A phosphorescent organic electroluminescent device sensitized by an exciplex

Abstract

The application discloses a kind of exciplex sensitized phosphorescent organic electroluminescent devices, including transparent substrate, anode, hole injection layer, hole transport layer, organic light emitting layer, electron transport layer, electron injection layer, cathode arranged in sequence;Wherein, the organic light emitting layer includes: the exciplex of donor material, acceptor material is formed;And phosphorescent light emitting material;And, the mass ratio of the donor material and acceptor material is 3:7-7:3.The device structure not only can effectively improve the luminous efficiency of each color phosphorescent device, and can significantly improve the luminescence stability of exciplex phosphorescent device, to realize the construction of high stability, high efficiency exciplex phosphorescent device.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescent devices. More specifically, it relates to a phosphorescent organic electroluminescent device sensitized by an exciton complex. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are optoelectronic devices that achieve electron-hole recombination and light emission by injecting electrons and holes into the carrier transport layer via the cathode and anode, respectively, and then transporting them to the light-emitting layer via the transport material. Due to their many characteristics and advantages, such as all-solid-state self-luminescence, wide viewing angle, fast response, low-voltage drive, wide range of material selection, and flexibility, they have great application prospects in lighting, display and other fields.

[0003] Currently, the short lifespan of organic light-emitting diodes (OLEDs) limits their further development and application. Improving the lifespan of OLEDs can be achieved through the rational design and optimization of the emissive layer, which can effectively enhance device stability. This includes selecting stable host and guest materials or employing a hybrid dual-host design. Constructing a dual-host emissive layer is particularly beneficial for achieving high-efficiency light emission and low-voltage drive. Furthermore, in the design of dual-host emissive layers, a dual-host emissive layer system known as an excimer compound can significantly improve device efficiency and reduce the device drive voltage.

[0004] Excitocomplexes are dual-host systems obtained by mixing appropriate donor and acceptor materials. Their emission spectra exhibit a redshift and broadening relative to the donor and acceptor materials, and their emission generally has thermal activation delay characteristics. Therefore, compared with traditional single-host materials, they increase the overlap between the host emission spectrum and the guest absorption spectrum, improve the utilization rate of triplet excitons, and achieve higher sensitization efficiency between the host and guest. The design of the excitocomplex donor-acceptor mixed luminescent layer is also conducive to achieving carrier balance and uniform exciton distribution, thereby improving device stability. However, the current design of light-emitting devices using excitocomplex systems has two problems: (1) insufficient device stability; (2) sensitized devices are mostly concentrated in long wavelength regions such as green and red light, and there is a lack of excitocomplex host systems that are universally applicable to the visible light region. Summary of the Invention

[0005] To address the above problems, the present invention aims to provide a phosphorescent organic electroluminescent device sensitized by an excimer complex. This device achieves high-efficiency and stable light emission from multi-color phosphorescent materials such as blue, green, orange, and red, and has universality in the visible light region, while also significantly improving the stability of the device.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A phosphorescent organic electroluminescent device sensitized by an excimer complex includes a transparent substrate, an anode, a hole injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer, an electron injection layer, and a cathode arranged sequentially.

[0008] The organic light-emitting layer includes:

[0009] Donor materials and acceptor materials that form excitocomplexes; and

[0010] Phosphorescent materials;

[0011] Furthermore, the mass ratio of the donor material to the acceptor material is 7:3-3:7, preferably 1:1.

[0012] In this organic light-emitting layer, the donor material and the acceptor material are the main materials, and the phosphorescent light-emitting material is the doped acceptor material.

[0013] Furthermore, the emission wavelength range of the excitocomplex is 420-450 nm.

[0014] Furthermore, the emission spectrum of the radical-excited composite partially overlaps with the absorption spectrum of the phosphorescent guest material used.

[0015] Furthermore, the phosphorescent material is a blue phosphorescent material, a green phosphorescent material, an orange phosphorescent material, or a red phosphorescent material.

