Light-emitting device, light-emitting apparatus, and display apparatus

Abstract

This invention provides a light-emitting device, a light-emitting apparatus, and a display device, relating to the fields of lighting and display technology. The light-emitting device includes: a substrate; a first light-transmitting layer located on one side of the substrate; a second light-transmitting layer located on the side of the first light-transmitting layer away from the substrate; a first electrode located on the side of the second light-transmitting layer away from the first light-transmitting layer; at least one light-emitting layer located on the side of the first electrode away from the second light-transmitting layer; and a second electrode located on the side of the at least one light-emitting layer away from the first electrode. The light-emitting device emits light in a direction along the second light-transmitting layer towards the first light-transmitting layer, and the refractive index of the first light-transmitting layer is greater than that of the second light-transmitting layer. This light-emitting device can achieve a red-shift of the dominant wavelength, expanding the application range of light-emitting devices.

Description

Technical Field

[0001] This invention relates to the field of lighting and display technology, and in particular to a light-emitting device, a light-emitting apparatus, and a display apparatus. Background Technology

[0002] As organic light-emitting diodes (OLEDs) enter the automotive field, automotive regulations have imposed stricter requirements on their reliability, chromaticity, and dominant wavelength for outdoor use. The dominant wavelength is the wavelength at which the spectral radiant power of the light-emitting device is at its maximum.

[0003] In related technologies, the main wavelength of deep red light-emitting devices is relatively short, which cannot meet the needs of vehicle lights. Summary of the Invention

[0004] The embodiments of the present invention provide a light-emitting device, a light-emitting apparatus, and a display device. The light-emitting device can achieve a redshift of the dominant wavelength, thereby expanding the application range of the light-emitting device.

[0005] The embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, embodiments of this application provide a light-emitting device, comprising:

[0007] Substrate;

[0008] The first light-transmitting layer is located on one side of the substrate;

[0009] The second light-transmitting layer is located on the side of the first light-transmitting layer away from the substrate;

[0010] The first electrode is located on the side of the second light-transmitting layer away from the first light-transmitting layer;

[0011] At least one light-emitting layer is located on the side of the first electrode away from the second light-transmitting layer;

[0012] The second electrode is located on the side of the at least one light-emitting layer away from the first electrode;

[0013] The light-emitting device emits light in a direction along the second light-transmitting layer toward the first light-transmitting layer, and the refractive index of the first light-transmitting layer is greater than the refractive index of the second light-transmitting layer.

[0014] Optionally, along the direction from the second light-transmitting layer to the first light-transmitting layer, the thickness of the first light-transmitting layer ranges from L1+k*T1, where L1 ranges from 80nm to 130nm, k is any natural number, and T1 ranges from 160nm to 180nm.

[0015] Optionally, along the direction from the second light-transmitting layer to the first light-transmitting layer, the thickness of the second light-transmitting layer ranges from L2+k*T2, where L2 ranges from 110nm to 150nm, k is any natural number, and T2 ranges from 160nm to 180nm.

[0016] Optionally, along the direction from the second light-transmitting layer to the first light-transmitting layer, the thickness of the first light-transmitting layer ranges from 80nm to 130nm or from 250nm to 290nm.

[0017] Optionally, along the direction from the second light-transmitting layer to the first light-transmitting layer, the thickness range of the second light-transmitting layer includes 120nm to 140nm or 280nm to 320nm.

[0018] Optionally, the refractive index of the first light-transmitting layer is in the range of 1.9 to 2.2; and the refractive index of the second light-transmitting layer is in the range of 1.4 to 1.6.

[0019] Optionally, the first light-transmitting layer includes at least one first light-transmitting sublayer; the second light-transmitting layer includes at least one second light-transmitting sublayer;

[0020] Along the light emission direction of the light-emitting device, the refractive index of each of the first light-transmitting sub-layers gradually increases, and the refractive index of each of the second light-transmitting sub-layers gradually increases.

[0021] Optionally, the light-emitting device includes one of the light-emitting layers;

[0022] The light-emitting device includes a first carrier injection layer, a first carrier transport layer, a second carrier blocking layer, the light-emitting layer, the first carrier blocking layer, the second carrier transport layer, and the second carrier injection layer, which are stacked sequentially on the first electrode.

[0023] Optionally, the light-emitting device includes two light-emitting layers, which are a first light-emitting layer and a second light-emitting layer, respectively.

[0024] The light-emitting device includes a first carrier injection layer, a first carrier transport layer, a second carrier blocking layer, a first light-emitting layer, a first carrier blocking layer, a second carrier transport layer, a first charge generation layer, a second charge generation layer, a third carrier transport layer, a fourth carrier blocking layer, a second light-emitting layer, a third carrier blocking layer, a fourth carrier transport layer, and a second carrier injection layer, which are stacked sequentially on the first electrode.

[0025] Secondly, embodiments of this application provide a light-emitting device, including any of the light-emitting devices described in the first aspect.

[0026] Thirdly, embodiments of this application provide a display device including any of the light-emitting devices described in the first aspect.

[0027] This application provides a light-emitting device, a light-emitting apparatus, and a display device. The light-emitting device includes: a substrate; a first light-transmitting layer located on one side of the substrate; a second light-transmitting layer located on the side of the first light-transmitting layer away from the substrate; a first electrode located on the side of the second light-transmitting layer away from the first light-transmitting layer; at least one light-emitting layer located on the side of the first electrode away from the second light-transmitting layer; and a second electrode located on the side of the at least one light-emitting layer away from the first electrode. The light-emitting direction of the light-emitting device is along the second light-transmitting layer towards the first light-transmitting layer, and the refractive index of the first light-transmitting layer is greater than the refractive index of the second light-transmitting layer.

[0028] In this way, along the light emission direction of the light-emitting device, the refractive index of the second light-transmitting layer is less than that of the first light-transmitting layer. This can increase the reflection effect at the interface between the first and second light-transmitting layers, increase the intensity of reflected light between the first and second light-transmitting layers, and thus enhance the microcavity effect of the light-emitting device. This can enhance the coupling efficiency of the deep red light emitted by the light-emitting device, achieve a red shift of the dominant wavelength of the light-emitting device, and expand the application range of the light-emitting device. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of a light-emitting device provided in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of another light-emitting device provided in an embodiment of the present invention;

[0032] Figure 3 A schematic diagram illustrating the principle of the microcavity effect in a light-emitting device provided in an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the structure of a light-emitting device with multiple light-transmitting sub-layers provided in an embodiment of the present invention;

[0034] Figure 5 A chromaticity diagram provided in an embodiment of the present invention;

[0035] Figure 6A graph showing the variation of the x-coordinate of the chromaticity diagram of a light-emitting device with the thickness of the hole transport layer, provided for an embodiment of the present invention.

