Light-emitting display device

Abstract

To provide a light emitting display device that improves both life and efficiency by changing its structure.SOLUTION: A light emitting display device includes a bank provided on a substrate to expose the first to fourth light emitting sections, first to fourth anodes provided on the first to fourth light emitting sections, a first light emitting stack provided on the first to fourth anodes, a charge generation layer and a second light emitting stack provided on the first light emitting stack and corresponding to the fourth light emitting section, and cathodes provided on the first stacks of the first to third light-emitting sections and on the second stack of the fourth light-emitting section.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a display device, and more particularly to a light-emitting display device capable of extending the lifespan by changing the structure of a light-emitting element, alleviating the color coordinate change characteristics due to changes in the viewing angle, and expanding the color gamut.

Background Art

[0002] With the advent of the full-fledged information age, the display field that visually represents electrical information signals has been rapidly developing. In response, various display devices with excellent performance in terms of thinning, weight reduction, and low power consumption have been developed.

[0003] Among these, a light-emitting display device that does not require a separate light source and has a light-emitting element in the display panel is considered a competitive application for device compactification and vivid color display without a separate light source.

[0004] The light-emitting element includes an anode and a cathode that face each other as electrodes, a light-emitting layer between the anode and the cathode, and may include a common layer that transmits holes and electrons to the light-emitting layer.

[0005] On the other hand, the light-emitting element uses a light-emitting material that emits light of different wavelengths for color representation, but there are differences in the efficiency and lifespan of the light-emitting material depending on the wavelength.

Summary of the Invention

Problems to be Solved by the Invention

[0006] Among the light-emitting materials, the light-emitting materials that emit short wavelengths close to the ultraviolet wavelength show opposite trends in lifespan and efficiency compared to the long-wavelength dopants.

[0007] Therefore, the light-emitting display device of the present invention aims to improve both the lifespan and efficiency by changing the structure, and applies different structures to the sub-pixels including the long-wavelength light-emitting layer and the sub-pixels including the short-wavelength light-emitting layer, so as to improve both the lifespan and efficiency of the element using the light-emitting layer containing the short-wavelength light-emitting material.

Means for Solving the Problems

[0008] The light-emitting display device according to an embodiment of the present invention includes a bank provided on a substrate and exposing the first to fourth light-emitting portions, first to fourth anodes provided in the first to fourth light-emitting portions, a first light-emitting stack provided on the first to fourth anodes, a charge generation layer and a second light-emitting stack provided on the first light-emitting stack corresponding to the fourth light-emitting portion, and a cathode provided on the first light-emitting stack of the first to third light-emitting portions and the second light-emitting stack of the fourth light-emitting portion.

[0009] The light-emitting display device according to another embodiment of the present invention includes a bank provided on a substrate and exposing the first to fourth light-emitting portions, first to fourth anodes respectively provided in the first to fourth light-emitting portions, a first light-emitting layer on the first anode, a second light-emitting layer on the second anode, and a third light-emitting layer on the third anode and the fourth anode, a charge generation layer and a fourth light-emitting layer provided in sequence on the third light-emitting layer and overlapping the fourth light-emitting portion without overlapping the third light-emitting portion, and a cathode on the first light-emitting layer, the second light-emitting layer, the third light-emitting layer on the first to third light-emitting portions, and the fourth light-emitting layer.

[0010] The light-emitting display device of the present invention has the following effects.

[0011] The light-emitting display device of the present invention divides the blue light-emitting part into a single-stack blue light-emitting part and a multi-stack blue light-emitting part, and includes a blue light-emitting layer containing a fluorescent dopant common to the single-stack blue light-emitting part and the multi-stack blue light-emitting part, and further includes a blue light-emitting layer selectively containing a phosphorescent dopant in the multi-stack blue light-emitting part. In this case, the blue light-emitting layer containing the fluorescent dopant can increase the color purity of blue, and the multi-stack blue light-emitting part containing the phosphorescent dopant can increase the efficiency.

[0012] Furthermore, it is binary-divided into a single-stack structure including a blue light-emitting layer having a fluorescent dopant and a multi-stack structure in which a blue light-emitting layer containing a fluorescent dopant and a blue light-emitting layer containing a phosphorescent dopant are stacked. By adjusting the area ratio of the blue light-emitting parts of the single-stack structure and the multi-stack structure, the lifetime characteristics can be optimized regardless of the specific blue light-emitting part.

[0013] Also, since it is binary-divided into a single-stack structure including a blue light-emitting layer having a fluorescent dopant and a multi-stack structure in which a blue light-emitting layer containing a fluorescent dopant and a blue light-emitting layer containing a phosphorescent dopant are stacked, whether only the single-stack structure is used, only the multi-stack structure is used, or the blue light-emitting layer containing the fluorescent dopant and the blue light-emitting layer containing the phosphorescent dopant are stacked and used in all the blue light-emitting layers, the color deviation due to the change in the viewing angle can be reduced compared to the case where the color deviation due to the change in the viewing angle is large. Therefore, it is possible to prevent or reduce the user's visual recognition due to the change in the viewing angle.

[0014] Furthermore, since a common stack is provided in the binary-divided structure, there is an advantage of process reduction by simplifying the process of forming the single-stack structure and the multi-stack structure. Therefore, there is an advantage of being environmentally friendly due to the simplified process.

Brief Description of the Drawings

[0015]

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Embodiments for Carrying Out the Invention

[0016] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The same reference numerals throughout the specification denote components that are substantially the same. In the following description, when it is determined that a specific description of the technology or configuration related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Also, the names of the components used in the following description are selected in consideration of easy specification preparation and may be different from the names of the parts of the actual product.

[0017] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining various embodiments of the present invention are exemplary, and thus the present invention is not limited to the matters shown in the drawings. Throughout this specification, the same reference numerals refer to the same components. Further, in the description of the present invention, when it is determined that a specific description of related known technologies may unnecessarily obscure the gist of the present invention, the detailed description thereof is omitted. When using terms such as "including", "having", "becoming", etc. mentioned in this specification, other parts can be added unless "only" is used. When expressing a component in the singular, it includes the case of including a plurality unless otherwise explicitly stated.

[0018] In interpreting the components included in various embodiments of the present invention, even without a separate explicit description, it is interpreted as including an error range.

[0019] In explaining various embodiments of the present invention, when explaining the positional relationship, for example, when explaining the positional relationship between two parts by using "on ~", "above ~", "below ~", "next to ~", etc., unless "immediately" or "directly" is used, one or more other parts can be located between the two parts.

[0020] In explaining various embodiments of the present invention, when explaining the time relationship, for example, when explaining the temporal precedence relationship by using "after ~", "subsequent to ~", "next to ~", "before ~", etc., unless "immediately" or "directly" is used, it can include the case where it is not continuous.

[0021] In explaining various embodiments of the present invention, terms such as "first ~", "second ~", etc. can be used to describe various components, but such terms are only used to distinguish mutually identical or similar components. Therefore, in this specification, the component modified by "first ~" can be the same as the component modified by "second ~" within the technical idea of the present invention unless otherwise mentioned.