[0016] Furthermore, the receptor material has the structure described in Formula I:

[0017]

[0018] Among them, L 11 L 12 L 13 R 11 R 12 R 13 Each can independently represent one of hydrogen, alkyl, aryl, heterocyclic aryl, or biaryl.

[0019] Further, the alkyl group is selected from one of straight-chain or branched alkyl groups with 1-20 carbon atoms and cyclic alkyl groups with 5-20 carbon atoms. Exemplary straight-chain or branched alkyl groups with 1-20 carbon atoms include, but are not limited to, those selected from methyl, ethyl, propyl, isopropyl, or tert-butyl; exemplary cyclic alkyl groups with 5-20 carbon atoms include, but are not limited to, those selected from cyclopentyl or cyclohexyl.

[0020] Furthermore, the aryl group is selected from phenyl or aryl groups having 10-26 carbon atoms formed by the fusion of two or more aromatic rings. Exemplary aryl groups include, but are not limited to, phenyl, naphthyl, anthracene, and spirodifluorenyl.

[0021] Further, the heterocyclic aryl group is selected from aryl groups containing heteroatoms and having 5-50 carbon atoms. Exemplary heterocyclic aryl groups include, but are not limited to, those selected from furanyl, thiopheneyl, pyrrolyl, thiazolyl, imidazolyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolyl, quinolinyl, quinoxalinyl, pteridinyl, acridineyl, isoindolyl, phenanthinyl, phenazinyl, phenanthrene, phenazinyl, phenthiazolyl, phenoxazinyl, oxazolyl, oxadiazolyl, furazinyl, dibenzothiophene, benzofuranyl, isobenzofuranyl, isoquinolinyl, phenylcarbazolyl, dimethylacridinyl, preferably pyridinyl, pyrrolyl, or imidazolyl.

[0022] Furthermore, the biaryl group is selected from groups consisting of two or more aromatic rings linked by a single bond. For example, the biaryl group is selected from biphenyl.

[0023] Further, the group L 11 L 12 L 13 Same, group R 11 R 12 R 13 same.

[0024] Furthermore, the above-mentioned receptor material is selected from 2,4,6-tris(1,1′-biphenyl)-1,3,5-triazine and its derivatives.

[0025] Furthermore, the receptor material is selected from one of the following formulas:

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039] Furthermore, the donor material has the structure described in Formula II:

[0040]

[0041] in:

[0042] L 21 L 22 R 21 R 22 R 23 R 24 Each is independently selected from hydrogen, alkyl, aryl, heterocyclic aryl, and biaryl.

[0043] Further, the alkyl group is selected from one of straight-chain or branched alkyl groups with 1-20 carbon atoms and cyclic alkyl groups with 5-20 carbon atoms. Exemplary straight-chain or branched alkyl groups with 1-20 carbon atoms include, but are not limited to, those selected from methyl, ethyl, propyl, isopropyl, or tert-butyl; exemplary cyclic alkyl groups with 5-20 carbon atoms include, but are not limited to, those selected from cyclopentyl or cyclohexyl.

[0044] Furthermore, the aryl group is selected from phenyl or aryl groups having 10-26 carbon atoms formed by the fusion of two or more aromatic rings. Exemplary aryl groups include, but are not limited to, phenyl, naphthyl, anthracene, and spirodifluorenyl.

[0045] Further, the heterocyclic aryl group is selected from aryl groups containing heteroatoms and having 5-50 carbon atoms. Exemplary heterocyclic aryl groups include, but are not limited to, those selected from furanyl, thiopheneyl, pyrrolyl, thiazolyl, imidazolyl, pyridinyl, pyrazinyl, pyrimidinyl, pyridazinyl, indolyl, quinolinyl, quinoxalinyl, pteridinyl, acridineyl, isoindolyl, phenanthinyl, phenazinyl, phenanthrene, phenazinyl, phenthiazolyl, phenoxazinyl, oxazolyl, oxadiazolyl, furazinyl, dibenzothiophene, benzofuranyl, isobenzofuranyl, isoquinolinyl, phenylcarbazolyl, dimethylacridinyl, preferably pyridinyl, pyrrolyl, or imidazolyl.

