Electroluminescent display device

Abstract

To provide an electroluminescent display device which is fabricated by a solution process and furthermore enables prevention of flowing of a light emission stack of any one subpixel to another subpixel.SOLUTION: The present disclosure provides an electroluminescent display device including: a substrate including a first subpixel and a second subpixel which are arranged in a first direction; first electrodes which are provided in the first subpixel and the second subpixel, respectively; a bank which is provided in a boundary between the first subpixel and the second subpixel on the substrate; light emission stacks which are provided on the first electrode and the bank, respectively; and a second electrode which is provided in the light emission stack. The bank includes a first bank and a second bank provided in the first bank. The light emission stack is provided in a first layer provided in each of the first subpixel and the second subpixel, and on the first layer, and includes a second layer continuous to the second subpixel from the first subpixel. The first bank is provided on a lower side of the second layer, and the second bank is provided on the second layer.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an electroluminescent display device, and more particularly, to an electroluminescent display device that can be manufactured using a solution process. [Background technology]

[0002] An electroluminescent display device includes a first electrode, a second electrode, and a light-emitting stack disposed between the first electrode and the second electrode, and displays images by causing the light-emitting stack to emit light in response to an electric field between the two electrodes.

[0003] The luminescent stack may comprise an organic material that emits light as excitons are annihilated by recombination of electrons and holes. An exciton is an electrically neutral particle that contains an electrostatically bound electron and hole. An exciton is generated when the organic material absorbs light with an energy higher than its band gap, exciting an electron from the valence band to the conduction band. When a conduction band electron in the exciton recombines with a hole in the valence band, the exciton is annihilated and the energy of the exciton may be converted to light. Summary of the Invention [Problem to be solved by the invention]

[0004] The light-emitting stack can be formed by a vacuum deposition process, but in this case, expensive vacuum deposition equipment is required, which may increase manufacturing costs. In particular, in the case of large electroluminescent displays, the mask for pattern formation and the vacuum deposition equipment become even larger, which reduces productivity during mass production.

[0005] Therefore, in order to reduce the manufacturing cost, a method of forming the light emitting stack through a solution process using an inkjet device or the like has been proposed.

[0006] However, when the light-emitting stack is formed by a solution process, a problem may occur in which, for example, the solution for forming the red light-emitting stack flows from the red sub-pixel to the adjacent green sub-pixel, degrading the image quality of the green sub-pixel.

[0007] SUMMARY OF THE PRESENT EMBODIMENTS The present invention provides an electroluminescent display device that can prevent a light-emitting stack of one sub-pixel from flowing into another sub-pixel while utilizing a solution process. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides an electroluminescence display device comprising: a substrate including first and second sub-pixels arranged in a first direction; a first electrode provided in each of the first and second sub-pixels on the substrate; a bank provided at a boundary between the first and second sub-pixels on the substrate; a light-emitting stack provided on the first electrode and the bank; and a second electrode provided on the light-emitting stack, the bank comprising a first bank and a second bank provided on the first bank, the light-emitting stack comprising a first layer provided in each of the first and second sub-pixels, and a second layer provided on the first layer and continuing from the first sub-pixel to the second sub-pixel, the first bank being provided below the second layer, and the second bank being provided on the second layer.

[0009] The present invention also provides an electroluminescence display device comprising: a substrate including a plurality of first sub-pixels and a plurality of second sub-pixels; first banks provided at boundaries between the plurality of first sub-pixels and the plurality of second sub-pixels, at boundaries between the plurality of first sub-pixels, and at boundaries between the plurality of second sub-pixels; second banks provided in a continuous linear structure along boundaries between the plurality of first sub-pixels and the plurality of second sub-pixels; and third banks provided in a discontinuous linear structure at boundaries between the plurality of first sub-pixels and at boundaries between the plurality of second sub-pixels. Effect of the Invention

[0010] According to the present invention as described above, the following effects are obtained.

[0011] According to one embodiment of the present invention, the first layer of the light-emitting stack, which needs to be separated into sub-pixels, is formed by a solution process such as an inkjet process, but the sub-pixels are separated by the first bank, so that adjacent sub-pixels are not continuous.

[0012] According to one embodiment of the present invention, the second and fourth layers of the light-emitting stack, which do not need to be separated for each sub-pixel, can be formed without a mask by a vacuum deposition method such as an evaporation method.