[0022] Each feature of various embodiments of the present invention can be partially or wholly combined or combined with each other, enabling various technical linkages and drives, and various embodiments can be implemented independently of each other or can be implemented together in an associated relationship.

[0023] As used herein, "doped" means that a substance having physical properties different from those of the substance that occupies the majority weight ratio of a layer (physical properties different from each other, for example, N-type and P-type, organic substance and inorganic substance) is added in a weight ratio of less than 30%. In other words, a "doped" layer means a layer that can be separated into a host substance and a dopant substance of a layer in consideration of the weight ratio. And "undoped" means all cases other than those corresponding to "doped". For example, when a layer is composed of a single substance or substances having the same or similar properties are mixed, that layer is included in the "undoped" layer. For example, if at least one of the substances constituting a layer is P-type and not all of the substances constituting that layer are N-type, that layer is included in the "undoped" layer. For example, if at least one of the substances constituting a layer is an organic substance and not all of the substances constituting that layer are inorganic substances, that layer is included in the "undoped" layer. For example, when all of the substances constituting a layer are organic substances, and at least one of the substances constituting that layer is N-type and at least one other is P-type, if the weight ratio of the N-type substance is less than 30% or the weight ratio of the P-type substance is less than 30%, it is included in the "doped" layer.

[0024] On the one hand, in this specification, the EL (electroluminescence) spectrum is calculated by the product of (1) the PL (photoluminescence) spectrum reflecting the inherent characteristics of luminescent substances such as dopant substances and host substances contained in the organic light-emitting layer, and (2) the out-coupling emittance spectrum curve determined by the structure and optical characteristics of the organic light-emitting device including the thickness of organic layers such as the electron transport layer.

[0025] Hereinafter, the light-emitting device of the present invention and the light-emitting display device including the same will be described with reference to the drawings.

[0026] FIG. 1 is a plan view showing a light-emitting display device according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the light-emitting display device according to an embodiment of the present invention. FIG. 3 is a plan view showing the light-emitting display device according to the first embodiment of the present invention. FIG. 4 is a cross-sectional view taken along line I-I of FIG. 1. FIG. 5 is a cross-sectional view taken along line II-II of FIG. 1 according to an embodiment of the present invention.

[0027] As shown in FIGS. 1 to 5, a light-emitting display device according to an embodiment of the present invention can include a bank 195 provided on a substrate 1000 and exposing first to fourth light-emitting portions R, G, B1, B2, first to third anodes 120a, 120b, 120c provided in the first to fourth light-emitting portions R, G, B1, B2, first light-emitting stacks RS, GS, BS1 provided on the first to third anodes 120a, 120b, 120c, a charge generation layer 170 and a second light-emitting stack BS2 provided on the first light-emitting stack BS1 of the fourth light-emitting portion B2, and a cathode 190 provided on the first light-emitting stacks RS, GS, BS1 of the first to third light-emitting portions R, G, B1 and the second light-emitting stack BS2 of the fourth light-emitting portion B2.

[0028] In the light-emitting display device of the present invention, the first to fourth light-emitting portions R, G, B1, B2 form a pixel P as a set, and the pixels P are repeatedly arranged on the substrate 1000.

[0029] In the light-emitting display device of the present invention, the third light-emitting part B1 and the fourth light-emitting part B2 are light-emitting parts that emit the same color, but there are differences in that their stacked structures are different. That is, the fourth light-emitting part B2 is different in that it further has a charge generation layer 170 and a second light-emitting stack BS2 than the third light-emitting part B1.

[0030] The first to third light-emitting parts R, G, B1 are examples, and can be respectively classified into a red light-emitting part, a green light-emitting part, and a blue light-emitting part. The first to third light-emitting parts can have combinations of light-emitting parts of other colors that can exhibit white in combination, in addition to the red, green, and blue mentioned above.

[0031] In the light-emitting display device of the present invention, the third light-emitting part B1 and the fourth light-emitting part B2 that emit the same color but have different numbers of light-emitting stack laminated structures mean light-emitting parts of a color with lower efficiency in the same stack structure than other color light-emitting parts provided in the light-emitting display device. Therefore, if the efficiency of the red light-emitting part or the green light-emitting part is lower than that of the blue light-emitting part in the same stack structure, the blue light-emitting part and the light-emitting parts of other colors can also have a binary laminated stack structure.

[0032] The first to third light-emitting parts R, G, B1 respectively include a red light-emitting layer 151, a green light-emitting layer 152, and a first blue light-emitting layer 153 in the first light-emitting stacks RS, GS, BS1.

[0033] The fourth light-emitting part B2 includes the first blue light-emitting layer 153 integrated with the first blue light-emitting layer 153 in the first light-emitting stack BS1, and includes a second blue light-emitting layer 180 in the second light-emitting stack BS2.

[0034] As shown in FIG. 4, the third light-emitting part B1 and the fourth light-emitting part B2 can be separated by a bank 195.

[0035] In the light-emitting display device according to an embodiment of the present invention, the third light-emitting part B1 is a light-emitting part that emits light with the shortest wavelength. The reason for providing the light-emitting parts that emit light with a short wavelength in the third light-emitting part B1 and the fourth light-emitting part B2 in the light-emitting display device of the present invention is as follows.

[0036] Therefore, in a structure having a light-emitting layer divided by a plurality of wavelengths on a plane and having the same stack, the blue light-emitting part has lower efficiency than the green light-emitting part and the red light-emitting part. In the light-emitting display device according to an embodiment of the present invention, the blue light-emitting part includes a fourth light-emitting part B2 having a plurality of light-emitting stacks together with a third light-emitting part B1 having a single light-emitting stack, and by increasing the blue efficiency in the fourth light-emitting part B2, the blue light-emitting efficiency of the entire light-emitting display device can be improved on average.

[0037] In addition, a light-emitting material with a relatively short wavelength has lower visibility and lower efficiency than a light-emitting material with a long wavelength having the same structure. Also, in order to display colors closer to natural colors gradually, it is necessary to expand the color gamut, and there is a great demand to expand the color gamut of the blue region rather than the saturated green region and red region. The light-emitting display device of the present invention attempts to expand the blue region, which is the region of the shortest wavelength blue expression, for example, when including a red light-emitting part, a green light-emitting part, and a blue light-emitting part.

[0038] Here, the third light-emitting part B1 and the fourth light-emitting part B2 commonly have the same first blue light-emitting layer 153, and the first blue light-emitting layer 153 commonly provided in the third light-emitting part B1 and the fourth light-emitting part B2 contains a fluorescent dopant with excellent lifetime characteristics. Optionally, the second blue light-emitting layer 180 provided in the fourth light-emitting part B2 contains a non-fluorescent dopant with excellent efficiency characteristics.