[0036] Figure 7 This is a schematic diagram of the structure of a stacked light-emitting device provided in an embodiment of the present invention;

[0037] Figure 8 This is a schematic diagram of another stacked light-emitting device provided in an embodiment of the present invention. Detailed Implementation

[0038] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0039] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this application. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific feature, structure, material, or characteristic may be included in any suitable manner in any one or more embodiments or examples.

[0040] Additionally, it should be noted that when describing the elements and embodiments thereof in this application, the articles “a,” “an,” “the,” and “the” are intended to indicate the presence of one or more elements; unless otherwise stated, “multiple” means two or more; the terms “comprising,” “including,” “containing,” and “having” are intended to be inclusive and indicate that additional elements may exist besides those listed; the terms “first,” “second,” “third,” etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or order of formation.

[0041] In related technologies, the emission wavelength range of red light-emitting devices includes 610nm to 650nm, and the main wavelength range of the light-emitting devices includes 610nm to 626nm. However, the regulations related to vehicle devices and accessories require the main wavelength of dark red taillights to reach 630nm. The light-emitting devices in related technologies cannot meet the regulatory requirements for dark red taillights.

[0042] Based on this, embodiments of this application provide a light-emitting device, referring to... Figure 1 The device includes: a substrate 1; a first light-transmitting layer 2 located on one side of the substrate 1; a second light-transmitting layer 3 located on the side of the first light-transmitting layer 2 away from the substrate 1; a first electrode 4 located on the side of the second light-transmitting layer 3 away from the first light-transmitting layer 2; at least one light-emitting layer 8 located on the side of the first electrode 4 away from the second light-transmitting layer 3; and a second electrode 12 located on the side of at least one light-emitting layer 8 away from the first electrode 4. The light emission direction of the light-emitting device is along the second light-transmitting layer 3 towards the first light-transmitting layer 2, and the refractive index of the first light-transmitting layer 2 is greater than the refractive index of the second light-transmitting layer 3.

[0043] In this application embodiment, the light-emitting device includes an OLED (Organic Light Emitting Diode) light-emitting device.

[0044] In some embodiments, refer to Figure 1 The light-emitting device can be a bottom-emitting structure light-emitting device, the substrate 1 can be a substrate, and the light emission direction of the light-emitting device is along the light-emitting layer 8 towards the substrate.

[0045] The substrate can be a flexible substrate, for example, a flexible glass substrate; or the substrate can be a rigid substrate, i.e., a substrate that cannot be bent, for example, a rigid glass substrate.

[0046] In other embodiments, reference is made to Figure 2 The light-emitting device can be a top-emitting structure light-emitting device, the substrate 1 can be an encapsulation layer, and the light emission direction of the light-emitting device is along the light-emitting layer 8 towards the encapsulation layer.

[0047] The encapsulation layer can be an organic encapsulation layer; or, the encapsulation layer can be an inorganic encapsulation layer.

[0048] In this embodiment, the first light-transmitting layer 2 includes a buffer layer. The material of the first light-transmitting layer 2 includes a light-transmitting material, which can be an inorganic light-transmitting material. For example, the material of the first light-transmitting layer 2 can be silicon oxide (SiO2). x For example, silicon dioxide; or, the light-transmitting material can be an organic light-transmitting material, which is not specifically limited in the embodiments of this application.

[0049] In some embodiments, the first light-transmitting layer 2 is a single-layer structure; in other embodiments, the first light-transmitting layer 2 includes multiple sublayers.

[0050] In this embodiment, the second light-transmitting layer 3 includes a passivation layer, and the material of the second light-transmitting layer 3 includes a light-transmitting material. The light-transmitting material can be an inorganic light-transmitting material; for example, the material of the second light-transmitting layer 3 can be silicon nitride (Si). x N yAlternatively, the light-transmitting material can be an organic light-transmitting material, which is not specifically limited in this application embodiment.

[0051] In some embodiments, the second light-transmitting layer 3 is a single-layer structure; in other embodiments, the second light-transmitting layer 3 includes multiple sublayers.

[0052] In this embodiment of the application, the refractive index of the first light-transmitting layer 2 is greater than the refractive index of the second light-transmitting layer 3. For example, the difference between the refractive index of the second light-transmitting layer 3 and the refractive index of the first light-transmitting layer 2 can be in the range of 0.3 to 0.8. For example, the difference between the refractive index of the second light-transmitting layer 3 and the refractive index of the first light-transmitting layer 2 can be 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8.

[0053] In the embodiments of this application, reference is made to Figure 3 The second electrode 12 has good reflectivity, and a resonant cavity can be formed between the second electrode 12 and the first light-transmitting layer 2. The light-emitting layer of the light-emitting device emits light rays L1 and L2, which undergo reflection, refraction, and interference effects within the resonant cavity formed by the first light-transmitting layer 2 and the second electrode 12. Figure 3 The thickness of the light rays indicates their relative intensity. Since the refractive index of the second light-transmitting layer 3 is less than that of the first light-transmitting layer 2, the reflection effect of the first light-transmitting layer 2 is stronger along the light-emitting direction. The intensity of the reflected light L3 from the first light-transmitting layer 2 increases, while the intensity of the light ray L4 emitted directly from the first light-transmitting layer decreases. The intensity of the light rays that undergo multiple reflections, refractions, and interference effects within the resonant cavity increases, enhancing the microcavity effect of the light-emitting device. This can improve the coupling efficiency of the deep red light emitted by the light-emitting device and achieve a redshift of the dominant wavelength of the light-emitting device.

[0054] For example, taking the emission of red light from the light-emitting layer 8 as an example, the main wavelength range of the light-emitting device in the related technology is 620nm to 626nm. For the same red light-emitting material, the main wavelength range of the light-emitting device in this application is 627nm to 633nm.