[0013] According to one embodiment of the present invention, a second bank is further formed on the second layer of the light-emitting stack, so that the third layer of the light-emitting stack, which needs to be separated into sub-pixels, is formed by a solution process such as an inkjet process, but is disconnected by the second bank and is no longer continuous between adjacent sub-pixels.

[0014] According to another embodiment of the present invention, a third bank is formed at the boundary between one subpixel emitting light of the same hue and another adjacent subpixel, and by ensuring a predetermined space for ink movement, the fluidity of the light-emitting stack is improved and the problem of mottling in a particular subpixel can be prevented. [Brief description of the drawings]

[0015] [Figure 1] 1 is a schematic plan view of an electroluminescence display device according to an embodiment of the present invention; [Diagram 2] 2 is a schematic cross-sectional view of an electroluminescence display device according to an embodiment of the present invention, taken along line AB of FIG. [Diagram 3] 1 is a schematic cross-sectional view of a light emitting stack according to one embodiment of the present invention. [Figure 4] 1 is a schematic cross-sectional view of an electroluminescence display device according to various embodiments of the present invention, illustrating a portion of a boundary region between a first sub-pixel and a second sub-pixel; [Diagram 5] 1 is a schematic cross-sectional view of an electroluminescence display device according to various embodiments of the present invention, illustrating a portion of a boundary region between a first sub-pixel and a second sub-pixel; [Figure 6] 1 is a schematic cross-sectional view of an electroluminescence display device according to various embodiments of the present invention, illustrating a portion of a boundary region between a first sub-pixel and a second sub-pixel; [Figure 7] 2 is a schematic cross-sectional view of an electroluminescence display device according to an embodiment of the present invention, taken along line CD in FIG. [Figure 8] 1 is a schematic plan view of an electroluminescence display device according to another embodiment of the present invention; [Figure 9] 9 is a schematic cross-sectional view of an electroluminescence display device according to another embodiment of the present invention, taken along line EF of FIG. [Figure 10] 1 is a schematic plan view of an electroluminescent display device according to various embodiments of the present invention; [Figure 11] 1 is a schematic plan view of an electroluminescent display device according to various embodiments of the present invention; [Figure 12] 1 is a schematic plan view of an electroluminescent display device according to various embodiments of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The advantages and features of the present invention, and the method of achieving them, will become apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. The embodiments are provided solely to complete the disclosure of the present invention and to fully inform those skilled in the art of the present invention of the scope of the invention. The present invention is defined only by the claims.

[0017] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative, and the present invention is not limited to the matters shown in the drawings. The same reference numerals refer to the same components throughout the specification. In addition, in the description of the present invention, if a specific description of related known technology is deemed to unnecessarily obscure the gist of the present invention, the detailed description will be omitted. When "including," "having," "consisting of," etc. are used in this specification, other parts may be added unless "only" is used. When a component is expressed in the singular, it includes the case where the plural is included unless otherwise explicitly stated.

[0018] When interpreting elements, they are interpreted as including a margin of error even if there is no explicit statement to the contrary.

[0019] When describing a positional relationship, for example when the positional relationship of two parts is described using "on top", "at the top", "at the bottom", "next to" etc., one or more other parts may be located between the two parts, unless "immediately" or "directly" is used.

[0020] When describing a temporal relationship, for example when the temporal sequence is described using "after", "following", "next to", "before", etc., it can include cases where the sequence is not consecutive, unless "immediately" or "directly" is used.

[0021] Although the terms "first", "second" and the like are used to describe various components, these components are not limited by these terms. These terms are merely used to distinguish one component from another. Therefore, the first component referred to below may be the second component within the technical spirit of the present invention.

[0022] The features of each of the examples of the present application may be partially or fully combined or combined with each other, and may be technically linked and driven in various ways, and each example may be implemented independently of each other, or may be implemented together in relation to each other.

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0024] FIG. 1 is a schematic plan view of an electroluminescent display device according to an embodiment of the present invention.

[0025] As can be seen from FIG. 1, an electroluminescence display device according to an embodiment of the present invention includes a substrate 100, a plurality of sub-pixels (SP1, SP2, SP3) formed on the substrate 100, a first electrode 300 formed in each of the plurality of sub-pixels (SP1, SP2, SP3), and banks 410, 420 formed in boundary regions between the plurality of sub-pixels (SP1, SP2, SP3).

