Organic electroluminescent panel

Abstract

The application discloses an organic electroluminescent panel, which is characterized in that: a covering layer is arranged on a surface of a cathode layer away from a substrate, conductive particles are doped in the covering layer, and the conductivity of the covering layer is not less than 5*10 ‑4 S / m, which can ensure the transmittance of the cathode layer and reduce the voltage drop of the cathode layer, and compared with a conventional scheme, the thickness of the cathode of the super-phosphor organic electroluminescent panel does not need to be reduced, so that the problem of uneven color and brightness caused by the color and brightness of the super-phosphor organic electroluminescent panel due to the increase of the transverse resistance of the cathode caused by the reduction of the thickness of the cathode of the super-phosphor organic electroluminescent panel is avoided.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to an organic electroluminescent panel. Background Art

[0002] The super-phosphorescent organic electroluminescent panel is a multi-doping system OLED (Organic Light Emitting Diode) panel. The principle of the super-phosphorescent organic electroluminescent panel is to use phosphorescent luminescent materials as sensitizers to excite high-performance luminescent materials, thereby improving the performance of the OLED panel. In traditional top-emitting super-phosphorescent organic electroluminescent panels, in order to ensure the light output efficiency of the super-phosphorescent organic electroluminescent panel, the thickness of the cathode of the super-phosphorescent organic electroluminescent panel is reduced, so that the cathode (Cathode) of the super-phosphorescent organic electroluminescent panel has a high transmittance while conducting current. However, when the thickness of the cathode of the super-phosphorescent organic electroluminescent panel is reduced, the lateral resistance of the cathode of the super-phosphorescent organic electroluminescent panel will also increase, resulting in a voltage drop in the super-phosphorescent organic electroluminescent panel and uneven color brightness. Summary of the Invention

[0003] The embodiments of the present application provide an organic electroluminescent panel, which can improve the problem of uneven color brightness in the organic electroluminescent panel.

[0004] An embodiment of the present application provides an organic electroluminescent panel, comprising:

[0005] substrate;

[0006] an anode layer, the anode layer being disposed on the substrate;

[0007] a light-emitting layer, the light-emitting layer being disposed on a side of the anode layer away from the substrate, the light-emitting layer comprising a host material, a phosphorescent sensitizer, and a fluorescent guest, wherein the phosphorescent sensitizer and the fluorescent guest are doped in the host material;

[0008] a cathode layer, the cathode layer being disposed on a side of the light-emitting layer away from the substrate;

[0009] The covering layer is provided on a surface of the cathode layer away from the substrate, the covering layer is doped with conductive particles, and the conductivity of the covering layer is not less than 5*10 -4 S / m.

[0010] Furthermore, the conductive particles in the covering layer have a concentration of 0.5% to 10% by mass.

[0011] Furthermore, the material of the conductive particles includes at least one of a metal material, an inorganic non-metallic material or an organic material.

[0012] Furthermore, the conductive particles are made of a metal material, and the metal material includes at least one of silver, magnesium, lithium, and ytterbium.

[0013] Furthermore, the conductive particles are made of an inorganic non-metallic material, and the inorganic non-metallic material includes at least one of oxides, carbides, nitrides, halogen compounds, borides, silicates, aluminates, phosphates, and borates.

[0014] Furthermore, the conductive particles are made of an organic material, and the organic material includes at least one of an organic aromatic compound or an organic heteroaromatic compound.

[0015] Furthermore, the organic electroluminescent panel also includes a hole transport layer and an electron blocking layer, the hole transport layer is located between the anode layer and the light-emitting layer, the electron blocking layer is located between the hole transport layer and the light-emitting layer, the HOMO energy level of the main material of the light-emitting layer is greater than the HOMO energy level of the electron blocking layer, and the HOMO energy level of the electron blocking layer is greater than the HOMO energy level of the hole transport layer.

[0016] Furthermore, the HOMO energy level of the hole transport layer, the HOMO energy level of the electron blocking layer, and the HOMO energy level of the host material of the light-emitting layer are arranged in a step-type arrangement.

[0017] Furthermore, the organic electroluminescent panel also includes a hole blocking layer and an electron transport layer, the hole blocking layer is located between the light-emitting layer and the cathode layer, the electron transport layer is located between the hole blocking layer and the cathode layer, the LUMO energy level of the main material of the light-emitting layer 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.