[0055] For example, the main wavelength of the light-emitting device in this application can be 627±2nm, 628±2nm, 629±2nm, 630±2nm, 631±2nm, 632±2nm or 633±2nm;

[0056] For example, the main wavelength of the light-emitting device in this application can be 627±1nm, 628±1nm, 629±1nm, 630±1nm, 631±1nm, 632±1nm or 633±1nm.

[0057] In an exemplary embodiment, the first electrode 4 can be an anode and the second electrode 12 can be a cathode.

[0058] For example, the material of the first electrode 4 includes a light-transmitting metal oxide, such as indium tin oxide (ITO) or indium zinc oxide (IZO).

[0059] Along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2, the thickness of the first electrode 4 is not specifically limited in this embodiment; for example, the thickness of the first electrode 4 can be in the range of 60nm to 80nm, such as 60nm, 63nm, 66nm, 70nm, 73nm, 76nm or 80nm.

[0060] For example, the material of the second electrode 12 can be a metal, such as at least one of aluminum (Al), silver (Ag) and magnesium (Mg);

[0061] For example, the material of the second electrode 12 can be an alloy, such as at least one of magnesium-silver alloy, magnesium-aluminum alloy and aluminum-silver alloy.

[0062] Along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2, the thickness of the second electrode 12 is not specifically limited in this embodiment; for example, the thickness of the second electrode 12 is in the range of 80nm to 100nm, for example, the thickness of the second electrode 12 can be 80nm, 90nm, 100nm, 110nm or 120nm.

[0063] In some embodiments, refer to Figure 1 The light-emitting device includes a light-emitting layer;

[0064] In other embodiments, the light-emitting device includes at least two light-emitting layers, for example, as shown in the reference. Figure 7 The light-emitting device includes two light-emitting layers; for example, refer to Figure 8 The light-emitting device consists of three light-emitting layers.

[0065] The specific color of the light-emitting layer 8 is not limited here. For example, the light-emitting layer 8 may emit red light; or, the light-emitting layer 8 may emit green light; or, the light-emitting layer 8 may emit blue light.

[0066] In an exemplary embodiment, the light-emitting layer 8 can emit red light.

[0067] For example, the red luminescent material may include any one or more of the following: red fluorescent luminescent host material, red fluorescent luminescent dye, red phosphorescent luminescent host material, red phosphorescent luminescent dye, undoped red luminescent material, and red quantum dot material.

[0068] In an exemplary embodiment, the light-emitting layer 8 can emit green light.

[0069] For example, green luminescent materials may include any one or more of the following: coumarin dyes, quinacrine copper derivatives, polycyclic aromatic hydrocarbons, diamine anthracene derivatives, carbazole derivatives, and metal complexes.

[0070] In an exemplary embodiment, the light-emitting layer 8 can emit blue light.

[0071] For example, blue luminescent materials may include any one or more of pyrene derivatives, anthracene derivatives, fluorene derivatives, perylene derivatives, styrene-amine derivatives, and metal complexes.

[0072] In an exemplary embodiment, the material of the light-emitting layer 8 includes a host material and a guest material. The host material has good hole and electron transport capabilities, good thermal stability and film-forming properties, and accounts for a large proportion in the light-emitting layer 8; the guest material accounts for a small proportion in the light-emitting layer 8.

[0073] For example, the red light host material is preferably a high glass transition temperature (Tg) material, and the host material includes a bipolar red light host material or a mixed host material of hole-type and electron-type materials; the red light guest material is preferably an iridium-based or platinum-based small molecule red phosphorescent dye.

[0074] In some embodiments, the light-emitting layer 8 includes one host material and one guest material; in other embodiments, the light-emitting layer 8 includes two host materials and one guest material.

[0075] Along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2, the thickness of the light-emitting layer 8 is not specifically limited in this embodiment; for example, the thickness of the light-emitting layer 8 is in the range of 40nm to 80nm. For example, the thickness of the second electrode 12 can be 40nm, 50nm, 60nm, 70nm or 80nm.

[0076] This application provides a light-emitting device, referring to... Figure 1The device includes: a substrate 1; a first light-transmitting layer 2 located on one side of the substrate 1; a second light-transmitting layer 3 located on the side of the first light-transmitting layer 2 away from the substrate 1; a first electrode 4 located on the side of the second light-transmitting layer 3 away from the first light-transmitting layer 2; at least one light-emitting layer 8 located on the side of the first electrode 4 away from the second light-transmitting layer 3; and a second electrode 12 located on the side of the at least one light-emitting layer 8 away from the first electrode 4. The light emission direction of the light-emitting device is along the second light-transmitting layer 3 towards the first light-transmitting layer 2, and the refractive index of the first light-transmitting layer 2 is greater than the refractive index of the second light-transmitting layer 3. Thus, along the light emission direction of the light-emitting device, the refractive index of the second light-transmitting layer 3 is less than the refractive index of the first light-transmitting layer 2, which increases the reflectivity of the first light-transmitting layer 2, increases the intensity of reflected light from the first light-transmitting layer 2, and further enhances the microcavity effect of the light-emitting device. This enhances the coupling efficiency of deep red light from the light-emitting device, achieves a redshift of the dominant wavelength of the light-emitting device, and expands the application range of the light-emitting device.

[0077] In some embodiments of this application, reference is made to Figure 1 Along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2, the thickness d1 of the first light-transmitting layer 2 is in the range of L1+k*T1, where L1 is in the range of 80nm~130nm, k is any natural number, and T1 is in the range of 160nm~180nm.

[0078] The range of L1 is 80nm to 130nm. For example, L1 can be 80±5nm, 90±5nm, 100±5nm, 110±5nm, 120±5nm or 130±5nm.

[0079] For example, L1 can be 80±2nm, 90±2nm, 100±2nm, 110±2nm, 120±2nm or 130±2nm;

[0080] It should be noted that the value of L1 can have some process fluctuations, for example, the value of L1 and the above center value have a process fluctuation of 3% or 5%.

[0081] The range of T1 is 160nm to 180nm. For example, T1 can be 160±5nm, 163±5nm, 166±5nm, 170±5nm, 173±5nm, 176±5nm or 180±5nm.

