 to 1000 nm (the thickness is not taken as 0), and the evaporation time is controlled within 30 minutes.

[0113] 4) After the evaporation of the DT material in step 3) is completed, the evaporation and deposition of the remaining film layers are carried out, and the remaining film layers are in turn respectively: a hole blocking layer 206, an electron transport layer 207, and an electron injection layer 208. The electron transport layer contains but is not limited to the commonly used electron transport materials in the art, such as Alq3, Gaq3, BPhen, TmPyPB, TPBI, etc., and a commercial electron transport material such as LG201 can also be used. The electron injection layer 208 contains but is not limited to Liq, LiF, etc.

[0114] The structural formula of Alq3 is:

[0115] The structural formula of Gaq3 is:

[0116] The structural formula of TPBI is:

[0117] The structural formula of BPhen is:

[0118] The structural formula of Liq is:

[0119] 5) The cathode 209 is prepared, and the cathode material can use metals (Al, Ag) or metal mixtures (Ag-doped Mg, Ag-doped Ca, etc.), or the cathode can be modified to form an electron injection layer / metal conductor layer structure, such as a common structure of LiF / Al, CsCO3 / Al, Yb / Al, Yb / Mg:Ag, etc.

[0120] 6) After the film layer structure is evaporated, the complete OLED light-emitting device unit is formed.

[0121] The OLED device lifetime is affected by many factors, and the functional layer material and the light-emitting material used in film formation are the main influencing factors, and halogen in the material is one of the factors that has been proved to have important influence on the lifetime. The halogen content is mainly affected by the quality of the supplier material, but generally no further refining treatment is done at the application end. The present application uses a heterocyclic compound to pretreat the evaporation chamber in the normal preparation of the conventional device, and the process is carried out before and after the key film layer process, which can complex the free halogen on the film layer surface and in the chamber atmosphere, and finally achieve the purpose of reducing the halogen content in the key film layer of the device, thereby improving the device lifetime.

[0122] The following are several specific implementation processes of the present application:

[0123] Example 1

[0124] A preparation method of a long-life OLED display device, comprising the following steps:

[0125] 1) An ITO substrate (specification 15Ω / □, ) is used, and after ultrasonic treatment with acetone and isopropanol at 40℃ for 15 min each, the ITO substrate is baked at 230℃ for 30 min, and then cooled to room temperature and placed in a plasma treatment chamber for plasma treatment under the conditions of 50W, 1.5min, pressure 100mTorr, and after the end; the hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, electron injection layer and DT material layer are respectively evaporated in a vacuum evaporation chamber, the vacuum degree is about 1.0E-7torr, and the evaporation rate is After each layer is made, the metal cathode is made, and the evaporation rate is about

[0126]

[0127] (As a comparison) Device A: The preparation method of the device is as follows: a hole injection layer is first evaporated on an ITO substrate, the material is m-MTDATA and F4TCNQ, the volume ratio of F4TCNQ is 3%; then a hole transport layer is evaporated, the material is NPB; then an electron blocking layer is evaporated, the material is tris(4-carbazoyl-9-ylphenyl) amine (TCTA); then a light-emitting layer is evaporated, the material is CBP: Ir complex, wherein the volume ratio of the Ir complex is 3%; then a hole blocking layer is evaporated, the material is 1,3,5-tris(N-phenyl-2-benzimidazolyl) benzene (TPBI); then an electron transport layer is evaporated, the material is Alq3; then an electron injection layer is evaporated, the material is LiF; finally, a cathode is prepared by using Al.

