Blue phosphorescent organic light-emitting device with high efficiency and long service life and display device

Abstract

The invention provides a blue phosphorescent organic light-emitting device with high efficiency and long service life and a display device. The blue phosphorescent organic light-emitting device comprises a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer and an electron transport layer, the light-emitting layer comprises a P-type main body material, an N-type main body material and a doping material; the peak value of the light-emitting spectrum of the P-type main body material is 365 nm to 400 nm, and the half-peak width is 35 nm to 45 nm; the peak value of the luminescent spectrum of the N-type host material is 410-450 nm, and the half-peak width of the N-type host material is 60-85 nm; the luminescent spectrum peak value of the doped material is 455nm to 470nm, and the half-peak width of the doped material is 18nm to 24nm; the T1 energy level of the P-type main body material is greater than the T1 energy level of the doped material; the T1 energy level of the N-type host material is greater than the T1 energy level of the doped material. The blue phosphorescent organic light-emitting device provided by the invention is high in efficiency and long in service life.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a high-efficiency and long-life blue phosphorescent organic light-emitting device and a display apparatus. Background Art

[0002] Organic laser display (OLED) technology is the third generation display technology following cathode ray tube (CRT) and liquid crystal display (LCD). Due to its advantages such as low energy consumption, wide viewing angle, fast response speed, high clarity, ultra-thin, flexible and self-luminous properties, it has great potential in the fields of lighting and display. It has been widely used in mobile phones, computers, televisions, cars, smart wearable devices and other fields.

[0003] According to the different luminescent materials, organic light-emitting semiconductor devices are mainly divided into fluorescent OLED, phosphorescent OLED and thermally activated delayed fluorescent OLED. Currently, fluorescent OLED and phosphorescent OLED are more commonly used commercially. Under electrical excitation, organic materials produce 25% singlet excitons and 75% triplet excitons. For fluorescent materials, according to the principle of spin conservation, only 25% of singlet excitons can generate photons through radiative transitions, resulting in the maximum internal quantum efficiency of fluorescent OLEDs not exceeding 25%. Even considering the TTA (triplet-triplet annihilation) effect, the maximum internal quantum efficiency is still not more than 40%. Unlike fluorescent materials, due to the spin-orbit coupling of heavy metals, the triplet excitons of phosphorescent materials can emit photons through radiative transitions, so that the maximum internal quantum efficiency of phosphorescent OLEDs can theoretically reach 100%, greatly improving the efficiency of the device. Therefore, the mass-produced red and green light devices are mainly phosphorescent OLED devices. However, blue phosphorescent devices have low efficiency and short lifespan, which cannot meet the needs of mass production; therefore, it is urgent to develop high-efficiency and long-life blue phosphorescent OLED devices. Summary of the invention

[0004] The purpose of this application is to provide a blue phosphorescent organic light-emitting device to improve the efficiency of the blue phosphorescent organic light-emitting device and extend the life of the blue phosphorescent organic light-emitting device. The specific technical solution is as follows:

[0005] The first aspect of the present application provides a blue phosphorescent organic light-emitting device, comprising: a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer and an electron transport layer; the light-emitting layer comprises a P-type main material, an N-type main material and a doping material; the peak value of the light-emitting spectrum of the P-type main material is 365nm-400nm, and the half-peak width is 35nm-45nm; the peak value of the light-emitting spectrum of the N-type main material is 410nm-450nm, and the half-peak width is 60nm-85nm; the peak value of the light-emitting spectrum of the doping material is 455nm-470nm, and the half-peak width is 18nm-24nm; the T1 energy level of the P-type main material is greater than the T1 energy level of the doping material; the T1 energy level of the N-type main material is greater than the T1 energy level of the doping material.

[0006] In some embodiments of the present application, in a blue phosphorescent organic light-emitting device, the difference between the T1 energy level of the P-type main material and the T1 energy level of the doping material is a first energy extreme difference, and the first energy extreme difference is 0.1eV-0.6eV; the difference between the T1 energy level of the N-type main material and the T1 energy level of the doping material is a second energy extreme difference, and the second energy extreme difference is 0.1eV-0.6eV.

[0007] In some embodiments of the present application, in a blue phosphorescent organic light-emitting device, the HOMO energy level of the hole transport layer is lower than the HOMO energy level of the electron blocking layer, and the HOMO energy level of the electron blocking layer is equal to the HOMO energy level of the P-type main material; the HOMO energy level of the P-type main material is greater than the HOMO energy level of the doping material; the LUMO energy level of the doping material is lower than the LUMO energy level of the hole blocking layer, and the LUMO energy level of the hole blocking layer is lower than the LUMO energy level of the electron transport layer; the LUMO energy level of the N-type main material is equal to the LUMO energy level of the hole blocking layer; the difference between the LUMO energy level of the N-type main material and the LUMO energy level of the doping material is a third energy extreme difference, and the third energy extreme difference is -0.2eV to 0.2eV.

[0008] In some embodiments of the present application, in a blue phosphorescent organic light-emitting device, the HOMO energy level of the doping material is 5.4eV-5.6eV; the LUMO energy level of the doping material is 2.5eV-2.75eV; the LUMO energy level of the N-type host material is 2.6eV-2.78eV; and the LUMO energy level of the electron transport layer is 2.8eV-3.0eV.

[0009] In some embodiments of the present application, in a blue phosphorescent organic light-emitting device, the HOMO energy level of the P-type host material is greater than the HOMO energy level of the dopant material, and the LUMO energy level of the dopant material is greater than the LUMO energy level of the P-type host material.

[0010] In some embodiments of the present application, in a blue phosphorescent organic light-emitting device, the difference between the HOMO energy level of the P-type main material and the HOMO energy level of the doping material is a fourth energy extreme difference, and the fourth energy extreme difference is less than or equal to 0.5 eV; the difference between the LUMO energy level of the doping material and the LUMO energy level of the P-type main material is a fifth energy extreme difference, and the fifth energy extreme difference is less than or equal to 0.5 eV; the difference between the LUMO energy level of the N-type main material and the LUMO energy level of the doping material is a third energy extreme difference, and the third energy extreme difference is -0.2 eV to 0.2 eV.

[0011] In some embodiments of the present application, in a blue phosphorescent organic light-emitting device, the hole reorganization energy of the P-type host material is 0.24 eV-0.28 eV; the electron reorganization energy of the N-type host material is 0.5 eV-0.7 eV.