[0082] For example, T1 can be 160±2nm, 163±2nm, 166±2nm, 170±2nm, 173±2nm, 176±2nm or 180±2nm;

[0083] It should be noted that the value of T1 may have some process fluctuations, for example, the value of T1 and the above center value may have a process fluctuation of 3% or 5%.

[0084] k is any natural number, for example, k can be 0, 1, 2, 3, 4 or 5. Taking L1 as 110±5nm and T1 as 170nm as an example, the thickness d1 of the first light-transmitting layer 2 can be 110±5nm, 290±5nm, 450±5nm, 620±5nm or 890±5nm.

[0085] In some embodiments of this application, the thickness d1 of the first light-transmitting layer 2 is in the range of 80nm~130nm or 250nm~290nm along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2.

[0086] For example, the thickness d1 of the first light-transmitting layer 2 can be 80nm, 90nm, 100nm, 110nm, 120nm or 130nm; or, the thickness d1 of the first light-transmitting layer 2 can be 250nm, 260nm, 270nm, 280nm or 290nm.

[0087] It should be noted that the above thickness values ​​are average values. The thickness d1 of the first light-transmitting layer 2 may have certain process fluctuations. For example, the thickness d1 value and the above average value have a process fluctuation of 3% or 5%.

[0088] In this embodiment, along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2, the thickness d1 of the first light-transmitting layer 2 ranges from L1 + k * T1, where L1 ranges from 80 nm to 130 nm, k is any natural number, and T1 ranges from 160 nm to 180 nm. Thus, along the light emission direction of the light-emitting device, the refractive index of the second light-transmitting layer 3 is less than that of the first light-transmitting layer 2, which increases the reflectivity of the first light-transmitting layer 2, increases the intensity of reflected light, and further enhances the microcavity effect of the light-emitting device. This enhances the coupling efficiency of deep red light from the light-emitting device, achieves a redshift of the dominant wavelength of the light-emitting device, and expands the application range of the light-emitting device.

[0089] In some embodiments of this application, reference is made to Figure 1 Along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2, the thickness d2 of the second light-transmitting layer 3 is in the range of L2+k*T2, where L2 is in the range of 110nm~150nm, k is any natural number, and T2 is in the range of 160nm~180nm.

[0090] The L2 range is 110 to 150 nm. For example, L2 can be 110±5 nm, 120±5 nm, 125±5 nm, 130±5 nm, 135±5 nm, 140±5 nm, or 150±5 nm.

[0091] For example, L2 can be 110±2nm, 120±2nm, 125±2nm, 130±2nm, 135±2nm, 140±2nm, or 150±2nm;

[0092] It should be noted that the value of L2 can have some process fluctuations, for example, the value of L2 and the above center value have a process fluctuation of 3% or 5%.

[0093] The range of T2 is 160nm to 180nm. For example, T2 can be 160±5nm, 163±5nm, 166±5nm, 170±5nm, 173±5nm, 176±5nm, or 180±5nm.

[0094] For example, T2 can be 160±2nm, 163±2nm, 166±2nm, 170±2nm, 173±2nm, 176±2nm, or 180±2nm;

[0095] It should be noted that the value of T2 can have some process fluctuations, for example, the value of T2 and the above center value have a process fluctuation of 3% or 5%.

[0096] k is any natural number, for example, k can be 0, 1, 2, 3, 4 or 5. Taking L2 as 130±5nm and T1 as 170nm as an example, the thickness d2 of the second transparent layer 3 can be 130±5nm, 300±5nm, 470±5nm, 640±5nm or 910±5nm.

[0097] In some embodiments of this application, the thickness d2 of the second light-transmitting layer 3 in the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2 ranges from 120nm to 140nm or from 280 to 320nm.

[0098] For example, the thickness d2 of the second light-transmitting layer 3 can be 120nm, 123nm, 126nm, 130nm, 133nm, 136nm or 140nm; or, the thickness d2 of the second light-transmitting layer 3 can be 280nm, 290nm, 295nm, 300nm, 305nm, 310nm or 220nm.

[0099] It should be noted that the above thickness values ​​are average values. The thickness d2 of the second light-transmitting layer 3 may have certain process fluctuations. For example, the thickness d2 value and the above average value have a process fluctuation of 3% or 5%.

[0100] In this embodiment, along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2, the thickness d2 of the second light-transmitting layer 3 ranges from L2 to k*T2, where L2 ranges from 110nm to 150nm, k is any natural number, and T2 ranges from 160nm to 180nm. Thus, along the light emission direction of the light-emitting device, the refractive index of the second light-transmitting layer 3 is less than that of the first light-transmitting layer 2, which can increase the reflection effect of the first light-transmitting layer 2, increase the intensity of reflected light from the first light-transmitting layer 2, and thus enhance the microcavity effect of the light-emitting device. This can enhance the coupling efficiency of deep red light from the light-emitting device, achieve a redshift of the dominant wavelength of the light-emitting device, and expand the application range of the light-emitting device.

[0101] In some embodiments of this application, the refractive index of the first light-transmitting layer 2 is in the range of 1.9 to 2.2; and the refractive index of the second light-transmitting layer 3 is in the range of 1.4 to 1.6.

[0102] For example, the refractive index of the first light-transmitting layer 2 can be 1.9, 1.95, 2.0, 2.1, 2.15, or 2.2;

[0103] For example, the material of the first light-transmitting layer 2 is silicon nitride (Si). x N y The refractive index of the first light-transmitting layer 2 can be 2.0.

[0104] For example, the refractive index of the second light-transmitting layer 3 can be 1.4, 1.43, 1.46, 1.5, 1.53, 1.56, or 1.6;

[0105] For example, the material of the second light-transmitting layer 3 is silicon oxide (SiO2). x The refractive index of the second transparent layer 3 can be 1.457.

[0106] In this embodiment, the refractive index of the first light-transmitting layer 2 ranges from 1.9 to 2.2; the refractive index of the second light-transmitting layer 3 ranges from 1.4 to 1.6. Thus, along the light emission direction of the light-emitting device, the refractive index of the second light-transmitting layer 3 is less than that of the first light-transmitting layer 2, which can increase the reflection effect of the first light-transmitting layer 2, increase the intensity of reflected light from the first light-transmitting layer 2, and thus enhance the microcavity effect of the light-emitting device. This can enhance the coupling efficiency of deep red light from the light-emitting device, achieve a redshift of the dominant wavelength of the light-emitting device, and expand the application range of the light-emitting device.