[0018] Furthermore, the LUMO energy level of the electron transport layer, the LUMO energy level of the hole blocking layer, and the LUMO energy level of the host material of the light-emitting layer are arranged in a step-type arrangement.

[0019] Furthermore, the LUMO energy level of the electron blocking layer is lower than the LUMO energy level of the host material of the light-emitting layer, and the HOMO energy level of the hole blocking layer is higher than the HOMO energy level of the host material of the light-emitting layer.

[0020] Beneficial effects of this application:

[0021] The present application provides an organic electroluminescent panel, which comprises the following steps: arranging the cover layer on a surface of the cathode layer away from the substrate, doping the cover layer with conductive particles, and setting the conductivity of the cover layer to be not less than 5*10 -4 S / m, while ensuring the transmittance of the cathode layer, it can also reduce the voltage drop of the cathode layer. Compared with the traditional solution, there is no need to reduce the thickness of the cathode layer of the super phosphorescent organic electroluminescent panel, thereby avoiding the problem of uneven color brightness caused by the voltage drop of the super phosphorescent organic electroluminescent panel due to the increase of the lateral resistance of the cathode layer caused by the reduction of the thickness of the cathode layer of the super phosphorescent organic electroluminescent panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of the organic electroluminescent panel of the present application.

[0023] 100-substrate; 200-anode layer; 300-hole injection layer; 400-hole transport layer; 500-electron blocking layer; 600-light-emitting layer; 700-hole blocking layer; 800-electron transport layer; 900-electron injection layer; 1000-cathode layer; 1100-covering layer. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. The technical solutions described below are only used to explain and illustrate the ideas of the present application and should not be regarded as limiting the scope of protection of the present application.

[0025] In addition, the terms "first", "second" and similar words do not indicate any order, quantity or importance, but are only used to distinguish different technical features. The term "plurality" and similar words mean two or more, unless otherwise expressly limited.

[0026] In a traditional top-emitting super-phosphorescent organic electroluminescent panel, in order to ensure the light output efficiency of the super-phosphorescent organic electroluminescent panel, the thickness of the cathode of the super-phosphorescent organic electroluminescent panel is reduced so that the cathode of the super-phosphorescent organic electroluminescent panel has a higher transmittance while conducting current. However, when the thickness of the cathode of the super-phosphorescent organic electroluminescent panel is reduced, the lateral resistance of the cathode of the super-phosphorescent organic electroluminescent panel will also increase, resulting in a voltage drop in the super-phosphorescent organic electroluminescent panel and uneven color brightness.

[0027] The embodiment of the present application provides an organic electroluminescent panel, referring to Figure 1The organic electroluminescent panel includes a substrate 100, an anode layer 200, a light-emitting layer 600, a cathode layer 1000, and a covering layer 1100. The anode layer 200 is provided on the substrate 100; the light-emitting layer 600 is provided on the side of the anode layer 200 away from the substrate 100, and the light-emitting layer 600 includes a host material, a phosphorescent sensitizer, and a fluorescent guest, and the phosphorescent sensitizer and the fluorescent guest are doped in the host material; the cathode layer 1000 is provided on the side of the light-emitting layer 600 away from the substrate 100; the covering layer 1100 is provided on a surface of the cathode layer 1000 away from the substrate 100, and the covering layer 1100 is doped with conductive particles, and the conductivity of the covering layer is not less than 5*10 -4 S / m.

[0028] Since super-phosphorescent organic electroluminescent panels have high efficiency, they are more sensitive to the reduction in brightness caused by the voltage drop at the cathode. Therefore, the voltage drop at the cathode should be kept consistent based on the super-phosphorescent organic electroluminescent panel. Therefore, the covering layer 1100 is arranged on a surface of the cathode layer 1000 away from the substrate 100, so that the covering layer 1100 is in direct contact with the cathode 1000 to improve the voltage drop at the cathode 1000; and when the covering layer 1100 is a pure organic material, the conductivity of the covering layer of the pure organic material is limited, so the improvement effect on the voltage drop at the cathode 1000 is limited; therefore, conductive particles are doped in the covering layer 1100, and the conductivity of the covering layer is set to be not less than 5*10 -4 S / m, while ensuring the transmittance of the cathode layer 1000, it can also reduce the voltage drop of the cathode layer 1000. Compared with the traditional solution, there is no need to reduce the thickness of the cathode layer 1000 of the super phosphorescent organic electroluminescent panel, thereby avoiding the problem of uneven color brightness caused by the voltage drop of the super phosphorescent organic electroluminescent panel due to the increase of the lateral resistance of the cathode layer 1000 caused by the reduction of the thickness of the cathode layer 1000 of the super phosphorescent organic electroluminescent panel.

