Light-emitting device and display panel

Abstract

The present application relates to a light-emitting device and a display panel. The light-emitting device comprises a first electrode, a first electron blocking layer, a first light-emitting layer, and a second electrode which are sequentially stacked; the materials of a first sub-electron blocking unit and a third sub-electron blocking unit are both the same as the material of a second sub-electron blocking unit; and a third light-emitting unit comprises a first main body material and a second main body material.

Description

Light-emitting device and display panel

[0001] This application claims priority to Chinese Patent Application No. 202410473149.5, filed on April 18, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of display, in particular to a light-emitting device and a display panel. BACKGROUND

[0003] With the development of display technology, the organic light-emitting diode (OLED) technology has been widely used in the display industry. For example, in recent years, it has been more and more widely used in the fields of vehicle display, computer display, television screen, mobile phone screen, commercial display, etc., and has broad application prospects. Compared with liquid crystal display (LCD), OLED has the advantages of self-luminous, wide viewing angle, high contrast, short response time, low power consumption, etc., and is a new generation of flexible display. Because OLED can be made into flexible products and its appearance can be customized, it has a very wide prospect in flexible display. Due to the various advantages of OLED, automobile manufacturers and suppliers have also developed OLED technology, which is involved in traditional instruments, central control, head-up display (HUD), streaming media rearview mirror, lighting, etc. SUMMARY

[0004] OLED also has some disadvantages, mainly in the aspects of complex structure, high process difficulty, high production cost, low efficiency, high power consumption, and short service life, etc.

[0005] The application provides a light-emitting device, which comprises a first electrode, a first electron blocking layer, a first light-emitting layer and a second electrode which are sequentially stacked; wherein the first light-emitting layer comprises a first light-emitting unit, a second light-emitting unit and a third light-emitting unit which have different light-emitting colors, the wavelength of the first light-emitting unit is greater than that of the second light-emitting unit, and the wavelength of the second light-emitting unit is greater than that of the third light-emitting unit; wherein the first electron blocking layer comprises a first sub-electron blocking unit corresponding to the first light-emitting unit, a second sub-electron blocking unit corresponding to the second light-emitting unit and a third sub-electron blocking unit corresponding to the third light-emitting unit; wherein the material of the first sub-electron blocking unit and the third sub-electron blocking unit is the same as that of the second sub-electron blocking unit; the absolute value of the difference between the HOMO energy level of the second light-emitting unit and the HOMO energy level of the second sub-electron blocking unit ranges from 0.02 eV to 0.04 eV, and the absolute value of the difference between the HOMO energy level of the third light-emitting unit and the HOMO energy level of the second sub-electron blocking unit ranges from 0.02 eV to 0.03 eV.

[0006] The application further provides a display panel, which comprises the light-emitting device, the light-emitting device comprises a first electrode, a first electron blocking layer, a first light-emitting layer and a second electrode which are sequentially stacked; wherein the first light-emitting layer comprises a first light-emitting unit, a second light-emitting unit and a third light-emitting unit which have different light-emitting colors, the wavelength of the first light-emitting unit is greater than that of the second light-emitting unit, and the wavelength of the second light-emitting unit is greater than that of the third light-emitting unit; wherein the first electron blocking layer comprises a first sub-electron blocking unit corresponding to the first light-emitting unit, a second sub-electron blocking unit corresponding to the second light-emitting unit and a third sub-electron blocking unit corresponding to the third light-emitting unit; wherein the material of the first sub-electron blocking unit and the third sub-electron blocking unit is the same as that of the second sub-electron blocking unit; the absolute value of the difference between the HOMO energy level of the second light-emitting unit and the HOMO energy level of the second sub-electron blocking unit ranges from 0.02 eV to 0.04 eV, and the absolute value of the difference between the HOMO energy level of the third light-emitting unit and the HOMO energy level of the second sub-electron blocking unit ranges from 0.02 eV to 0.03 eV. BRIEF DESCRIPTION OF DRAWINGS

[0007] In order to more clearly illustrate the technical solutions in the embodiments, the drawings needed to be used in the following embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments disclosed, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0008] Fig. 1 is a structural schematic diagram of a light emitting device according to Embodiment 1 of the present application;

[0009] Fig. 2 is a structural schematic diagram of a light emitting device according to Embodiment 2 of the present application;

[0010] Fig. 3 is a structural schematic diagram of a light emitting device according to Embodiment 3 of the present application;

[0011] Fig. 4 is a structural schematic diagram of a light emitting device according to Embodiment 4 of the present application;

[0012] Fig. 5 is a structural schematic diagram of a display panel according to an embodiment of the present application.

[0013] Explanation of Reference Numerals:

[0014] 100: light emitting device; 200: display panel;

[0015] 1: first electrode; 2: first electron blocking layer; 3: first light emitting layer; 4: second electrode; 5: second electron blocking layer; 6: hole injection layer; 7: first hole transport layer; 8: first hole blocking layer; 9: first electron injection layer; 10: light extraction layer; 11: third electron blocking layer; 12: second light emitting layer; 13: second hole blocking layer; 14: first charge generation layer; 15: second charge generation layer; 16: second hole transport layer; 17: fourth electron blocking layer;

[0016] 31: first light emitting unit; 32: second light emitting unit; 33: third light emitting unit;

[0017] 21: first sub-electron blocking unit; 22: second sub-electron blocking unit; 23: third sub-electron blocking unit;

[0018] 121: fourth light emitting unit; 122: fifth light emitting unit; 123: sixth light emitting unit;

[0019] 111: fourth sub-electron blocking unit; 112: fifth sub-electron blocking unit; 113: sixth sub-electron blocking unit. Embodiments of the present application

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person skilled in the art without any creative work fall within the scope of protection of the present application.

[0021] In the description of the present application, it needs to be understood that the terms "upper", "lower", and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0022] The present application can repeatedly refer to numbers and / or letters in different embodiments. Such repetition is for the purpose of simplification and clarity, and in itself does not indicate the relationship between the various embodiments and / or arrangements discussed.

[0023] The present application provides a light-emitting device, comprising: a first electrode, a first electron blocking layer, a first light-emitting layer and a second electrode which are sequentially stacked; wherein the first light-emitting layer comprises first, second and third light-emitting units with different light-emitting colors, the wavelength of the first light-emitting unit is greater than that of the second light-emitting unit, and the wavelength of the second light-emitting unit is greater than that of the third light-emitting unit; wherein the first electron blocking layer comprises a first sub-electron blocking unit corresponding to the first light-emitting unit, a second sub-electron blocking unit corresponding to the second light-emitting unit and a third sub-electron blocking unit corresponding to the third light-emitting unit; wherein the material of the first sub-electron blocking unit and the third sub-electron blocking unit is the same as that of the second sub-electron blocking unit; the absolute value of the difference between the HOMO energy level of the second light-emitting unit and the HOMO energy level of the second sub-electron blocking unit ranges from 0.02 eV to 0.04 eV, and the absolute value of the difference between the HOMO energy level of the third light-emitting unit and the HOMO energy level of the second sub-electron blocking unit ranges from 0.02 eV to 0.03 eV.