[0039] The non-fluorescent dopant can include a phosphorescent dopant or a thermally activated delayed fluorescent (TADF) dopant. The non-fluorescent dopant has an external quantum efficiency superior to that of the fluorescent dopant. However, since the non-fluorescent dopant may have its lifetime reduced by the quenching characteristics in the light-emitting layer over time, in the light-emitting display device of the present invention, the third light-emitting unit B1 uses a single first light-emitting stack BS1 and includes a first blue light-emitting layer 153 having only a fluorescent dopant, and the fourth light-emitting unit B2 includes the first light-emitting stack BS1 including the first blue light-emitting layer 153 having a fluorescent dopant and a second light-emitting stack BS2 including a second blue light-emitting layer 180 having a phosphorescent dopant or a thermally activated delayed fluorescent dopant, which are stacked. Thereby, it is possible to prevent the lifetime reduction and the pure color efficiency reduction occurring in a structure using only the non-fluorescent dopant.

[0040] The third anode 120c of the third light-emitting unit B1 and the third anode 120c of the fourth light-emitting unit B2 are integrally formed with each other and can be connected laterally. In some cases, the third anode 120c of the third light-emitting unit B1 and the third anode 120c of the fourth light-emitting unit B2 can also be arranged separately from each other.

[0041] A bank 195 is provided between the third anode 121c and the fourth anode 121d, and the third light-emitting unit B1 and the fourth light-emitting unit B2 are divided into different regions, and blue light is emitted from different stacked stacks to compensate for efficiency and lifetime. Also, the third light-emitting unit B1 and the fourth light-emitting unit B2 that emit the same color have a laminated structure in which they are bifurcated, and finally, the full width at half maximum of the light emitted from the third light-emitting unit B1 and the fourth light-emitting unit B2 can be made different, so that the color coordinate deviation due to the viewing angle change can be reduced.

[0042] In the light-emitting display device of the present invention, the third light-emitting unit B1 and the fourth light-emitting unit B2, when expressing blue, not only show the average value of the efficiencies of the first blue light-emitting layer 153 and the second blue light-emitting layer 180, but also have a low blue coordinate capable of expressing pure blue, and can increase the overlapping region of the desired color gamut range. Therefore, it has a remarkable effect in that the pure color expression of blue can be improved. Recently, the most representative standard color gamuts are BT2020 and DCI-P3. BT2020 is the next-generation standard color region first approved by the International Telecommunication Union (ITU) in June 2014. It is a color region devised to cope with the UHDTV environment, supports the expression of brightness of 10,000 nits, and takes HDR mastering into account.

[0043] DCI-P3 is a color region defined by Digital Cinema Initiatives for use as the color region of digital projectors in the U.S. movie industry. It can express a color region 25% wider than sRGB and has a particularly wide coverage in the red part. The light-emitting display device of the present invention can expand the blue efficiency and the pure color reproduction rate to have an overlap level of 99% or more with respect to the color region of DCI-P3.

[0044] Specific effects will be described with reference to the table according to experimental examples.

[0045] The first light-emitting stacks RS, GS, BS1 can include the first to third anodes 120a, 120b, 120c and a first common layer 130 located between the red light-emitting layer 151, the green light-emitting layer 152, and the first blue light-emitting layer 153.

[0046] Here, the first common layer 130 can include a hole injection layer HIL and a hole transport layer HTL. The hole injection layer HIL and the hole transport layer HTL can, in some cases, be formed as a single layer. Also, the hole injection layer HIL and the hole transport layer HTL can, if necessary, have at least one of the layers include multiple layers. Further, the first common layer 130 can be formed in a structure where the first material and the second material are alternately laminated to perform hole injection and hole transport together.

[0047] And the first light emitting stacks RS, GS, BS1 can further include a second common layer 160 on the first red light emitting layer 151, the green light emitting layer 152, and the first blue light emitting layer 153.

[0048] The second common layer 160 can include a hole blocking layer HBL and an electron transport layer ETL. The hole blocking layer restricts holes within the red light emitting layer 151, the green light emitting layer 152, and the first blue light emitting layer 153, and has a lower HOMO level value than the electron transport layer ETL in order to prevent holes from leaking out in the direction of the electron transport layer ETL.

[0049] In some cases, the second common layer 160 can omit either the hole blocking layer or the electron transport layer. Also, at least one of the hole blocking layer and the electron transport layer can be formed as multiple layers.

[0050] In the light emitting display device according to an embodiment of the present invention, the light emitting parts of the first to third light emitting parts R, G, B1 have one first light emitting stack RS, GS, BS1, and the fourth light emitting part B2 has both the first and second light emitting stacks BS1, BS2, which is a difference. The fourth light emitting part B2 is different in that it further has a charge generation layer 170 between the first light emitting stack BS1 and the second light emitting stack BS2.

[0051] The first to third light-emitting units R, G, B1 having the first light-emitting stack BS1 may have different optimal resonance distances. Therefore, in order to adjust the resonance distance for each emission color, hole transport auxiliary layers 123, 125 may be further provided between the first common layer 130 and the light-emitting layers 151, 152 of the first light-emitting stack.

[0052] As shown in FIG. 2, the first light-emitting stack BS1 may further include an electron blocking layer 140 that restricts electrons in the light-emitting layers 151, 152, 153 common to the first to fourth light-emitting units R, G, B1, B2 and prevents the electrons from escaping in the directions of the first to third anodes 120a, 120b, 120c. The electron blocking layer 140 is optional and can be omitted in some cases. Alternatively, the electron blocking layer 140 may have different required thicknesses and components in the red light-emitting layer 151, the green light-emitting layer 152, and the first blue light-emitting layer 153. In this case, the electron blocking layer 140 can be selectively provided only in a specific light-emitting unit or the thickness of the electron blocking layer 140 provided in a specific light-emitting unit can be increased.

[0053] The hole transport auxiliary layers 123, 125 can be provided to compensate for the resonance distance for each emission color. As shown in FIG. 2, they can also be provided between the first common layer and the electron blocking layer, or in some cases, between the electron blocking layer and the light-emitting layers of the first light-emitting stack.

[0054] By selectively applying the hole transport auxiliary layers 123, 125, the thicknesses of the first light-emitting stacks RS, GS of the first light-emitting unit R and the second light-emitting unit G can be greater than the thickness of the first light-emitting stack BS1 of the third light-emitting unit B1 and the fourth light-emitting unit B2. Also, the thickness of the first light-emitting stack RS of the first light-emitting unit R can be greater than the thickness of the first light-emitting stack GS of the second light-emitting unit G. The thickness of the first light-emitting stack RS of the first light-emitting unit R can be the greatest among the first to fourth light-emitting units R, G, B1, B2.

[0055] The second light-emitting stack BS2 can further include a hole transport layer 175 below the second blue light-emitting layer 180 and an electron transport layer 185 above the second blue light-emitting layer 180 in addition to the second blue light-emitting layer 180.

[0056] Each of the hole transport layer 175 and the electron transport layer 185 may be a plurality of layers as needed.

[0057] The charge generation layer 170 can be formed by laminating an n-type charge generation layer and a p-type charge generation layer. In some cases, the hole transport layer may be omitted from the second light-emitting stack BS2, and the p-type charge generation layer in the charge generation layer 170 can also function as a hole transport layer.

