Electroluminescent display device

Abstract

An electroluminescent display device includes: a substrate including a first sub-pixel, a second sub-pixel, and a third sub-pixel; a first electrode located on each of the first to third sub-pixels on the substrate; a light-emitting unit located on the first electrode; and a second electrode located on the light-emitting unit, wherein the light-emitting unit includes a first stack including a first light-emitting layer and a second stack including a second light-emitting layer; and a charge-generating layer disposed between the first stack and the second stack, wherein the charge-generating layer includes a first charge-generating layer disposed in the first sub-pixel; and a second charge-generating layer disposed in the second and third sub-pixels, wherein the second charge-generating layer does not overlap with the first sub-pixel and the second charge-generating layer spanning the second and third sub-pixels is continuous.

Description

Technical Field

[0001] This disclosure relates to an apparatus, and more specifically, for example, but not limited to, an electroluminescent display apparatus. Prior Technology

[0002] An electroluminescent display device includes a first electrode, a second electrode, and a light-emitting layer disposed between the first electrode and the second electrode, and displays an image by emitting light through the electric field between the first electrode and the second electrode.

[0003] An electroluminescent display device may include multiple stacked layers disposed above and below a charge generation layer. In this case, leakage current may be generated between adjacent sub-pixels via the charge generation layer, therefore a method has been designed to disconnect the charge generation layer between adjacent sub-pixels.

[0004] However, in this case, the following problem exists: leakage current is generated in the vertical direction due to the difference in residual charge between the stack below the charge generation layer and the stack above the charge generation layer, resulting in screen defects such as flickering. Summary of the Invention

[0005] This disclosure addresses the aforementioned problems, and one aspect of this disclosure is to provide an electroluminescent display device that can prevent or reduce leakage current in the vertical direction by increasing the potential of a charge generation layer by reducing the horizontal resistance between sub-pixels, thereby overcoming screen defects such as flicker.

[0006] According to one aspect of this disclosure, the aforementioned and other technical effects can be achieved by providing an electroluminescent display device. The electroluminescent display device includes: a substrate including a first sub-pixel, a second sub-pixel, and a third sub-pixel; a first electrode located in each of the first to third sub-pixels on the substrate; a light-emitting unit located on the first electrode; and a second electrode located on the light-emitting unit, wherein the light-emitting unit includes a first stack, the first stack including a first light-emitting layer; a second stack, the second stack including a second light-emitting layer; and a charge-generating layer disposed between the first stack and the second stack, wherein the charge-generating layer includes a first charge-generating layer disposed in the first sub-pixel; and a second charge-generating layer disposed in the second sub-pixel and the third sub-pixel, and wherein the second charge-generating layer does not overlap with the first sub-pixel and the second charge-generating layer spanning the second sub-pixel and the third sub-pixel is continuous.

[0007] Furthermore, according to one aspect of this disclosure, the aforementioned and other technical effects can be achieved by providing an electroluminescent display device. The electroluminescent display device includes: pixels comprising a first sub-pixel, a second sub-pixel, and a third sub-pixel, and disposed along a first direction and a second direction; and a light-emitting unit disposed in the pixels and comprising a charge-generating layer, wherein the charge-generating layer comprises a first charge-generating layer disposed in the first sub-pixel; and a second charge-generating layer that does not overlap with the first sub-pixel and is continuous across the second and third sub-pixels, and the second charge-generating layer is continuous across two or more pixels disposed along the first direction.

[0008] Other systems, methods, features, and advantages will become apparent or will become apparent to those skilled in the art upon review of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included in this description, within the scope of this disclosure, and protected by the following claims. Nothing in this section should be construed as limiting the scope of equivalent claims. Other aspects and advantages are discussed below in conjunction with embodiments of this disclosure.

[0009] It should be understood that both the foregoing general description and the following detailed description are illustrative and explanatory, and are intended to provide a further explanation of the inventive concepts claimed as in the claims. Simple Explanation of the Diagram

[0010] The accompanying drawings are incorporated in and form part of this application, serving to provide a better understanding of the disclosure and to illustrate embodiments thereof, and together with the specification, to explain the principles of the disclosure. In the drawings: Figure 1 is a cross-sectional schematic diagram of an electroluminescent display device according to an embodiment of the present disclosure; Figure 2 is a cross-sectional schematic diagram of a light-emitting unit according to an embodiment of the present disclosure; Figure 3 is a cross-sectional schematic diagram of a light-emitting unit according to another embodiment of the present disclosure; Figures 4 to 8 are planar schematic diagrams of electroluminescent display devices according to various embodiments of the present disclosure; Figure 9 is a cross-sectional schematic diagram of a light-emitting unit according to another embodiment of the present disclosure; Figure 10 is a cross-sectional schematic diagram of a light-emitting unit according to another embodiment of the present disclosure; Figure 11 is a cross-sectional schematic diagram of a light-emitting unit according to another embodiment of the present disclosure; and Figures 12 to 16 are planar schematic diagrams of electroluminescent display devices according to various embodiments of the present disclosure.

[0011] Throughout the diagrams and detailed descriptions, unless otherwise stated, it should be understood that the same reference numbers in the diagrams refer to the same components, features, and structures. Implementation

[0012] Detailed reference will now be made to embodiments disclosed herein, and examples of such embodiments are illustrated in the accompanying drawings. The described processing steps and / or the sequence of operations are one example; however, the sequence of such steps and / or operations is not limited to those set forth herein and may be varied as is known to those skilled in the art, except for steps and / or operations that necessarily occur in a particular order. The names of individual elements used in the following explanation may be chosen solely for the convenience of writing the specification and may therefore differ from those used by users in actual products.

[0013] The advantages, features, and implementation methods of this disclosure will be illustrated by the examples described below with reference to the accompanying drawings. However, this disclosure may be embodied in different forms and should not be construed as limited to the examples set forth herein. Rather, such examples are provided so that the description of this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art. Furthermore, the scope of this disclosure is limited only by the claims appended.

[0014] The shapes, sizes, dimensions (e.g., length, width, height, thickness, radius, diameter, area, etc.), ratios, angles, number of elements, and the like described in the accompanying drawings for the purpose of illustrating embodiments of this disclosure are merely examples, and this disclosure is not limited thereto.

[0015] Any embodiment described herein as an "example" is not necessarily to be construed as superior to or other embodiments.

[0016] The dimensions of each component in the drawings, including size and thickness, are provided for ease of description, and this disclosure is not limited to the size and thickness of the components described. However, it should be noted that the relative dimensions relating to the relative size, position, and thickness of the components described in the various drawings submitted herein are part of this disclosure.

[0017] Throughout this specification, the same reference numerals refer to the same components. In the following description, detailed descriptions of relevant known functions or configurations will be omitted where they are deemed unnecessary to obscure a key point of this disclosure. Where "including," "having," and "comprising" are used in this disclosure, an additional part may be added unless "only~" is used. Singular terms may contain multiple forms unless otherwise stated.

[0018] When interpreting components, even if an error range is not explicitly described separately, it is interpreted as including an error range.

[0019] When describing a positional relationship, for example, when the positional relationship is described as "on," "above," "below," and "adjacent to," one or more of these parts may be placed between two other parts, unless "exactly" or "directly" is used. Terms such as "below," "lower," "above," and "upper" may be used in this document to describe the relationships between elements illustrated in the diagrams. It should be understood that these terms are spatially relative and based on the orientation depicted in the diagrams.

[0020] A description of a temporal relationship may include instances where the temporal prior relationship is described as "after", "following", or "before", and is not continuous unless "immediately" or "directly" is used.