[0024] In some embodiments, the third light-emitting unit comprises: a first host material and a second host material; the absolute value of the difference between the HOMO energy level of the first host material of the third light-emitting unit and the HOMO energy level of the second sub-electron blocking unit ranges from 0.02 eV to 0.03 eV; or the absolute value of the difference between the HOMO energy level of the second host material of the third light-emitting unit and the HOMO energy level of the second sub-electron blocking unit ranges from 0.02 eV to 0.03 eV.

[0025] In some embodiments, the first host material comprises one of a first N-type material, a first P-type material, and a first PN-type material, and the second host material comprises another one of the first N-type material, the first P-type material, and the first PN-type material; or the first host material and the second host material are both the first PN-type material; wherein the LUMO energy level range of the first N-type material and the first PN-type material is -2.05 eV to 3.32 eV, the HOMO energy level range of the first P-type material and the first PN-type material is -5.46 eV to -6.54 eV, the absolute value of the difference between the HOMO energy level of the first P-type material and the LUMO energy level of the first N-type material is greater than or equal to 2.6 eV, the absolute value of the difference between the HOMO energy level of the first PN-type material and the LUMO energy level of the first PN-type material is greater than or equal to 2.6 eV, and the absolute value of the difference between the LUMO energy level of the first host material and the LUMO energy level of the second host material ranges from 0.2 eV to 0.4 eV.

[0026] In some embodiments, the mass ratio of the sum of the first N-type material in the first host material and the first N-type material in the second host material to the sum of the first P-type material in the first host material and the first P-type material in the second host material ranges from 5:5 to 7:3.

[0027] In some embodiments, the light-emitting device further comprises a second electron blocking layer disposed corresponding to the first light-emitting unit and between the first sub-electron blocking unit and the first light-emitting unit.

[0028] In some embodiments, the light-emitting device further comprises a third electron blocking layer and a second light-emitting layer stacked in sequence; wherein the second light-emitting layer is disposed between the first electron blocking layer and the first electrode or between the first light-emitting layer and the second electrode; wherein the second light-emitting layer comprises a fourth light-emitting unit, a fifth light-emitting unit, and a sixth light-emitting unit having different light-emitting colors, and the light-emitting colors of the fourth light-emitting unit, the fifth light-emitting unit, and the sixth light-emitting unit are the same as those of the first light-emitting unit, the second light-emitting unit, and the third light-emitting unit, respectively; wherein the third electron blocking layer comprises a fourth sub-electron blocking unit corresponding to the fourth light-emitting unit, a fifth sub-electron blocking unit corresponding to the fifth light-emitting unit, and a sixth sub-electron blocking unit corresponding to the sixth light-emitting unit.

[0029] In some embodiments, the fourth sub-electron blocking unit and the sixth sub-electron blocking unit are made of the same material as the fifth sub-electron blocking unit; the absolute value of the difference between the HOMO energy level of the fifth light-emitting unit and the HOMO energy level of the fifth sub-electron blocking unit ranges from 0.02 eV to 0.04 eV; and the absolute value of the difference between the HOMO energy level of the sixth light-emitting unit and the HOMO energy level of the fifth sub-electron blocking unit ranges from 0.02 eV to 0.03 eV.

[0030] In some embodiments, the sixth light-emitting unit comprises a third host material and a fourth host material; the absolute value of the difference between the HOMO energy level of the third host material of the sixth light-emitting unit and the HOMO energy level of the fifth sub-electron blocking unit ranges from 0.02 eV to 0.03 eV; or the absolute value of the difference between the HOMO energy level of the fourth host material of the sixth light-emitting unit and the HOMO energy level of the fifth sub-electron blocking unit ranges from 0.02 eV to 0.03 eV.

[0031] In some embodiments, the third host material comprises one of a second N-type material, a second P-type material and a second PN-type material, and the fourth host material comprises another of the second N-type material, the second P-type material and the second PN-type material; or the third host material and the fourth host material are both the second PN-type material; wherein the LUMO energy level of the second N-type material and the second PN-type material ranges from -2.05 eV to 3.32 eV, the HOMO energy level of the second P-type material and the second PN-type material ranges from -5.46 eV to -6.54 eV, the absolute value of the difference between the HOMO energy level of the second P-type material and the LUMO energy level of the second N-type material is greater than or equal to 2.6 eV, the absolute value of the difference between the HOMO energy level of the second PN-type material and the LUMO energy level of the second PN-type material is greater than or equal to 2.6 eV, and the absolute value of the difference between the LUMO energy level of the third host material and the LUMO energy level of the fourth host material ranges from 0.2 eV to 0.4 eV.

[0032] In some embodiments, the light-emitting device further comprises a fourth electron blocking layer arranged corresponding to the fourth light-emitting unit and located between the fourth sub-electron blocking unit and the fourth light-emitting unit.

[0033] The material of the first sub-electron blocking unit and the third sub-electron blocking unit of the application is the same as that of the second sub-electron blocking unit, which can simplify the structure of the first electron blocking layer and reduce the production cost; the first sub-electron blocking unit, the third sub-electron blocking unit and the second sub-electron blocking unit can be prepared simultaneously by using one common metal mask plate to form the first electron blocking layer, which can reduce the mask plate cost and further reduce the production cost compared with using three fine metal mask plates to prepare the first sub-electron blocking unit, the third sub-electron blocking unit and the second sub-electron blocking unit.

[0034] The third light-emitting unit of the application includes a first host material and a second host material, which can delay the transmission of electrons in the third light-emitting unit, improve the hole transmission caused by the first electron blocking layer to the third light-emitting unit, improve the energy transmission of the first host material and the second host material to the first dopant material in the third light-emitting unit, move the exciton recombination region to the inside of the third light-emitting unit, widen the exciton recombination region, delay the aging of the light-emitting device, prolong the service life of the light-emitting device, reduce the operating voltage of the light-emitting device, and improve the current efficiency and luminous brightness of the light-emitting device.

[0035] The material of the fourth sub-electron blocking unit and the sixth sub-electron blocking unit of the application is the same as that of the fifth sub-electron blocking unit, which can simplify the structure of the third electron blocking layer and reduce the production cost; the fourth sub-electron blocking unit, the sixth sub-electron blocking unit and the fifth sub-electron blocking unit can be prepared simultaneously by using one common metal mask plate to form the third electron blocking layer, which can reduce the mask plate cost and further reduce the production cost compared with using three fine metal mask plates to prepare the fourth sub-electron blocking unit, the sixth sub-electron blocking unit and the fifth sub-electron blocking unit.