[0012] In some embodiments of the present application, the blue phosphorescent organic light-emitting device satisfies at least one of the following conditions:

[0013] (1) The hole transport layer comprises a compound represented by formula (I):

[0014]

[0015] wherein R1, R2, R3, R4 and R5 are each independently selected from hydrogen, C 1-40 Alkyl, C 6-40 Aryl, C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S;

[0016] Y1 is selected from O or S;

[0017] (2) The N-type host material includes a compound represented by formula (II):

[0018]

[0019] Among them, R 1aare each independently selected from hydrogen, deuterium, C 1-40 Alkyl, C 6-40 Aryl, C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S;

[0020] m is each independently selected from 0, 1, 2, 3 or 4;

[0021] X1, X2, X3 and X4 are each independently selected from C, N, O or S;

[0022] (3) The electron transport layer comprises a compound represented by formula (III):

[0023]

[0024] Among them, R 1b , R 2b , R 3b , R 4b , R 5b and R 6b Each independently selected from hydrogen, unsubstituted or replaced by C 6-12 Aryl substituted C 1-40 Alkyl, C 6-40 Aryl, C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S;

[0025] (4) The P-type host material includes a compound represented by formula (IV):

[0026]

[0027] Among them, R 1c Selected from hydrogen, C unsubstituted or partially substituted with deuterium 6-40 Aryl, unsubstituted or partially hydrogen substituted by deuterium C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S;

[0028] R 2c are each independently selected from hydrogen, deuterium, C 6-18 Aryl or C 1-3 alkyl;

[0029] n is each independently selected from 0, 1, 2, 3 or 4;

[0030] (5) The doping material includes a compound represented by formula (V):

[0031]

[0032] Among them, R 1d , R 3d and R 4d are each independently selected from hydrogen, C 1-40 Alkyl, C 6-40 Aryl, C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S;

[0033] R 2d Selected from hydrogen, C unsubstituted or partially substituted with deuterium 6-40 Aryl, unsubstituted or partially hydrogen substituted by deuterium C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S;

[0034] p is selected from 0, 1, 2, 3 or 4.

[0035] In some embodiments of the present application, in a blue phosphorescent organic light-emitting device,

[0036] In formula (I), R1, R2, R3, R4 and R5 are each independently selected from hydrogen, C 1-10 Alkyl, C 6-18 Aryl, C 2-18 Heteroaryl, C 6-18 Aryloxy, C 1-10 Alkoxy, C 6-18 Arylamine, C 3-10 Cycloalkyl, C 3-10 Heterocycloalkyl, C 1-10 Alkylsilyl, C 1-10 Alkyl boron, C 6-18 Aryl boron, C 6-18 Arylphosphino or C 6-18 Arylsilyl;

[0037] In formula (II), R 1a are each independently selected from hydrogen, deuterium, C 1-10 Alkyl, C 6-18 Aryl, C 2-18 Heteroaryl, C 6-18 Aryloxy, C 1-10 Alkoxy, C 6-18 Arylamine, C 3-10 Cycloalkyl, C 3-10 Heterocycloalkyl, C 1-10 Alkylsilyl, C 1-10Alkyl boron, C 6-18 Aryl boron, C 6-18 Arylphosphino or C 6-18 Arylsilyl;

[0038] In formula (III), R 1b , R 2b , R 3b , R 4b , R 5b and R 6b are each independently selected from hydrogen, unsubstituted or phenyl-substituted C 1-10 Alkyl, C 6-18 Aryl, C 2-18 Heteroaryl, C 6-18 Aryloxy, C 1-10 Alkoxy, C 6-18 Arylamine, C 3-10 Cycloalkyl, C 3-10 Heterocycloalkyl, C 1-10 Alkylsilyl, C 1-10 Alkyl boron, C 6-18 Aryl boron, C 6-18 Arylphosphino or C 6-18 Arylsilyl;

[0039] In formula (IV), R 1c Selected from C 6-18 Aryl, unsubstituted or partially hydrogen substituted by deuterium C 2-30 heteroaryl;

[0040] In formula (V), R 1d , R 3d and R4 are each independently selected from hydrogen, C 1-10 Alkyl, C 6-18 Aryl, C 2-18 Heteroaryl, C 6-18 Aryloxy, C 1-10 Alkoxy, C 6-18 Arylamine, C 3-10 Cycloalkyl, C 3-10 Heterocycloalkyl, C 1-10 Alkylsilyl, C 1-10 Alkyl boron, C 6-18 Aryl boron, C 6-18 Arylphosphino or C 6-18 Arylsilyl; R 2d Selected from hydrogen, C unsubstituted or partially substituted with deuterium 6-18 Aryl, unsubstituted or partially hydrogen substituted by deuterium C 2-18 Heteroaryl, C 6-18 Aryloxy, C 1-10 Alkoxy, C6-18 Arylamine, C 3-10 Cycloalkyl, C 3-10 Heterocycloalkyl, C 1-10 Alkylsilyl, C 1-10 Alkyl boron, C 6-18 Aryl boron, C 6-18 Arylphosphino or C 6-18 Arylsilyl.

[0041] The second aspect of the present application provides a display device, which includes the blue phosphorescent organic light-emitting device described in the first aspect of the present application.

[0042] Beneficial effects of this application:

[0043] The present application provides a blue phosphorescent organic light-emitting device (blue phosphorescent OLED), which controls the compounds in a P-type host material and a N-type host material to form an exciplex, so that the peak positions of the luminescent spectra of the P-type host material and the N-type host material (P-type Host + N-type Host) and the luminescent spectrum of the dopant material (Dopant) are close to and overlap as much as possible, and the luminescent spectrum of the P-type Host + N-type Host surrounds the luminescent spectrum of the Dopant, so that the P-type Host + N-type Host can resonate with the Dopant when excited, which is beneficial to transfer energy to the Dopant, and obtain a blue phosphorescent OLED with high efficiency and long life.

[0044] Of course, implementing any product or method of the present application does not necessarily require achieving all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0046] Figure 1 A schematic diagram of the structure of a blue phosphorescent organic light-emitting device according to an embodiment of the present application;

[0047] Figure 2 A schematic structural diagram of a blue phosphorescent organic light-emitting device according to another embodiment of the present application;

[0048] Figure 3 The luminescence spectra of BD-PL and P-type Host+N-type Host-PL according to an embodiment of the present application are shown;

[0049] Figure 4 An energy level diagram for an embodiment of the present application;

[0050] Figure 5 A schematic diagram of the energy transfer process from Host to Dopant according to an embodiment of the present application;

[0051] Figure 6 A schematic diagram of HOMO / LUMO (P-type Host) surrounding HOMO / LUMO (Dopant) according to an embodiment of the present application;

[0052] Figure 7 The luminescence spectra of P-type Host+N-type Host-PL and BD-PL in Example 1, Comparative Example 1 and Comparative Example 2 of the present application;

[0053] Figure 8 It is a result diagram of the exciton recombination area of ​​the device of Example 1 and Comparative Example 1 of the present application;

[0054] In the figure, 10. substrate, 11. anode electrode, 12. hole injection layer, 13. hole transport layer, 14. electron blocking layer, 15. light emitting layer, 16. hole blocking layer, 17. electron transport layer, 18. electron injection layer, 19. cathode electrode. DETAILED DESCRIPTION

[0055] The following will be combined with the embodiments of the present application and the accompanying drawings to clearly and completely describe the technical solutions in the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the present application belong to the scope of protection of the present application.