[0021] Although the terms "first," "second," and "like" are used to describe various components, the term "component" is not limited to "component." The term "component" is used only to distinguish one component from another. Therefore, a first component mentioned below can be considered a second component within the technical concept disclosed herein.

[0022] It should be understood that although the terms "first," "second," "A," "B," "(a)," and "(b)" may be used herein to describe various elements, these terms should not be used to limit the elements. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of this disclosure.

[0023] If a component is described as "connected", "coupled" or "attached" to another component, then the component may be directly connected, coupled or attached to the other component. However, it should be understood that other components may be inserted between each component, and components may be indirectly connected, coupled or attached without any specific description.

[0024] It should be understood that if a component or layer is stated to be "in contact" or "overlapping" with another component or layer, then the component or layer may be in direct contact or overlap with the other component or layer, but other components may be inserted between the components, and the components may be indirectly in contact or overlap without explicit statement.

[0025] To elaborate further, as used herein, the term "connection" is intended to have the broadest possible meaning. Specifically, the phrase "A connected to B" includes both a direct connection (where no intervening component or element exists) and an indirect connection (where one or more intermediate components or elements exist between A and B). In other words, "A connected to B" includes both direct physical or electrical coupling and indirect coupling through one or more intervening components. Unless explicitly stated otherwise, these terms do not require direct physical or electrical contact. The terms "coupled" and "contact" should be interpreted in the same manner.

[0026] The expression "a first element," "a second element," and " / or" "a third element" should be understood as one of the first, second, and third elements, or any or all combinations of the first, second, and third elements. For example, A, B, and / or C can refer to only A; only B; only C; any or some combinations of A, B, and C; or all of A, B, and C.

[0027] The term "at least one" should be understood to include any and all combinations of one or more of the relevant listed items. For example, "at least one of a first element, a second element, or a third element" means all combinations of the three listed elements, combinations of any two of the three elements, and each individual element, the first element, the second element, or the third element.

[0028] The terms "first direction," "second direction," "third direction," "X-axis direction," "Y-axis direction," and "Z-axis direction" should not be interpreted merely as a geometric relationship of mutual perpendicularity, but can be understood as meaning that the configuration disclosed herein has a wider range of directions within the scope of the configuration disclosed herein that can function.

[0029] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art. It should be further understood that terms such as those defined in common dictionaries shall be interpreted as having the same meaning as they have in the relevant art and in the context of this application, and shall not be interpreted in an idealized or overly formalized sense, unless expressly defined herein. For example, the terms "part" or "unit" may apply to, for example, a discrete circuit or structure, an integrated circuit, a computational block of a circuit device, or any structure configured to perform the described functions, as would be understood by one of ordinary skill in the art.

[0030] Rather, these embodiments are provided so that this disclosure is sufficiently thorough and complete to assist those skilled in the art in fully understanding the scope of this disclosure. Furthermore, this disclosure is limited only to the scope of the claims.

[0031] The features of each of the various instances disclosed herein may be partially or wholly coupled or combined with each other, and various interlocking and driving systems are technically possible. Furthermore, each of the instances may be implemented independently of each other or together in a related relationship.

[0032] One embodiment of this disclosure will be described in detail below with reference to the accompanying drawings.

[0033] Figure 1 is a cross-sectional schematic diagram of an electroluminescent display device according to an embodiment of the present disclosure.

[0034] As shown in FIG1, the electroluminescent display device according to the present disclosure embodiment includes a substrate 100, a circuit element layer 200, a passivation layer 310, a planarization layer 320, a first electrode 400, a dam 450, a light-emitting unit 500, a second electrode 600, and a capping layer 700.

[0035] The substrate 100 may be made of glass, plastic or semiconductor material, but this disclosure is not limited thereto. The electroluminescent display device according to the embodiments of this disclosure can be made into a top-emitting type, and accordingly, not only transparent materials can be used as materials for the first substrate 100, but also opaque materials can be used as materials for the first substrate 100.

[0036] The circuit element layer 200 is disposed on the substrate 100.

[0037] The circuit element layer 200 includes driving thin-film transistors for each of the red sub-pixel R, the green sub-pixel G, and the blue sub-pixel B.

[0038] The driving thin-film transistor includes an active layer 210 disposed on a substrate 100, a gate insulating layer 220 disposed on the active layer 210, a gate electrode 230 disposed on the gate insulating layer 220, an interlayer insulating layer 240 disposed on the gate electrode 230, and a source electrode 250 and a drain electrode 260 disposed on the interlayer insulating layer 240.

[0039] The source electrode 250 and the drain electrode 260 are connected to one side and the other side of the active layer 210 through a plurality of holes disposed in the interlayer insulating layer 240 and the gate insulating layer 220.

[0040] Although the figures show a driving thin-film transistor with a top gate structure having a gate electrode 230 disposed on the active layer 210, this disclosure may include a driving thin-film transistor having a bottom gate structure having the gate electrode 230 disposed below the active layer 210. Furthermore, although the gate insulating layer 220 is disposed on the entire surface of the substrate 100, the gate insulating layer 220 may be patterned below the gate electrode 230 in the same manner as the gate electrode 230. The driving thin-film transistor may be modified to various forms known in the art.

[0041] In addition, although not shown, the circuit element layer 200 may further include: various signal lines including gate lines, data lines, power lines and reference lines, various thin film transistors including switching thin film transistors and sensing thin film transistors, and capacitors.

[0042] The switching thin-film transistor switches according to the gate signal supplied to the gate line to supply the data voltage supplied from the data line to the driving thin-film transistor.

[0043] The driving thin-film transistor switches according to the data voltage supplied by the self-switching thin-film transistor to generate data current from the power supply supplied by the power line and supply the data current to the first electrode 400.

[0044] The sensing thin-film transistor can sense the threshold voltage deviation of the driving thin-film transistor that causes image quality degradation, and respond to the sensing control signal supplied from the gate line or independent sensing line to supply the current of the driving thin-film transistor to the reference line.

[0045] The capacitor can maintain the data voltage supplied to the driving thin-film transistor in a frame, and the capacitor is connected to the gate terminal and the source terminal of the driving thin-film transistor respectively.

[0046] A passivation layer 310 is disposed on the circuit element layer 200. Specifically, the passivation layer 310 is disposed on the source electrode 250 and the drain electrode 260. The passivation layer 310 may be formed of an inorganic insulating material, but this disclosure is not limited thereto.

[0047] A planarization layer 320 is disposed on the passivation layer 310. The planarization layer 320 may be made of an organic insulating material.

[0048] The passivation layer 310 and the planarization layer 320 include contact holes, through which the source electrode 250 can be exposed, and the first electrode 400 can be connected to the source electrode 250 exposed through the contact holes. In some cases, the drain electrode 260 can be exposed through the contact holes provided in the passivation layer 310 and the planarization layer 320, and the first electrode 400 can be connected to the drain electrode 260 exposed through the contact holes.

[0049] The first electrode 400 is disposed in each of the sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B) on the planarization layer 320.

[0050] The first electrode 400 is connected to the source electrode 250 or the drain electrode 260 through contact holes disposed in the passivation layer 310 and the planarization layer 320.

[0051] The electroluminescent display device according to the embodiments disclosed herein may be formed of a top-emitting type, and therein, the first electrode 400 may include a reflective electrode.

[0052] The embankment 450 is disposed on the planarization layer 320 and is disposed at the boundary between the sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B).

[0053] A dam 450 is disposed on the first electrode 400 to cover the edge of the first electrode 400. The light-emitting area can be defined by the dam 450. Specifically, the portion of the first electrode 400 exposed but not covered by the dam 450 can be the light-emitting area.