[0036] The sixth light-emitting unit of the application includes a third host material and a fourth host material, which can delay the transmission of electrons in the sixth light-emitting unit, improve the hole transmission caused by the third electron blocking layer to the sixth light-emitting unit, improve the energy transmission of the third host material and the fourth host material to the second dopant material in the sixth light-emitting unit, move the exciton recombination region to the inside of the sixth light-emitting unit, widen the exciton recombination region, delay the aging of the light-emitting device, prolong the service life of the light-emitting device, reduce the operating voltage of the light-emitting device, and improve the current efficiency and luminous brightness of the light-emitting device.

[0037] Example 1

[0038] As shown in FIG. 1, the embodiment provides a light emitting device 100. The light emitting device 100 comprises a first electrode 1, a first electron blocking layer 2, a first light emitting layer 3 and a second electrode 4 which are sequentially stacked.

[0039] The first electrode 1 can be a single-layer ITO structure or a stacked structure of ITO / Ag / ITO, and the present application does not limit the first electrode 1.

[0040] The first light emitting layer 3 comprises a first light emitting unit 31, a second light emitting unit 32 and a third light emitting unit 33 which have different light emitting colors. The wavelength of the first light emitting unit 31 is greater than that of the second light emitting unit 32, and the wavelength of the second light emitting unit 32 is greater than that of the third light emitting unit 33. In the embodiment, the first light emitting unit 31, the second light emitting unit 32 and the third light emitting unit 33 are red light emitting units, green light emitting units and blue light emitting units respectively. The thickness of the first light emitting layer 3 ranges from 15 nm to 40 nm. The first light emitting unit 31, the second light emitting unit 32 and the third light emitting unit 33 can adopt the same Host-Dopant material or different Host-Dopant materials. The third light emitting unit 33 can be a fluorescent material, a TADF material, a superfluorescent material or a phosphorescent material, and the first light emitting unit 31 and the second light emitting unit 32 can adopt a Single Host-Dopant phosphorescent material or a Pre-mix Host-Dopant material.

[0041] The first electron blocking layer 2 comprises a first sub-electron blocking unit 21 corresponding to the first light emitting unit 31, a second sub-electron blocking unit 22 corresponding to the second light emitting unit 32 and a third sub-electron blocking unit 23 corresponding to the third light emitting unit 33. In the embodiment, the first sub-electron blocking unit 21, the second sub-electron blocking unit 22 and the third sub-electron blocking unit 23 are red electron blocking units, green electron blocking units and blue electron blocking units respectively. The thickness of the first electron blocking layer 2 ranges from 5 nm to 50 nm. The first electron blocking layer 2 adopts a material having a hole transport and electron blocking effect, and is not limited to one material or multiple materials.

[0042] The first sub-electron blocking unit 21 and the third sub-electron blocking unit 23 are made of the same material as the second sub-electron blocking unit 22, the absolute value of the difference between the HOMO energy level of the second light-emitting unit 32 and the HOMO energy level of the second sub-electron blocking unit 22 ranges from 0.02 eV to 0.04 eV, and the absolute value of the difference between the HOMO energy level of the third light-emitting unit 33 and the HOMO energy level of the second sub-electron blocking unit 22 ranges from 0.02 eV to 0.03 eV. In this way, the structure of the first electron blocking layer 2 can be simplified, and the production cost can be reduced. The first sub-electron blocking unit 21, the third sub-electron blocking unit 23, and the second sub-electron blocking unit 22 can be formed simultaneously by using one ordinary metal mask plate to form the first electron blocking layer 2, which can reduce the cost of the mask plate and further reduce the production cost, as compared with using three fine metal mask plates to form the first sub-electron blocking unit 21, the third sub-electron blocking unit 23, and the second sub-electron blocking unit 22.

[0043] The third light-emitting unit 33 includes a first host material and a second host material. The absolute value of the difference between the HOMO energy level of the first host material of the third light-emitting unit and the HOMO energy level of the second sub-electron blocking unit 22 ranges from 0.02 eV to 0.03 eV, or the absolute value of the difference between the HOMO energy level of the second host material of the third light-emitting unit 33 and the HOMO energy level of the second sub-electron blocking unit 22 ranges from 0.02 eV to 0.03 eV.

[0044] The first host material includes one of a first N-type material, a first P-type material, and a first PN-type material, and the second host material includes another one of the first N-type material, the first P-type material, and the first PN-type material, or the first host material and the second host material are both the first PN-type material. The LUMO of the first N-type material and the energy level range of the first PN-type material both range from -2.05 eV to 3.32 eV, the HOMO of the first P-type material and the energy level range of the first PN-type material both range from -5.46 eV to -6.54 eV, the absolute value of the difference between the HOMO energy level of the first P-type material and the LUMO energy level of the first N-type material is greater than or equal to 2.6 eV, the absolute value of the difference between the HOMO energy level of the first PN-type material and the LUMO energy level of the first PN-type material is greater than or equal to 2.6 eV, and the absolute value of the difference between the LUMO energy level of the first host material and the LUMO energy level of the second host material ranges from 0.2 eV to 0.4 eV.

[0045] Since the HOMO energy level of the second sub-electron blocking unit 22 is less different from the HOMO energy level of the first light-emitting unit 31, the material of the first sub-electron blocking unit 21 is set to be the same as that of the second sub-electron blocking unit 22, which has less influence on the performance of the first light-emitting unit 31. However, the HOMO energy level of the second sub-electron blocking unit 22 is greatly different from the HOMO energy level of the third light-emitting unit 33, so the material of the third sub-electron blocking unit 23 is set to be the same as that of the second sub-electron blocking unit 22, which has great influence on the performance of the third light-emitting unit.

[0046] The present application uses the first host material and the second host material to delay the transmission of electrons in the third light-emitting unit 33, improve the hole transmission of the first electron blocking layer 2 to the third light-emitting unit 33, improve the energy transmission of the first host material and the second host material to the first doping material in the third light-emitting unit 33, move the exciton recombination region to the inside of the third light-emitting unit 33, widen the exciton recombination region, delay the aging of the light-emitting device 100, prolong the service life of the light-emitting device 100, reduce the operating voltage of the light-emitting device 100, and improve the current efficiency of the light-emitting device 100 and the luminous brightness of the light-emitting device 100.

[0047] The mass ratio of the sum of the first N-type material in the first host material and the first N-type material in the second host material to the sum of the first P-type material in the first host material and the first P-type material in the second host material is in the range of 5:5-7:3. By adjusting the mass ratio of the sum of the first N-type material to the sum of the first P-type material, the mass ratio of the first N-type material and the first P-type material is appropriate, the exciton recombination region is widened, the exciton quenching is reduced, the luminous efficiency of the light-emitting device 100 is improved, and the exciton recombination region can be moved to the inside of the third light-emitting unit 33, thereby improving the interface aging and prolonging the service life of the light-emitting device 100.