[0058] A cathode 190 is provided on the electron transport layer 185 of the second common layer 160 of the first to third light-emitting portions R, G, B1 and the second light-emitting stack BS2 of the fourth light-emitting portion B2.

[0059] The cathode 190 can be composed of a plurality of layers. When the cathode 190 is composed of a plurality of layers, a metal layer or an inorganic compound layer having the function of an electron injection layer can be included in the structure of the plurality of layers on the surface where the second common layer 160 and the electron transport layer 185 are in contact.

[0060] A capping layer 200 can be further included on the cathode 190.

[0061] The capping layer 200 can include a first capping layer 210 and a second capping layer 220 made of different substances. The first capping layer 210 and the second capping layer 220 can be transparent insulating films having different refractive indices. Alternatively, the first capping layer 210 and the second capping layer 220 can be insulating films having physical differences between inorganic and organic.

[0062] The capping layer 200 covers the cathode 190, protects the light-emitting element composed of the anodes 120a to 120c and the cathode 190, the first light-emitting stacks RS, GS, BS1 between the anodes 120a to 120c and the cathode 190, the charge generation layer 170, and the second light-emitting stack BS2, and functions to enhance the light extraction effect from the light-emitting element.

[0063] In the fourth light-emitting part B2, either the first blue light-emitting layer 153 or the second blue light-emitting layer 180 contains a fluorescent dopant, and the other contains a phosphorescent dopant, thereby enhancing color purity and expanding the color gamut.

[0064] In particular, in the light-emitting display device according to an embodiment of the present invention, among the third light-emitting part B1 and the fourth light-emitting part B2 that emit the same color, the first blue light-emitting layer 153 commonly provided in the third and fourth light-emitting parts B1 and B2 contains a fluorescent dopant, and the second blue light-emitting layer 180 provided only in a part of the fourth light-emitting part B2 contains a phosphorescent dopant. As a result, compared with a structure including a single stack structure, the efficiency and lifespan can be improved, and the change in color deviation due to the expansion of the color gamut and the change in the viewing angle can be significantly reduced.

[0065] Further, in the light-emitting display device according to an embodiment of the present invention, a structure of a blue light-emitting layer in which a plurality of stack structures are applied to a single light-emitting part and fluorescent dopants and phosphorescent dopants are used in different stacks has a large change in color coordinate characteristics due to a change in the viewing angle. Compared with this, the change in color deviation due to the change in the viewing angle can be significantly reduced.

[0066] The light-emitting display device according to the first embodiment of the present invention is characterized in that it includes first and second anodes 120a and 120b respectively provided in the first light-emitting part R and the second light-emitting part G, and a third anode 120c commonly provided in the third light-emitting part B1 and the fourth light-emitting part B2.

[0067] The stacked configuration of the first to fourth light-emitting parts R, G, B1, and B2 has the same or a similar configuration as that described above with reference to FIG. 2.

[0068] That is, as shown in FIGS. 3 and 4, the first light-emitting part R includes a first common layer 130 of a hole injection functional layer on the first anode 120a, a hole transport or electron blocking functional layer 140 on the first common layer 130, a red light-emitting layer 151 on the electron blocking functional layer 140, a second common layer 160 of an electron transport functional layer on the red light-emitting layer 151, and a cathode 190 on the second common layer 160 in this order.

[0069] As shown in FIGS. 3 and 5, the second light-emitting unit G includes a first common layer 130 of a hole injection functional layer on the second anode 120b, a hole transport or electron blocking functional layer 140 on the first common layer 130, a green light-emitting layer 152 on the electron blocking functional layer 140, a second common layer 160 of an electron transport functional layer on the green light-emitting layer 152, and a cathode 190 on the second common layer 160 in this order.

[0070] As shown in FIGS. 3 and 4, the third light-emitting unit B1 includes a first common layer 130 of a hole injection functional layer on the third anode 120c, a hole transport or electron blocking functional layer 140 on the first common layer 130, a first blue light-emitting layer 153 on the electron blocking functional layer 140, a second common layer 160 of an electron transport functional layer on the first blue light-emitting layer 153, and a cathode 190 on the second common layer 160 in this order.

[0071] Then, as shown in FIGS. 3 and 5, the fourth light-emitting unit B2 further includes a charge generation layer 170 and a second light-emitting stack including a hole transport layer 175, a second blue light-emitting layer 180, and an electron transport layer 185, compared with the third light-emitting unit B1.

[0072] The red light-emitting layer 151 is a light-emitting layer having a light emission peak at a wavelength of 600 nm to 650 nm.

[0073] The green light-emitting layer 152 is a light-emitting layer having a light emission peak at a wavelength of 500 nm to 590 nm.

[0074] The first blue light-emitting layer 153 and the second blue light-emitting layer 180 are light-emitting layers having a light emission peak at 420 nm to 490 nm. The first blue light-emitting layer 153 includes a fluorescent dopant, and the second blue light-emitting layer 180 can include, for example, a non-fluorescent dopant such as a phosphorescent dopant or a delayed fluorescent dopant.

[0075] In some cases, the charge generation layer 170 can be an n-type charge generation layer, and the hole transport layer 175 can be integrated with a p-type charge generation layer.

[0076] A cathode 190 and a capping layer 200 are sequentially formed on a second common layer 160 of the first to third light-emitting units R, G, B1 and an electron transport layer 185 on a fourth light-emitting unit B2.

[0077] Here, the lower surface of the cathode 190 is in contact with the second common layer 160 in the first to third light-emitting units R, G, B1 and in contact with the electron transport layer 185 in the fourth light-emitting unit B2. The lower surface of the cathode 190 can be in contact with the second common layer 160 and the electron transport layer 185 that commonly have an electron transport function in the first to fourth light-emitting units R, G, B1, B2.

[0078] The first anode 120a, the second anode 120b, and the third anode 120c are connected to a thin film transistor TFT provided on a substrate 100, and a driving current is applied.

[0079] On the other hand, in the light-emitting display device of the present invention, the substrate 1000 on which the first to third anodes 120a, 120b, 120c are formed is referred to as a thin film transistor array substrate including a substrate 100, a thin film transistor TFT, and a protective film 108 that protects the thin film transistor TFT.

[0080] Here, the substrate 100 includes at least one of plastic, glass, and a metal plate. The substrate 100 can have flexible or rigid characteristics depending on the material or the component.

[0081] The protective film 108 can be a plurality of films in some cases. The upper film has a planarizing functionality, and the first to fourth light-emitting units R, G, B1, B2 can be defined on the upper surface of the planar protective film 108.

[0082] The thin-film transistor TFT includes, as an example, a gate electrode 102, a semiconductor layer 104 overlapping the gate electrode 102, and first and second electrodes 106a and 106b connected to both sides of the semiconductor layer 104. A gate insulating film 101 is interposed between the gate electrode 102 and the semiconductor layer 104. A channel protection layer 105 is provided over the channel of the semiconductor layer 104, thereby preventing direct connection between the channel portion of the semiconductor layer 104 and the first and second electrodes 106a and 106b and enabling the maintenance of intrinsic characteristics.