[0107] In some embodiments of this application, the first light-transmitting layer 2 includes at least one first light-transmitting sublayer; the second light-transmitting layer 3 includes at least one second light-transmitting sublayer;

[0108] Along the light emission direction of the light-emitting device, the refractive index of each first phototransparent layer gradually increases, and the refractive index of each second phototransparent layer gradually increases.

[0109] In this embodiment of the application, the sum of the number of the first phototransparent layer and the second phototransparent layer is greater than or equal to 3;

[0110] For example, the first light-transmitting layer 2 includes a first light-transmitting sublayer, and the second light-transmitting layer 3 includes at least two second light-transmitting sublayers;

[0111] For example, the first light-transmitting layer 2 includes at least two first light-transmitting sublayers, and the second light-transmitting layer 3 includes at least two second light-transmitting sublayers;

[0112] For example, the first light-transmitting layer 2 includes at least two first light-transmitting sublayers, and the second light-transmitting layer 3 includes at least two second light-transmitting sublayers.

[0113] For example, refer to Figure 4 The first light-transmitting layer 2 includes two first light-transmitting sublayers 201 and 202, and the second light-transmitting layer 3 includes two second light-transmitting sublayers 301 and 302. Along the light-emitting direction of the light-emitting device, the refractive index of the light-transmitting sublayer 301 is less than the refractive index of the light-transmitting sublayer 302, and the refractive index of the light-transmitting sublayer 201 is less than the refractive index of the light-transmitting sublayer 202.

[0114] In this embodiment, the first light-transmitting layer 2 includes at least one first light-transmitting sublayer; the second light-transmitting layer 3 includes at least one second light-transmitting sublayer; along the light emission direction of the light-emitting device, the refractive index of each first light-transmitting sublayer gradually increases, and the refractive index of each second light-transmitting sublayer gradually increases; thus, the reflection effect of the interface between each first light-transmitting sublayer increases, and the reflection effect of the interface between each second light-transmitting sublayer increases, which can further increase the intensity of reflected light in each first light-transmitting sublayer or each second light-transmitting sublayer, thereby enhancing the microcavity effect of the light-emitting device, enhancing the coupling light emission efficiency of deep red light of the light-emitting device, realizing the red shift of the main wavelength of the light-emitting device, and expanding the application range of the light-emitting device.

[0115] In some embodiments of this application, reference is made to Figure 1 The light-emitting device includes a first carrier injection layer 5, a first carrier transport layer 6, a second carrier blocking layer 7, a light-emitting layer 8, a first carrier blocking layer 9, a second carrier transport layer 10, and a second carrier injection layer 11, which are stacked sequentially on the first electrode 4.

[0116] In an exemplary embodiment, the first electrode 4 can be an anode, the first charge carrier can be a hole, and the second electrode 12 can be a cathode, the second charge carrier can be an electron. (Refer to...) Figure 1 The light-emitting device includes a substrate 1, a first light-transmitting layer 2, a second light-transmitting layer 3, an anode 4, a hole injection layer 5, a hole transport layer 6, an electron blocking layer 7, a light-emitting layer 8, a hole blocking layer 9, an electron transport layer 10, an electron injection layer 11, and a cathode 12.

[0117] In an exemplary embodiment, the hole injection layer 5 is used to reduce the hole injection barrier and improve the hole injection efficiency. For example, the material of the hole injection layer 5 (HIL) includes one of the following: organic small molecule materials, polymer materials, polymer materials, and inorganic materials with hole injection properties; for example, the material of the hole injection layer 5 can be hexaazatriphenyl diacetonitrile (HAT-CN), tetrafluoro-tetracyano-dimethyl-p-benzoquinone (F4-TCNQ), or 7,7,8,8-tetracyanobenzoquinone dimethane (TCNQ); or, the material of the hole injection layer 3 can be a doped material, such as NPB:PD [N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'biphenyl-4,4'-diamine], where PD represents the injection type material, and PD can be one of HATCN, F4-TCNQ, or TCNQ; the concentration of PD in the doped material ranges from 0.5% to 10%, for example, the concentration of PD can be 0.5%, 1%, 2%, 5%, 8%, or 10%.

[0118] Along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2, the thickness of the hole injection layer 5 is not specifically limited in this embodiment; for example, the thickness of the hole injection layer 5 is in the range of 5nm to 15nm, for example, the thickness of the second electrode 12 can be 5nm, 7nm, 9nm, 10nm, 12nm or 15nm.

[0119] In an exemplary embodiment, the material of the hole transport layer 6 comprises an organic small molecule material with hole transport properties; for example, the material of the hole transport layer 6 comprises NPB [N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'biphenyl-4,4'-diamine], α-NPD [2,2'-dimethyl-N4,N4'-di(naphthyl-1-yl)-N4,N4'-diphenyl-[1,1'-biphenyl]-4,4'-diamine] or TAPC [4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline]].

[0120] Along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2, the thickness of the hole transport layer 6 is not specifically limited in this embodiment; for example, the thickness of the hole transport layer 6 is in the range of 200nm to 300nm. For example, the thickness of the second electrode 12 can be 200nm, 220nm, 240nm, 250nm, 270nm or 300nm.

[0121] In an exemplary embodiment, the electron barrier layer 7 (EBL) is made of organic small molecule materials or polymer materials with electron transport properties, wherein the LUMO (Lowest Unoccupied Molecular Orbital) energy level of the electron barrier layer 7 material is >-2.3 eV, and the T1 (first triplet state energy level) is >2.2 eV; for example, the electron barrier layer 7 material includes TCTA [4,4',4'-tris(carbazole-9-yl)triphenylamine].

[0122] Along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2, the thickness of the electron blocking layer 7 is not specifically limited in this embodiment; for example, the thickness of the electron blocking layer 7 is in the range of 30nm to 50nm. For example, the thickness of the second electrode 12 can be 30nm, 35nm, 40nm, 43nm, 46nm or 50nm.

[0123] In an exemplary embodiment, the material of the hole barrier layer 9 (HBL) comprises an organic small molecule material with hole transport properties; for example, the material of the hole barrier layer 9 comprises BCP [2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline].