[0026] The plurality of sub-pixels (SP1, SP2, SP3) may include a first sub-pixel (SP1), a second sub-pixel (SP2), and a third sub-pixel (SP3) arranged in a first direction, for example, the X-axis direction.

[0027] The first sub-pixel (SP1) may emit light of a first hue, the second sub-pixel (SP2) may emit light of a second hue, and the third sub-pixel (SP3) may emit light of a third hue.

[0028] The multiple first sub-pixels (SP1) can be arranged in a second direction intersecting the first direction, for example the Y-axis direction, and similarly, the multiple second sub-pixels (SP2) and the multiple third sub-pixels (SP3) can also be arranged in the second direction.

[0029] The arrangement structure of the plurality of sub-pixels (SP1, SP2, SP3) can be changed to various forms known in the art.

[0030] The first electrode 300 may function as an anode of an electroluminescent display device, may be patterned in each of the sub-pixels SP1, SP2, and SP3, and may be surrounded by the banks 410 and 420.

[0031] The banks 410 and 420 are provided in boundary regions between the sub-pixels (SP1, SP2, SP3) and can individually define the sub-pixel regions (SP1, SP2, SP3).

[0032] The banks 410 , 420 comprise a first bank 410 and a second bank 420 .

[0033] The first bank 410 may be formed in a mesh structure in boundary regions between the sub-pixels (SP1, SP2, SP3). In particular, the first bank 410 may be formed in boundary regions between the first sub-pixel (SP1), the second sub-pixel (SP2), and the third sub-pixel (SP3) arranged in the first direction, and may also be formed in boundary regions between the first sub-pixels (SP1), the second sub-pixels (SP2), and the third sub-pixels (SP3) arranged in the second direction.

[0034] The second bank 420 may be formed in a different pattern from the first bank 410. In particular, the second bank 420 may be formed in boundary regions between the first sub-pixel (SP1), the second sub-pixel (SP2), and the third sub-pixel (SP3) arranged in the first direction, but may not be formed in boundary regions between the first sub-pixels (SP1), the second sub-pixels (SP2), and the third sub-pixels (SP3) arranged in the second direction. Therefore, the second bank 420 may be formed in a stripe structure that is elongated in the second direction and spaced apart at a predetermined interval in the first direction.

[0035] Figure 2 is a schematic cross-sectional view of an electroluminescence display device according to an embodiment of the present invention, which corresponds to a cross-section taken along line AB in Figure 1. That is, Figure 2 is a cross-sectional view including boundary regions between a first sub-pixel (SP1), a second sub-pixel (SP2), and a third sub-pixel (SP3) that emit light of different colors.

[0036] As can be seen from FIG. 2, an electroluminescent display device according to one embodiment of the present invention includes a substrate 100, a circuit element layer 200, a first electrode 300, banks 410, 420, a light-emitting stack 500, a second electrode 600, an encapsulation layer 700, a color filter 800, a light-shielding layer 850, and a protective layer 900.

[0037] The substrate 100 may be made of glass or transparent plastic, but is not limited thereto, and may be made of a semiconductor material such as a silicon wafer. When the electroluminescent display according to an embodiment of the present invention is of a top emission type, not only a transparent material but also an opaque material may be used for the substrate 100. However, when the electroluminescent display according to an embodiment of the present invention emits light of a bottom emission type, a transparent material is used for the substrate 100.

[0038] The circuit element layer 200 is formed on a substrate 100 .

[0039] The circuit element layer 200 includes a driving thin film transistor.

[0040] The driving thin film transistor includes an active layer 210 provided on the substrate 100, a gate insulating film 220 provided on the active layer 210, a gate electrode 230 provided on the gate insulating film 220, an interlayer insulating film 240 provided on the gate electrode 230, and a source electrode 251 and a drain electrode 252 provided on the interlayer insulating film 240 and connected to the active layer 210 through holes provided in the interlayer insulating film 240 and the gate insulating film 220. Although the drawing shows a driving thin film transistor having a top gate structure in which the gate electrode 230 is provided on the active layer 210, the present invention may include a driving thin film transistor having a bottom gate structure in which the gate electrode 230 is provided under the active layer 210.