[0083] Either one of the first and second electrodes 106a and 106b of the thin-film transistor TFT can be a source electrode, and the other can be a drain electrode. Either one of the first and second electrodes 106a and 106b can be connected to respective anodes 120a, 120b, 120c.

[0084] The bank 195 is configured to expose the light-emitting portions R, G, B1, B2 of the first to third anodes 120a, 120b, 120c. The bank 195 can be provided so as to overlap the edges of the first and second anodes 120a, 120b. In the light-emitting display device according to the first embodiment of the present invention, as shown in FIGS. 4 and 5, the third anode 120c is integrally provided in the third and fourth light-emitting portions B1, B2, and the bank 195 can be provided not only at the edge but also between the regions of the third and fourth light-emitting portions B1, B2. The third and fourth light-emitting portions B1, B2 include one third anode 120c, and the third anode 120c is connected to the same thin-film transistor TFT and can transmit drive current to the third light-emitting portion B1 and the fourth light-emitting portion B2.

[0085] Here, a first common layer 130 of a hole injection functional layer is provided on the third anode 120c, a hole transport or electron blocking functional layer 140 is provided on the first common layer 130, a first blue light-emitting layer 153 is provided on the electron blocking functional layer 140, a second common layer 160 of an electron transport functional layer is provided on the first blue light-emitting layer 153, and a cathode 190 is provided on the second common layer 160 in this order.

[0086] Between the third light-emitting section B1 and the fourth light-emitting section B2, the lower surface of the electron transport layer 185 in the second light-emitting stack BS2 of the fourth light-emitting section B2 is formed wider than the second blue light-emitting layer 180 and is in contact with the second common layer 160 of the first light-emitting stack BS1. Therefore, by providing different laminated structures in the third light-emitting section B1 and the fourth light-emitting section B2, the portion having a step is covered by the electron transport layer 185, and outside the step, the electron transport layer 185 is in contact with the second common layer 160 common to the first to fourth light-emitting sections R, G, B1, B2. The lower surface of the cathode 190 is in contact with the electron transport layer 185 having the same electron transport function and the second common layer 160 in the first to fourth light-emitting sections R, G, B1, B2.

[0087] On the other hand, on the capping layer 200, there are provided a first to third anodes 120a, 120b, 120c and a cathode 190 provided in the first to fourth light-emitting sections R, G, B1, B2, and a first light-emitting stack RS, GS, BS1 and a second light-emitting stack BS2 between the first to third anodes 120a, 120b, 120c and the cathode 190, and a sealing layer 300 for protecting the light-emitting element.

[0088] The sealing layer 300 can include at least one inorganic sealing layer and at least one organic sealing layer. The inorganic sealing layer and the organic sealing layer of the sealing layer 300 can have a structure formed alternately with each other.

[0089] As shown in FIGS. 4 and 5, a light-emitting display device according to an embodiment of the present invention includes a first anode 120a provided in a region including at least a first light-emitting portion R, a second anode 120b provided in a region including at least a second light-emitting portion G, and a third anode 120c provided across third and fourth light-emitting portions B1 and B2. The first anode 120a, the second anode 120b, and the third anode 120c are separated from each other. The third anode 120c is commonly provided in the third light-emitting portion B1 and the fourth light-emitting portion B2 partitioned by the bank 195 and can be driven in response to the same signal. Further, a light-emitting display device according to an embodiment of the present invention includes a first light-emitting layer 151 on the first anode 120a, a second light-emitting layer 152 on the second anode 120b, and a third light-emitting layer 153 on the third anode 120c. The third light-emitting layer 153 overlaps both the third light-emitting portion B1 and the fourth light-emitting portion B2 and is provided on the third anode 120c.

[0090] Further, the light-emitting display device overlaps the fourth light-emitting portion B2 without overlapping the third light-emitting portion B1, and a charge generation layer 170 and a fourth light-emitting layer 180 are sequentially provided on the third light-emitting layer 153, and a cathode 190 and a capping layer 200 are commonly provided on the first to fourth light-emitting portions R, G, B1, B2.

[0091] Here, the cathode 190 is provided on the first light-emitting layer 151, the second light-emitting layer 152, and the third light-emitting layer 153 provided in a single stack on the first to third light-emitting portions R, G, B1, and is provided on the fourth light-emitting layer 180 on the fourth light-emitting portion B2 composed of a plurality of stacks.

[0092] The bank 195 is provided on the substrate 1000 and exposes the anodes 120a, 120b, 120c of the first to fourth light-emitting portions R, G, B1, B2.

[0093] In the first to third light-emitting portions R, G, B1, the lower surface of the cathode 190 can be directly in contact with the second common layer 160 that functions as an electron transport layer, and in the fourth light-emitting portion B2, the lower surface of the cathode 190 can be directly in contact with the electron transport layer 185 having an electron transport function.

[0094] The third light-emitting layer 153, which is provided in common to the third light-emitting unit B1 and the fourth light-emitting unit B2, contains a fluorescent dopant, and the fourth light-emitting layer 180, which is selectively provided in the fourth light-emitting unit B2, contains a non-fluorescent dopant, which is different in this respect.

[0095] Here, the non-fluorescent dopant can be a phosphorescent dopant or a delayed fluorescence dopant.

[0096] A first common layer 130 in which a hole injection layer having a hole injection function and an electron injection layer having an electron transport function are laminated can be included between the first to third anodes 120a, 120b, 120c and the first to third light-emitting layers 151, 152, 153. And an electron blocking layer 140 that restricts holes can be provided on the first common layer 130 with the first to third light-emitting layers 151, 152, 153. And a second common layer 160 having an electron transport function is provided between the first to third light-emitting layers 151, 152, 153 and the cathode 190.

[0097] The fourth light-emitting unit B2 can selectively further include an additional stack, and can further include an electron transport layer 185 between the fourth light-emitting layer 180 and the cathode 190. Further, a hole transport layer 175 having a hole transport function can be further included between the charge generation layer 170 selectively provided in the fourth light-emitting unit B2 and the fourth light-emitting layer 180.

[0098] The charge generation layer 170 can be formed by being divided into an n-type charge generation layer and a p-type charge generation layer. In this case, the n-type charge generation layer can also function to transport electrons to the second common layer 160 of the lower stack while generating electrons.

[0099] Further, the p-type charge generation layer can also function to transport holes to the upper stack provided in the fourth light-emitting unit B2 while generating holes. In this case, the hole transport layer below the fourth light-emitting layer 180 is omitted, and the p-type charge generation layer can also function as the hole transport layer of the upper stack.

[0100] The first light-emitting layer 151 is a layer that emits red light having a peak wavelength in the wavelength range of 600 nm to 650 nm, and the second light-emitting layer 152 can be a green light-emitting layer or a yellow-green light-emitting layer having a peak wavelength in the wavelength range of 510 nm to 590 nm.

[0101] The third light-emitting layer 153 and the fourth light-emitting layer 180 are each a layer that emits blue light having a peak wavelength in the wavelength range of 420 nm to 490 nm, and they differ depending on whether or not they contain a fluorescent dopant.