[0056] Since the energy of blue light is higher than that of red light and green light, the T1 energy level of blue phosphorescent materials is higher than that of red phosphorescent materials and green phosphorescent materials; however, it is difficult to find a blue phosphorescent host material (Host) with a high T1 energy level and good material stability in the prior art, resulting in the energy of the dopant material (Dopant) being transferred back to the Host material, making the efficiency of blue phosphorescent OLEDs low. Therefore, it is an urgent problem to seek a Host material suitable for blue phosphorescent Dopant that can transfer energy to the Dopant material well, thereby obtaining a high-efficiency blue phosphorescent device. In addition, since the electron-hole recombination center is close to the center of the light-emitting layer (EML), the accumulation of the T1 energy level is reduced, the energy level quenching is reduced, and the cracking of the material is solved, so improving the life of the blue phosphorescent device is also an urgent problem to be solved.

[0057] The first aspect of the present application provides a blue phosphorescent organic light-emitting device, such as Figure 1 As shown, it includes a hole transport layer (HTL) 13, an electron blocking layer (EBL) 14, an emitting layer (EML) 15, a hole blocking layer (HBL) 16 and an electron transport layer (ETL) 17. In some embodiments of the present application, the electron blocking layer 14 is disposed on one side of the emitting layer 15; the hole transport layer 13 is disposed on the side of the electron blocking layer 14 away from the emitting layer 15; the hole blocking layer 16 is disposed on the side of the emitting layer 15 away from the electron blocking layer 14; and the electron transport layer 17 is disposed on the side of the hole blocking layer 16 away from the emitting layer 15.

[0058] like Figure 2 As shown, the blue phosphorescent organic light-emitting device described in the present application may also include: a substrate 10, an anode electrode 11, a hole injection layer (HIL) 12, an electron injection layer (EIL) 18 and a cathode electrode 19; wherein the hole injection layer 12 is arranged on a side of the hole transport layer 13 away from the electron blocking layer 14; the anode electrode 11 is arranged on a side of the hole injection layer 12 away from the hole transport layer 13; the substrate 10 is arranged on a side of the anode electrode 11 away from the hole injection layer 12; the electron injection layer 18 is arranged on a side of the electron transport layer 17 away from the hole blocking layer 16, and the cathode electrode 19 is arranged on a side of the electron injection layer 18 away from the electron transport layer 17.

[0059] This application provides Figure 1 and Figure 2 Only the positional relationship between the layers in the blue phosphorescent organic light-emitting device is shown, wherein the height relationship between the layers does not limit the thickness relationship between the layers, which can be adjusted according to actual needs.

[0060] In the present application, the light-emitting layer includes a P-type host material (P-type Host) for transporting holes, an N-type host material (N-type Host) for transporting electrons, and a dopant material (Dopant); the peak value (peak) of the luminescence spectrum of the P-type Host is 365nm-400nm, and the half-peak width (FWHM) is 35nm-45nm; the peak value of the luminescence spectrum of the N-type Host is 410nm-450nm, and the half-peak width is 60nm-85nm; the peak value of the luminescence spectrum of the Dopant is 455nm-470nm, and the half-peak width is 18nm-24nm; the T1 energy level of the P-type Host is greater than the T1 energy level of the Dopant; the T1 energy level of the N-type Host is greater than the T1 energy level of the Dopant.

[0061] In this application, the P-type Host + N-type Host materials are mixed and used as the Host of the blue phosphorescent Dopant material. Figure 3As shown, the present application controls the peak values ​​and half-peak widths of the P-type Host, N-type Host and Dopant to be within the above ranges, respectively. The relationship between the T1 energy levels of the P-type Host, N-type Host and Dopant is as above. The P-type Host + N-type Host restricted in this way needs to form an exciplex, so that the peak positions of the emission spectrum of the P-type Host + N-type Host and the Dopant emission spectrum are close to and overlap as much as possible, and the emission spectrum of the P-type Host + N-type Host surrounds the Dopant emission spectrum, so that the P-type Host + N-type Host can resonate with the Dopant when excited, which is more conducive to transferring energy to the Dopant, thereby obtaining a blue phosphorescent OLED with high efficiency and long life.

[0062] In some embodiments of the present application, the difference between the T1 energy level of the P-type Host and the T1 energy level of the Dopant is a first energy extreme difference, and the first energy extreme difference is 0.1eV-0.6eV. In some embodiments of the present application, the value of the first energy extreme difference can be 0.1eV, 0.2eV, 0.3eV, 0.4eV, 0.5eV, 0.6eV or a range consisting of any two values ​​therebetween. The present application controls the first energy extreme difference within the above range, which is conducive to obtaining a blue phosphorescent OLED with higher efficiency and longer life.

[0063] In some embodiments of the present application, the difference between the T1 energy level of the N-type Host and the T1 energy level of the Dopant is the second energy extreme difference, and the second energy extreme difference is 0.1eV-0.6eV. In some embodiments of the present application, the value of the second energy extreme difference can be 0.1eV, 0.2eV, 0.3eV, 0.4eV, 0.5eV, 0.6eV or a range consisting of any two values ​​therebetween. The present application controls the second energy extreme difference within the above range, which is conducive to obtaining a blue phosphorescent OLED with higher efficiency and longer life.

[0064] In some embodiments of the present application, the HOMO energy level of the hole transport layer (HTL) is lower than the HOMO energy level of the electron blocking layer (EBL), and the HOMO energy level of the electron blocking layer is equal to the HOMO energy level of the P-type main material; the HOMO energy level of the P-type main material is greater than the HOMO energy level of the doping material; the LUMO energy level of the doping material is lower than the LUMO energy level of the hole blocking layer (HBL), and the LUMO energy level of the hole blocking layer is lower than the LUMO energy level of the electron transport layer (ETL); the LUMO energy level of the N-type main material is equal to the LUMO energy level of the hole blocking layer; the difference between the LUMO energy level of the N-type main material and the LUMO energy level of the doping material is a third energy extreme difference, and the third energy extreme difference is -0.2eV to 0.2eV. In some embodiments of the present application, the value of the third energy extreme difference can be -0.2eV, -0.15eV, -0.1eV, 0eV, 0.1eV, 0.15eV, 0.2eV or a range consisting of any two values ​​therebetween. The present application controls the device to have good HOMO / LUMO energy level matching between the materials in each layer, which is beneficial to the injection of holes and electrons, thereby obtaining a high-efficiency, long-life blue phosphorescent OLED.