[0048] The material of the second electrode 4 includes Mg-Ag, Ag, Al, Al-Ca alloy, etc. In this embodiment, the first electrode 1 is an anode, and the second electrode 4 is a cathode. In other embodiments, the first electrode 1 can be a cathode, and the second electrode 4 can be an anode. The thickness of the second electrode 4 is in the range of 9nm-15nm.

[0049] The light-emitting device 100 further comprises a second electron blocking layer 5. The second electron blocking layer 5 is arranged corresponding to the first light-emitting unit 31 and is located between the first sub-electron blocking unit 21 and the first light-emitting unit 31. The material of the second electron blocking layer 5 can be the same as or different from that of the first electron blocking layer 2, which is not limited in the present application.

[0050] Since the microcavity length of the second light emitting unit 32 and the microcavity length of the third light emitting unit 33 are less different, the thickness of the first electron blocking layer in the embodiment is thinner than the thickness of the green electron blocking layer and thicker than the thickness of the blue electron blocking layer, and then the microcavity length of the second light emitting unit 32 and the microcavity length of the third light emitting unit are adjusted by adjusting the thickness of the second light emitting unit 32 and the thickness of the third light emitting unit 33 respectively. However, the microcavity length of the first light emitting unit 31 is greatly different from the microcavity length of the third light emitting unit 33 and the microcavity length of the second light emitting unit 32, and there is a technical problem that the microcavity length of the first light emitting unit 31 cannot be adjusted by adjusting the thickness of the first light emitting unit 31.

[0051] Therefore, the second electron blocking layer 5 is arranged in the present application, and the microcavity length of the first light emitting unit 31 is increased by the second electron blocking layer 5.

[0052] As shown in FIG. 1, the light emitting device 100 further comprises a hole injection layer 6, a first hole transport layer 7, a first hole blocking layer 8, a first electron injection layer 9 and a light extraction layer 10.

[0053] The hole injection layer 6 is made of a hole injection type, a doping of a strong oxidant, and an aromatic hole transport material, which is not limited to one or more materials, but is evaporated in one evaporation chamber. The thickness of the hole injection layer 6 ranges from 7 nm to 15 nm.

[0054] The first hole transport layer 7 is made of a hole transport type material, which is not limited to one or more materials. The thickness of the first hole transport layer 7 ranges from 80 nm to 150 nm.

[0055] The first hole blocking layer 8 is made of a material having the functions of blocking holes and transporting electrons, which is not limited to one or more materials. The thickness of the first hole blocking layer 8 ranges from 5 nm to 15 nm.

[0056] The first electron injection layer 9 can be an ET type material doped with LiQ, which is not limited to one or more materials. The ET type material contains an electron-withdrawing functional group and a high electron transport group, such as an electron-deficient nitrogen heterocycle and an anthracene structure. The function of the ET type material is to enhance the electron mobility, reduce the device driving voltage and improve the performance. The thickness of the first electron injection layer 9 ranges from 20 nm to 35 nm.

[0057] The light extraction layer 10 is arranged on the side of the second electrode 4 away from the first electrode 1. The light extraction layer 10 can be made of a high refractive index material with a refractive index ≥ 2.0, which is not limited to one or more combined materials. The thickness of the light extraction layer 10 ranges from 50 nm to 90 nm.

[0058] Embodiment 2

[0059] As shown in FIG. 2, the present embodiment includes most of the technical features of the embodiment 1. The difference between the present embodiment and the embodiment 1 is that the light emitting device 100 in the present embodiment further comprises a third electron blocking layer 11 and a second light emitting layer 12 which are sequentially stacked.

[0060] The second light emitting layer 12 is arranged between the first electron blocking layer 2 and the first electrode 1 or between the first light emitting layer 3 and the second electrode 4. In the present embodiment, the second light emitting layer 12 is arranged between the first light emitting layer 3 and the second electrode 4.

[0061] The second light emitting layer 12 comprises a fourth light emitting unit 121, a fifth light emitting unit 122 and a sixth light emitting unit 123 which have different light emitting colors. The light emitting colors of the fourth light emitting unit 121, the fifth light emitting unit 122 and the sixth light emitting unit 123 are the same as those of the first light emitting unit 31, the second light emitting unit 32 and the third light emitting unit 33, respectively. That is, the fourth light emitting unit 121, the fifth light emitting unit 122 and the sixth light emitting unit 123 are also red light emitting units, green light emitting units and blue light emitting units, respectively. By arranging the second light emitting layer 12, the brightness of the light emitting device 100 can be increased.

[0062] The third electron blocking layer 11 comprises a fourth sub-electron blocking unit 111 corresponding to the fourth light emitting unit 121, a fifth sub-electron blocking unit 112 corresponding to the fifth light emitting unit 122 and a sixth sub-electron blocking unit 113 corresponding to the sixth light emitting unit 123. The difference between the third electron blocking layer 11 in the present embodiment and the first electron blocking layer 2 is that the fourth sub-electron blocking unit 111, the fifth sub-electron blocking unit 112 and the sixth sub-electron blocking unit 113 are formed by using three fine metal masks (Fine Metal Mask) instead of one common metal mask (Common Metal Mask).

[0063] The light emitting device 100 further comprises a second hole blocking layer 13, a first charge generation layer 14, a second charge generation layer 15 and a second hole transport layer 16.

[0064] The second hole blocking layer 13 is arranged between the first light emitting layer 3 and the third electron blocking layer 11. The second hole blocking layer 13 is made of a material which can block holes and transport electrons, and is not limited to one kind of material or multiple kinds of materials. The thickness of the second hole blocking layer 13 ranges from 5 nm to 15 nm.

[0065] The first charge generation layer 14 is arranged between the second hole blocking layer 13 and the third electron blocking layer 11. In this embodiment, the first charge generation layer 14 is an N-type charge generation layer, which can be a compound of an electron transport material and a metal ion dopant (Yb, Li, Na, CS, etc.). The thickness of the first charge generation layer 14 ranges from 7 nm to 18 nm.

[0066] The second charge generation layer 15 is arranged between the first charge generation layer 14 and the third electron blocking layer 11. In this embodiment, the second charge generation layer 15 is a P-type charge generation layer, which can be a compound of a strong oxidant and a hole transport material, not limited to one or more materials. The thickness of the second charge generation layer 15 ranges from 7 nm to 15 nm.

[0067] The second hole transport layer 16 is arranged between the second charge generation layer 15 and the third electron blocking layer 11. The second hole transport layer 16 is made of a hole transport material, not limited to one or more materials. The thickness of the second hole transport layer 16 ranges from 80 nm to 150 nm.

[0068] Embodiment 3

[0069] As shown in FIG. 3, this embodiment includes most of the technical features of Embodiment 1. The difference between this embodiment and Embodiment 1 is that the light-emitting device 100 of this embodiment further includes a third electron blocking layer 11 and a second light-emitting layer 12 arranged in sequence.