[0102] The first to fourth light-emitting layers 151, 152, 153, 180 can each include one or more hosts and one or more dopants.

[0103] FIG. 6 is a plan view of a light-emitting display device according to a second embodiment of the present invention, and FIG. 7 is a cross-sectional view of the light-emitting display device according to the second embodiment of the present invention.

[0104] As shown in FIGS. 6 and 7, the light-emitting display device according to the second embodiment of the present invention is different in that the anodes of the third light-emitting portion B1 and the fourth light-emitting portion B2 are formed separately as compared with the light-emitting display device of the first embodiment described above. That is, the third anode 120c of the third light-emitting portion B1 and the fourth anode 120d of the fourth light-emitting portion B2 are separated, and each of the third anode 120c and the fourth anode 120d is connected to an independent thin-film transistor, and an individual drive current is applied.

[0105] Also in the light-emitting display device according to the second embodiment of the present invention, the first light-emitting stack BS1 including the first blue light-emitting layer 153 is commonly formed in the third light-emitting portion B1 and the fourth light-emitting portion B2, and the second light-emitting stack BS2 including the second blue light-emitting layer 180 is selectively provided in the fourth light-emitting portion B2.

[0106] Hereinafter, the effects of the light-emitting display device of the present invention will be described based on experiments.

[0107] Since the light-emitting display device of the present invention has changes in the blue light-emitting part, changes in color coordinates and viewing angle will be described based on experimental examples with different structures of the blue light-emitting part respectively.

[0108] FIG. 8 is a cross-sectional view showing the light-emitting display device according to the first and second experimental examples of the present invention.

[0109] As shown in FIG. 8, the light-emitting display devices of the first experimental example and the second experimental example are those in which a two-stack structure is laminated in common on the blue light-emitting part.

[0110] The light-emitting display device of the first experimental example uses the same type of light-emitting dopant for each light-emitting part in the first light-emitting stack and the second light-emitting stack. In the blue light-emitting part, the blue light-emitting layers in the first and second light-emitting stacks each contain a blue fluorescent dopant.

[0111] The light-emitting display device of the second experimental example differs only in that the blue light-emitting layer uses a blue phosphorescent dopant in the second light-emitting stack of the blue light-emitting part of the light-emitting display device of the first experimental example.

[0112] On the other hand, the light-emitting display device of the third experimental example is based on the structure of the light-emitting display device according to the first embodiment of the present invention described in FIGS. 2, 4, and 5.

[0113] That is, the light-emitting display device according to the third experimental example includes a blue light-emitting part including a third light-emitting part B1 and a fourth light-emitting part B2. The third light-emitting part B1 includes a first light-emitting stack BS1 having a first blue light-emitting layer 153 containing a fluorescent dopant. The fourth light-emitting part B2 further includes the first light-emitting stack BS1 and a second light-emitting stack BS2 including a charge generation layer 170 and a second blue light-emitting layer 180 containing a phosphorescent dopant on the first light-emitting stack BS1.

[0114]

Table 1

[0115]

Table 2

[0116] FIG. 9 is a graph showing the luminance change according to the viewing angle of the light-emitting display device according to the first to third experimental examples of the present invention. FIGS. 10A and 10B are graphs showing the change in color coordinates according to the viewing angle change of the light-emitting display device according to the second and third experimental examples of the present invention.

[0117] As shown in Table 1, Table 2, and FIG. 9, it can be confirmed that the phenomenon of luminance decrease due to the viewing angle change is the smallest in the third experimental example according to the first embodiment of the present invention.

[0118] Furthermore, as shown in FIG. 8, the light-emitting display device of the second experimental example including the first and second light-emitting stacks in one blue light-emitting portion, where the first blue light-emitting layer contains a blue fluorescent dopant and the second blue light-emitting layer contains a blue phosphorescent dopant, shows a Δuv color coordinate change of 0.0071 for a viewing angle change of 0° to 30° and a deviation of 0.0051 for a viewing angle change of 30° to 45°, as shown in Table 1, Table 2, and FIG. 10A. The color coordinate deviation due to the viewing angle change is large, and the color difference due to the viewing angle change is likely to be prominent.

[0119] On the other hand, as shown in FIGS. 2 to 5, the light-emitting display device according to the first embodiment of the present invention includes a third light-emitting portion B1 having a first light-emitting stack BS1 having a first blue light-emitting layer 153 in which the blue light-emitting portion contains a blue fluorescent dopant, and a second light-emitting stack BS2 having a second blue light-emitting layer 180 containing a phosphorescent dopant is laminated on the first light-emitting stack BS1. Therefore, the light-emitting display device according to the first embodiment of the present invention shows a Δu'v' color coordinate change of 0.0048 for a viewing angle change of 0° to 30° and a deviation of 0.0039 for a viewing angle change of 30° to 45°, as shown in Table 1, Table 2, and FIG. 10B. Thus, the color coordinate deviation due to the viewing angle change is reduced, and therefore, even when the viewing angle changes, the recognition of the color difference can be reduced.

[0120] On the one hand, in FIGS. 10a, 10b and Table 1, JND (Just Noticeable Differences) quantifies the degree of deviation of the color coordinate variation range due to the change in the viewing angle with respect to the viewing angle value at 0 degrees. In FIGS. 10a and 10b, the inner ellipse represents the JND8 value, and the outer ellipse represents the JND10 value. In Table 1, the JND values of the light-emitting display devices according to the first to third experimental examples for each viewing angle represent the JND values at each viewing angle of the corresponding experimental example, and a smaller JND value means a smaller degree of deviation from the color coordinates at a viewing angle of 0 degrees.

[0121] As shown in FIG. 10a and Table 1, the light-emitting display device according to the second experimental example (Ex2) has a JND value of 5.2 particularly at 0° to 30° where it is mainly observed. As shown in FIG. 10b and Table 1, it can be determined that a significant color deviation is visually recognized in the light-emitting display device according to the third experimental example (Ex3) compared to the JND value of 1.8.

[0122] Hereinafter, together with the above-described first to third experimental examples (Ex1, Ex2, Ex3), the By characteristics, color gamut, and emission spectrum of the fourth experimental example (Ex4) in which two light-emitting stacks of FIG. 8 are stacked and include a phosphorescent dopant common to the blue light-emitting layer were observed. Here, in the third experimental example (Ex3), the area ratio of the third light-emitting part B1 having a single blue light-emitting stack structure to the fourth light-emitting part B2 having a plurality of blue light-emitting stack structures was set to 1:1.

[0123] In a modified example of the third experimental example (Ex3), the By characteristics and color gamut of the fifth to eighth experimental examples (Ex5a, Ex5b, Ex5c, Ex5d) in which the area ratio of the third light-emitting part B1 having a single blue light-emitting stack structure to the fourth light-emitting part B2 having a plurality of blue light-emitting stack structures was changed to 3:1, 2:1, 1:2, and 1:3, respectively, were observed together.

[0124] FIG. 11 is a graph showing the emission spectra of the first to eighth experimental examples.