[0029] In this embodiment, the concentration of the conductive particles in the cover layer 1100 is 0.5% to 10% by weight. Setting the concentration of the conductive particles in the cover layer 1100 to 0.5% to 10% by weight improves the conductivity of the cover layer 1100 while preventing the cover layer 1100 from excessively affecting the transmittance and refractive index of light, thereby affecting the display quality of the organic electroluminescent panel. Preferably, the concentration of the conductive particles in the cover layer 1100 is 0.5%, 1.0%, 2.0%, 5.0%, or 10% by weight.

[0030] In this embodiment, the concentration of the conductive particles in the covering layer 1100 is 5%-10% by mass.

[0031] In this embodiment, the concentration of the conductive particles doped on the side of the cover layer 1100 away from the cathode layer 1000 is greater than the concentration of the conductive particles doped on the side of the cover layer 1100 close to the cathode layer 1000 .

[0032] In this embodiment, the conductivity of the side of the cover layer 1100 away from the cathode layer 1000 is greater than the conductivity of the side of the cover layer 1100 close to the cathode layer 1000. -4 S / m, it can ensure the transmittance of the cathode layer 1000 while reducing the voltage drop of the cathode layer 1000. However, since the conductivity of the covering layer 1100 is too large, it is also easy to cause part of the current of the super phosphorescent organic electroluminescent panel to bypass the light-emitting layer and flow to the covering layer 1100 with high conductivity; at the same time, when the mass ratio of the concentration of the conductive particles in the covering layer 1100 is 5%-10%, the covering layer 1100 is highly doped, and the surface roughness of the covering layer 1100 will also increase, increasing the risk of current leakage toward the covering layer 1100, resulting in a decrease in the luminous efficiency of the super phosphorescent organic electroluminescent panel. Therefore, the conductivity of the side of the covering layer 1100 away from the cathode layer 1000 is set to be greater than the conductivity of the side of the covering layer 1100 close to the cathode layer 1000. On the one hand, a stronger electric field is formed on the side of the covering layer 1100 away from the cathode layer 1000, which is more conducive to the flow of current along the light-emitting layer. On the other hand, since the conductivity of the side of the covering layer 1100 away from the cathode layer 1000 is greater than the conductivity of the side of the covering layer 1100 close to the cathode layer 1000, that is, the concentration of conductive particles doped on the side of the covering layer 1100 close to the cathode layer 1000 is less than the concentration of conductive particles doped on the side of the covering layer 1100 away from the cathode layer 1000, it is ensured that the contact surface between the covering layer 1100 and the cathode layer 1000 has a smaller roughness than the surface of the covering layer 1100 away from the cathode layer 1000, which is also more conducive to the flow of current along the light-emitting layer, thereby reducing the risk of current leakage and improving the light efficiency of the super phosphorescent organic electroluminescent panel.

[0033] In an embodiment, the conductivity of the covering layer decreases gradually from the side of the covering layer away from the cathode layer to the side of the covering layer close to the cathode layer. In this embodiment, the material of the conductive particles includes at least one of a metal material, an inorganic non-metallic material, or an organic material.

[0034] In this embodiment, the material of the conductive particles includes metal materials and inorganic non-metallic materials.

[0035] In this embodiment, the material of the conductive particles includes metal material and organic material.

[0036] In this embodiment, the material of the conductive particles includes inorganic non-metallic materials and organic materials.

[0037] In this embodiment, the conductive particles are made of a metal material, and the metal material includes at least one of silver, magnesium, lithium, and ytterbium.

[0038] In this embodiment, the conductive particles are made of an inorganic non-metallic material, and the inorganic non-metallic material includes at least one of oxides, carbides, nitrides, halogen compounds, borides, silicates, aluminates, phosphates, and borates.