[0070] The second light-emitting layer 12 is arranged between the first electron blocking layer 2 and the first electrode 1 or between the first light-emitting layer 3 and the second electrode 4. In this embodiment, the second light-emitting layer 12 is arranged between the first electron blocking layer 2 and the first electrode 1.

[0071] The second light-emitting layer 12 includes a fourth light-emitting unit 121, a fifth light-emitting unit 122, and a sixth light-emitting unit 123, which emit light of different colors. The light-emitting colors of the fourth, fifth, and sixth light-emitting units 121, 122, and 123 are the same as those of the first, second, and third light-emitting units 31, 32, and 33, respectively. That is, in this embodiment, the fourth, fifth, and sixth light-emitting units 121, 122, and 123 are red, green, and blue light-emitting units, respectively. The second light-emitting layer 12 can increase the brightness of the light-emitting device 100.

[0072] The third electron blocking layer 11 includes a fourth sub-electron blocking unit 111 corresponding to the fourth light emitting unit 121, a fifth sub-electron blocking unit 112 corresponding to the fifth light emitting unit 122, and a sixth sub-electron blocking unit 113 corresponding to the sixth light emitting unit 123. The third electron blocking layer 11 in the embodiment is different from the first electron blocking layer 2 in that the fourth sub-electron blocking unit 111, the fifth sub-electron blocking unit 112, and the sixth sub-electron blocking unit 113 are formed by using three fine metal masks (Fine Metal Mask), instead of one common metal mask (Common Metal Mask).

[0073] The light emitting device 100 further includes a second hole blocking layer 13, a first charge generation layer 14, a second charge generation layer 15, and a second hole transport layer 16.

[0074] The second hole blocking layer 13 is disposed between the second light emitting layer 12 and the first electron blocking layer 2. The second hole blocking layer 13 is made of a material that blocks holes and transports electrons, and is not limited to one or more materials. The thickness of the second hole blocking layer 13 ranges from 5 nm to 15 nm.

[0075] The first charge generation layer 14 is disposed between the second hole blocking layer 13 and the first electron blocking layer 2. In the embodiment, the first charge generation layer 14 is an N-type charge generation layer, and can be made of an electron transport type material and a metal ion doped (Yb, Li, Na, CS, etc.) compound. The thickness of the first charge generation layer 14 ranges from 7 nm to 18 nm.

[0076] The second charge generation layer 15 is disposed between the first charge generation layer 14 and the first electron blocking layer 2. In the embodiment, the second charge generation layer 15 is a P-type charge generation layer, and can be made of a P-type doped strong oxidant and a hole transport type material, and is not limited to one or more materials. The thickness of the second charge generation layer 15 ranges from 7 nm to 15 nm.

[0077] The second hole transport layer 16 is disposed between the second charge generation layer 15 and the first electron blocking layer 2. The second hole transport layer 16 is made of a hole transport type material, and is not limited to one or more materials. The thickness of the second hole transport layer 16 ranges from 80 nm to 150 nm.

[0078] Embodiment 4

[0079] As shown in FIG. 4, the present embodiment includes most of the technical features of Embodiment 1. The difference between the present embodiment and Embodiment 1 is that the light emitting device 100 in the present embodiment further includes a third electron blocking layer 11 and a second light emitting layer 12 which are sequentially stacked.

[0080] The second light emitting layer 12 is arranged between the first electron blocking layer 2 and the first electrode 1 or between the first light emitting layer 3 and the second electrode 4. In the present embodiment, the second light emitting layer 12 is arranged between the first light emitting layer 3 and the second electrode 4.

[0081] The second light emitting layer 12 includes a fourth light emitting unit 121, a fifth light emitting unit 122 and a sixth light emitting unit 123 which have different light emitting colors. The light emitting colors of the fourth light emitting unit 121, the fifth light emitting unit 122 and the sixth light emitting unit 123 are the same as those of the first light emitting unit 31, the second light emitting unit 32 and the third light emitting unit 33, respectively. That is, in the present embodiment, the fourth light emitting unit 121, the fifth light emitting unit 122 and the sixth light emitting unit 123 are red light emitting units, green light emitting units and blue light emitting units, respectively. The second light emitting layer 12 can increase the brightness of the light emitting device 100.

[0082] The third electron blocking layer 11 includes a fourth sub-electron blocking unit 111 corresponding to the fourth light emitting unit 121, a fifth sub-electron blocking unit 112 corresponding to the fifth light emitting unit 122 and a sixth sub-electron blocking unit 113 corresponding to the sixth light emitting unit 123. In the present embodiment, the fourth sub-electron blocking unit 111, the fifth sub-electron blocking unit 112 and the sixth sub-electron blocking unit 113 are red electron blocking units, green electron blocking units and blue electron blocking units, respectively. The thickness of the third electron blocking layer 11 ranges from 5 nm to 50 nm. The third electron blocking layer 11 is made of a material having a hole transporting and electron blocking effect, which is not limited to one material or multiple materials.

[0083] The fourth sub-electron blocking unit 111 and the sixth sub-electron blocking unit 113 are made of the same material as the fifth sub-electron blocking unit 112. The absolute value of the difference between the HOMO energy level of the fifth light-emitting unit 122 and the HOMO energy level of the fifth sub-electron blocking unit 112 ranges from 0.02 eV to 0.04 eV. The absolute value of the difference between the HOMO energy level of the sixth light-emitting unit 123 and the HOMO energy level of the fifth sub-electron blocking unit 112 ranges from 0.02 eV to 0.03 eV. In this way, the structure of the third electron blocking layer 11 can be simplified, and the production cost can be reduced. One ordinary metal mask plate can be used to simultaneously manufacture the fourth sub-electron blocking unit 111, the fifth sub-electron blocking unit 112, and the sixth sub-electron blocking unit 113 to form the third electron blocking layer 11. Compared with using three fine metal mask plates to manufacture the fourth sub-electron blocking unit 111, the fifth sub-electron blocking unit 112, and the sixth sub-electron blocking unit 113, the mask plate cost can be reduced, and the production cost can be further reduced.

[0084] The sixth light-emitting unit 123 includes a third host material and a fourth host material. The absolute value of the difference between the HOMO energy level of the third host material of the sixth light-emitting unit 123 and the HOMO energy level of the fifth sub-electron blocking unit 112 ranges from 0.02 eV to 0.03 eV. Alternatively, the absolute value of the difference between the HOMO energy level of the fourth host material of the sixth light-emitting unit 123 and the HOMO energy level of the fifth sub-electron blocking unit 112 ranges from 0.02 eV to 0.03 eV.

[0085] The third host material includes one of a second N-type material, a second P-type material, and a second PN-type material, and the fourth host material includes another one of the second N-type material, the second P-type material, and the second PN-type material. Alternatively, the third host material and the fourth host material are both the second PN-type material. The LUMO energy level of the second N-type material and the second PN-type material ranges from -2.05 eV to 3.32 eV. The HOMO energy level of the second P-type material and the second PN-type material ranges from -5.46 eV to -6.54 eV. The absolute value of the difference between the HOMO energy level of the second P-type material and the LUMO energy level of the second N-type material is greater than or equal to 2.6 eV. The absolute value of the difference between the HOMO energy level of the second PN-type material and the LUMO energy level of the second PN-type material is greater than or equal to 2.6 eV. The absolute value of the difference between the LUMO energy level of the third host material and the LUMO energy level of the fourth host material ranges from 0.2 eV to 0.4 eV.