[0124] Along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2, the thickness of the hole blocking layer 9 is not specifically limited in this embodiment; for example, the thickness of the hole blocking layer 9 is in the range of 2nm to 7nm. For example, the thickness of the second electrode 12 can be 2nm, 3nm, 4nm, 5nm, 6nm or 7nm.

[0125] In an exemplary embodiment, the electron transport layer 10 (ETL) is made of small organic molecules, polymers, or other materials with electron transport properties. Specifically, the material of the electron transport layer 10 may be [8-hydroxyquinoline and aluminum] (Alq3), [4,7-diphenyl-1,10-phenanthroline] (Bphen), or [1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene] (TPBi).

[0126] Along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2, the thickness of the electron transport layer 10 is not specifically limited in this embodiment; for example, the thickness of the electron transport layer 10 ranges from 20nm to 40nm, such as 20nm, 23nm, 26nm, 30nm, 33nm, 36nm or 40nm.

[0127] In an exemplary embodiment, the electron injection layer 11 (EIL) is made of a metal or metal oxide material with electron injection properties; for example, the material of the electron injection layer 11 includes ytterbium (Yb), lithium (Li), 8-hydroxyquinoline-lithium (Liq), and cesium carbonate (CsCO3).

[0128] Along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2, the thickness of the electron injection layer 11 is not specifically limited in this embodiment; for example, the thickness of the electron injection layer 11 ranges from 0.5nm to 2nm. For example, the thickness of the electron transport layer 10 can be 0.5nm, 0.7nm, 0.9nm, 1nm, 1.3nm, 1.6nm or 2nm.

[0129] Reference Figure 1 Below are the specific structures of some single-layer light-emitting devices and the corresponding test data for each device:

[0130] Control group 1: First light-transmitting layer 2 (SiO2) x ), second light-transmitting layer 3 (SiO) x ), anode 4 (ITO, 70nm), hole injection layer 5 (NPB:3%PD, 10nm), hole transport layer 6 (NPB, 200nm), electron blocking layer 7 (TCTA, 40nm), light emitting layer 8 (RH1:RH2:4%RD, 60nm, where RH1 represents the first host material, RH2 represents the second host material, and RD represents the guest material), hole blocking layer 9 (BCP, 5nm), electron transport layer 10 (Bphen:Liq(7:3), 30nm), electron injection layer 11 (Yb, 1nm), cathode 12 (Al, 100nm).

[0131] Control group 2: First light-transmitting layer 2 (Si) x N y ), second light-transmitting layer 3 (Si) x N y The rest was the same as control group 1.

[0132] Control group 3: First light-transmitting layer 2 (O x ), second light-transmitting layer 3 (Si) x N y The rest was the same as control group 1.

[0133] Experimental group 1: First light-transmitting layer 2 (Si) x N y 290nm), second transparent layer 3 (SiO) x100nm, 80nm), 250nm, 70nm, 80nm, 80nm, 70nm, 80nm, 80nm, 90nm, 1 ...

[0134] Experimental group 2: First light-transmitting layer 2 (Si) x N y 315nm), second transparent layer 3 (SiO) x (80nm), otherwise the same as experimental group 1.

[0135] Experimental group 3: First light-transmitting layer 2 (Si) x N y 300nm), second transparent layer 3 (SiO) x (100nm), otherwise the same as experimental group 1.

[0136] Experimental group 4: First light-transmitting layer 2 (Si) x N y 300nm), second transparent layer 3 (SiO) x (130nm), otherwise the same as experimental group 1.

[0137] Table 1. Performance test results of single-layer red light-emitting devices

[0138] Voltage efficiency CIE-x Dominant wavelength (nm) Control group 1 100％ 100％ 0.702 626 Control group 2 100％ 100％ 0.702 626 Control group 3 100％ 100％ 0.702 626 Experimental group 1 100％ 103％ 0.707 630 Experimental group 2 100％ 110％ 0.708 630 Experimental group 3 100％ 110％ 0.708 630 Experimental group 4 100％ 109％ 0.708 630

[0139] Wherein, voltage and efficiency are normalized parameters based on data from control group 1; the CIE color system is the color system developed by the International Commission on Illumination. The CIE color system uses red, green, and blue as three primary colors, and all other colors are derived from these three colors, as referenced. Figure 5 CIE-x is the x-chromaticity coordinate of the emission color of the light-emitting device in the chromaticity diagram. The larger the value of CIE-x, the redder the color.

[0140] According to the data in Table 1, compared to the related technologies where the refractive index of the first light-transmitting layer 2 is greater than or equal to the refractive index of the second light-transmitting layer 3, the scheme provided in the embodiment of this application, where the refractive index of the first light-transmitting layer 2 is greater than the refractive index of the second light-transmitting layer 3, can increase the reflectivity of the first light-transmitting layer 2 while keeping the voltage of the light-emitting device constant. This increases the intensity of the reflected light from the first light-transmitting layer 2, thereby enhancing the microcavity effect of the light-emitting device. It can also enhance the coupling efficiency of deep red light from the light-emitting device, achieving a redshift of the dominant wavelength of the light-emitting device from 626nm to 630nm. Furthermore, in the embodiment of this application, the CIE-x of the emitted color of the light-emitting device is increased, expanding the color gamut range of the light-emitting device.

[0141] Figure 5 The curves showing the relationship between the thickness of the hole transport layer (HTL) and CIE-x for control group 1, control group 2, control group 3 and experimental group 1 are shown. Figure 5 The horizontal axis represents the thickness of the HTL layer, and the vertical axis represents CIE-x.

[0142] according to Figure 6 For the same range of hole transport layer thickness, Embodiment 1 of this application can significantly extend the CIE-x range of the light-emitting device.

[0143] In some embodiments of this application, the light-emitting device includes two light-emitting layers, namely a first light-emitting layer 8 and a second light-emitting layer 17.

[0144] The light-emitting device includes a first carrier injection layer 5, a first carrier transport layer 6, a second carrier blocking layer 7, a first light-emitting layer 8, a first carrier blocking layer 9, a second carrier transport layer 10, a first charge generation layer 13, a second charge generation layer 14, a third carrier transport layer 15, a fourth carrier blocking layer 16, a second light-emitting layer 17, a third carrier blocking layer 18, a fourth carrier transport layer 19, and a second carrier injection layer 12, which are stacked sequentially on the first electrode 4.