[0128] Device B: The preparation method of the device is as follows: a hole injection layer is first evaporated on an ITO substrate, the material is m-MTDATA and F4TCNQ, the doping ratio of F4TCNQ is 3%; then a hole transport layer is evaporated, the material is NPB; then an electron blocking layer is evaporated, the material is tris(4-carbazoyl-9-ylphenyl) amine (TCTA); before the light-emitting layer is prepared, the chamber is evaporated with a DT material DT4-6, a baffle is used, and the evaporation time is controlled to be 30 min; the DT material can be uniformly attached to the inner wall of the chamber, and the DT material is not deposited on the electron blocking layer due to the blocking of the baffle before the substrate is evaporated; the thickness of the DT material layer is 0.1-0.2 nm. then a light-emitting layer is evaporated, the material is CBP: Ir complex, wherein the doping ratio of the Ir complex is 3%; after the light-emitting layer is prepared, the chamber is evaporated with a DT material, a baffle is used, and the evaporation time is controlled to be 30 min; the DT material can be uniformly attached to the inner wall of the chamber, and the DT material is not deposited on the light-emitting layer due to the blocking of the baffle before the substrate is evaporated; the thickness of the DT material layer is 0.1-0.2 nm. then a hole blocking layer is evaporated, the material is 1,3,5-tris(N-phenyl-2-benzimidazolyl) benzene (TPBI); then an electron transport layer is evaporated, the material is Alq3; then an electron injection layer is evaporated, the material is LiF; finally, a cathode is prepared by using Al.

[0129] Two device structures are prepared according to the above method, and the materials and thicknesses of the materials evaporated on the anode in sequence are as follows:

[0130] Device A: m-MTDATA:F4TCNQ(3%) / NPB / TCTA / CBP:Ir complex(3%) / TPBI / Alq3 / LiF / Al(1100); Device B: m-MTDATA:F4TCNQ(3%) / NPB / TCTA / DT4-6 / TCTA / CBP:Ir complex(3%) / TPBI / Alq3 / LiF / Al(1100); Device C: m-MTDATA:F4TCNQ(3%) / NPB / TCTA / CBP:Ir complex(3%) / DT4-6 / TCTA / TPBI / Alq3 / LiF / Al(1100); Device D: m-MTDATA:F4TCNQ(3%) / NPB / TCTA / DT4-6 / TCTA / CBP:Ir complex(3%) / TPBI / Alq3 / LiF / Al(1100); Device E: m-MTDATA:F4TCNQ(3%) / NPB / TCTA / CBP:Ir complex(3%) / DT4-6 / TPBI / Alq3 / LiF / Al(1100);

[0131] ​​​Device B: m-MTDATA:F4TCNQ :3%) / NPB / TCTA / DT4-6 / CBP:Ir complex :3%) / DT4-6 / TPBI / Alq3 / LiF / Al

[0132] 2) After the device is completed, encapsulation is performed in a N2 protective atmosphere: after the dry agent is attached, the glass cover plate is attached and UV frame glue is coated and ultraviolet and thermal curing is used, and after the completion of the preparation, electrical parameter measurement (Keithley 2650) and spectral measurement (CS2000A) are performed.

[0133] After the above preparation is completed, the lifetime test is performed, and the test spectrum is collected as follows: respectively as Figure 4 (J-V curve), Figure 5 (EL spectrum curve), Figure 6 (lifetime curve), the efficiency standard is @10mA / cm^2, and the lifetime decay data test condition is @50mA / cm^2. The test data summary table is shown in Table 1.

[0134] Table 1 shows the test results of the devices prepared in each embodiment

[0135] Serial number Experimental conditions Voltage @ 10 J Luminance (cd / cm^2) Cd / A CIEx CIEy T95 / h 1 Device A 3.41 2779.1 27.79 0.6507 0.3484 68 2 Device B 3.69 2660.0 26.60 0.6606 0.3385 94 3 Device C 4.02 2856.3 28.56 0.667 0.332 About 130

[0136] As shown in the above table, by comparing the device Device B treated with DT in Example 1 with the standard device Device A, it is found that the voltage rises by 0.28V due to the extension of the film layer residence time, and the overall lifetime is improved by 38% due to the improvement of the chamber atmosphere by DT4-6 treatment; at the same time, the spectrum curve is slightly deformed and the CIEx is improved from 0.6507 to 0.6606, which is beneficial to the improvement of color purity.