[0125]

Table 3

[0126] As shown in Table 3 and FIG. 11, in the blue light-emitting part, it can be seen that as the amount of the phosphorescent dopant increases as in the fourth experimental example (Ex4), the By value increases and the color purity decreases. In particular, as shown in FIG. 11, it can be confirmed that as the amount of the phosphorescent dopant increases, the blue light-emitting spectrum shifts to the right side.

[0127] On the other hand, in structures including the third light-emitting part B1 with a single blue light-emitting stack structure and the fourth light-emitting part B2 with a plurality of blue stack structures as in the third experimental example (Ex3) and the fifth to eighth experimental examples (Ex5a, Ex5b, Ex5c, Ex5d), since the color gamut overlapping in DCI-P3 is 100% together, it can be confirmed that a color gamut meeting the requirements in DCI-P3 is shown.

[0128] Table 4 below compares the lifetime characteristics according to the area ratio of the third light-emitting part B1 and the fourth light-emitting part B2 in the third experimental example (Ex3), the fifth experimental example (Ex5a), and the eighth experimental example (Ex5d).

[0129] Based on the fact that when the area ratio of the third light-emitting part B1 and the fourth light-emitting part B2 is 1:1 as in the third experimental example (Ex3), the lifetime characteristics of the third light-emitting part B1 and the fourth light-emitting part B2 are 1.0 and 1.0 respectively.

[0130] When the area of the third light-emitting part B1 is three times the area of the fourth light-emitting part B2 as in the fifth experimental example (Ex5a), when the lifetime of the third light-emitting part B1 is 1.0, the fourth light-emitting part B2 shows a tendency that its lifetime is extended 4.1 times by supplying the same driving current to an area reduced to 1 / 3 of the third light-emitting part B1.

[0131] On the other hand, when the area of the fourth light-emitting part B2 is three times the area of the third light-emitting part B1 as in the eighth experimental example (Ex5d), when the lifetime of the third light-emitting part B1 is 1.0, the fourth light-emitting part B2 including two stacks of blue light-emitting stacks shows a tendency that its lifetime is reduced to 0.1 times by supplying the same driving current to an area three times that of the third light-emitting part B1.

[0132] As described above and as shown in Table 3 and FIG. 11, from the viewpoints of color purity and color gamut, it is effective to include only the third light-emitting unit B1 and the fourth light-emitting unit B2 together. However, as shown in Table 4, from the viewpoints of driving and lifespan, if a lifespan reduction occurs in a specific light-emitting unit, the light-emitting display device depends on the lifespan characteristics of the light-emitting unit in which the lifespan reduction has occurred. Therefore, it is preferable that light-emitting units that emit the same color have similar or identical lifespan characteristics. In this regard, when the third light-emitting unit B1 and the fourth light-emitting unit B2 are provided with similar or identical areas, it can be predicted that, regardless of the lifespan characteristics of a specific light-emitting unit, a similar lifespan improvement effect can be obtained in the entire light-emitting display device.

[0133]

Table 4

[0134] However, the light-emitting display device of the present invention is not limited to those in which the third light-emitting unit and the fourth light-emitting unit have the same or similar area ratio. From the above-described experiments, it can be confirmed that simply including the third and fourth light-emitting units in common can improve color purity and color gamut. In the light-emitting display device of the present invention, the area ratio of the third light-emitting unit to the fourth light-emitting unit can be in the range of 1:10 to 10:1.

[0135] The light-emitting display device of the present invention divides a blue light-emitting unit into a single-stack blue light-emitting unit and a multi-stack blue light-emitting unit, includes a blue light-emitting layer that commonly includes a fluorescent dopant in the single-stack blue light-emitting unit and the multi-stack blue light-emitting unit, and further includes a blue light-emitting layer that selectively includes a phosphorescent dopant in the multi-stack blue light-emitting unit. In this case, the blue light-emitting layer including the fluorescent dopant can increase the blue color purity, and the multi-stack blue light-emitting unit including the phosphorescent dopant can increase the efficiency.

[0136] Furthermore, it is bifurcated into a single-stack structure including a blue light-emitting layer having a fluorescent dopant and a multi-stack structure in which a blue light-emitting layer including a fluorescent dopant and a blue light-emitting layer including a phosphorescent dopant are stacked. By adjusting the area ratio of the blue light-emitting portions of the single-stack structure and the multi-stack structure, the lifetime characteristics can be optimized regardless of a specific blue light-emitting portion.

[0137] Also, since it is bifurcated into a single-stack structure including a blue light-emitting layer having a fluorescent dopant and a multi-stack structure in which a blue light-emitting layer including a fluorescent dopant and a blue light-emitting layer including a phosphorescent dopant are stacked, compared with the case where a large color deviation due to a change in the viewing angle occurs when only the single-stack structure is used, only the multi-stack structure is used, or when the blue light-emitting layer including a fluorescent dopant and the blue light-emitting layer including a phosphorescent dopant are stacked and used in all the blue light-emitting layers, the color deviation due to a change in the viewing angle can be reduced. Therefore, it is possible to prevent or reduce the user's visual recognition due to a change in the viewing angle.

[0138] Furthermore, since a common stack is provided in the bifurcated structure, there is an advantage of process reduction by simplifying the process of forming the single-stack structure and the multi-stack structure. Therefore, there is an advantage of being environmentally friendly due to the simplified process.

[0139] The light-emitting display device according to an embodiment of the present invention includes a bank provided on a substrate and exposing first to fourth light-emitting portions, first to fourth anodes provided in the first to fourth light-emitting portions, a first light-emitting stack provided on the first to fourth anodes, a charge generation layer and a second light-emitting stack provided on the first light-emitting stack corresponding to the fourth light-emitting portion, and a cathode provided on the first light-emitting stack of the first to third light-emitting portions and the second light-emitting stack of the fourth light-emitting portion.

[0140] Each of the first and third light-emitting units may include a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer in the first light-emitting stack. The fourth light-emitting unit may include a first blue light-emitting layer that is the same layer as the blue light-emitting layer in the first light-emitting stack, and may include a second blue light-emitting layer in the second light-emitting stack.

[0141] The third anode and the fourth anode may be connected laterally.

[0142] The first light-emitting stack further includes a first common layer located between the first to fourth anodes, the red light-emitting layer, the green light-emitting layer, the blue light-emitting layer, and the first blue light-emitting layer, and a second common layer located on the red light-emitting layer, the green light-emitting layer, the blue light-emitting layer, and the first blue light-emitting layer. The second light-emitting stack may further include a hole transport functional layer between the charge generation layer and the second blue light-emitting layer, and an electron transport functional layer between the second blue light-emitting layer and the cathode.

[0143] The electron transport functional layer may be in contact with the second common layer on the bank between the third light-emitting unit and the fourth light-emitting unit.

[0144] The first common layer includes a hole injection layer, a hole transport layer, and an electron blocking layer. Each of the first light-emitting unit and the second light-emitting unit may further include a hole transport auxiliary layer between the hole transport layer and the electron blocking layer.