[0145] In an exemplary embodiment, the first electrode 4 can be an anode, the first and third charge carriers can be holes, the first charge generation layer 14 can be an N-type charge generation layer, the second charge generation layer 15 can be a P-type charge generation layer, the second electrode 12 can be a cathode, and the second and fourth charge carriers can be electrons. (Refer to...) Figure 7The light-emitting device includes a substrate 1, a first light-transmitting layer 2, a second light-transmitting layer 3, an anode 4, a hole injection layer 5, a first hole transport layer 6, a first electron blocking layer 7, a first light-emitting layer 8, a first hole blocking layer 9, a first electron transport layer 10, a first N-type charge generating layer 13, a first P-type charge generating layer 14, a second hole transport layer 15, a second electron blocking layer 16, a second light-emitting layer 17, a second hole blocking layer 18, a second electron transport layer 19, an electron injection layer 11, and a cathode 12.

[0146] In an exemplary embodiment, the material of the N-type charge generation layer 13 (CGL) can be a single material; for example, the material of the N-type charge generation layer 13 includes graphene (C60).

[0147] Alternatively, the material of the N-type charge generation layer 13 can be a mixed material. For example, the mixed material includes a mixture of a material with electron transport properties and ytterbium (Yb) and lithium (Li). For example, the concentration of ytterbium can be 1% and the concentration of lithium can be 0.5%.

[0148] Along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2, the thickness of the N-type charge generation layer 13 is not specifically limited in this embodiment; for example, the thickness of the N-type charge generation layer 13 is in the range of 10nm to 30nm. For example, the thickness of the electron transport layer 10 can be 10nm, 13nm, 16nm, 20nm, 23nm, 26nm or 30nm.

[0149] In an exemplary embodiment, the material of the P-type charge generation layer 14 (CGL) can be a single material. For example, the material of the P-type charge generation layer 14 can be copper phthalocyanine (CuPc).

[0150] Alternatively, the material of the P-type charge generation layer 14 can be a hybrid material, which includes a mixture of a material with hole transport properties and a material PD with hole injection properties (PD can be one of HATCN, F4-TCNQ, and TCNQ), wherein the concentration of PD can be in the range of 5% to 10%, for example, the concentration of PD can be 5%, 6%, 7%, 8%, 9%, and 10%.

[0151] Along the direction from the second light-transmitting layer 3 to the first light-transmitting layer 2, the thickness of the P-type charge generation layer 14 is not specifically limited in this embodiment; for example, the thickness of the P-type charge generation layer 14 is in the range of 5nm to 30nm. For example, the thickness of the electron transport layer 10 can be 5nm, 10nm, 15nm, 20nm, 25nm or 30nm.

[0152] Reference Figure 7 Below are the specific structures of some stacked light-emitting devices and the corresponding test data for each device:

[0153] Experimental group 5: First light-transmitting layer 2 (Si) x N y 290nm), second transparent layer 3 (SiO) x 80nm), Anode 4 (ITO, 70nm), Hole injection layer 5 (NPB: 3% PD, 10nm), First hole transport layer 6 (NPB, 250nm), First electron blocking layer 7 (TCTA, 40nm), First light-emitting layer 8 (RH1:RH2:4% RD, 60nm, where RH1 represents the first host material, RH2 represents the second host material, and RD represents the guest material), First hole blocking layer 9 (BCP, 5nm), First electron transport layer 10 (Bphen: 30% Liq, 30nm), N-type charge The structure includes a generation layer 13 (Bphen: 1% Yb, 20 nm), a P-type charge generation layer 14 (NPB: 10% PD, 10 nm), a second hole transport layer 15 (NPB, 30 nm), a second electron blocking layer 16 (TCTA, 40 nm), a second light-emitting layer 17 (RH1:RH2: 4% RD, 60 nm), a second hole blocking layer 18 (BCP, 5 nm), a second electron transport layer 19 (Bphen: 30% Liq, 30 nm), an electron injection layer 11 (Yb, 1 nm), and a cathode 12 (Al, 100 nm).

[0154] Experimental group 6: First light-transmitting layer 2 (Si) x N y 315nm), second transparent layer 3 (SiO) x (80nm), other films are the same as in experimental group 5.

[0155] Experimental group 7: First light-transmitting layer 2 (Si) x N y 300nm), second transparent layer 3 (SiO) x (100nm), other films are the same as in experimental group 5.

[0156] Experimental group 8: First light-transmitting layer 2 (Si) x N y 300nm), second transparent layer 3 (SiO) x (130nm), other films are the same as in experimental group 5.

[0157] Table 2. Performance test results of the stacked red light-emitting device

[0158] Voltage efficiency CIE-x Dominant wavelength (nm) Example 5 180％ 218％ 0.709 630 Example 6 180％ 220％ 0.708 630 Example 7 180％ 221％ 0.709 630 Example 8 180％ 216％ 0.708 630

[0159] Where voltage and efficiency are normalized parameters based on data from control group 1;

[0160] Combining the data in Tables 1 and 2, it can be seen that, compared to the refractive index of the first light-transmitting layer 2 being less than or equal to the refractive index of the second light-transmitting layer 3 in related technologies, the scheme provided by the embodiments of this application, in which the refractive index of the first light-transmitting layer 2 is greater than the refractive index of the second light-transmitting layer 3, can increase the reflectivity of the first light-transmitting layer 2, increase the intensity of reflected light between the first light-transmitting layer 2 and the second light-transmitting layer 3, thereby enhancing the microcavity effect of the light-emitting device, enhancing the coupling efficiency of deep red light from the light-emitting device, achieving a redshift of the dominant wavelength of the light-emitting device, and effectively improving the dominant wavelength of the light-emitting device, increasing the dominant wavelength of the light-emitting device in related technologies from 626nm to 630nm.

[0161] In some embodiments of this application, the light-emitting device includes three light-emitting layers, as shown in the reference. Figure 8 The three light-emitting layers are the first light-emitting layer 8, the second light-emitting layer 17, and the third light-emitting layer 24, respectively.