[0137] Example 2

[0138] A preparation method of a long-life OLED display device, comprising the following steps:

[0139] According to the method of the device Device B prepared in Example 1, the only difference is that during the evaporation of the DT material, no baffle is used, and the DT material is deposited not only on the inner wall of the chamber but also on the substrate, at this time the thickness of the DT material deposited on the device is The specific preparation process is as follows:

[0140] On an ITO substrate, a hole injection layer is first deposited sequentially using m-MTDATA and F4TCNQ, with F4TCNQ comprising 3% of the volume. Next, a hole transport layer is deposited using NPB. Then, an electron blocking layer is deposited using tris(4-carbazolyl-9-ylphenyl)amine (TCTA). Before fabricating the light-emitting layer, DT material DT4-6 is deposited into the chamber without a baffle, allowing the DT material to adhere uniformly to the inner wall of the chamber and deposit onto the electron blocking layer. The thickness of the DT material layer is [missing information]. A light-emitting layer is then deposited using a CBP:Ir complex, with an Ir doping ratio of 3%. After preparing the light-emitting layer, DT material is deposited into the chamber without baffles. The DT material adheres uniformly to the inner wall of the chamber and is deposited onto the light-emitting layer. The thickness of the DT material layer is... A hole-blocking layer is then deposited by evaporation using 1,3,5-tris(N-phenyl-2-benzimidazolyl)benzene (TPBI); an electron transport layer is then deposited using Alq3; an electron injection layer is then deposited using LiF; and finally, a cathode is prepared using Al.

[0141] The materials and thicknesses sequentially deposited on the anode of the device structure prepared in Example 2 are as follows:

[0142] Device C: m-MTDATA:F4TCNQ( 3% / NPB / TCTA / DT4-6 / CBP:Ir complex ( :3%) / DT4-6 / TPBI / Alq3 / LiF / Al

[0143] In Example 2, DT4-6 is deposited onto the substrate during the device evaporation process. A comparison of the DT-treated Device C and the standard Device A revealed that the voltage increased by 0.61V due to the increased film layer. Simultaneously, the overall lifetime was improved by 91% due to the improved chamber atmosphere resulting from the DT4-6 treatment. While the peak of this device showed a slight blue shift compared to Device B, the CIE of the color point was larger, resulting in higher color purity. Furthermore, it exhibited higher brightness at the same current, with a brightness improvement of approximately 7% compared to Device B. Although Example 2's optimization direction differed from Example 1, both examples improved lifetime levels to varying degrees.

[0144] Example 3

[0145] A method of making a long lifetime OLED display device, comprising the steps of:

[0146] Device Device D was made following the method of Device B made in Example 1, with the exception that the DT material was replaced with DT1-2;

[0147] The materials and thicknesses of the layers deposited on the anode of the device structure made in Example 3 were as follows:

[0148] Device Device D: m-MTDATA:F4TCNQ (3%) / NPB / TCTA / DT1-2 / CBP:Ir complex (3%) / DT1-2 / TPBI / Alq3 / LiF / Al

[0149] Example 4

[0150] A method of making a long lifetime OLED display device, comprising the steps of:

[0151] Device Device E was made following the method of Device B made in Example 1, with the exception that the DT material was replaced with DT3-3;

[0152] The materials and thicknesses of the layers deposited on the anode of the device structure made in Example 3 were as follows:

[0153] Device Device E: m-MTDATA:F4TCNQ (3%) / NPB / TCTA / DT3-3 / CBP:Ir complex (3%) / DT3-3 / TPBI / Alq3 / LiF / Al

[0154] ​​​​The test data summary table of Device A, Device D and Device E is shown in Table 2.