[0086] Since the HOMO energy level of the fifth sub-electron blocking unit 112 is less different from the HOMO energy level of the fourth light-emitting unit 121, the material of the fourth sub-electron blocking unit 111 is set to be the same as that of the fifth sub-electron blocking unit 112, which has less influence on the performance of the fourth light-emitting unit 121. However, the HOMO energy level of the fifth sub-electron blocking unit 112 is greatly different from the HOMO energy level of the sixth light-emitting unit 123, so the material of the sixth sub-electron blocking unit 113 is set to be the same as that of the fifth sub-electron blocking unit 112, which has great influence on the performance of the sixth light-emitting unit 123.

[0087] The present application uses the first host material and the second host material to delay the transmission of electrons in the sixth light-emitting unit 123, improve the hole transmission of the third electron blocking layer 11 to the sixth light-emitting unit 123, improve the energy transmission of the first host material and the second host material to the first doping material in the sixth light-emitting unit 123, move the exciton recombination region to the inside of the sixth light-emitting unit 123, widen the exciton recombination region, delay the aging of the light-emitting device 100, prolong the service life of the light-emitting device 100, reduce the operating voltage of the light-emitting device 100, and improve the current efficiency of the light-emitting device 100, and improve the luminous brightness of the light-emitting device 100.

[0088] The light-emitting device 100 further comprises a second hole blocking layer 13, a first charge generation layer 14, a second charge generation layer 15, and a second hole transport layer 16.

[0089] The second hole blocking layer 13 is arranged between the first light-emitting layer 3 and the third electron blocking layer 11. The second hole blocking layer 13 uses a material that blocks holes and transports electrons, which is not limited to one or more materials. The thickness of the second hole blocking layer 13 ranges from 5 nm to 15 nm.

[0090] The first charge generation layer 14 is arranged between the second hole blocking layer 13 and the third electron blocking layer 11. In this embodiment, the first charge generation layer 14 is an N-type charge generation layer, which can use an electron transport type material and a metal ion doped (Yb, Li, Na, CS, etc.) compound. The thickness of the first charge generation layer 14 ranges from 7 nm to 18 nm.

[0091] The second charge generation layer 15 is arranged between the first charge generation layer 14 and the third electron blocking layer 11. In this embodiment, the second charge generation layer 15 is a P-type charge generation layer, which can use a P-type doped strong oxidant and a hole transport type material, which is not limited to one or more materials. The thickness of the second charge generation layer 15 ranges from 7 nm to 15 nm.

[0092] The second hole transport layer 16 is arranged between the second charge generation layer 15 and the third electron blocking layer 11. The second hole transport layer 16 adopts a hole transport type material, which is not limited to one material or multiple materials. The thickness of the second hole transport layer 16 ranges from 80 nm to 150 nm.

[0093] The light emitting device 100 further includes a fourth electron blocking layer 17. The fourth electron blocking layer 17 is arranged corresponding to the fourth light emitting unit 121 and located between the fourth sub-electron blocking unit 111 and the fourth light emitting unit 121. The material of the fourth electron blocking layer 17 can be the same as or different from the material of the third electron blocking layer 11, which is not limited in the present application.

[0094] Since the microcavity length of the fifth light emitting unit 122 and the microcavity length of the sixth light emitting unit 123 are relatively small, the thickness of the third electron blocking layer in the present embodiment is thinner than the thickness of the green electron blocking layer and thicker than the thickness of the blue electron blocking layer. Then, the thickness of the fifth light emitting unit 122 and the thickness of the sixth light emitting unit 123 are adjusted to adjust the microcavity length of the fifth light emitting unit 122 and the microcavity length of the sixth light emitting unit 123. However, the microcavity length of the fourth light emitting unit 121 is significantly different from the microcavity length of the sixth light emitting unit 123 and the fifth light emitting unit 122, and there is a technical problem that the thickness of the fourth light emitting unit 121 cannot be adjusted to adjust the microcavity length of the fourth light emitting unit 121.

[0095] Therefore, the present application sets the fourth electron blocking layer 17 to increase the microcavity length of the fourth light emitting unit 121 by the fourth electron blocking layer 17.

[0096] Table 1

[0097] Parameter Comparative Example Example 1 Example 2 Example 3 Vop (V) 100% 99% 99% 98% C.E. (Cd / A) 100% 103% 104% 105% Lifetime (hrs) @25℃ 100% 102% 102% 102% Lifetime (hrs) @80℃ 100% 105% 104% 109% Lifetime (hrs) @-20℃ 100% 112% 114% 120%

[0098] In Table 1, the comparative example is a design scheme in which the first sub-electron blocking unit, the second sub-electron blocking unit and the third sub-electron blocking unit are respectively prepared by using three fine metal mask plates to form the first electron blocking layer, and the fourth sub-electron blocking unit, the fifth sub-electron blocking unit and the sixth sub-electron blocking unit are respectively prepared by using three fine metal mask plates to form the third electron blocking layer.

[0099] As shown in Table 1, the operating voltage (Vop) of Example 1, Example 2 and Example 3 is reduced compared with the operating voltage (Vop) of the comparative example, and the reduction of the operating voltage means that the power consumption can be reduced.

[0100] As shown in Table 1, the current efficiency (C.E.) of Example 1, Example 2 and Example 3 is improved compared with the current efficiency (C.E.) of the comparative example, and thus it can be seen that the design scheme of the present application can improve the working efficiency of the light-emitting device.

[0101] As shown in Table 1, the lifetime (hrs)@25℃ refers to the service life of the light-emitting device at a normal temperature of 25℃. The lifetime (hrs)@25℃ of Example 1, Example 2 and Example 3 is improved compared with the lifetime (hrs)@25℃ of the comparative example, and thus it can be seen that the design scheme of the present application can improve the service life of the light-emitting device.

[0102] As shown in Table 1, the lifetime (hrs)@80℃ refers to the service life of the light-emitting device at a high temperature of 80℃. The lifetime (hrs)@80℃ of Example 1, Example 2 and Example 3 is improved compared with the lifetime (hrs)@80℃ of the comparative example, and thus it can be seen that the design scheme of the present application can improve the service life of the light-emitting device.

[0103] As shown in Table 1, the lifetime (hrs)@-20℃ refers to the service life of the light-emitting device at a low temperature of -20℃. The lifetime (hrs)@-20℃ of Example 1, Example 2 and Example 3 is improved compared with the lifetime (hrs)@-20℃ of the comparative example, and thus it can be seen that the design scheme of the present application can improve the service life of the light-emitting device.