[0054] The light-emitting unit 500 is disposed in the light-emitting area defined by the embankment 450. The light-emitting unit 500 is disposed on the first electrode 400; specifically, the light-emitting unit 500 is disposed on a portion of the first electrode 400 exposed and not covered by the embankment 450. Alternatively, the light-emitting unit 500 may be disposed on the upper surface of the embankment 450. In other words, the light-emitting unit 500 may also be disposed at the boundaries between the sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B).

[0055] The light-emitting unit 500 can form various patterns as described below.

[0056] The second electrode 600 is disposed on the light-emitting unit 500.

[0057] The second electrode 600 is formed as a continuous span across the sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B).

[0058] The electroluminescent display device according to the embodiments disclosed herein can be configured as a top-emitting type, and therefore the second electrode 600 can include a transparent electrode or a semi-transparent electrode.

[0059] A capping layer 700 is disposed on the second electrode 600. The capping layer 700 may contain an organic insulating material and may cover particles that may remain on the surface of the second electrode 600.

[0060] Although not shown in the figure, an additional encapsulation layer may be provided on the capping layer 700.

[0061] Figure 2 is a cross-sectional schematic diagram of a light-emitting unit according to an embodiment of the present disclosure.

[0062] As shown in Figure 2, the light-emitting unit 500 according to the present disclosure embodiment includes a first stack 1st Stack, a second stack 2nd Stack, and a charge generation layer CGL.

[0063] The first stack includes a hole injection layer HIL, a first hole transport layer HTL1, first light emission layers R-EML1, G-EML1, B-EML1, and a first electron transport layer ETL1.

[0064] The hole injection layer HIL is disposed on the first electrode 400 and the embankment 450 in Figure 1 above, and can be formed to continuously span across the red sub-pixel R, the green sub-pixel G, and the blue sub-pixel B.

[0065] In this disclosure, when the material layer is formed to continuously span the sub-pixels, it means that the material layer is continuous in the sub-pixels and in the boundary regions between the sub-pixels.

[0066] The first hole transport layer HTL1 is disposed on the hole injection layer HIL, and can be formed to continuously span across the red sub-pixel, green sub-pixel and blue sub-pixel (red sub-pixel R sub-pixel, green sub-pixel G sub-pixel and blue sub-pixel B sub-pixel).

[0067] The first light-emitting layers R-EML1, G-EML1 and B-EML1 are disposed on the first hole transport layer HTL1.

[0068] The first light-emitting layers R-EML1, G-EML1 and B-EML1 include: a first red light-emitting layer R-EML1 disposed in the red sub-pixel, a first green light-emitting layer G-EML1 disposed in the green sub-pixel and a first blue light-emitting layer B-EML1 disposed in the blue sub-pixel.

[0069] The first red emitting layer R-EML1, the first green emitting layer G-EML1, and the first blue emitting layer B-EML1 may not overlap, but this disclosure is not limited thereto. In addition, the first red emitting layer R-EML1, the first green emitting layer G-EML1, and the first blue emitting layer B-EML1 may be formed so that they are not in contact with each other.

[0070] The first electron transport layer ETL1 is disposed on the first light-emitting layers R-EML1, G-EML1 and B-EML1, and can be formed to continuously span the red sub-pixel, green sub-pixel and blue sub-pixel (red sub-pixel R sub-pixel, green sub-pixel G sub-pixel and blue sub-pixel B sub-pixel).

[0071] Although not illustrated, the first stack may further include a hole blocking layer HBL disposed between the first light-emitting layers R-EML1, G-EML1 and B-EML1 and the first electron transport layer ETL1.

[0072] The second stack includes a second hole transport layer HTL2, third hole transport layers HTL3-1, HTL3-2 and HTL3-3, second light-emitting layers R-EML2, G-EML2, B-EML2, second electron transport layer ETL2 and electron injection layer EIL.

[0073] The second hole transport layer HTL2 is disposed on the charge generation layer CGL. More specifically, the second hole transport layer HTL2 is disposed on the P-type charge generation layers P-CGL1 and P-CGL2. Furthermore, the second hole transport layer HTL2 can be formed to continuously span across the red sub-pixel, green sub-pixel, and blue sub-pixel (red sub-pixel R, green sub-pixel G, and blue sub-pixel B). The second hole transport layer HTL2 can be formed of the same material as the first hole transport layer HTL1, but this disclosure is not limited thereto.

[0074] The third hole transport layers HTL3-1, HTL3-2 and HTL3-3 are set on the second hole transport layer HTL2.

[0075] The third hole transport layers HTL3-1, HTL3-2, and HTL3-3 include a 3-1 hole transport layer HTL3-1 disposed in the red sub-pixel (red sub-pixel R), a 3-2 hole transport layer HTL3-2 disposed in the green sub-pixel (green sub-pixel G), and a 3-3 hole transport layer HTL3-3 disposed in the blue sub-pixel (blue sub-pixel B).

[0076] The third hole transport layers HTL3-1, HTL3-2, and HTL3-3 are configured to obtain a microcavity effect for each sub-pixel (red sub-pixel R, green sub-pixel G, and blue sub-pixel B). Hole transport layer HTL3-1 is used to obtain a microcavity effect in the red sub-pixel (red sub-pixel R), hole transport layer HTL3-2 is used to obtain a microcavity effect in the green sub-pixel (green sub-pixel G), and hole transport layer HTL3-3 is used to obtain a microcavity effect in the blue sub-pixel (blue sub-pixel B).

[0077] Considering that the wavelength of red is longer than that of green, and the wavelength of green is longer than that of blue, the thickness of hole transport layer 3-1 HTL3-1 can be greater than the thickness of hole transport layer 3-2 HTL3-2, and the thickness of hole transport layer 3-2 HTL3-2 can be greater than the thickness of hole transport layer 3-3 HTL3-3. In the blue sub-pixel (blue sub-pixel B), a microcavity effect can be obtained through the second hole transport layer HTL2, and in this case, hole transport layer 3-3 HTL3-3 can be omitted.

[0078] The third hole transport layers HTL3-1, HTL3-2, and HTL3-3 may be formed of the same material as the second hole transport layer HTL2 or the first hole transport layer HTL1, but this disclosure is not limited thereto. The third hole transport layers HTL3-1, HTL3-2, and HTL3-3 may be formed of the same material, but this disclosure is not limited thereto.

[0079] Hole transport layers HTL3-1 (3-1), HTL3-2 (3-2), and HTL3-3 (3-3) may not overlap. Furthermore, these layers may be formed so that they do not contact each other.

[0080] In some cases, the third hole transport layers HTL3-1, HTL3-2, and HTL3-3 may not be formed in the second stack, but may be formed in the first stack. Specifically, the third hole transport layers HTL3-1, HTL3-2, and HTL3-3 may not be formed between the second hole transport layer HTL2 and the second luminescent layers R-EML2, G-EML2, and B-EML2, but may be formed between the first hole transport layer HTL1 and the first luminescent layers R-EML1, G-EML1, and B-EML1.

[0081] The second light-emitting layers R-EML2, G-EML2 and B-EML2 are disposed on the third hole transport layers HTL3-1, HTL3-2 and HTL3-3.

[0082] The second light-emitting layers R-EML2, G-EML2 and B-EML2 include a second red light-emitting layer R-EML2 disposed in the red sub-pixel (red sub-pixel R sub-pixel), a second green light-emitting layer G-EML2 disposed in the green sub-pixel (green sub-pixel G sub-pixel) and a second blue light-emitting layer B-EML2 disposed in the blue sub-pixel (blue sub-pixel B sub-pixel).