[0046] Furthermore, the biaryl group is selected from groups consisting of two or more aromatic rings linked by a single bond. For example, the biaryl group is selected from biphenyl.

[0047] Further, the group L 21 L 22 Same, group R 21 R 22 R 23 R 24 same.

[0048] Furthermore, the donor material is selected from 3,3′-bis(9H-carbazole-9-yl)-1,1′-biphenyl and its derivatives.

[0049] Furthermore, the donor material is selected from one of the following formulas:

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057] Further, the phosphorescent material is a blue phosphorescent material, wherein the emission peak wavelength of the blue phosphorescent material is 450-490 nm, and its doping concentration in the organic light-emitting layer is less than or equal to 10 wt%; or

[0058] The phosphorescent material is a green phosphorescent material, wherein the emission peak wavelength of the green phosphorescent material is 500-560 nm, and its doping concentration in the organic light-emitting layer is less than or equal to 5 wt%; or

[0059] The phosphorescent material is an orange phosphorescent material, wherein the emission peak wavelength of the orange phosphorescent material is 570-600 nm, and its doping concentration in the organic light-emitting layer is less than or equal to 5 wt%; or

[0060] The phosphorescent material is a red phosphorescent material, wherein the emission peak wavelength of the red phosphorescent material is 615-650nm, and its doping concentration in the organic light-emitting layer is less than or equal to 5wt%.

[0061] Furthermore, when the phosphorescent material is a blue phosphorescent material, a first blocking layer is provided between the hole transport layer and the organic light-emitting layer; a second blocking layer is provided between the organic light-emitting layer and the second blocking layer; and

[0062] The thickness of the first barrier layer is 3-5 nm, and its material may be the same as or different from that of the excitocomplex.

[0063] The thickness of the second barrier layer is 5-10 nm, and its material may be the same as or different from that of the excitocomposite.

[0064] Furthermore, the triplet energy levels of the first and second blocking layers are greater than or equal to the triplet energy levels of the blue phosphorescent material. In this case, the first and second blocking layers can effectively confine the excitons in the emitting layer.

[0065] The materials of the first and second blocking layers mentioned above can be donor materials, acceptor materials, or other materials whose triplet energy levels are higher than the triplet energy levels of the blue phosphorescent material.

[0066] The beneficial effects of this invention are as follows:

[0067] The phosphorescent organic light-emitting device provided in this invention constructs an exciton complex system that emits deep blue light, achieving high-efficiency sensitization of multi-color phosphorescent materials such as blue, green, orange, and red. Furthermore, this phosphorescent organic light-emitting device exhibits high efficiency, low driving voltage, and wide applicability. In addition, this invention uses stable donor-acceptor materials to construct the exciton complex system, improving device stability and extending the lifespan of the phosphorescent device. Attached Figure Description

[0068] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0069] Figure 1 The diagram shows the structure of the phosphorescent organic electroluminescent device based on the excitocomplex system of the present invention: where 01 is the anode, 02 is the hole injection layer, 03 is the hole transport layer, 04 is the hole transport layer, 05 is the blocking layer, 06 is the light-emitting layer, 07 is the blocking layer, 08 is the electron transport layer, 09 is the electron injection layer, and 10 is the cathode.

[0070] Figure 2a The current density-voltage-brightness curves of the blue phosphorescent device based on the excitocomplex system described in this invention are shown.

[0071] Figure 2b The current density-voltage-brightness curves of the green phosphorescent device based on the excitocomplex system described in this invention are shown.

[0072] Figure 2c The current density-voltage-brightness curves of the orange phosphorescent device based on the excitocomplex system described in this invention are shown.

[0073] Figure 2d The current density-voltage-brightness curves of the red phosphorescent device based on the excitocomplex system described in this invention are shown.

[0074] Figure 3a The brightness-current efficiency curve of the blue phosphorescent device based on the excitocomplex system described in this invention is shown.