[0104] The embodiment of the present application also provides a display panel, as shown in Figure 5, which is a structural schematic diagram of the display panel provided by the embodiment of the present application, the display panel 200 comprises the light-emitting device 100, the light-emitting device 100 can be the light-emitting device 100 provided by any one of the above embodiments, and the light-emitting device 100 can realize the same technical effects as the above embodiments in the display panel 200.

[0105] The above describes in detail the light-emitting device provided by the present application, and the principles and implementation manners of the present application are described by applying specific examples; the above embodiment is only used to help understand the method and core idea of the present application; meanwhile, according to the idea of the present application, the specific implementation manner and application range will be changed by the person skilled in the art, and the above description should not be understood as limiting the present application.

Claims

1. A light emitting device comprising: The first electrode (1), the first electron blocking layer (2), the first light emitting layer (3) and the second electrode (4) are sequentially stacked; The first light emitting layer (3) comprises a first light emitting unit (31), a second light emitting unit (32) and a third light emitting unit (33) with different light emitting colors, the wavelength of the first light emitting unit (31) is greater than that of the second light emitting unit (32), and the wavelength of the second light emitting unit (32) is greater than that of the third light emitting unit (33); The first electron blocking layer (2) comprises a first sub-electron blocking unit (21) corresponding to the first light emitting unit (31), a second sub-electron blocking unit (22) corresponding to the second light emitting unit (32) and a third sub-electron blocking unit (23) corresponding to the third light emitting unit (33); The material of the first sub-electron blocking unit (21) and the third sub-electron blocking unit (23) is the same as that of the second sub-electron blocking unit (22); The absolute value of the difference between the HOMO energy level of the second light emitting unit (32) and the HOMO energy level of the second sub-electron blocking unit (22) ranges from 0.02 eV to 0.04 eV, and the absolute value of the difference between the HOMO energy level of the third light emitting unit (33) and the HOMO energy level of the second sub-electron blocking unit (22) ranges from 0.02 eV to 0.03 eV.

2. The light-emitting device according to claim 1, wherein The third light emitting unit (33) comprises a first host material and a second host material; The absolute value of the difference between the HOMO energy level of the first host material of the third light emitting unit (33) and the HOMO energy level of the second sub-electron blocking unit (22) ranges from 0.02 eV to 0.03 eV; or The absolute value of the difference between the HOMO energy level of the second host material of the third light emitting unit (33) and the HOMO energy level of the second sub-electron blocking unit (22) ranges from 0.02 eV to 0.03 eV.

3. The light emitting device of claim 2, wherein, The first host material comprises one of a first N-type material, a first P-type material and a first PN-type material, and the second host material comprises another one of the first N-type material, the first P-type material and the first PN-type material; or the first host material and the second host material are both the first PN-type material. The LUMO energy level range of the first N-type material and the first PN-type material is-2.05eV to 3.32eV, the HOMO energy level range of the first P-type material and the first PN-type material is-5.46eV to-6.54eV, the absolute value of the difference between the HOMO energy level of the first P-type material and the LUMO energy level of the first N-type material is greater than or equal to 2.6eV, the absolute value of the difference between the HOMO energy level of the first PN-type material and the LUMO energy level of the first PN-type material is greater than or equal to 2.6eV, and the absolute value of the difference between the LUMO energy level of the first host material and the LUMO energy level of the second host material ranges from 0.2eV to 0.4eV.

4. The light-emitting device according to claim 3, wherein The mass ratio of the sum of the first N-type material in the first host material and the first N-type material in the second host material to the sum of the first P-type material in the first host material and the first P-type material in the second host material ranges from 5:5 to 7:

3.

5. The light emitting device of claim 1, wherein, The light-emitting device further comprises: A second electron blocking layer (5) is arranged corresponding to the first light-emitting unit (31) and is located between the first sub-electron blocking unit (21) and the first light-emitting unit (31).

6. The light-emitting device according to claim 1, wherein The light-emitting device further comprises a third electron blocking layer (11) and a second light-emitting layer (12) arranged in sequence; The second light-emitting layer (12) is arranged between the first electron blocking layer (2) and the first electrode (1) or between the first light-emitting layer (3) and the second electrode (4); The second light-emitting layer (12) comprises fourth, fifth and sixth light-emitting units (121, 122 and 123) with different light-emitting colors, and the light-emitting colors of the fourth, fifth and sixth light-emitting units (121, 122 and 123) are the same as those of the first, second and third light-emitting units (31, 32 and 33), respectively; The third electron blocking layer (11) comprises a fourth sub-electron blocking unit (111) corresponding to the fourth light-emitting unit (121), a fifth sub-electron blocking unit (112) corresponding to the fifth light-emitting unit (122), and a sixth sub-electron blocking unit (113) corresponding to the sixth light-emitting unit (123).

7. The light-emitting device according to claim 6, wherein The materials of the fourth sub-electron blocking unit (111) and the sixth sub-electron blocking unit (113) are the same as that of the fifth sub-electron blocking unit (112); The absolute value of the difference between the HOMO energy level of the fifth light-emitting unit (122) and the HOMO energy level of the fifth sub-electron blocking unit (112) ranges from 0.02eV to 0.04eV, and the absolute value of the difference between the HOMO energy level of the sixth light-emitting unit (123) and the HOMO energy level of the fifth sub-electron blocking unit (112) ranges from 0.02eV to 0.03eV.

8. The light-emitting device according to claim 7, wherein The sixth light-emitting unit (123) comprises a third host material and a fourth host material; An absolute value of a difference between a HOMO energy level of the third host material of the sixth light-emitting unit (123) and a HOMO energy level of the fifth sub-electron blocking unit (112) ranges from 0.02 eV to 0.03 eV; or An absolute value of a difference between a HOMO energy level of the fourth host material of the sixth light-emitting unit (123) and a HOMO energy level of the fifth sub-electron blocking unit (112) ranges from 0.02 eV to 0.03 eV.

9. The light-emitting device according to claim 8, wherein The third host material comprises one of a second N-type material, a second P-type material and a second PN-type material, and the fourth host material comprises another one of the second N-type material, the second P-type material and the second PN-type material; or the third host material and the fourth host material are both the second PN-type material; The LUMO energy level of the second N-type material and the second PN-type material ranges from -2.05 eV to 3.32 eV, the HOMO energy level of the second P-type material and the second PN-type material ranges from -5.46 eV to -6.54 eV, an absolute value of a difference between the HOMO energy level of the second P-type material and the LUMO energy level of the second N-type material is greater than or equal to 2.6 eV, an absolute value of a difference between the HOMO energy level of the second PN-type material and the LUMO energy level of the second PN-type material is greater than or equal to 2.6 eV, and an absolute value of a difference between the LUMO energy level of the third host material and the LUMO energy level of the fourth host material ranges from 0.2 eV to 0.4 eV.