[0083] The second red emitting layer R-EML2, the second green emitting layer G-EML2, and the second blue emitting layer B-EML2 may not overlap, but this disclosure is not limited thereto. The second red emitting layer R-EML2, the second green emitting layer G-EML2, and the second blue emitting layer B-EML2 may be formed so that they are not in contact with each other.

[0084] The second red emitting layer R-EML2 and the first red emitting layer R-EML1 can be formed from the same material, but this disclosure is not limited to this. The second green emitting layer G-EML2 and the first green emitting layer G-EML1 can be formed from the same material, but this disclosure is not limited to this. The second blue emitting layer B-EML2 and the first blue emitting layer B-EML1 can be formed from the same material, but this disclosure is not limited to this.

[0085] The second electron transport layer ETL2 is disposed on the second light-emitting layers R-EML2, G-EML2 and B-EML2, and can be formed to continuously span the red sub-pixel, green sub-pixel and blue sub-pixel (red sub-pixel R sub-pixel, green sub-pixel G sub-pixel and blue sub-pixel B sub-pixel).

[0086] Although not illustrated, the second stack may further include a hole blocking layer HBL disposed between the second light-emitting layers R-EML2, G-EML2 and B-EML2 and the second electron transport layer ETL2.

[0087] The electron injection layer EIL is disposed on the second electron transport layer ETL2 and can be formed as a continuous span across red, green and blue sub-pixels (red sub-pixel R, green sub-pixel G and blue sub-pixel B).

[0088] According to the embodiments disclosed herein, the first light-emitting layers R-EML1, G-EML1, and B-EML1 include a first red light-emitting layer R-EML1, a first green light-emitting layer G-EML1, and a first blue light-emitting layer B-EML1, and the second light-emitting layers R-EML2, G-EML2, and B-EML2 include a second red light-emitting layer R-EML2, a second green light-emitting layer G-EML2, and a second blue light-emitting layer B-EML2. Accordingly, without the need for a separate color filter, red light can be emitted from the red sub-pixel (red sub-pixel R), green light can be emitted from the green sub-pixel (green sub-pixel G), and blue light can be emitted from the blue sub-pixel (blue sub-pixel B).

[0089] However, this disclosure is not necessarily limited thereto. For example, according to another embodiment of this disclosure, one of the plurality of first light-emitting layers located between the first hole transport layer HTL1 and the first electron transport layer ETL1, and one of the plurality of second light-emitting layers located between the third hole transport layers HTL3-1, HTL3-2, and HTL3-3 and the second electron transport layer ETL2, includes a blue light-emitting layer that continuously spans a red sub-pixel, a green sub-pixel, and a blue sub-pixel, and the remaining light-emitting layers include a yellow-green light-emitting layer that continuously spans a red sub-pixel, a green sub-pixel, and a blue sub-pixel (red sub-pixel R sub-pixel, green sub-pixel G sub-pixel, and blue sub-pixel B sub-pixel). In this case, a red color filter is additionally disposed in the red sub-pixel (red sub-pixel R sub-pixel), a green color filter is additionally disposed in the green sub-pixel (green sub-pixel G sub-pixel), and a blue color filter is additionally disposed in the blue sub-pixel (blue sub-pixel B sub-pixel).

[0090] The charge generation layer CGL is disposed between the first stack (1st Stack) and the second stack (2nd Stack). Alternatively, the charge generation layer CGL can be disposed between the first electron transport layer ETL1 and the second hole transport layer HTL2.

[0091] The charge generation layer CGL includes an N-type charge generation layer N-CGL, a P-type charge generation layer P-CGL1, and a P-type charge generation layer P-CGL2.

[0092] The N-type charge-generating layer N-CGL supplies electrons to the first stack 1st stack, while the P-type charge-generating layers P-CGL1 and P-CGL2 supply holes to the second stack 2nd stack.

[0093] The N-type charge generation layer N-CGL is disposed on the first electron transport layer ETL1 and can be formed to continuously span the red sub-pixel, green sub-pixel and blue sub-pixel (red sub-pixel R sub-pixel, green sub-pixel G sub-pixel and blue sub-pixel B sub-pixel).

[0094] P-type charge generation layers P-CGL1 and P-CGL2 are disposed on N-type charge generation layer N-CGL. P-type charge generation layers P-CGL1 and P-CGL2 include a first P-type charge generation layer P-CGL1 and a second P-type charge generation layer P-CGL2.

[0095] The first P-type charge generation layer P-CGL1 is disposed in the red sub-pixel (red sub-pixel R), and the second P-type charge generation layer P-CGL2 is disposed in the green sub-pixel and the blue sub-pixel (green sub-pixel G and blue sub-pixel B).

[0096] The first P-type charge generation layer P-CGL1 can be patterned into an island structure in the red sub-pixel (red sub-pixel R), and the second P-type charge generation layer P-CGL2 can be formed to continuously span across the green sub-pixel (green sub-pixel G) and the blue sub-pixel (blue sub-pixel B).

[0097] The first P-type charge generation layer P-CGL1 and the second P-type charge generation layer P-CGL2 do not overlap or contact each other.

[0098] P-type charge generation layers P-CGL1 and P-CGL2 can be formed by doping organic materials with metal dopants or non-metal dopants such as inorganic or organic materials, and thus have good conductivity. Therefore, if the P-type charge generation layers P-CGL1 and P-CGL2 are formed to continuously span the red sub-pixel, green sub-pixel, and blue sub-pixel (red sub-pixel R, green sub-pixel G, and blue sub-pixel B), then charges can move freely between these sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B) through the P-type charge generation layers P-CGL1 and P-CGL2, thereby generating leakage current in adjacent sub-pixels.

[0099] Therefore, to prevent or reduce this leakage current problem, it is desirable that the P-type charge generation layers P-CGL1 and P-CGL2 between the red, green and blue sub-pixels (red sub-pixel R, green sub-pixel G and blue sub-pixel B) be formed in a discontinuous and non-continuous manner.

[0100] However, if the P-type charge generation layers P-CGL1 and P-CGL2 between the red, green, and blue sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B) are formed discontinuously, the resistance between these sub-pixels will increase in the horizontal direction. Therefore, charge cannot move smoothly in the boundary regions between these sub-pixels and will remain. When an electric field is applied to these sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B), leakage current flows into the layer with lower resistance due to the potential asymmetry between the first stack and the second stack. Therefore, when the emitted light brightness is higher than the desired brightness, a screen defect such as flashing will occur. This type of screen defect is more pronounced at low grayscale levels.

[0101] Generally speaking, considering that the driving current decreases in the order of blue sub-pixel (blue sub-pixel B), red sub-pixel (red sub-pixel R), and green sub-pixel (green sub-pixel G), a large amount of electron charge remaining in the boundary region will flow into the green sub-pixel (green sub-pixel G), and screen defects such as flash will increase in the green sub-pixel (green sub-pixel G).

[0102] Therefore, according to one embodiment of this disclosure, for example, by connecting the second P-type charge generation layer P-CGL2 of the blue sub-pixel (blue sub-pixel B) with the relatively largest driving current and the second P-type charge generation layer P-CGL2 of the green sub-pixel (green sub-pixel G) with the relatively smallest driving current, residual electronic charge in the boundary region can be prevented or reduced by reducing the horizontal resistance between the blue sub-pixel (blue sub-pixel B) and the green sub-pixel (green sub-pixel G), thereby eliminating screen defects such as flicker.

[0103] However, this disclosure is not necessarily limited to this, and the second P-type charge generation layer P-CGL2 can be continuously formed across two sub-pixels in the blue sub-pixel (blue sub-pixel B), red sub-pixel (red sub-pixel R), and green sub-pixel (green sub-pixel G), and the first P-type charge generation layer P-CGL1 can be formed in the remaining sub-pixels.