[0041] The circuit element layer 200 may further include a passivation layer 260 and a planarization layer 270 disposed on the driving thin film transistor. The passivation layer 260 is disposed on the source electrode 251 and the drain electrode 252, and the planarization layer 270 is disposed on the passivation layer 260.

[0042] The passivation layer 260 and the planarization layer 270 may include a contact hole through which the first electrode 300 may be connected to the drain electrode 252. In some cases, the first electrode 300 may be connected to the source electrode 251 through the contact hole.

[0043] Meanwhile, the circuit element layer 200 may further include, in addition to the driving thin film transistor, 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.

[0044] The switching thin film transistor is switched by a gate signal supplied to the gate line and serves to supply a data voltage supplied from the data line to the driving thin film transistor.

[0045] The driving thin film transistor is switched by the data voltage supplied from the switching thin film transistor, generates a data current from the power source supplied from the power line, and supplies the data current to the first electrode 300.

[0046] The sensing thin film transistor serves to sense a threshold voltage deviation of the driving thin film transistor, which may cause degradation of image quality, and supplies a current of the driving thin film transistor to the reference line in response to a sensing control signal supplied from the gate line or a separate sensing line.

[0047] The capacitor serves to maintain the data voltage supplied to the driving thin film transistor for one frame, and is connected to a gate terminal and a source terminal of the driving thin film transistor, respectively.

[0048] Each of the switching thin film transistor, the driving thin film transistor, and the sensing thin film transistor may be modified to have various structures known in the art, such as a bottom gate structure or a top gate structure.

[0049] In addition, the circuit element layer 200 may further include a passivation layer for protecting the switching thin film transistor, the driving thin film transistor, and the sensing thin film transistor, and a planarization layer provided on the passivation layer.

[0050] The first electrode 300 is formed for each of the sub-pixels (SP1, SP2, SP3) on the circuit element layer 200. The first electrode 300 may function as an anode of the electroluminescent display device. The first electrode 300 may include a transparent electrode when the electroluminescent display device according to the present invention is a bottom emission type, and may include a reflective electrode when the electroluminescent display device according to the present invention is a top emission type.

[0051] The banks 410 , 420 are provided on the circuit element layer 200 and include a first bank 410 and a second bank 420 .

[0052] The first bank 410 is formed on the circuit element layer 200 to cover both ends of the first electrode 300, and is formed at the boundaries between a plurality of sub-pixels (SP1, SP2, SP3).

[0053] The first bank 410 may be formed in a two-layer structure including a lower bank layer 410a and an upper bank layer 410b.

[0054] The lower bank layer 410a may be formed to contact the first electrode 300 and the circuit element layer 200. The lower bank layer 410a may be formed to have a thickness smaller than that of the upper bank layer 410b and a width larger than that of the upper bank layer 410b. The lower bank layer 410a may be made of a hydrophilic material, but is not limited thereto, and may be made of a hydrophobic material in some cases.

[0055] The upper bank layer 410b is patterned on the lower bank layer 410a. The upper bank layer 410b is formed at the boundary between the first sub-pixel (SP1) and the second sub-pixel (SP2) and the boundary between the second sub-pixel (SP2) and the third sub-pixel (SP3). As will be seen from FIG. 7, which will be described later, the upper bank layer 410b may not be formed at the boundary between the first sub-pixels (SP1), the boundary between the second sub-pixels (SP2), and the boundary between the third sub-pixels (SP3).

[0056] The upper bank layer 410b may be patterned by a photolithography process after applying a solution in which a hydrophobic material such as fluorine is mixed with a hydrophilic organic insulator. The hydrophobic material such as fluorine may migrate to the upper side of the upper bank layer 410b by light irradiated during the photolithography process, so that the upper part of the upper bank layer 410b may have hydrophobic properties and the other parts may have hydrophilic properties. That is, the lower part of the upper bank layer 410b in contact with the lower bank layer 410a may have hydrophilic properties, and the upper part of the upper bank layer 410b may have hydrophobic properties. However, the present invention is not limited thereto, and the entire upper bank layer 410b may have hydrophobic properties. In this way, the upper part of the upper bank layer 410b having hydrophobic properties may prevent a problem that a solution for forming the light emitting stack 500, particularly the first layer 510, spreads and mixes between adjacent sub-pixels (SP1, SP2, SP3).