10. The light-emitting device according to claim 6, wherein The light-emitting device further comprises: A fourth electron blocking layer (17) is arranged corresponding to the fourth light-emitting unit (121) and is located between the fourth sub-electron blocking unit (111) and the fourth light-emitting unit (121).

11. A display panel, the display panel (200) comprising a light emitting device (100), the light emitting device comprising: A first electrode (1), a first electron blocking layer (2), a first light-emitting layer (3) and a second electrode (4) are sequentially stacked; The first light-emitting layer (3) comprises a first light-emitting unit (31), a second light-emitting unit (32) and a third light-emitting unit (33) with different light-emitting colors, the wavelength of the first light-emitting unit (31) is greater than that of the second light-emitting unit (32), and the wavelength of the second light-emitting unit (32) is greater than that of the third light-emitting unit (33); The first electron blocking layer (2) comprises a first sub-electron blocking unit (21) corresponding to the first light-emitting unit (31), a second sub-electron blocking unit (22) corresponding to the second light-emitting unit (32) and a third sub-electron blocking unit (23) corresponding to the third light-emitting unit (33); The material of the first sub-electron blocking unit (21) and the third sub-electron blocking unit (23) is the same as that of the second sub-electron blocking unit (22). An absolute value of a difference between a HOMO energy level of the second light-emitting unit (32) and a HOMO energy level of the second sub-electron blocking unit (22) ranges from 0.02 eV to 0.04 eV, and an absolute value of a difference between a HOMO energy level of the third light-emitting unit (33) and the HOMO energy level of the second sub-electron blocking unit (22) ranges from 0.02 eV to 0.03 eV.

12. The display panel of claim 11, wherein, The third light-emitting unit (33) comprises a first host material and a second host material. An absolute value of a difference between a HOMO energy level of the first host material of the third light-emitting unit (33) and a HOMO energy level of the second sub-electron blocking unit (22) ranges from 0.02 eV to 0.03 eV; or An absolute value of a difference between a HOMO energy level of the second host material of the third light-emitting unit (33) and a HOMO energy level of the second sub-electron blocking unit (22) ranges from 0.02 eV to 0.03 eV.

13. The display panel of claim 12, wherein, The first host material comprises one of a first N-type material, a first P-type material and a first PN-type material, and the second host material comprises another one of the first N-type material, the first P-type material and the first PN-type material; or the first host material and the second host material are both the first PN-type material. The LUMO energy level of the first N-type material and the LUMO energy level of the first PN-type material both range from -2.05 eV to 3.32 eV, the HOMO energy level of the first P-type material and the HOMO energy level of the first PN-type material both range from -5.46 eV to -6.54 eV, an absolute value of a difference between the HOMO energy level of the first P-type material and the LUMO energy level of the first N-type material is greater than or equal to 2.6 eV, an absolute value of a difference between the HOMO energy level of the first PN-type material and the LUMO energy level of the first PN-type material is greater than or equal to 2.6 eV, and an absolute value of a difference between the LUMO energy level of the first host material and the LUMO energy level of the second host material ranges from 0.2 eV to 0.4 eV.

14. The display panel of claim 13, wherein, A mass ratio of a sum of the first N-type material in the first host material and the first N-type material in the second host material to a sum of the first P-type material in the first host material and the first P-type material in the second host material ranges from 5:5 to 7:

3.

15. The display panel of claim 11, wherein, The light-emitting device further comprises: A second electron blocking layer (5) is arranged corresponding to the first light-emitting unit (31) and is located between the first sub-electron blocking unit (21) and the first light-emitting unit (31).

16. The display panel of claim 11, wherein, The light-emitting device further comprises a third electron blocking layer (11) and a second light-emitting layer (12) which are sequentially stacked; The second light-emitting layer (12) is arranged between the first electron blocking layer (2) and the first electrode (1) or between the first light-emitting layer (3) and the second electrode (4). wherein the second light-emitting layer (12) comprises a fourth light-emitting unit (121), a fifth light-emitting unit (122) and a sixth light-emitting unit (123) having different light-emitting colors, and the light-emitting colors of the fourth light-emitting unit (121), the fifth light-emitting unit (122) and the sixth light-emitting unit (123) are respectively the same as the light-emitting colors of the first light-emitting unit (31), the second light-emitting unit (32) and the third light-emitting unit (33); The third electron blocking layer (11) includes a fourth sub-electron blocking unit (111) corresponding to the fourth light-emitting unit (121), a fifth sub-electron blocking unit (112) corresponding to the fifth light-emitting unit (122), and a sixth sub-electron blocking unit (113) corresponding to the sixth light-emitting unit (123).

17. The display panel of claim 16, wherein, The materials of the fourth sub-electron blocking unit (111) and the sixth sub-electron blocking unit (113) are the same as the material of the fifth sub-electron blocking unit (112); The absolute value of the difference between the HOMO energy level of the fifth light-emitting unit (122) and the HOMO energy level of the fifth sub-electron blocking unit (112) ranges from 0.02 eV to 0.04 eV; the absolute value of the difference between the HOMO energy level of the sixth light-emitting unit (123) and the HOMO energy level of the fifth sub-electron blocking unit (112) ranges from 0.02 eV to 0.03 eV.

18. The display panel of claim 17, wherein, The sixth light-emitting unit (123) comprises: a third host material and a fourth host material; The absolute value of the difference between the HOMO energy level of the third host material of the sixth light-emitting unit (123) and the HOMO energy level of the fifth sub-electron blocking unit (112) ranges from 0.02 eV to 0.03 eV; or The absolute value of the difference between the HOMO energy level of the fourth host material of the sixth light-emitting unit (123) and the HOMO energy level of the fifth sub-electron blocking unit (112) ranges from 0.02 eV to 0.03 eV.

19. The display panel of claim 18, wherein, The third main material includes one of the second N-type material, the second P-type material, and the second PN-type material; the fourth main material includes the other of the second N-type material, the second P-type material, and the second PN-type material; or, both the third main material and the fourth main material are the second PN-type material; The LUMO energy level range of the second N-type material and the second PN-type material is -2.05 eV to 3.32 eV, the HOMO energy level range of the second P-type material and the second PN-type material is -5.46 eV to -6.54 eV, the absolute value of the difference between the HOMO energy level of the second P-type material and the LUMO energy level of the second N-type material is greater than or equal to 2.6 eV, the absolute value of the difference between the HOMO energy level of the second PN-type material and the LUMO energy level of the second PN-type material is greater than or equal to 2.6 eV, and the absolute value of the difference between the LUMO energy level of the third host material and the LUMO energy level of the fourth host material ranges from 0.2 eV to 0.4 eV.

20. The display panel of claim 16, wherein, The light-emitting device further comprises: A fourth electron blocking layer (17) is arranged corresponding to the fourth light-emitting unit (121) and located between the fourth sub-electron blocking unit (111) and the fourth light-emitting unit (121).

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