[0104] To reduce the horizontal resistance between the blue sub-pixel (blue sub-pixel B) and the green sub-pixel (green sub-pixel G), the conductivity of the second P-type charge generation layer P-CGL2 can be greater than that of the first P-type charge generation layer P-CGL1.

[0105] The first P-type charge generation layer P-CGL1 can be formed by doping a first organic material with a first dopant such as a metal, and the second P-type charge generation layer P-CGL2 can be formed by doping a second organic material with a second dopant such as a metal.

[0106] In this case, the first organic material and the second organic material may be made of the same material, but are not necessarily limited to this. Additionally, the first dopant and the second dopant may be made of the same material, but are not necessarily limited to this.

[0107] However, since the doping concentration of the second dopant is higher than that of the first dopant, the conductivity of the second P-type charge generation layer P-CGL2 can be higher than that of the first P-type charge generation layer P-CGL1.

[0108] Alternatively, the doping concentration of the second dopant is the same as that of the first dopant, but the conductivity of the second P-type charge generation layer P-CGL2 can be made greater than that of the first P-type charge generation layer P-CGL1 by using a second dopant with a higher conductivity than the first dopant.

[0109] Meanwhile, according to Figure 2, the N-type charge generation layer N-CGL is formed to continuously span the red sub-pixel, green sub-pixel and blue sub-pixel (red sub-pixel R sub-pixel, green sub-pixel G sub-pixel and blue sub-pixel B sub-pixel). However, this disclosure is not limited to this, and the N-type charge generation layer N-CGL can also be patterned in the same way as the P-type charge generation layers P-CGL1 and P-CGL2.

[0110] Specifically, the N-type charge generation layer N-CGL can also be composed of a first N-type charge generation layer patterned into an island structure in the red sub-pixel (red sub-pixel R sub-pixel) and a second N-type charge generation layer continuously formed across the green sub-pixel (green sub-pixel G sub-pixel) and the blue sub-pixel (blue sub-pixel B sub-pixel).

[0111] In this case, the first N-type charge generation layer and the first P-type charge generation layer P-CGL1 can have the same pattern, and the second N-type charge generation layer and the second P-type charge generation layer P-CGL2 can have the same pattern.

[0112] The conductivity of the second N-type charge generation layer can be greater than that of the first N-type charge generation layer. For example, the dopant concentration in the second N-type charge generation layer can be configured to be higher than that in the first N-type charge generation layer, or the dopant in the second N-type charge generation layer can have a higher conductivity than the dopant in the first N-type charge generation layer.

[0113] In some cases, the P-type charge generation layer is continuously formed across the red, green, and blue sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B), and the N-type charge generation layer N-CGL can be formed by a first N-type charge generation layer and a second N-type charge generation layer. However, since screen defects such as flicker are more likely to occur through the P-type charge generation layer rather than the N-type charge generation layer, it is preferable to form the P-type charge generation layer as including a first P-type charge generation layer P-CGL1 and a second P-type charge generation layer P-CGL2, as shown in Figure 2.

[0114] Figure 3 is a cross-sectional schematic diagram of a light-emitting unit according to another embodiment of the present disclosure.

[0115] The difference between Figure 3 and Figure 2 is that the second hole transport layer HTL2 is changed. Therefore, identical components are denoted by the same reference numerals, while different components are described below. This also applies to the other embodiments described below.

[0116] As shown in Figure 3, the second hole transport layer HTL2 includes hole transport layer HTL2-1 (2-1) and hole transport layer HTL2-2 (2-2).

[0117] 2-1 Hole transport layer HTL2-1 is set in the red sub-pixel (red sub-pixel R), and 2-2 Hole transport layer HTL2-2 is set in the green sub-pixel and the blue sub-pixel (green sub-pixel G and blue sub-pixel B).

[0118] 2-1 Hole transport layer HTL2-1 and first P-type charge generation layer P-CGL1 can be formed in the same pattern, and 2-2 Hole transport layer HTL2-2 and second P-type charge generation layer P-CGL2 can be formed in the same pattern.

[0119] Therefore, the 2-1 hole transport layer HTL2-1 can be patterned into an island structure in the red sub-pixel (red sub-pixel R), and the 2-2 hole transport layer HTL2-2 can be continuously formed across the green and blue sub-pixels (green sub-pixel G and blue sub-pixel B).

[0120] Hole transport layers 2-1 and 2-2 (HTL2-1 and HTL2-2 respectively) may be formed so that they do not overlap or contact each other. Alternatively, hole transport layers 2-1 and 2-2 (HTL2-2 respectively) may be formed so that they do not contact each other.

[0121] Therefore, electronic charges cannot move horizontally between hole transport layers HTL2-1 (2-1) and HTL2-2 (2-2), thus preventing leakage current from being generated through the second hole transport layer HTL2-1 between the red sub-pixel (red sub-pixel R) and the green sub-pixel (green sub-pixel G), and the second hole transport layer HTL2-2 between the red sub-pixel (red sub-pixel R) and the blue sub-pixel (blue sub-pixel B).

[0122] 2-1 Hole transport layer HTL2-1 and 2-2 Hole transport layer HTL2-2 may be formed of the same material, but this disclosure is not limited thereto.

[0123] Figures 4 to 8 are schematic plan views of electroluminescent display devices according to various embodiments of the present disclosure. For convenience, only the patterns of the first P-type charge generation layer P-CGL1 and the second P-type charge generation layer P-CGL2 disposed in the sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B) according to Figures 2 to 3 are illustrated in Figures 4 to 8.

[0124] As shown in Figures 4 to 8, the electroluminescent display device according to various embodiments of the present disclosure includes a plurality of pixels, which include red sub-pixels (red sub-pixels R sub-pixels), green sub-pixels (green sub-pixels G sub-pixels) and blue sub-pixels (blue sub-pixels B sub-pixels).

[0125] Each of the pixels disclosed herein may be formed by a combination of red sub-pixels (red sub-pixels R sub-pixels), green sub-pixels (green sub-pixels G sub-pixels) and blue sub-pixels (blue sub-pixels B sub-pixels), but is not necessarily limited thereto, and may further include a fourth sub-pixel.

[0126] As shown in Figures 4 to 8, the first P-type charge generation layer P-CGL1 can overlap with the entire area of ​​the red sub-pixel (red sub-pixel R). Furthermore, the first P-type charge generation layer P-CGL1 can partially overlap with one portion of the boundary region between the red sub-pixel (red sub-pixel R) and the green sub-pixel (green sub-pixel G), and can also partially overlap with one portion of the boundary region between the red sub-pixel (red sub-pixel R) and the blue sub-pixel (blue sub-pixel B).

[0127] The first P-type charge generation layer P-CGL1 does not overlap with the green sub-pixel (green sub-pixel G) or the blue sub-pixel (blue sub-pixel B). Furthermore, the first P-type charge generation layer P-CGL1 is spaced apart from the second P-type charge generation layer P-CGL2.

[0128] The second P-type charge generation layer P-CGL2 overlaps with the entire regions of the green sub-pixel (G sub-pixel) and the blue sub-pixel (B sub-pixel). Furthermore, the second P-type charge generation layer P-CGL2 overlaps with the entire region of the boundary between the green sub-pixel (G sub-pixel) and the blue sub-pixel (B sub-pixel). Additionally, the second P-type charge generation layer P-CGL2 overlaps with a portion of the boundary region between the red sub-pixel (R sub-pixel) and the green sub-pixel (G sub-pixel), and a portion of the boundary region between the red sub-pixel (R sub-pixel) and the blue sub-pixel (B sub-pixel).