[0145] The thickness of the first light-emitting stack may be the thickest for the first light-emitting unit, or may be the thinnest for the third light-emitting unit and the fourth light-emitting unit.

[0146] The blue light-emitting layer and the first blue light-emitting layer include a fluorescent dopant, and the second blue light-emitting layer may include a non-fluorescent dopant.

[0147] The non-fluorescent dopant can be a phosphorescent dopant or a thermally activated delayed fluorescent (TADF) dopant.

[0148] The combined area of the third light-emitting part and the fourth light-emitting part may be larger than the respective areas of the first light-emitting part and the second light-emitting part, and the area ratio of the third light-emitting part to the fourth light-emitting part can be 1:10 to 10:1.

[0149] The light-emitting display device according to another embodiment of the present invention is provided on a substrate, and includes a bank that exposes the first to fourth light-emitting parts, first to fourth anodes respectively provided on the first to fourth light-emitting parts, a first light-emitting layer on the first anode, a second light-emitting layer on the second anode, and a third light-emitting layer on the third anode and the fourth anode, a charge generation layer and a fourth light-emitting layer that overlap with the fourth light-emitting part without overlapping with the third light-emitting part and are sequentially provided on the third light-emitting layer, and a cathode on the first to third light-emitting parts and on the first light-emitting layer, the second light-emitting layer, the third light-emitting layer, and the fourth light-emitting layer.

[0150] The third light-emitting layer and the fourth light-emitting layer can have a light emission peak at 420 nm to 490 nm.

[0151] The third light-emitting layer can include a fluorescent dopant, and the fourth light-emitting layer can include a non-fluorescent dopant.

[0152] The non-fluorescent dopant can be a phosphorescent dopant or a delayed fluorescence dopant.

[0153] It can further include a first common layer between the first to fourth anodes and the first to third light-emitting layers, a second common layer between the first to third light-emitting layers and the cathode, and an electron transport functional layer between the fourth light-emitting layer and the cathode.

[0154] In the first to third light-emitting units, the lower surface of the cathode can be in contact with the second common layer, and in the fourth light-emitting unit, the lower surface of the cathode can be in contact with the electron transport functional layer.

[0155] On the other hand, the present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it will be apparent to those having ordinary knowledge in the technical field to which the present invention pertains that various substitutions, modifications, and changes are possible without departing from the technical idea of the present invention.

Explanation of Reference Numerals

[0156] 100 Substrate 120a - 120d Anode R First Light-Emitting Unit G Second Light-Emitting Unit B1 Third Light-Emitting Unit B2 Fourth Light-Emitting Unit RS, GS, BS1 First Light-Emitting Stack BS2 Second Light-Emitting Stack 151 Red Light-Emitting Layer 152 Green Light-Emitting Layer 153 First Blue Light-Emitting Layer 180 Second Blue Light-Emitting Layer 170 Charge Generation Layer 190 Cathode 200 Capping Layer 300 Encapsulation Layer

Claims

1. A bank provided on a substrate, exposing the first to fourth light emitting parts; First to fourth anodes respectively provided in the first to fourth light emitting parts; A first light emitting stack provided on the first to fourth anodes; A charge generation layer and a second light emitting stack provided on the first light emitting stack corresponding to the fourth light emitting part; A cathode provided on the first light emitting stack of the first to third light emitting parts and the second light emitting stack of the fourth light emitting part, including; The third light emitting part and the fourth light emitting part include a blue light emitting layer; The third anode and the fourth anode are laterally connected, a light emitting display device.

2. Each of the first to third light emitting parts includes a red light emitting layer, a green light emitting layer, and a blue light emitting layer in the first light emitting stack; The fourth light emitting part includes a first blue light emitting layer in the same layer as the blue light emitting layer in the first light emitting stack in the first light emitting stack, and a second blue light emitting layer in the second light emitting stack, the light emitting display device according to claim 1.

3. The first light emitting stack further includes a first common layer located between the first to fourth anodes, the red light emitting layer, the green light emitting layer, the blue light emitting layer, and the first blue light emitting layer, and a second common layer located on the red light emitting layer, the green light emitting layer, the blue light emitting layer, and the first blue light emitting layer; The second light emitting stack further includes a hole transport functional layer between the charge generation layer and the second blue light emitting layer, and an electron transport functional layer between the second blue light emitting layer and the cathode, the light emitting display device according to claim 2.

4. The electron transport functional layer is in contact with the second common layer on the bank between the third light emitting part and the fourth light emitting part, the light emitting display device according to claim 3.

5. The first common layer includes a hole injection layer, a hole transport layer, and an electron blocking layer; Each of the first light emitting part and the second light emitting part further includes a hole transport auxiliary layer between the hole transport layer and the electron blocking layer, the light emitting display device according to claim 3.

6. The thickness of the first light emitting stack is such that the thickness of the first light emitting part is the thickest, and the thicknesses of the third light emitting part and the fourth light emitting part are the thinnest, the light emitting display device according to claim 1.

7. The blue light emitting layer and the first blue light emitting layer include a fluorescent dopant; The second blue light emitting layer includes a non-fluorescent dopant, the light emitting display device according to claim 2.

8. The light-emitting display device according to claim 7, wherein the non-fluorescent dopant is a phosphorescent dopant or a thermally activated delayed fluorescent (TADF) dopant.

9. The total area of the third light-emitting portion and the fourth light-emitting portion is larger than the respective areas of the first light-emitting portion and the second light-emitting portion. The light-emitting display device according to claim 1, wherein the area ratio of the third light-emitting portion to the fourth light-emitting portion is 1:10 to 10:

1.

10. A bank provided on a substrate and exposing the first to fourth light-emitting portions; First to fourth anodes respectively provided in the first to fourth light-emitting portions; A first light-emitting layer on the first anode, a second light-emitting layer on the second anode, and a third light-emitting layer on the third anode and the fourth anode; A charge generation layer and a fourth light-emitting layer that overlap the fourth light-emitting portion without overlapping the third light-emitting portion and are sequentially provided on the third light-emitting layer; Including the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer on the first to third light-emitting portions, and a cathode on the fourth light-emitting layer; The light-emitting display device, wherein each of the third light-emitting layer and the fourth light-emitting layer has a light emission peak at 420 nm to 490 nm.

11. The light-emitting display device according to claim 10, wherein the third light-emitting layer includes a fluorescent dopant and the fourth light-emitting layer includes a non-fluorescent dopant.

12. The light-emitting display device according to claim 11, wherein the non-fluorescent dopant is a phosphorescent dopant or a delayed fluorescence dopant.

13. A first common layer between the first to fourth anodes and the first to third light-emitting layers; A second common layer between the first to third light-emitting layers and the cathode; The light-emitting display device according to claim 10, further including an electron transport functional layer between the fourth light-emitting layer and the cathode.

14. In the first to third light-emitting portions, the lower surface of the cathode is in contact with the second common layer, and in the fourth light-emitting portion, the lower surface of the cathode is in contact with the electron transport functional layer. The light-emitting display device according to claim 13.

Images