[0039] In this embodiment, the oxide includes indium oxide (ITO), zinc oxide (ZnO), aluminum-doped zinc oxide (AZO), tin oxide (SnO 2 ) or tungsten oxide (WO 3 ).

[0040] In this embodiment, the carbide includes silicon carbide (SiC), tungsten carbide (WC), titanium carbide (TiC), zirconium carbide (ZrC), or aluminum carbide (Al4C3).

[0041] In this embodiment, the nitride includes silicon nitride (Si 3 N 4 ), aluminum nitride (AlN), titanium nitride (TiN), or germanium nitride (GeN).

[0042] In this embodiment, the halogen compound includes tin fluoride (SnF2) or aluminum fluoride (AlF3).

[0043] In this embodiment, the boride includes titanium boride (TiB 2 ) or aluminum boride (AlB 2 ).

[0044] In this embodiment, the silicate includes aluminum silicate (Al2SiO5) or magnesium silicate (MgSiO3).

[0045] In this embodiment, the aluminate includes sodium aluminate (NaAlO 2 ) or magnesium aluminate (MgAl 2 O 4 ).

[0046] In this embodiment, the phosphate includes aluminum phosphate (AlPO 4 ).

[0047] In this embodiment, the borate includes sodium borate (Na2B4O7) and aluminum borate (AlB3O6).

[0048] In this embodiment, the conductive particles are made of an organic material, and the organic material includes at least one of an organic aromatic compound and an organic heteroaromatic compound.

[0049] In this embodiment, the organic aromatic compound includes polyaniline (PANI), polythiophene (PTh), polystyrene (PS), polyparabenzoquinone, or aniline.

[0050] In this embodiment, the organic heteroaromatic compound includes polypyrrole (PPy), poly(3,4-ethylenedioxythiophene) (PEDOT), or HATCN (1,3,4,6-tetraazepin-3-one).

[0051] In this embodiment, the host material of the cover layer 1100 includes polystyrene.

[0052] In this embodiment, the organic electroluminescent panel further includes a hole transport layer 400 between the anode layer 200 and the light-emitting layer 600, and an electron blocking layer 500 between the hole transport layer 400 and the light-emitting layer 600, wherein the HOMO energy level of the host material of the light-emitting layer 600 is greater than the HOMO energy level of the electron blocking layer 500, and the HOMO energy level of the electron blocking layer 500 is greater than the HOMO energy level of the hole transport layer 400.

[0053] In this embodiment, the organic electroluminescent panel further includes a hole injection layer 300 between the anode layer 200 and the hole transport layer 400.

[0054] In this embodiment, the host material of the light-emitting layer 600 is a radical complex.

[0055] In this embodiment, the light-emitting layer 600 further includes a phosphorescent sensitizer and a fluorescent guest.

[0056] In this embodiment, the phosphorescent sensitizer and the fluorescent guest are doped in the host material.

[0057] In this embodiment, the phosphorescent sensitizer of the light-emitting layer 600 includes fac-Ir(iprpmi)3 (tris[1-(2,6-isopropylphenyl)-2-phenyl-1H-imidazole] iridium (III)) or Ir(ppy)3 (tris(2-phenylpyridine) iridium (III)).

[0058] In this embodiment, the fluorescent guest of the light-emitting layer 600 includes TBPe (1,4,7,10-tetra-tert-butyl dinaphtho[2,1-d:1',2'-f]chrysene) or TBRb (2,8-di-tert-butyl-5,11-di(4-tert-butylphenyl)-6,12-diphenyltetracene).

[0059] In this embodiment, the concentration of the phosphorescent sensitizer of the light-emitting layer 600 is less than the concentration of the phosphorescent sensitizer of the light-emitting layer 600.

[0060] In this embodiment, the concentration of the phosphorescent sensitizer of the light-emitting layer 600 is equal to the concentration of the phosphorescent sensitizer of the light-emitting layer 600.

[0061] In this embodiment, the HOMO energy level of the hole transport layer 400, the HOMO energy level of the electron blocking layer 500, and the HOMO energy level of the host material of the light-emitting layer 600 are arranged in a stepped manner. By arranging the HOMO energy level of the hole transport layer 400, the HOMO energy level of the electron blocking layer 500, and the HOMO energy level of the host material of the light-emitting layer 600 in a stepped manner, the transport and injection of hole carriers can be facilitated.