[0155] Table 2 Test results of Device A, Device D and Device E

[0156] Serial number Experimental conditions Voltage @ 10 J Luminance (cd / cm^2) Cd / A CIEx CIEy T95 / h 1 Device A 3.41 2779.1 27.79 0.6507 0.3484 68 2 Device D 3.65 2680.0 26.80 0.6537 0.3376 88 3 Device E 3.63 2730.5 27.30 0.6545 0.3390 95

[0157] As shown in the above table, by comparing the Device D of Example 3 with the standard Device A, it is found that the voltage rises by 0.24V due to the extension of the evaporation chamber residence time. In Example 4, the Device E treated by DT3-3, the voltage rises by 0.22V. At the same time, due to the improvement of the chamber atmosphere by the treatment of DT1-2 and DT3-3, the overall lifetime is increased by 29.4% and 39.7% respectively.

[0158] The above description of the embodiments is to enable those skilled in the art to understand and use the invention. Those skilled in the art can easily make various modifications to the embodiments and apply the general principles described herein to other embodiments without creative labor. Therefore, the invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art within the scope of the invention without departing from the scope of the invention should be within the protection scope of the invention.

Claims

1. A method for fabricating a long-life OLED display device, characterized in that, The preparation method includes the following steps: Before and after the luminescent layer is deposited, DT material, which is a nitrogen-containing heterocyclic compound, is deposited.

2. The preparation method according to claim 1, characterized in that, The DT material is vapor-deposited, and a baffle is used during the DT material vapor deposition process, with the deposition time controlled within 30 minutes.

3. The preparation method according to claim 1, characterized in that, No baffle is used when evaporating DT material. DT material forms a DT material layer on the substrate with a thickness of 0 to 1000 nm, and the thickness is not 0 nm.

4. The preparation method according to claim 1, characterized in that, When evaporating DT material, a baffle is used and the evaporation time is controlled within 30 minutes; then, without using the baffle, DT material is continued to be evaporated to form a DT material layer on the substrate with a thickness of 0-1000 nm, and the thickness is not 0 nm.

5. The preparation method according to any one of claims 1-4, characterized in that, The structural formula of the DT material is: In the structural formula: X is selected from carbon, nitrogen, or oxygen; n is selected from 0 or 1; Y is selected from carbon, nitrogen, or oxygen; n1 is selected from an integer between 0 and 5. It is represented as one of the heterocyclic aryl or aliphatic cyclic amines containing a nitrogen-containing five- or six-membered ring, where n2 = 1, 2, or 3; R1 and R2 are independently selected from any one of hydrogen, deuterium, substituted or unsubstituted hydrocarbon groups of C1-C20, and substituted or unsubstituted alkoxy groups of C1-C20; m is selected from an integer between 1 and 4.

6. The preparation method according to claim 5, characterized in that, If X is carbon, m is selected from 1 to 4; if X is nitrogen, m is selected from 1 to 3; or if X is oxygen, m is selected from 1 to 2.

7. The preparation method according to claim 5, characterized in that, In the structural formula Choose one of the following general formulas: (1), (2), (3), (4), (5), (6), and (7): General formula (1): General formula (2): General formula (3): General formula (4): General formula (5): General formula (6): General formula (7): R1 and R2 are independent of each other, and R1 and R2 are independently selected from any one of hydrogen, deuterium, substituted or unsubstituted hydrocarbon groups of C1-C20, and substituted or unsubstituted alkoxy groups of C1-C20.

8. The preparation method according to claim 1 or 7, characterized in that, The DT material has any of the following structures: DT1-1: DT1-2: DT1-3: DT1-4: DT2-1: DT2-2: DT3-1: DT3-2: DT3-3: DT4-1: DT4-2: DT4-3: DT4-4: DT4-5: DT4-6:

9. A long-life OLED display device prepared by the preparation method according to any one of claims 1-8.

10. An application of the long-life OLED display device according to claim 9, characterized in that, For use in OLED display devices.

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