[0129] The second P-type charge generation layer P-CGL2 does not overlap with the red sub-pixel (red sub-pixel R sub-pixel).

[0130] Each of these pixels in Figures 4 through 8 will be described in detail below.

[0131] As shown in Figure 4, the blue sub-pixel (blue sub-pixel B) can be spaced apart from the green sub-pixel (green sub-pixel G) and the red sub-pixel (red sub-pixel R) in a first direction (e.g., in the horizontal direction). The blue sub-pixel can be disposed on one side of the green sub-pixel (green sub-pixel G) and the red sub-pixel (red sub-pixel R), and for example, the blue sub-pixel (blue sub-pixel B) can be disposed to the left of the green sub-pixel (green sub-pixel G) and the red sub-pixel (red sub-pixel R) so as to face each of the green sub-pixel (green sub-pixel G) and the red sub-pixel (red sub-pixel R).

[0132] Green sub-pixels (G sub-pixels) and red sub-pixels (R sub-pixels) may be spaced apart from each other in a second direction (e.g., in the vertical direction).

[0133] The area of ​​the blue sub-pixel (blue sub-pixel B) can be larger than the area of ​​the green sub-pixel (green sub-pixel G) and the area of ​​the red sub-pixel (red sub-pixel R), and the area of ​​the green sub-pixel (green sub-pixel G) can be larger than the area of ​​the red sub-pixel (red sub-pixel R), but this disclosure is not limited thereto.

[0134] Each of the blue sub-pixel (blue sub-pixel B), the green sub-pixel (green sub-pixel G), and the red sub-pixel (red sub-pixel R) may have a rectangular structure, for example, a rectangular structure with curved edges.

[0135] A pixel comprising a combination of blue sub-pixels (blue sub-pixel B), green sub-pixels (green sub-pixel G), and red sub-pixels (red sub-pixel R) can be repeatedly set in both the first and second directions.

[0136] The second P-type charge generation layer P-CGL2, which spans two or more pixels horizontally, is continuous across the blue sub-pixels (blue sub-pixels B and green sub-pixels G).

[0137] The second P-type charge generation layer P-CGL2 spanning two or more pixels in the vertical direction may be discontinuous, but this disclosure is not limited thereto. The second P-type charge generation layer P-CGL2 spanning two or more pixels in the vertical direction may be continuous.

[0138] The second P-type charge generation layer P-CGL2, which spans all pixels in both the horizontal and vertical directions, can be continuous.

[0139] The first P-type charge generation layer P-CGL1 is patterned into an island structure in the red sub-pixel (red sub-pixel R). The first P-type charge generation layer P-CGL1 can have an island structure in the red sub-pixel (red sub-pixel R) of all pixels.

[0140] As shown in Figure 5, the blue sub-pixel (blue sub-pixel B), the green sub-pixel (green sub-pixel G), and the red sub-pixel (red sub-pixel R) can be sequentially set in the first direction, for example, in the horizontal direction.

[0141] The area of ​​the blue sub-pixel (blue sub-pixel B) can be larger than the area of ​​the green sub-pixel (green sub-pixel G) and the area of ​​the red sub-pixel (red sub-pixel R), and the area of ​​the green sub-pixel (green sub-pixel G) can be larger than the area of ​​the red sub-pixel (red sub-pixel R), but this disclosure is not limited thereto.

[0142] Each of the blue sub-pixel (blue sub-pixel B), the green sub-pixel (green sub-pixel G), and the red sub-pixel (red sub-pixel R) may have a rectangular structure, for example, a rectangular structure with curved edges.

[0143] A pixel comprising a combination of blue sub-pixels (blue sub-pixel B), green sub-pixels (green sub-pixel G), and red sub-pixels (red sub-pixel R) can be repeatedly arranged in the first and second directions.

[0144] The second P-type charge generation layer P-CGL2, which spans two or more pixels vertically across all blue sub-pixels (blue sub-pixels B) and green sub-pixels (green sub-pixels G), is continuous. However, the second P-type charge generation layer P-CGL2, which spans these pixels horizontally, is discontinuous.

[0145] The first P-type charge generation layer P-CGL1 of red sub-pixels spanning two or more pixels vertically can be continuous. However, the first P-type charge generation layer P-CGL1 of red sub-pixels (red sub-pixels R sub-pixels) spanning these pixels horizontally is discontinuous.

[0146] As shown in Figure 6, the green sub-pixel (green sub-pixel G sub-pixel) and the blue sub-pixel (blue sub-pixel B sub-pixel) can be spaced apart from the red sub-pixel (red sub-pixel R sub-pixel) in a first direction (e.g., in the horizontal direction).

[0147] Green sub-pixels (G sub-pixels) and red sub-pixels (R sub-pixels) may be spaced apart from each other in a second direction (e.g., in the vertical direction).

[0148] Green sub-pixels (G sub-pixel), blue sub-pixels (B sub-pixel), and red sub-pixels (R sub-pixel) can be arranged to form the vertices of a triangle.

[0149] Each of the green sub-pixel (green sub-pixel G sub-pixel), the blue sub-pixel (blue sub-pixel B sub-pixel), and the red sub-pixel (red sub-pixel R sub-pixel) may have a circular structure.

[0150] A pixel comprising a combination of blue sub-pixels (blue sub-pixel B), green sub-pixels (green sub-pixel G), and red sub-pixels (red sub-pixel R) can be repeatedly set in both the first and second directions.

[0151] The second P-type charge generation layer P-CGL2 spanning two or more blue and green sub-pixels is continuous. However, the second P-type charge generation layer P-CGL2 spanning these pixels horizontally is discontinuous.

[0152] The first P-type charge generation layer P-CGL1 of red sub-pixels (red sub-pixels R) that spans two or more pixels vertically can be continuous. However, the first P-type charge generation layer P-CGL1 of red sub-pixels (red sub-pixels R) that spans these pixels horizontally is discontinuous.

[0153] As shown in Figure 7, the green sub-pixel (green sub-pixel G) and the blue sub-pixel (blue sub-pixel B) can be separated from the red sub-pixel (red sub-pixel R) in a diagonal direction (e.g., from the upper right to the lower left).

[0154] Green sub-pixels (G sub-pixels) and red sub-pixels (R sub-pixels) can be spaced apart from each other diagonally (e.g., from top left to bottom right).

[0155] A combination of a green sub-pixel (green sub-pixel G sub-pixel) and a red sub-pixel (red sub-pixel R sub-pixel) is repeatedly set in a first direction (e.g., in the horizontal direction) to form a zigzag pattern.

[0156] Green sub-pixels (green sub-pixel G), blue sub-pixels (blue sub-pixel B), and red sub-pixels (red sub-pixel R) can be configured to form triangle vertices.

[0157] Each of the green sub-pixel (green sub-pixel G sub-pixel), the blue sub-pixel (blue sub-pixel B sub-pixel), and the red sub-pixel (red sub-pixel R sub-pixel) may have a circular structure.

[0158] A pixel comprising a combination of blue sub-pixels (blue sub-pixel B), green sub-pixels (green sub-pixel G), and red sub-pixels (red sub-pixel R) can be repeatedly set in both the first and second directions.

[0159] The second P-type charge generation layer P-CGL2, which spans two or more pixels horizontally, is continuous across the entire blue sub-pixel (blue sub-pixel B) and green sub-pixel (green sub-pixel G).