[0062] In this embodiment, the organic electroluminescent panel also includes a hole blocking layer 700 and an electron transport layer 800, the hole blocking layer 700 is located between the light-emitting layer 600 and the cathode layer 1000, and the electron transport layer 800 is located between the hole blocking layer 700 and the cathode layer 1000, the LUMO energy level of the main material of the light-emitting layer 600 is lower than the LUMO energy level of the hole blocking layer 700, and the LUMO energy level of the hole blocking layer 700 is lower than the LUMO energy level of the electron transport layer 800.

[0063] In this embodiment, the organic electroluminescent panel further includes an electron injection layer 900 , which is located between the electron transport layer 800 and the cathode layer 1000 .

[0064] In this embodiment, the LUMO energy level of the electron transport layer 800, the LUMO energy level of the hole blocking layer 700, and the LUMO energy level of the host material of the light-emitting layer 600 are arranged in a stepped manner. By arranging the LUMO energy level of the electron transport layer 800, the LUMO energy level of the hole blocking layer 700, and the LUMO energy level of the host material of the light-emitting layer 600 in a stepped manner, the transport and injection of electron carriers can be facilitated.

[0065] In this embodiment, the LUMO energy level of the electron blocking layer 500 is lower than the LUMO energy level of the host material of the light-emitting layer 600, and the HOMO energy level of the hole blocking layer 700 is higher than the HOMO energy level of the host material of the light-emitting layer 600. By setting the LUMO energy level of the electron blocking layer 500 lower than the LUMO energy level of the host material of the light-emitting layer 600, the larger LUMO energy level difference can limit the outflow of electron carriers, thereby ensuring that the light efficiency of the organic electroluminescent panel is not reduced. At the same time, by setting the HOMO energy level of the hole blocking layer 700 higher than the HOMO energy level of the host material of the light-emitting layer 600, the larger HOMO energy level difference can limit the outflow of hole carriers, thereby ensuring that the light efficiency of the organic electroluminescent panel is not reduced.

[0066] Experimental example:

[0067] Conductivity test of the cover layer 1100: Thin films of doped cover layer 1100 with different materials were deposited on comb-shaped electrodes (comb teeth spacing of 20μm). The conductivity was tested and the current values ​​at 20V were compared. Silver and magnesium were selected as metallic materials, HATCN was selected as an organic material, and zinc oxide was selected as an inorganic non-metallic material for the doping experiments. The experiments were conducted with the conductive particle concentrations of the cover layer 1100 at 0%, 0.5%, 1%, 2%, 5%, 8%, 10%, and 20%. The conductivity test data are shown in Table 1:

[0068]

[0069] Table 1

[0070] According to Table 1, among the four materials of silver, magnesium, HATCN and zinc oxide, the order of conductivity is: silver>magnesium>HATCN>zinc oxide.

[0071] Refractive index and transmittance experiments of the cover layer 1100: silver and magnesium were selected as metal materials, HATCN was selected as organic material, and zinc oxide was selected as inorganic non-metallic material for doping experiments. The concentrations of the conductive particles in the cover layer 1100 were tested at six concentrations: 0%, 0.5%, 1%, 2%, 5%, 8%, and 10%. 460nm light was selected as the test wavelength.

[0072] The experimental data of refractive index (tested with 460nm wavelength light) are shown in Table 2 below:

[0073] / 0 0.5％ 1％ 2％ 5％ 10％ 20％ 50％ silver 2.12 2.10 2.05 2.02 1.99 1.94 1.91 1.85 magnesium 2.12 2.09 2.04 2.01 1.97 1.92 1.90 1.83 HATCN 2.12 2.09 2.03 2.00 1.96 1.92 1.88 1.82 zinc oxide 2.12 2.10 2.03 1.99 1.95 1.91 1.84 1.80

[0074] Table 2

[0075] The experimental data of transmittance (tested with 460nm wavelength light) are shown in Table 3:

[0076] / 0 0.5％ 1％ 2％ 5％ 10％ 20％ 50％ silver 99％ 97％ 93％ 89％ 77％ 65％ 49％ 21％ magnesium 99％ 97％ 95％ 90％ 85％ 71％ 47％ 33％ HATCN 99％ 98％ 97％ 93％ 88％ 75％ 50％ 40％ zinc oxide 99％ 98％ 97％ 91％ 85％ 69％ 45％ 35％

[0077] Table 3

[0078] Analysis of Tables 1, 2, and 3 shows that the higher the concentration of conductive particles doped in the cover layer 1100, the higher the conductivity. However, the refractive index and transmittance are affected to varying degrees. When the conductive particle doping concentration in the cover layer 1100 exceeds 10%, the transmittance of the cover layer 1100 is significantly affected. When the conductive particle concentration in the cover layer 1100 is 2% by weight, the conductivity of the cover layer 1100 is increased by two orders of magnitude, while the transmittance of the cover layer 1100 is maintained at 90%, and the refractive index of the cover layer 1100 is not significantly affected. Therefore, the conductive particle concentration in the cover layer 1100 is preferably 0.5% to 10% by weight. Preferably, the conductive particle concentration in the cover layer 1100 is 2% by weight.

[0079] The above describes in detail the specific embodiments of the present application. The above embodiments disclosed in this application are merely preferred embodiments of the present application. Those skilled in the art will appreciate that many variations and improvements can be made without departing from the spirit of the present application. These variations and improvements fall within the scope of protection defined by the claims of this application.

Claims

1. An organic electroluminescent panel, characterized in that: include: substrate; an anode layer, the anode layer being disposed on the substrate; a light-emitting layer, the light-emitting layer being disposed on a side of the anode layer away from the substrate, the light-emitting layer comprising a host material, a phosphorescent sensitizer, and a fluorescent guest, wherein the phosphorescent sensitizer and the fluorescent guest are doped in the host material; a cathode layer, the cathode layer being disposed on a side of the light-emitting layer away from the substrate; The covering layer is provided on a surface of the cathode layer away from the substrate, the covering layer is doped with conductive particles, and the conductivity of the covering layer is not less than ; The conductive particles in the covering layer have a concentration of 0.5% to 10% by mass.

2. The organic electroluminescent panel according to claim 1, wherein: The conductive particles are made of at least one of a metal material, an inorganic non-metal material or an organic material.

3. The organic electroluminescent panel according to claim 1, wherein: The conductive particles are made of a metal material, which includes at least one of silver, magnesium, lithium, and ytterbium.

4. The organic electroluminescent panel according to claim 1, wherein: The conductive particles are made of an inorganic non-metallic material, which includes at least one of oxides, carbides, nitrides, halogen compounds, borides, silicates, aluminates, phosphates, and borates.

5. The organic electroluminescent panel according to claim 1, wherein: The organic electroluminescent panel also includes a hole transport layer and an electron blocking layer, the hole transport layer is located between the anode layer and the light-emitting layer, the electron blocking layer is located between the hole transport layer and the light-emitting layer, the HOMO energy level of the main material of the light-emitting layer is greater than the HOMO energy level of the electron blocking layer, and the HOMO energy level of the electron blocking layer is greater than the HOMO energy level of the hole transport layer.

6. The organic electroluminescent panel according to claim 5, characterized in that: The HOMO energy level of the hole transport layer, the HOMO energy level of the electron blocking layer, and the HOMO energy level of the host material of the light-emitting layer are arranged in a step-type manner.

7. The organic electroluminescent panel according to claim 5, wherein: The organic electroluminescent panel also includes a hole blocking layer and an electron transport layer, the hole blocking layer is located between the light-emitting layer and the cathode layer, the electron transport layer is located between the hole blocking layer and the cathode layer, the LUMO energy level of the main material of the light-emitting layer 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.

8. The organic electroluminescent panel according to claim 7, wherein: The LUMO energy level of the electron transport layer, the LUMO energy level of the hole blocking layer, and the LUMO energy level of the host material of the light-emitting layer are arranged in a step-type arrangement.

9. The organic electroluminescent panel according to claim 7, wherein: The LUMO energy level of the electron blocking layer is lower than the LUMO energy level of the host material of the light-emitting layer, and the HOMO energy level of the hole blocking layer is higher than the HOMO energy level of the host material of the light-emitting layer.

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