[0075] Figure 3bThe brightness-current efficiency curves of the green phosphorescent device based on the excitocomplex system described in this invention are shown.

[0076] Figure 3c The brightness-current efficiency curves of the orange phosphorescent device based on the excitocomplex system described in this invention are shown.

[0077] Figure 3d The brightness-current efficiency curves of the red phosphorescent device based on the excitocomplex system described in this invention are shown.

[0078] Figure 4 The electroluminescence spectra of various phosphorescent devices based on the excitocomplex system described in this invention are shown.

[0079] Figure 5a The lifetime decay curve of the blue phosphorescent device based on the excitocomplex system described in this invention is shown.

[0080] Figure 5b The lifetime decay curve of the green phosphorescent device based on the excitocomplex system described in this invention is shown.

[0081] Figure 6 The brightness-current efficiency curves of the blue light device based on the mCBP:PO-T2T excitopolymer system of the present invention are shown. Detailed Implementation

[0082] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further explains the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0083] The meanings of the abbreviations in the examples are as follows:

[0084] ITO: Indium Tin Oxide, used as a transparent anode;

[0085] HAT-CN: 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, a hole injection material that is beneficial for hole injection;

[0086] TAPC: 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline], hole transport material;

[0087] TCTA: 4,4',4”-tris(carbazole-9-yl)triphenylamine, used as a blocking layer to prevent electrons from entering the hole transport layer;

[0088] mCBP: 3,3′-bis(9H-carbazole-9-yl)-1,1′-biphenyl, used as an electron donor material in excitocomplexes.

[0089] T2T: 2,4,6-tris(1,1′-biphenyl)-1,3,5-triazine, used as an electron acceptor material in exciton complexes;

[0090] Firpic: Bis(4,6-difluorophenylpyridine-C2,N)pyridinecarboxyiridium, a blue phosphorescent material;

[0091] Ir(ppy)3: Tris(2-phenylpyridine)iridium, a green phosphorescent material;

[0092] Ir(2-phq)3: Tris(2-phenylquinoline)iridium, an orange phosphorescent material;

[0093] Ir(piq)2acac: Bis(1-phenylisoquinolinyl)acetylacetonate, iridium compound, red phosphorescent material;

[0094] ET225: 2-(3-(phenanthrene-9-yl)-5-(pyridin-3-yl)phenyl)-4,6-diphenyl-1,3,5-triazine, electron transport material;

[0095] Liq: 8-hydroxyquinoline-lithium, an electron injection layer material;

[0096] Al: Aluminum, with a thickness of 100nm, used as the cathode.

[0097] Example 1

[0098] Organic light-emitting devices are fabricated using a multi-source organic material vapor deposition apparatus. The detailed process is as follows:

[0099] ITO conductive glass was used as the substrate in the experiment. First, the substrate was ultrasonically cleaned three times with detergent, ultrapure water, acetone, and ethanol, each time for 7 minutes, to remove surface particulate contaminants. The cleaned substrate was then dried in an oven and finally treated with an oxygen plasma cleaner for 10 minutes. The treated substrate was then rapidly transferred to the deposition equipment, where a vacuum of 5 × 10⁻⁶ was achieved. -4 Below Pa, the material is heated to prepare each thin film layer, with the evaporation rate of the organic layer controlled at [value missing]. The evaporation rate of metallic aluminum is The electroluminescence spectrum, brightness, and current-voltage characteristics of the device were simultaneously measured using a PR650 spectrometer, a CS200 colorimeter, a Keithley-2400 ammeter, and a computer testing system. All tests were conducted in a laboratory environment with a temperature of 20°C and a relative humidity of 18%. The device performance testing method is as follows: First, a suitable test voltage range of 3V to 10V was applied to the device using the Keithley-2400 ammeter, with step voltage values ​​of 300mV to 500mV, and the brightness of the device was tested using the CS200 colorimeter. Second, the emission spectrum of the device under different voltages was tested using the PR650 spectrometer, with the device voltage controlled by the Keithley-2400 ammeter, ranging from 4V to 8V. Finally, the data was processed using dedicated software.