[0160] The second P-type charge generation layer P-CGL2, which spans two or more pixels vertically, may be discontinuous, but this disclosure is not limited thereto. Furthermore, the second P-type charge generation layer P-CGL2 can be continuous and uninterrupted by extending vertically through a boundary region between two red sub-pixels (R sub-pixels) within those pixels. In this case, the second P-type charge generation layer P-CGL2 can be continuous in all pixels, both horizontally and vertically.

[0161] The first P-type charge generation layer P-CGL1 can have an island-like structure while not discontinuously spanning the red sub-pixels (red sub-pixels R) of these pixels. However, this disclosure is not limited to this, and the first P-type charge generation layer P-CGL1 spanning two or more red sub-pixels (red sub-pixels R) in the horizontal direction can be continuous.

[0162] As shown in Figure 8, a pixel can contain two green sub-pixels (green sub-pixels G sub-pixels). For example, the two green sub-pixels (green sub-pixels G sub-pixels) can be spaced apart from the blue sub-pixels (blue sub-pixels B sub-pixels) along the diagonal direction of one of the blue sub-pixels (blue sub-pixels B sub-pixels).

[0163] A green sub-pixel (green sub-pixel G) can be separated from a blue sub-pixel (blue sub-pixel B) to the lower right of the blue sub-pixel (blue sub-pixel B), and another green sub-pixel (green sub-pixel G) can be separated from a blue sub-pixel (blue sub-pixel B) to the lower left of the blue sub-pixel.

[0164] Additionally, the red sub-pixel (red sub-pixel R) can be spaced apart from the blue sub-pixel (blue sub-pixel B) in a second direction (e.g., in the vertical direction).

[0165] Each of the blue sub-pixel (blue sub-pixel B), the green sub-pixel (green sub-pixel G), and the red sub-pixel (red sub-pixel R) may have a rectangular structure, for example, a rectangular structure with curved edges.

[0166] A pixel with a rectangular structure is formed by a combination of two green sub-pixels (green sub-pixel G), a blue sub-pixel (blue sub-pixel B), and a red sub-pixel (red sub-pixel R), and this pixel can be repeated in the diagonal direction.

[0167] The second P-type charge generation layer P-CGL2, spanning the entire blue sub-pixel (blue sub-pixel B) and green sub-pixel (green sub-pixel G), is continuous.

[0168] The first P-type charge generation layer P-CGL1 can have an island-like structure while not discontinuously spanning the red sub-pixels (red sub-pixels R sub-pixels) of these pixels.

[0169] Figure 9 is a cross-sectional schematic diagram of a light-emitting unit according to another embodiment of the present disclosure.

[0170] The difference between Figure 9 and Figure 2 above is that the P-type charge generation layers P-CGL1 and P-CGL2 are changed.

[0171] As shown in Figure 9, the first P-type charge generation layer P-CGL1 can be formed to continuously span across the red sub-pixel, green sub-pixel, and blue sub-pixel (red sub-pixel R sub-pixel, green sub-pixel G sub-pixel, and blue sub-pixel B sub-pixel).

[0172] As shown in Figure 2 above, the second P-type charge generation layer P-CGL2 can be formed to continuously span the green sub-pixel and the blue sub-pixel (green sub-pixel G sub-pixel and blue sub-pixel B sub-pixel).

[0173] The second P-type charge generation layer P-CGL2 is disposed below the first P-type charge generation layer P-CGL1 and can contact the first P-type charge generation layer P-CGL1.

[0174] According to another embodiment of this disclosure, by connecting the second P-type charge generation layer P-CGL2 of the blue sub-pixel (blue sub-pixel B) with the relatively largest driving current and the second P-type charge generation layer P-CGL2 of the green sub-pixel (green sub-pixel G) with the relatively smallest driving current, residual electronic charge in the boundary region can be prevented or reduced by reducing the horizontal resistance between the blue sub-pixel (blue sub-pixel B) and the green sub-pixel (green sub-pixel G), thereby eliminating screen defects such as flicker.

[0175] However, this disclosure is not necessarily limited to this, and the second P-type charge generation layer P-CGL2 can be continuously formed between blue sub-pixels (blue sub-pixel B sub-pixel) and red sub-pixels (red sub-pixel R sub-pixel) or between red sub-pixels (red sub-pixel R sub-pixel) and green sub-pixels (green sub-pixel G sub-pixel).

[0176] Meanwhile, as shown in Figure 2, the N-type charge generation layer N-CGL may include a first N-type charge generation layer formed continuously across red, green, and blue sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B), and a second N-type charge generation layer formed continuously across green and blue sub-pixels (green sub-pixel G and blue sub-pixel B). That is, the first N-type charge generation layer may be formed with the same pattern as the first P-type charge generation layer P-CGL1, and the second N-type charge generation layer may be formed with the same pattern as the second P-type charge generation layer P-CGL2.

[0177] In some cases, the P-type charge generation layer can be formed to continuously span red, green and blue sub-pixels (red sub-pixel R, green sub-pixel G and blue sub-pixel B), and the N-type charge generation layer N-CGL can be formed by a first N-type charge generation layer and a second N-type charge generation layer.

[0178] Figure 10 is a cross-sectional schematic diagram of a light-emitting unit according to another embodiment of the present disclosure.

[0179] The difference between Figure 10 and Figure 9 is that the second P-type charge generation layer P-CGL2 is disposed on the first P-type charge generation layer P-CGL1 and is in contact with the first P-type charge generation layer P-CGL1.

[0180] Figure 11 is a cross-sectional schematic diagram of a light-emitting unit according to another embodiment of the present disclosure.

[0181] The difference between Figure 11 and Figure 9 above is that the second hole transport layer HTL2 is changed.

[0182] As shown in Figure 11, the second hole transport layer HTL2 includes hole transport layer 2-1 HTL2-1 and hole transport layer 2-2 HTL2-2.

[0183] 2-1 Hole transport layer HTL2-1 is set in the red sub-pixel (red sub-pixel R), and 2-2 Hole transport layer HTL2-2 is set in the green sub-pixel and the blue sub-pixel (green sub-pixel G and blue sub-pixel B).

[0184] The 2-1 hole transport layer HTL2-1 can be patterned into an island structure in the red sub-pixel (red sub-pixel R), and the 2-2 hole transport layer HTL2-2 spanning the green and blue sub-pixels (green sub-pixel G and blue sub-pixel B) can be formed as a continuous structure.

[0185] Hole transport layers HTL2-1 (2-1) and HTL2-2 (2-2) can be formed without overlapping each other. Furthermore, hole transport layers HTL2-1 (2-1) and HTL2-2 (2-2) can be formed without contacting each other.

[0186] Therefore, the electron charge cannot move horizontally between the 2-1 hole transport layer HTL2-1 and the 2-2 hole transport layer HTL2-2, and thus no leakage current is generated through the 2-1 hole transport layer HTL2-1 between the red sub-pixel (red sub-pixel R) and the green sub-pixel (green sub-pixel G), and the 2-2 hole transport layer HTL2-2 between the red sub-pixel (red sub-pixel R) and the blue sub-pixel (blue sub-pixel B).

[0187] 2-1 Hole transport layer HTL2-1 and 2-2 Hole transport layer HTL2-2 may be formed of the same material, but this disclosure is not limited thereto.

[0188] Figures 12 to 16 are schematic plan views of electroluminescent display devices according to various embodiments of the present disclosure. For convenience, only the patterns of the first P-type charge generation layer P-CGL1 and the second P-type charge generation layer P-CGL2 disposed in the sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B) of Figures 9 to 11 are shown in Figures 12 to 16.

[0189] The difference between Figure 12 and Figure 4 is that the first P-type charge generation layer P-CGL1, which spans all sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B) across these pixels in both the horizontal and vertical directions, is continuous.