[0065] In this application, if Figure 4 As shown, HOMO(HTL)<HOMO(EBL)=HOMO(P-type Host, i.e. Figure 4 Medium P-Type BH); HOMO (P-type Host) > HOMO (Dopant, that is Figure 4 Medium BD); LUMO (Dopant) < LUMO (HBL) < LUMO (ETL); LUMO (N-type Host, that is Figure 4 In the embodiment of the present invention, N-Type BH)=LUMO(HBL); the difference between LUMO(N-type Host) and LUMO(Dopant) is -0.2eV to 0.2eV, that is, LUMO(N-type Host) can be greater than, equal to or less than LUMO(Dopant).

[0066] In some embodiments of the present application, the HOMO energy level of the doping material is 5.4eV-5.6eV; the LUMO energy level of the doping material is 2.5eV-2.75eV; the LUMO energy level of the N-type host material is 2.6eV-2.78eV; and the LUMO energy level of the electron transport layer is 2.8eV-3.0eV. In some embodiments of the present application, the HOMO energy level of the doping material can be 5.4eV, 5.5eV, 5.6eV, or a range consisting of any two values ​​therebetween; the LUMO energy level of the doping material can be 2.5eV, 2.55eV, 2.6eV, 2.65eV, 2.7eV, 2.75eV, or a range consisting of any two values ​​therebetween; the LUMO energy level of the N-type host material can be 2.6eV, 2.65eV, 2.7eV, 2.75eV, 2.78eV, or a range consisting of any two values ​​therebetween; the LUMO energy level of the electron transport layer is 2.8eV, 2.9eV, 3.0eV, or a range consisting of any two values ​​therebetween. The present application controls HOMO (Dopant), LUMO (Dopant), LUMO (N-type Host), and LUMO (ETL) within the above ranges, and each layer of material has a good HOMO / LUMO energy level match, which is beneficial to the injection of holes and electrons, thereby obtaining a high-efficiency, long-life blue phosphorescent OLED.

[0067] In some embodiments of the present application, the HOMO energy level of the P-type host material is greater than the HOMO energy level of the dopant material, and the LUMO energy level of the dopant material is greater than the LUMO energy level of the P-type host material. In the present application, HOMO(P-type Host)>HOMO(Dopant), and LUMO(Dopant)>LUMO(P-type Host), that is, HOMO / LUMO(P-type Host) surrounds HOMO / LUMO(Dopant). Figure 5 As shown in the figure, the energy transfer process from Host to Dopant is that the P-type Host captures holes, the N-type Host captures electrons for recombination, and transfers energy to BD (Blue Dopant), which then emits light after absorbing the energy.

[0068] In some embodiments of the present application, the difference between the HOMO energy level of the P-type main material and the HOMO energy level of the doping material is a fourth energy extreme difference, and the fourth energy extreme difference is less than or equal to 0.5eV; the difference between the LUMO energy level of the doping material and the LUMO energy level of the P-type main material is a fifth energy extreme difference, and the fifth energy extreme difference is less than or equal to 0.5eV; the difference between the LUMO energy level of the N-type main material and the LUMO energy level of the doping material is a third energy extreme difference, and the third energy extreme difference is -0.2eV to 0.2eV. In some embodiments of the present application, the value of the fourth energy extreme difference can be 0.01eV, 0.05eV, 0.1eV, 0.2eV, 0.3eV, 0.4eV, 0.5eV, or a range consisting of any two values ​​therebetween. In some embodiments of the present application, the value of the fifth energy extreme difference can be 0.01eV, 0.05eV, 0.1eV, 0.2eV, 0.3eV, 0.4eV, 0.5eV or a range consisting of any two values ​​therebetween. In some embodiments of the present application, the value of the third energy extreme difference can be -0.2eV, -0.15eV, -0.1eV, 0eV, 0.1eV, 0.15eV, 0.2eV or a range consisting of any two values ​​therebetween, that is, LUMO (N-type Host) can be greater than, equal to or less than LUMO (Dopant). Figure 5 and Figure 6 As shown, LUMO(N-type Host) is larger than LUMO(Dopant).

[0069] The present application controls the fourth energy level difference, the fifth energy level difference, and the third energy level difference within the above range, that is, the closer the HOMO of BD is to the HOMO of P-type Host, and the closer the LUMO of BD is to the LUMO of N-type Host, the shallower the trap formed is, the smaller the probability of holes / electrons being captured by the trap, the more electron holes are used for composite luminescence, and the higher the efficiency of the blue phosphorescent OLED device is.

[0070] In some embodiments of the present application, the hole reorganization energy (ROE) of the P-type host material is 0.24eV-0.28eV; the electron reorganization energy of the N-type host material is 0.5eV-0.7eV. In some embodiments of the present application, the value of the hole reorganization energy of the P-type Host can be 0.24eV, 0.25eV, 0.26eV, 0.27eV, 0.28eV, or a range consisting of any two values ​​therebetween. In some embodiments of the present application, the value of the electron reorganization energy of the N-type Host can be 0.5eV, 0.55eV, 0.6eV, 0.65eV, 0.7eV, or a range consisting of any two values ​​therebetween. The reorganization energy calculation software used in this application is the Schrodinger simulation software, and the computer group is B3LYP 6-31G**. In the present application, the greater the reorganization energy, the greater the degree of molecular distortion when transferring charge, and the more difficult it is to transfer charge. Therefore, the smaller the reorganization energy, the easier it is to transfer charge, which is conducive to obtaining a high-efficiency, long-life blue phosphorescent OLED device.

[0071] In some embodiments of the present application, the blue phosphorescent organic light-emitting device satisfies at least one of the following conditions:

[0072] (1) The hole transport layer comprises a compound represented by formula (I):

[0073]

[0074] wherein R1, R2, R3, R4 and R5 are each independently selected from hydrogen, C 1-40 Alkyl, C 6-40 Aryl, C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S;

[0075] Y1 is selected from O or S;

[0076] (2) The N-type host material includes a compound represented by formula (II):

[0077]

[0078] Among them, R 1a are each independently selected from hydrogen, deuterium, C 1-40 Alkyl, C 6-40 Aryl, C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S;

[0079] m is each independently selected from 0, 1, 2, 3 or 4;

[0080] X1, X2, X3 and X4 are each independently selected from C, N, O or S;

[0081] (3) The electron transport layer comprises a compound represented by formula (III):

[0082]

[0083] Among them, R 1b , R 2b , R 3b , R 4b , R 5b and R 6b Each independently selected from hydrogen, unsubstituted or replaced by C 6-12 Aryl substituted C 1-40 Alkyl, C 6-40 Aryl, C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S;

[0084] (4) The P-type host material includes a compound represented by formula (IV):

[0085]

[0086] Among them, R 1c Selected from hydrogen, C unsubstituted or partially substituted with deuterium 6-40 Aryl, unsubstituted or partially hydrogen substituted by deuterium C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S;

[0087] R 2c are each independently selected from hydrogen, deuterium, C 6-18 Aryl or C 1-3 alkyl;

[0088] n is each independently selected from 0, 1, 2, 3 or 4;

[0089] (5) The doping material includes a compound represented by formula (V):

[0090]

[0091] Among them, R 1d , R 3d and R 4d are each independently selected from hydrogen, C 1-40 Alkyl, C 6-40 Aryl, C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S;

[0092] R 2d Selected from hydrogen, C unsubstituted or partially substituted with deuterium 6-40 Aryl, unsubstituted or partially hydrogen substituted by deuterium C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S; and p is selected from 0, 1, 2, 3 or 4.