[0100] In this example, the blue phosphorescent device structure consists of the following layers deposited sequentially on an ITO substrate: a 10nm hole injection layer (HATCN), a 50nm hole transport layer (TAPC), a 5nm TCTA, a 5nm exciton blocking layer (mCBP), a 20nm emissive layer (where donor and acceptor materials are mixed in a 1:1 mass ratio), and a 10wt% doped luminescent material (Firpic). The structure also includes a 10nm exciton blocking layer (T2T), a 35nm electron transport layer (where ET225 and Liq are mixed in a 1:1 mass ratio), a 1nm electron injection layer (Liq), and a 100nm aluminum electrode. The overall structure is: ITO / HATCN (10nm) / TAPC (50nm) / TCTA (5nm) / mCBP (5nm) / mCBP:T2T:10%Firpic (20nm) / T2T (10nm) / ET225:Liq (35nm) / Liq (1nm) / Al (100nm).

[0101] Compared to blue light devices, other color devices lack the 5nm exciton blocking layer mCBP and the 10nm exciton blocking layer T2T, and differ in the doping concentration and type of phosphorescent materials. Specifically:

[0102] The structure of the green light device is: ITO / HATCN (10nm) / TAPC (50nm) / TCTA (5nm) / mCBP:T2T:5%Ir(ppy)3 (20nm) / ET225:Liq (35nm) / Liq (1nm) / Al (100nm).

[0103] The structure of the orange light device is: ITO / HATCN (10nm) / TAPC (50nm) / TCTA (5nm) / mCBP:T2T:5%Ir(2-phq)3 (20nm) / ET225:Liq (35nm) / Liq (1nm) / Al (100nm).

[0104] The structure of the red light device is: ITO / HATCN (10nm) / TAPC (50nm) / TCTA (5nm) / mCBP:T2T:5%Ir(piq)2acac (20nm) / ET225:Liq (35nm) / Liq (1nm) / Al (100nm).

[0105] Example 2

[0106] The fabrication process and structure of the blue light device in this example are exactly the same as those in Example 1. The difference lies in the following: at 1000 cd / m 2 The lifetime of the device was tested at the initial brightness level (LT50).

[0107] Example 3

[0108] The fabrication process and structure of the green light device in this example are exactly the same as those in Example 1. The difference lies in the following: at 10000 cd / m 2 The lifetime of the device was tested at the initial brightness level (LT50).

[0109] Comparative Example 1

[0110] The fabrication process and testing methods for the various phosphorescent devices in this example are exactly the same as those in Example 1. The difference is that, to compare the excellent device performance of the excimer composite host, the excimer composite emitting layer in this example is replaced with a single-host mCBP doped with blue, green, orange, and red phosphorescent materials respectively. It does not include the acceptor material T2T.

[0111] The blue light structure is: ITO / HATCN (10nm) / TAPC (50nm) / TCTA (5nm) / mCBP (5nm) / mCBP:10%Firpic (20nm) / T2T (10nm) / ET225:Liq (35nm) / Liq (1nm) / Al (100nm).

[0112] The green light structure is: ITO / HATCN (10nm) / TAPC (50nm) / TCTA (5nm) / mCBP5%Ir(ppy)3 (20nm) / ET225:Liq (35nm) / Liq (1nm) / Al (100nm).

[0113] The orange light structure is: ITO / HATCN (10nm) / TAPC (50nm) / TCTA (5nm) / mCBP:5%Ir(2-phq)3 (20nm) / ET225:Liq (35nm) / Liq (1nm) / Al (100nm).

[0114] The red light structure is: ITO / HATCN (10nm) / TAPC (50nm) / TCTA (5nm) / mCBP:5%Ir(piq)2acac (20nm) / ET225:Liq (35nm) / Liq (1nm) / Al (100nm).