[0162] The light-emitting device includes a first carrier injection layer 5, a first carrier transport layer 6, a second carrier blocking layer 7, a first light-emitting layer 8, a first carrier blocking layer 9, a second carrier transport layer 10, a first charge generation layer 13, a second charge generation layer 14, a third carrier transport layer 15, a fourth carrier blocking layer 16, a second light-emitting layer 17, a third carrier blocking layer 18, a fourth carrier transport layer 19, a third charge generation layer 20, a fourth charge generation layer 21, a fifth carrier transport layer 22, a sixth carrier blocking layer 23, a third light-emitting layer 24, a fifth carrier blocking layer 25, a sixth carrier transport layer 26, and a second carrier injection layer 12, which are sequentially stacked on the first electrode 4.

[0163] In an exemplary embodiment, the first electrode 4 can be an anode, the first, third, and fifth charge carriers can be holes, the first charge generation layer 13 and the third charge generation layer 20 can be N-type charge generation layers, the second charge generation layer 14 and the fourth charge generation layer 21 can be P-type charge generation layers, the second electrode 12 can be a cathode, and the second, fourth, and sixth charge carriers can be electrons.

[0164] This application provides a light-emitting device, including any of the light-emitting devices described above.

[0165] Among them, the light-emitting device is used as a light source to realize the lighting function. For example, the light-emitting device includes taillights, vehicle side marker lights, lamps for internal or external lighting, or various signal lights.

[0166] For example, light-emitting devices can be used as backlight modules in display devices.

[0167] The light-emitting device provided in this application includes the above-mentioned light-emitting device. The dominant wavelength of the light-emitting device is red-shifted, which can expand the application range of the light-emitting device.

[0168] This application provides a display device including any of the above-described light-emitting devices.

[0169] For example, the light-emitting device described above can be a light-emitting unit of a display device, such as a light-emitting unit of an OLED display device.

[0170] The display device can be an OLED display or other display device, as well as any product or component with display function, such as a television, digital camera, mobile phone, or tablet computer that includes such display devices.

[0171] The display device provided in this application includes the above-mentioned light-emitting device. The dominant wavelength of the light-emitting device is red-shifted, which can expand the color gamut of the display device. Furthermore, the enhanced microcavity effect of the light-emitting device can improve the coupling light emission efficiency of the display device.

[0172] It should be noted that the light-emitting device or display device includes a driving circuit, which can be electrically connected to the first electrode 4 of the light-emitting device.

[0173] This application provides a vehicle that includes the aforementioned light-emitting device.

[0174] The vehicle includes cars, trucks, trains, and subways, and the light-emitting device can serve as the taillight or side marker light of the vehicle; for example, if the vehicle is a car, the light-emitting device serves as the taillight or side marker light of the car.

[0175] The vehicle provided in this application includes the aforementioned light-emitting device, which comprises the aforementioned light-emitting element. The dominant wavelength of the light-emitting element is red-shifted, which can meet the regulatory requirements for deep red lights on relevant vehicles, thus expanding the application range of the light-emitting device. The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A light emitting device, characterized by, The application relates to a light-emitting device, comprising: a substrate; a first light-transmitting layer on one side of the substrate; a second light-transmitting layer on the side of the first light-transmitting layer away from the substrate; a first electrode on the side of the second light-transmitting layer away from the first light-transmitting layer; at least one light-emitting layer on the side of the first electrode away from the second light-transmitting layer; a second electrode on the side of the at least one light-emitting layer away from the first electrode; wherein the light-emitting direction of the light-emitting device is the direction along the second light-transmitting layer towards the first light-transmitting layer, and the refractive index of the first light-transmitting layer is greater than the refractive index of the second light-transmitting layer; the first light-transmitting layer comprises at least one first light-transmitting sub-layer; and the second light-transmitting layer comprises at least one second light-transmitting sub-layer; in the light-emitting direction of the light-emitting device, the refractive index of each first light-transmitting sub-layer gradually increases, and the refractive index of each second light-transmitting sub-layer gradually increases.

2. The light emitting device of claim 1, wherein In the direction along the second light-transmitting layer towards the first light-transmitting layer, the thickness of the first light-transmitting layer ranges from L1+k*T1, wherein L1 ranges from 80nm to 130nm, k is any natural number, and T1 ranges from 160nm to 180nm.

3. The light emitting device of claim 1, wherein, In the direction along the second light-transmitting layer towards the first light-transmitting layer, the thickness of the second light-transmitting layer ranges from L2+k*T2, wherein L2 ranges from 110nm to 150nm, k is any natural number, and T2 ranges from 160nm to 180nm.

4. The light emitting device of claim 2, wherein, In the direction along the second light-transmitting layer towards the first light-transmitting layer, the thickness of the first light-transmitting layer ranges from 80nm to 130nm or from 250nm to 290nm.

5. The light emitting device of claim 3, wherein the first and second light emitting devices are arranged in a vertical direction. In the direction along the second light-transmitting layer towards the first light-transmitting layer, the thickness of the second light-transmitting layer ranges from 120nm to 140nm or from 280nm to 320nm.

6. The light emitting device of claim 1, wherein The refractive index of the first light-transmitting layer ranges from 1.9 to 2.2, and the refractive index of the second light-transmitting layer ranges from 1.4 to 1.

6.

7. The light emitting device according to any one of claims 1 to 6, wherein The light-emitting device comprises one light-emitting layer. The light-emitting device comprises, in sequence from the first electrode, a first carrier injection layer, a first carrier transport layer, a second carrier blocking layer, the light-emitting layer, a first carrier blocking layer, a second carrier transport layer, and a second carrier injection layer.

8. The light emitting device according to any one of claims 1 to 6, wherein The light-emitting device comprises two light-emitting layers, which are a first light-emitting layer and a second light-emitting layer. The light-emitting device comprises, in sequence from the first electrode, a first carrier injection layer, a first carrier transport layer, a second carrier blocking layer, the first light-emitting layer, a first carrier blocking layer, a second carrier transport layer, a first charge generation layer, a second charge generation layer, a third carrier transport layer, a fourth carrier blocking layer, the second light-emitting layer, a third carrier blocking layer, a fourth carrier transport layer, and a second carrier injection layer.

9. A light-emitting device, characterized in that, The application relates to a light-emitting device, comprising any one of the light-emitting devices in claims 1 to 8.

10. A display device, characterized by comprising: The application relates to a light-emitting device, comprising any one of the light-emitting devices in claims 1 to 8.

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