[0093] In some embodiments of the present application, in formula (I), R1, R2, R3, R4 and R5 are each independently selected from hydrogen, C 1-10 Alkyl, C 6-18 Aryl, C 2-18 Heteroaryl, C 6-18 Aryloxy, C 1-10 Alkoxy, C 6-18 Arylamine, C 3-10 Cycloalkyl, C 3-10 Heterocycloalkyl, C 1-10 Alkylsilyl, C 1-10 Alkyl boron, C 6-18 Aryl boron, C 6-18 Arylphosphino or C 6-18 Arylsilyl;

[0094] In formula (II), R 1a are each independently selected from hydrogen, deuterium, C 1-10 Alkyl, C 6-18 Aryl, C 2-18 Heteroaryl, C 6-18 Aryloxy, C 1-10 Alkoxy, C 6-18 Arylamine, C 3-10 Cycloalkyl, C 3-10 Heterocycloalkyl, C 1-10 Alkylsilyl, C 1-10 Alkyl boron, C 6-18 Aryl boron, C 6-18 Arylphosphino or C6-18 Arylsilyl;

[0095] In formula (III), R 1b , R 2b , R 3b , R 4b , R 5b and R 6b are each independently selected from hydrogen, unsubstituted or phenyl-substituted C 1-10 Alkyl, C 6-18 Aryl, C 2-18 Heteroaryl, C 6-18 Aryloxy, C 1-10 Alkoxy, C 6-18 Arylamine, C 3-10 Cycloalkyl, C 3-10 Heterocycloalkyl, C 1-10 Alkylsilyl, C 1-10 Alkyl boron, C 6-18 Aryl boron, C 6-18 Arylphosphino or C 6-18 Arylsilyl;

[0096] In formula (IV), R 1c Selected from C 6-18 Aryl, unsubstituted or partially hydrogen substituted by deuterium C 2-30 Heteroaryl; for example, R 1c Selected from

[0097] In formula (V), R 1d , R 3d and R 4d are each independently selected from hydrogen, C 1-10 Alkyl, C 6-18 Aryl, C 2-18 Heteroaryl, C 6-18 Aryloxy, C 1-10 Alkoxy, C 6-18 Arylamine, C 3-10 Cycloalkyl, C 3-10 Heterocycloalkyl, C 1-10 Alkylsilyl, C 1-10 Alkyl boron, C 6-18 Aryl boron, C 6-18 Arylphosphino or C 6-18 Arylsilyl;

[0098] R 2d Selected from hydrogen, C unsubstituted or partially substituted with deuterium 6-18 Aryl, unsubstituted or partially hydrogen substituted by deuterium C 2-18 Heteroaryl, C 6-18Aryloxy, C 1-10 Alkoxy, C 6-18 Arylamine, C 3-10 Cycloalkyl, C 3-10 Heterocycloalkyl, C 1-10 Alkylsilyl, C 1-10 Alkyl boron, C 6-18 Aryl boron, C 6-18 Arylphosphino or C 6-18 Arylsilyl.

[0099] The “partial hydrogen is replaced by deuterium” mentioned in the present application may mean that a part of hydrogen is replaced by deuterium, or all hydrogen is replaced by deuterium.

[0100] In some embodiments of the present application, the hole transport layer includes at least one compound as shown below:

[0101]

[0102] The N-type main material includes at least one compound as shown below:

[0103]

[0104]

[0105] The electron transport layer includes at least one compound as shown below:

[0106]

[0107] The P-type main material includes at least one compound as shown below:

[0108]

[0109] The doping material includes at least one compound as shown below:

[0110]

[0111]

[0112] The above compounds of the present application can be purchased commercially or prepared by conventional synthesis methods in the art.

[0113] The present application does not particularly limit the materials used for other components such as the hole injection layer, the electron blocking layer, the hole blocking layer, the electron injection layer, etc., and they may be materials commonly used in the art.

[0114] The second aspect of the present application provides a display device, which comprises the blue phosphorescent organic light-emitting device described in the first aspect of the present application. The display device includes but is not limited to a display, a television, a tablet computer, a mobile communication terminal, etc.

[0115] The method for preparing the blue phosphorescent organic light-emitting device of the present application is not particularly limited, and any method known in the art can be used, for example, referring to Figure 2 , can be prepared by the following preparation method:

[0116] (1) cleaning the anode electrode 11 on the top-emitting OLED device substrate 10 by using a cleaning machine through steps such as chemical cleaning, water cleaning, brushing, high-pressure water cleaning, and air knife cleaning, and then performing a heat treatment;

[0117] (2) vacuum evaporating a hole injection material on the anode electrode 11 to form a hole injection layer 12;

[0118] (3) vacuum evaporating a hole transport material on the hole injection layer 12 to form a hole transport layer 13;

[0119] (4) vacuum evaporating an electron blocking material on the hole transport layer 13 to form the electron blocking layer 14;

[0120] (5) vacuum evaporating a light-emitting layer 15 on the electron blocking layer 14, wherein the light-emitting layer 15 includes a main material and a doping material;

[0121] (6) vacuum evaporating a hole blocking material on the light emitting layer 15 to form a hole blocking layer 16;

[0122] (7) vacuum evaporating an electron transport material on the hole blocking layer 16 to form an electron transport layer 17;

[0123] (8) vacuum evaporating an electron injection material on the electron transport layer 17 to form the electron injection layer 18;

[0124] (9) A cathode material is vacuum-deposited on the electron injection layer 18 to form the cathode electrode 19 .

[0125] The above only describes a typical structure of a blue phosphorescent organic light-emitting device and its preparation method. It should be understood that the present application is not limited to this structure. The present application can use any preparation method known in the art to prepare the blue phosphorescent organic light-emitting device.