[0115] Comparative Example 2

[0116] The fabrication process and testing methods for the blue phosphorescent device in this example are exactly the same as those in Example 2. The difference is that, to compare the good device stability of the excimer compound host, the excimer compound emitting layer in this example is replaced with a single-host mCBP-doped blue phosphorescent material. It does not contain the acceptor material T2T.

[0117] The device structure is: ITO / HATCN (10nm) / TAPC (50nm) / TCTA (5nm) / mCBP (5nm) / mCBP:10%Firpic (20nm) / T2T (10nm) / ET225:Liq (35nm) / Liq (1nm) / Al (100nm).

[0118] Comparative Example 3

[0119] The fabrication process and testing methods of the green phosphorescent device in this example are exactly the same as those in Example 3. The difference is that, to compare the good device stability of the excimer compound host, the excimer compound emitting layer in this example is replaced with a single-host mCBP-doped green phosphorescent material. It does not contain the acceptor material T2T.

[0120] The device structure is: ITO / HATCN (10nm) / TAPC (50nm) / TCTA (5nm) / mCBP5%Ir(ppy)3 (20nm) / ET225:Liq (35nm) / Liq (1nm) / Al (100nm).

[0121] Figure 2 shows the current density-voltage-brightness curves of the phosphorescent devices of various colors in Example 1 and Comparative Example 1. It can be seen that the current density and brightness of the phosphorescent devices of each color in the examples are significantly higher than those in the corresponding comparative examples. This indicates that the dual-host structure of the excimer composite has better carrier transport characteristics than the single-host structure, which is more conducive to achieving device charge balance. At the same time, the turn-on voltage of the devices in the examples is 0.5V lower than that in the comparative examples.

[0122] Figure 3 shows the brightness-current efficiency curves of the phosphorescent devices of various colors in Example 1 and Comparative Example 1. The current efficiency of each color phosphorescent device in the examples is higher than that of the corresponding comparative example devices. This is mainly because the use of the dual host of the excimer compound reduces the device driving voltage and increases the device brightness, thereby significantly improving the current efficiency of the devices in the examples.

[0123] Figure 4 The electroluminescence spectra of the phosphorescent devices of various colors in Example 1 are shown. It can be seen that the excimer complex dual-host system can be applied to various phosphorescent systems, and can achieve effective energy transfer, avoid host emission, and has wide applicability.

[0124] Figure 5 shows the lifetime decay curves of blue and green phosphorescent devices in Examples 2 and 3 and Comparative Examples 2 and 3. It can be seen that the device lifetime of the Examples 2 and 3 is twice that of the Comparative Examples in both blue and green light applications. This indicates that the active composite system constructed in this invention has good device stability.

[0125] The device results in Examples 1-3 demonstrate that the phosphorescent devices constructed using the excimer complex dual-host structure as the emitting layer not only achieve effective sensitization of phosphorescent devices in various colors and exhibit high device current efficiency, but also have a lifespan that is twice that of single-host devices. This indicates that the excimer complex system constructed in this invention has broad applicability and stability as a phosphorescent material host.

[0126] Comparative Example 4

[0127] Similar to Example 1, except that in the blue light device, the acceptor material is changed to PO-T2T, while the other conditions remain the same. The resulting device structure is: ITO / HATCN (10nm) / TAPC (50nm) / TCTA (5nm)mCBP (5nm) / mCBP:PO-T2T:10%Firpic (20nm) / PO-T2T (10nm) / ET225:Liq (35nm) / Liq (1nm) / Al (100nm)

[0128] Figure 6 The luminance-current efficiency curves of the blue light-emitting devices in Example 1 and Comparative Example 4 are shown. It can be seen that the selected mCBP:T2T excimer complex system has a higher device efficiency than the mCBP:PO-T2T excimer complex system, with a maximum current efficiency of 33.8 cd / A, which is three times that of the mCBP:PO-T2T excimer complex system. This demonstrates that the selected excimer complex system has excellent device performance.