[0190] The difference between Figure 13 and Figure 5 is that the first P-type charge generation layer P-CGL1, which spans all sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B) across these pixels in both the horizontal and vertical directions, is continuous.

[0191] The difference between Figure 14 and Figure 6 is that the first P-type charge generation layer P-CGL1, which spans all sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B) across these pixels in both the horizontal and vertical directions, is continuous.

[0192] The difference between Figure 15 and Figure 7 is that the first P-type charge generation layer P-CGL1, which spans all sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B) across these pixels in both the horizontal and vertical directions, is continuous.

[0193] The difference between Figure 16 and Figure 8 is that the first P-type charge generation layer P-CGL1, which spans all the sub-pixels (red sub-pixel R, green sub-pixel G, and blue sub-pixel B) along the diagonal direction, is continuous.

[0194] Those skilled in the art will understand that the foregoing disclosure is not limited to the foregoing embodiments and accompanying drawings, and that various substitutions, modifications, and variations can be made to the disclosure without departing from the technical concept or scope thereof. Therefore, the scope of the disclosure is defined by the appended claims, and all variations or modifications intended to be derived from the meaning, scope, and equivalent concepts of the claims fall within the scope of the disclosure.

[0195] The various embodiments described above can be combined to provide further embodiments. Such and other changes may be made to the embodiments in light of the above detailed description. Generally, the terminology used in the following claims should not be construed as limiting the claims to the specific embodiments disclosed in the specification and claims, but should be construed as encompassing all possible embodiments, including the full scope of equivalents entitled to in such claims. Accordingly, the claims are not limited by this disclosure.

[0196] 100:Substrate 200: Circuit Component Layer 210: Active Layer 220: Gate insulation layer 230: Gate electrode 240: Interlayer insulation layer 250: Source electrode 260: Drain electrode 310: Passivation layer 320: Planarization layer 400: First electrode 450:Dike 500: Light-emitting unit 600: Second electrode 700: Capping layer CGL: Charge Generation Layer EIL: Electron Injection Layer ETL1: First Electron Transport Layer ETL2: Second Electron Transport Layer HIL: Hole Injection Layer HTL1: First Hole Transport Layer HTL2: Second Hole Transport Layer HTL2-1:2-1 Hole Transport Layer HTL2-2:2-2 Hole Transport Layer HTL3-1:3-1 Hole Transport Layer HTL3-2:3-2 Hole Transport Layer HTL3-3:3-3 Hole Transport Layer N-CGL: N-type charge generation layer P-CGL1: First P-type charge generation layer P-CGL2: Second P-type charge generation layer R-EML1: First red luminescent layer R-EML2: Second Red Emissive Layer G-EML1: First Green Emissive Layer G-EML2: Second Green Emissive Layer B-EML1: First Blue Emitting Layer B-EML2: Second Blue Emissive Layer R sub-pixel: Red sub-pixel G sub-pixel: Green sub-pixel B sub-pixel: Blue sub-pixel 1st Stack: The first stack layer 2nd Stack

Claims

1. An electroluminescent display device, comprising: a substrate including a first sub-pixel, a second sub-pixel, and a third sub-pixel; a first electrode located on the substrate for each of the first sub-pixel to the third sub-pixel; a light-emitting unit located on the first electrode; and a second electrode located on the light-emitting unit, wherein the light-emitting unit includes: a first stack including a first light-emitting layer, a second stack including a second light-emitting layer, and a charge-generating layer disposed between the first stack and the second stack, wherein the charge-generating layer includes: a first charge-generating layer disposed in the first sub-pixel, and a second charge-generating layer disposed in the second sub-pixel and the third sub-pixel, and wherein the second charge-generating layer does not overlap with the first sub-pixel and the second charge-generating layer spanning the second sub-pixel and the third sub-pixel is continuous.

2. The electroluminescent display device as claimed in claim 1, wherein the conductivity of one of the second charge generating layers is greater than the conductivity of one of the first charge generating layers.

3. The electroluminescent display device as claimed in claim 1, wherein the charge generating layer comprises an N-type charge generating layer and a P-type charge generating layer, and the P-type charge generating layer comprises the first charge generating layer and the second charge generating layer.

4. The electroluminescent display device as claimed in claim 1, wherein one of the second sub-pixel and the third sub-pixel is a blue sub-pixel, and the other of the second sub-pixel and the third sub-pixel is a green sub-pixel.

5. The electroluminescent display device as claimed in claim 1, wherein the first charge generating layer does not overlap with the second sub-pixel and the third sub-pixel.

6. The electroluminescent display device as claimed in claim 1, wherein the first charge generating layer and the second charge generating layer are spaced apart.

7. The electroluminescent display device as claimed in claim 1, wherein the first charge generation layer spanning the first sub-pixel, the second sub-pixel, and the third sub-pixel is continuous.

8. The electroluminescent display device as claimed in claim 7, wherein the second charge generating layer is disposed above or below the first charge generating layer.

9. The electroluminescent display device as claimed in claim 1, wherein the second stack includes a hole transport layer disposed on the charge generation layer, wherein the hole transport layer includes: a first hole transport layer disposed in the first sub-pixel and a second hole transport layer disposed in the second sub-pixel and the third sub-pixel, and wherein the second hole transport layer does not overlap with the first sub-pixel and the second hole transport layer spanning the second sub-pixel and the third sub-pixel is continuous.

10. The electroluminescent display device as claimed in claim 9, wherein the first hole transport layer has a pattern identical to one of the patterns of the first charge generation layer, and the second hole transport layer has a pattern identical to one of the patterns of the second charge generation layer.

11. An electroluminescent display device, comprising: a plurality of pixels, including a first sub-pixel, a second sub-pixel and a third sub-pixel, wherein the pixels are disposed in a first direction and a second direction; and a light-emitting unit disposed in the pixels, the light-emitting unit including a charge-generating layer, wherein the charge-generating layer includes a first charge-generating layer and a second charge-generating layer, the first charge-generating layer being disposed in the first sub-pixel, the second charge-generating layer not overlapping with the first sub-pixel and the second charge-generating layer spanning the second sub-pixel and the third sub-pixel being continuous, and wherein the second charge-generating layer spanning two or more of the pixels disposed along the first direction is continuous.

12. The electroluminescent display device as claimed in claim 11, wherein the second charge-generating layer across the pixels disposed along the second direction is discontinuous.

13. The electroluminescent display device as claimed in claim 11, wherein the second charge-generating layer of all the pixels disposed across the first direction and the second direction is continuous.

14. The electroluminescent display device as claimed in claim 11, wherein the first charge generating layer is configured as an island structure in all of the pixels disposed in the first direction and the second direction.

15. The electroluminescent display device as claimed in claim 11, wherein the first charge-generating layer spanning two or more of the pixels disposed along the first direction is continuous.

16. The electroluminescent display device as claimed in claim 11, wherein the first charge-generating layer spanning all the pixels along the first direction and the second direction is continuous.

17. The electroluminescent display device as claimed in claim 11, wherein the conductivity of one of the second charge generating layers is greater than the conductivity of one of the first charge generating layers.

18. The electroluminescent display device as claimed in claim 11, wherein the charge generating layer comprises an N-type charge generating layer and a P-type charge generating layer, and the P-type charge generating layer comprises the first charge generating layer and the second charge generating layer.

19. The electroluminescent display device as claimed in claim 11, wherein one of the second sub-pixel and the third sub-pixel is a blue sub-pixel, and the other of the second sub-pixel and the third sub-pixel is a green sub-pixel.

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