[0126] Example

[0127] The following examples and comparative examples are given to more specifically describe the embodiments of the present application. Various tests and evaluations were performed according to the following methods. In addition, unless otherwise specified, "parts" and "%" are based on mass.

[0128] Test methods and equipment:

[0129] 1. Determination of luminescence spectrum

[0130] Fluorescence measurement is an analytical technique that uses the intensity, decay rate, lifetime and other characteristics of the fluorescence radiation emitted by a substance after being excited to analyze and study the substance. The present application uses a fluorescence spectrophotometer to measure the luminescence spectrum.

[0131] 2. Determination of T1 energy level

[0132] This application calculates the T1 energy level by measuring phosphorescence using an FLS980 steady-state transient fluorescence / phosphorescence spectrometer. Under low temperature 77K conditions, the phosphorescence emission spectrum is measured, a tangent is drawn at the peak of the spectrum, the value at the intersection of the tangent and the x-axis is taken, and then the energy is obtained by dividing this value by 1240, thereby determining the excited state energy level of the material.

[0133] 3. Determination of HOMO and LUMO energy levels

[0134] This application uses a photoelectron spectrophotometer AC3 to measure the HOMO energy level and LUMO energy level. By irradiating the sample with ultraviolet light, the kinetic energy of the secondary electrons at the low energy end is measured, and then the HOMO energy level position of the material is determined. Specifically, when the sample is irradiated with ultraviolet light of a specific wavelength, a part of the energy is used to overcome the electron binding energy, and the remaining part enables the electron to gain kinetic energy. By analyzing the position of these physical parameters in the spectrum, the HOMO energy level of the material can be obtained. The absorption spectrum of the test material, the intersection of the wind tangent line of the absorption spectrum and the horizontal coordinate, divide 1240 by the intersection to obtain Eg, LUMO = HOMO-Eg.

[0135] 4. Determination of hole reorganization energy and electron reorganization energy

[0136] This application uses Gaussian molecular simulation software to measure hole reorganization energy and electron reorganization energy, which mainly relies on quantum chemical calculation methods, especially density functional theory (DFT) methods, to explore the electron transfer process.

[0137] 5. Determination of device exciton recombination area

[0138] The present application uses a current and voltage test device to measure the exciton recombination area of ​​the device. By adjusting the thickness of the spacer layer of the device light-emitting layer, the position of the exciton recombination area can be effectively regulated, thereby affecting the luminescence performance of the device, and the change of the exciton recombination area can be observed.

[0139] 6. Performance measurement of blue phosphorescent OLED devices

[0140] At the same brightness, the driving voltage (V), current efficiency (Cd / A) and device life of the blue phosphorescent OLED device prepared in each embodiment and comparative example were measured using a digital source meter and a brightness meter. Specifically, the voltage was increased at a rate of 0.1V per second, and the voltage when the brightness of the blue phosphorescent OLED device reached 1000nit, that is, the driving voltage, was measured, and the current density at this time was measured; the ratio of brightness to current density is the current efficiency; the life test of LT95 is as follows: using a brightness meter at a brightness of 1000nit, maintaining a constant current, and measuring the time in hours when the brightness of the blue phosphorescent OLED device drops to 950nit. The measurement results are all based on the results of comparative example 1 as 100%, and the relative results of other embodiments and comparative examples are calculated.

[0141] Example 1

[0142] (1) A glass plate coated with an ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone-ethanol mixed solvent, baked in a clean environment until the water was completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0143] (2) Place the glass substrate with the anode in a vacuum chamber and evacuate the chamber to a vacuum of less than 5×10 -8 A hole injection layer is vacuum-deposited on the anode layer film. The hole injection layer includes a hole injection layer material NPB and a p-type dopant HATCN. The deposition is performed by a multi-source co-evaporation method. The deposition rate of the hole injection layer material NPB is adjusted to 0.2 nm / s, the deposition rate of the p-type dopant HATCN is adjusted to 2% of the deposition rate of the hole injection layer material NPB, and the deposition film thickness is 10 nm. The structural formulas of the hole injection layer material NPB and the p-type dopant HATCN are as follows:

[0144]

[0145] (3) On the hole injection layer, a hole transport material HTL-A1 is vacuum-deposited as a hole transport layer, wherein the evaporation rate is 0.2 nm / s, the evaporation film thickness is 120 nm, and the structure of the hole transport material HTL-A1 is as follows:

[0146]

[0147] (4) Vacuum evaporation of an electron blocking material P-type Host-C1 as an electron blocking layer on the hole transport layer, wherein the evaporation rate is 0.2 nm / s, the evaporation film thickness is 5 nm, and the electron blocking material P-type Host-C1 has the following structural formula:

[0148]

[0149] (5) Vacuum-evaporating a light-emitting layer on the electron blocking layer, the light-emitting layer comprising an N-type host material N-type Host-B1, a P-type host material P-type Host-C1 and a dopant material BD-D1, and evaporating the layer by a multi-source co-evaporation method, wherein the evaporation rates of the N-type host material N-type Host-B1 and the P-type host material P-type Host-C1 are adjusted to 0.2 nm / s, the evaporation rate of the fluorescent dopant BD-D1 is 10% of the evaporation rate of the P-type host material P-type Host-C1, and the evaporation film thickness is 40 nm; the structural formulas of the N-type host material N-type Host-B1, the P-type host material P-type Host-C1 and the dopant material BD-D1 are as follows:

[0150]

[0151] (6) Vacuum evaporation of a hole blocking material N-type Host-B1 as a hole blocking layer on the light-emitting layer, wherein the evaporation rate is 0.2 nm / s, the evaporation film thickness is 5 nm, and the structure of the hole blocking material N-type Host-B1 is as follows:

[0152]

[0153] (7) Vacuum evaporation of electron transport material ETL-E1 as an electron transport layer on the hole blocking layer, wherein the evaporation rate is 0.2 nm / s, the evaporation film thickness is 40 nm, and the electron transport material ETL-E1 has the following structural formula:

[0154]

[0155] (8) Vacuum evaporation of an electron injection material LIQ on the electron transport layer as an electron injection layer, wherein the evaporation rate is 0.2 nm / s, the evaporation film thickness is 40 nm, and the electron injection material LIQ has the following structural formula:

[0156]

[0157] (9) A 100 nm thick Al layer was vacuum evaporated on the electron injection layer as the cathode electrode of the blue phosphorescent organic light-emitting device, wherein the evaporation rate was 0.5 nm / s.

[0158] Example 2-Example 4

[0159] Except for adjusting the compounds used as shown in Table 1, the rest is the same as Example 1.

[0160] Comparative Example 1

[0161] Except for adjusting the compounds used as shown in Table 1, the rest is the same as Example 1.