[0129] Comparative Example 5

[0130] When the donor material is replaced with TCTA, the emission peak of the resulting excitocomplex is located near 510 nm, which belongs to the green light region and cannot serve as the host of the blue phosphorescent material.

[0131] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A phosphorescent organic electroluminescent device sensitized by an exciton complex, characterized in that, It includes a transparent substrate, an anode, a hole injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer, an electron injection layer, and a cathode arranged sequentially. The organic light-emitting layer includes: Donor materials and acceptor materials that form excitocomplexes; and Phosphorescent materials; Furthermore, the mass ratio of the donor material to the acceptor material is 3:7-7:3; The emission wavelength range of the excitocomplex is 420-450 nm; The emission spectrum of the excitocomplex partially overlaps with the absorption spectrum of the phosphorescent guest material used. The receptor material has the structure shown in Formula I: I； In the structure shown in Equation I: L 11 L 12 L 13 Each can independently represent hydrogen or alkyl groups, R 11 R 12 R 13 Each can independently represent one of hydrogen, alkyl, or phenyl. The alkyl group is selected from one of straight-chain or branched alkyl groups with 1-4 carbon atoms and cyclic alkyl groups with 5-6 carbon atoms; The donor material has the structure described in Formula II: II; In the structure described in Formula II: L 21 L 22 R 21 R 22 R 23 R 24 Each is independently selected from hydrogen and alkyl groups. The alkyl group is selected from one of straight-chain or branched alkyl groups with 1-20 carbon atoms and cyclic alkyl groups with 5-20 carbon atoms.

2. The phosphorescent organic electroluminescent device according to claim 1, characterized in that, The mass ratio of the donor material to the acceptor material is 1:

1.

3. The phosphorescent organic electroluminescent device according to claim 1, characterized in that, The phosphorescent material is a blue phosphorescent material, a green phosphorescent material, an orange phosphorescent material, or a red phosphorescent material.

4. The phosphorescent organic electroluminescent device according to claim 1, characterized in that, The L 11 L 12 L 13 Same, R 11 R 12 R 13 same.

5. The phosphorescent organic electroluminescent device according to claim 4, characterized in that, The receptor material is selected from one of the following formulas: 。 6. The phosphorescent organic electroluminescent device according to claim 1, characterized in that, The L 21 L 22 Same, R 21 R 22 R 23 R 24 same.

7. The phosphorescent organic electroluminescent device according to claim 6, characterized in that, The donor material is selected from one of the following formulas: 。 8. The phosphorescent organic electroluminescent device according to claim 1, characterized in that, The phosphorescent material is a blue phosphorescent material, wherein the emission peak wavelength of the blue phosphorescent material is 450-490 nm, and its doping concentration in the organic light-emitting layer is less than or equal to 10 wt%; or The phosphorescent material is a green phosphorescent material, wherein the emission peak wavelength of the green phosphorescent material is 500-560 nm, and its doping concentration in the organic light-emitting layer is less than or equal to 5 wt%; or The phosphorescent material is an orange phosphorescent material, wherein the emission peak wavelength of the orange phosphorescent material is 570-600 nm, and its doping concentration in the organic light-emitting layer is less than or equal to 5 wt%; or The phosphorescent material is a red phosphorescent material, wherein the emission peak wavelength of the red phosphorescent material is 615-650nm, and its doping concentration in the organic light-emitting layer is less than or equal to 5wt%.

9. The phosphorescent organic electroluminescent device according to claim 8, characterized in that, The phosphorescent material is a blue phosphorescent material, and a first blocking layer is provided between the hole transport layer and the organic light-emitting layer; a second blocking layer is provided between the organic light-emitting layer and the second blocking layer; and The thickness of the first barrier layer is 3-5 nm, and its material may be the same as or different from that of the excitocomplex. The thickness of the second barrier layer is 5-10 nm, and its material may be the same as or different from that of the excitocomposite. Furthermore, the triplet energy levels of the first and second blocking layers are greater than or equal to the triplet energy levels of the blue phosphorescent material.

Images