[0162] Table 1 Compounds used in various examples and comparative examples

[0163]

[0164]

[0165] In Table 1, the structural formulas of HTL-A2, HTL-A3, HTL-A4, N-type Host-B2, N-type Host-B3, N-type Host-B4, P-type Host-C2, P-type Host-C3, P-type Host-C4, BD-D2, BD-D3, BD-D4, ETL-E2, ETL-E3, ETL-E4, N-type Host-b1, P-type Host-c1, BD-d1, NPB, and TPBi are as follows:

[0166]

[0167]

[0168]

[0169] Comparative Example 2-Comparative Example 5

[0170] Except for adjusting the compounds of the hole transport material, N-type main material, P-type main material, doping material, and electron transport material, the rest is the same as that of Example 1.

[0171] The relevant material parameters and performance parameters involved in each embodiment and proportion are shown in Table 2, Table 3, Table 4 and Table 5 respectively.

[0172] Table 2 Luminescence spectrum related parameters of each embodiment and comparative example

[0173]

[0174]

[0175] Table 3 Energy level related parameters of various embodiments and comparative examples

[0176]

[0177] Table 4 Reorganization energy related parameters of each embodiment and comparative example

[0178]

[0179]

[0180] Table 5 Performance parameters of blue phosphorescent organic light-emitting devices of various embodiments and comparative examples

[0181] V / V E / Cd / A LT95@1000nit Example 1 88％ 122％ 281％ Example 2 96％ 229％ 433％ Example 3 92％ 150％ 180％ Example 4 91％ 115％ 190％ Comparative Example 1 100％ 100％ 100％ Comparative Example 2 98％ 105％ 126％ Comparative Example 3 110％ 98％ 118％ Comparative Example 4 128％ 85％ 98％ Comparative Example 5 104％ 72％ 109％

[0182] Figure 7 The luminescence spectra of P-type Host+N-type Host-PL and BD-PL in Example 1, Comparative Example 1 and Comparative Example 2 of the present application are shown in FIG. Figure 7 As can be seen from Table 2 and Table 5, in Example 1, the peak and half-peak width of the P-type Host, N-type Host and Dopant are controlled within the scope of the present application, and the first energy range difference is greater than or equal to 0.1eV, and the second energy range difference is greater than or equal to 0.1eV, so that the peak positions of the luminescence spectrum of the P-type Host + N-type Host and the luminescence spectrum of the Dopant are overlapped as much as possible, and the luminescence spectrum of the P-type Host + N-type Host surrounds the luminescence spectrum of the Dopant, so that the P-type Host + N-type Host can resonate with the Dopant when excited, and better transfer energy to the Dopant, thereby obtaining a blue phosphorescent OLED with high efficiency and long life. However, the P-type Host + N-type Host in Comparative Example 1 and the P-type Host + N-type Host in Comparative Example 2 do not surround the Dopant luminescence spectrum, and the peak positions of the luminescence spectrum of the P-type Host + N-type Host in Comparative Example 1 and the Dopant luminescence spectrum are quite different, resulting in low luminescence efficiency and short life of the blue phosphorescent OLED.

[0183] Figure 8 This is a diagram showing the exciton recombination region results of the device in Example 1 and Comparative Example 1 of the present application. Figure 1 It can be seen that the exciton recombination area of ​​the device in comparative example 1 is small and narrow, the device efficiency is low, and the service life is short; while the exciton recombination area of ​​the device in embodiment 1 is wide and large, the device efficiency is high, and the service life is long.

[0184] As can be seen from Table 3 and Table 5, Example 2 controls the HOMO / LUMO energy level relationship between the materials of each layer within the scope of the present application, and the values ​​of HOMO(Dopant), LUMO(Dopant), LUMO(N-type Host), and LUMO(ETL) are within the scope of the present application, and the materials of each layer have good HOMO / LUMO energy level matching, which is conducive to the injection of holes and electrons, thereby obtaining a high-efficiency, long-life blue phosphorescent OLED. In Comparative Example 3, HOMO(EBL)=HOMO(P-type Host)<5.75eV, HOMO(Dopant)<5.4eV, LUMO(Dopant)>2.8eV, and LUMO(N-type Host)=LUMO(HBL)>2.8eV are not within the scope of the present application, and the obtained blue phosphorescent OLED has low luminous efficiency and short life.

[0185] It can be seen from Table 4 and Table 5 that, by controlling the hole reorganization energy of the P-type host material and the electron reorganization energy of the N-type host material within the scope of the present application, Examples 3 and 4 can obtain high-efficiency and long-life blue phosphorescent OLED devices. In Comparative Examples 4 and 5, the hole reorganization energy of the P-type host material and the electron reorganization energy of the N-type host material are not within the scope of the present application, and the obtained blue phosphorescent OLED has low luminous efficiency and short life.

[0186] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A blue phosphorescent organic light-emitting device, comprising: hole transport layer, electron blocking layer, light emitting layer, hole blocking layer and electron transport layer; The light-emitting layer includes a P-type main material, an N-type main material and a doping material; The peak value of the luminescence spectrum of the P-type host material is 365nm-400nm, and the half-peak width is 35nm-45nm; The peak value of the luminescence spectrum of the N-type host material is 410nm-450nm, and the half-peak width is 60nm-85nm; The peak value of the luminescence spectrum of the doping material is 455nm-470nm, and the half-peak width is 18nm-24nm; The T1 energy level of the P-type main material is greater than the T1 energy level of the doping material; The T1 energy level of the N-type main material is greater than the T1 energy level of the doping material.

2. The blue phosphorescent organic light emitting device according to claim 1, wherein: The difference between the T1 energy level of the P-type main material and the T1 energy level of the doping material is a first energy difference, and the first energy difference is 0.1eV-0.6eV; The difference between the T1 energy level of the N-type main material and the T1 energy level of the doping material is a second energy extreme difference, and the second energy extreme difference is 0.1 eV-0.6 eV.

3. The blue phosphorescent organic light emitting device according to claim 1, wherein: The HOMO energy level of the hole transport layer is less than the HOMO energy level of the electron blocking layer, and the HOMO energy level of the electron blocking layer is equal to the HOMO energy level of the P-type host material; The HOMO energy level of the P-type host material is greater than the HOMO energy level of the doping material; The LUMO energy level of the doping material is lower than the LUMO energy level of the hole blocking layer, and the LUMO energy level of the hole blocking layer is lower than the LUMO energy level of the electron transport layer; The LUMO energy level of the N-type host material is equal to the LUMO energy level of the hole blocking layer; The difference between the LUMO energy level of the N-type main material and the LUMO energy level of the doping material is a third energy extreme difference, and the third energy extreme difference is -0.2 eV to 0.2 eV.

4. The blue phosphorescent organic light emitting device according to claim 3, wherein: The HOMO energy level of the doping material is 5.4eV-5.6eV; The LUMO energy level of the doping material is 2.5eV-2.75eV; The LUMO energy level of the N-type host material is 2.6eV-2.78eV; The LUMO energy level of the electron transport layer is 2.8 eV-3.0 eV.

5. The blue phosphorescent organic light emitting device according to claim 1, wherein: The HOMO energy level of the P-type host material is greater than the HOMO energy level of the doping material, and the LUMO energy level of the doping material is greater than the LUMO energy level of the P-type host material.

6. The blue phosphorescent organic light emitting device according to claim 5, wherein: The difference between the HOMO energy level of the P-type main material and the HOMO energy level of the doping material is a fourth energy extreme difference, and the fourth energy extreme difference is less than or equal to 0.5 eV; The difference between the LUMO energy level of the doping material and the LUMO energy level of the P-type main material is a fifth energy extreme difference, and the fifth energy extreme difference is less than or equal to 0.5 eV; The difference between the LUMO energy level of the N-type main material and the LUMO energy level of the doping material is a third energy extreme difference, and the third energy extreme difference is -0.2 eV to 0.2 eV.

7. The blue phosphorescent organic light emitting device according to claim 1, wherein: The hole reorganization energy of the P-type host material is 0.24eV-0.28eV; The electron reorganization energy of the N-type host material is 0.5 eV-0.7 eV.

8. The blue phosphorescent organic light-emitting device according to any one of claims 1 to 7, wherein: The blue phosphorescent organic light-emitting device satisfies at least one of the following conditions: (1) The hole transport layer comprises a compound represented by formula (I): wherein R1, R2, R3, R4 and R5 are each independently selected from hydrogen, C 1-40 Alkyl, C 6-40 Aryl, C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S; Y1 is selected from O or S; (2) The N-type host material includes a compound represented by formula (II): Among them, R 1a are each independently selected from hydrogen, deuterium, C 1-40 Alkyl, C 6-40 Aryl, C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S; m is each independently selected from 0, 1, 2, 3 or 4; X1, X2, X3 and X4 are each independently selected from C, N, O or S; (3) The electron transport layer comprises a compound represented by formula (III): Among them, R 1b , R 2b , R 3b , R 4b , R 5b and R 6b Each independently selected from hydrogen, unsubstituted or replaced by C 6-12 Aryl substituted C 1-40 Alkyl, C 6-40 Aryl, C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S; (4) The P-type host material includes a compound represented by formula (IV): Among them, R 1c Selected from hydrogen, C unsubstituted or partially substituted with deuterium 6-40 Aryl, unsubstituted or partially hydrogen substituted by deuterium C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S; R 2c are each independently selected from hydrogen, deuterium, C 6-18 Aryl or C 1-3 alkyl; n is each independently selected from 0, 1, 2, 3 or 4; (5) The doping material includes a compound represented by formula (V): Among them, R 1d , R 3d and R 4d are each independently selected from hydrogen, C 1-40 Alkyl, C 6-40 Aryl, C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S; R 2d Selected from hydrogen, C unsubstituted or partially substituted with deuterium 6-40 Aryl, unsubstituted or partially hydrogen substituted by deuterium C 2-60 Heteroaryl, C 6-60 Aryloxy, C 1-39 Alkoxy, C 6-39 Arylamine, C 3-39 Cycloalkyl, C 3-39 Heterocycloalkyl, C 1-39 Alkylsilyl, C 1-39 Alkyl boron, C 6-39 Aryl boron, C 6-39 Arylphosphino or C 6-39 Arylsilyl; said C 2-60 The heteroaryl group and the C 3-39 The heteroatoms in the heterocycloalkyl group are each independently selected from N, O or S; p is selected from 0, 1, 2, 3 or 4.

9. The blue phosphorescent organic light emitting device according to claim 8, wherein: In formula (I), R1, R2, R3, R4 and R5 are each independently selected from hydrogen, C 1-10 Alkyl, C 6-18 Aryl, C 2-18 Heteroaryl, C 6-18 Aryloxy, C 1-10 Alkoxy, C 6-18 Arylamine, C 3-10 Cycloalkyl, C 3-10 Heterocycloalkyl, C 1-10 Alkylsilyl, C 1-10 Alkyl boron, C 6-18 Aryl boron, C 6-18 Arylphosphino or C 6-18 Arylsilyl; In formula (II), R 1a are each independently selected from hydrogen, deuterium, C 1-10 Alkyl, C 6-18 Aryl, C 2-18 Heteroaryl, C 6-18 Aryloxy, C 1-10 Alkoxy, C 6-18 Arylamine, C 3-10 Cycloalkyl, C 3-10 Heterocycloalkyl, C 1-10 Alkylsilyl, C 1-10 Alkyl boron, C 6-18 Aryl boron, C 6-18 Arylphosphino or C 6-18 Arylsilyl; In formula (III), R 1b , R 2b , R 3b , R 4b , R 5b and R 6b are each independently selected from hydrogen, unsubstituted or phenyl-substituted C 1-10 Alkyl, C 6-18 Aryl, C 2-18 Heteroaryl, C 6-18 Aryloxy, C 1-10 Alkoxy, C 6-18 Arylamine, C 3-10 Cycloalkyl, C 3-10 Heterocycloalkyl, C 1-10 Alkylsilyl, C 1-10 Alkyl boron, C 6-18 Aryl boron, C 6-18 Arylphosphino or C 6-18 Arylsilyl; In formula (IV), R 1c Selected from C 6-18 Aryl, unsubstituted or partially hydrogen substituted by deuterium C 2-30 heteroaryl; In formula (V), R 1d , R 3d and R 4d are each independently selected from hydrogen, C 1-10 Alkyl, C 6-18 Aryl, C 2-18 Heteroaryl, C 6-18 Aryloxy, C 1-10 Alkoxy, C 6-18 Arylamine, C 3-10 Cycloalkyl, C 3-10 Heterocycloalkyl, C 1-10 Alkylsilyl, C 1-10 Alkyl boron, C 6-18 Aryl boron, C 6-18 Arylphosphino or C 6-18 Arylsilyl; R 2d Selected from hydrogen, C unsubstituted or partially substituted with deuterium 6-18 Aryl, unsubstituted or partially hydrogen substituted by deuterium C 2-18 Heteroaryl, C 6-18 Aryloxy, C 1-10 Alkoxy, C 6-18 Arylamine, C 3-10 Cycloalkyl, C 3-10 Heterocycloalkyl, C 1-10 Alkylsilyl, C 1-10 Alkyl boron, C 6-18 Aryl boron, C 6-18 Arylphosphino or C 6-18 Arylsilyl.

10. A display device comprising the blue phosphorescent organic light-emitting device according to any one of claims 1 to 9.

Images