[0057] The second bank 420 is formed at the boundary between the sub-pixels (SP1, SP2, SP3) on the upper side of the first bank 410. A second layer 520 of the light-emitting stack 500 is provided between the second bank 420 and the first bank 410, so that the second bank 420 is not in contact with the first bank 410. The width of the second bank 420 may be smaller than the width of the first bank 410, but is not necessarily limited thereto. The light-emitting stack 500 may include a plurality of layers made of different materials, some of which may emit light and some of which may not emit light, but may facilitate light emission by other layers in the light-emitting stack 500. As an example, the light-emitting stack 500 may include one or more organic light-emitting stacks. The light-emitting stack 500 may also include at least one layer selected from the group consisting of a hole injection layer, a hole transport layer, a charge generation layer, an electron transport layer, and / or an electron injection layer.

[0058] The second bank 420 may be formed of the same material and through the same process as the upper bank layer 410b, so that a lower portion of the second bank 420 may have a hydrophilic property and an upper portion of the second bank 420 may have a hydrophobic property. Alternatively, the entire second bank 420 may be configured to have a hydrophobic property. In this manner, the upper portion of the second bank 420 having a hydrophobic property may prevent a problem in which a solution for forming the third layer 530 of the light emitting stack 500 spreads and mixes between adjacent sub-pixels (SP1, SP2, SP3).

[0059] The light-emitting stack 500 is formed on the first electrode 300 and the banks 410, 420. The light-emitting stack 500 includes a first layer 510, a second layer 520, a third layer 530, and a fourth layer 540, which are stacked in sequence.

[0060] The first layer 510 is formed on the first electrode 300 by a solution process using an inkjet device, etc. The first layer 510 includes an emitting layer made of an organic material that emits light.

[0061] The first layer 510 is patterned in a plurality of sub-pixels (SP1, SP2, SP3) and is not continuous but is disconnected between the plurality of sub-pixels (SP1, SP2, SP3). That is, the first layer 510 in the first sub-pixel (SP1), the first layer 510 in the second sub-pixel (SP2), and the first layer 510 in the third sub-pixel (SP3) are not connected to each other but are disconnected, thereby preventing emission from occurring in the boundary regions between the sub-pixels (SP1, SP2, SP3).

[0062] Because the upper portion of the upper bank layer 410b has hydrophobic properties, the first layer 510 does not spread onto the upper portion of the upper bank layer 410b, and is patterned in a discontinuous manner within a plurality of sub-pixels (SP1, SP2, SP3).

[0063] The first layer 510 is formed to contact the lower bank layer 410a of the first bank 410, and may also extend to the upper bank layer 410b of the first bank 410 to contact the side of the upper bank layer 410b, although this is not shown in detail in the figure.

[0064] The second layer 520 may be formed by a deposition process, such as an evaporation process, on the first layer 510. The second layer 520 may not include an emissive stack of organic materials that emit light, but may instead include a functional layer that injects or transports electrons or a functional layer that generates charges.

[0065] The second layer 520 may be formed to be continuous without any breaks in the internal regions of the sub-pixels (SP1, SP2, SP3) and their boundary regions. Therefore, the second layer 520 in the first sub-pixel (SP1), the second layer 520 in the second sub-pixel (SP2), and the second layer 520 in the third sub-pixel (SP3) are connected to each other without any breaks. In other words, the second layer 520 is continuous from the first sub-pixel (SP1) to the third sub-pixel (SP3). The second layer 520 may cover the entire top surface of the first bank 410.

[0066] The third layer 530 is formed on the second layer 520 by a solution process using an inkjet device, etc. The third layer 530 includes an emitting layer of an organic material that emits light.

[0067] The third layer 530 is patterned in a plurality of sub-pixels (SP1, SP2, SP3) and is not continuous but is disconnected between the plurality of sub-pixels (SP1, SP2, SP3). That is, the third layer 530 in the first sub-pixel (SP1), the third layer 530 in the second sub-pixel (SP2), and the third layer 530 in the third sub-pixel (SP3) are not connected to each other but are disconnected, thereby preventing emission from occurring in the boundary regions between the sub-pixels (SP1, SP2, SP3).

[0068] According to one embodiment of the present invention, the second bank 420 is further formed on the upper surface of the second layer 520 before forming the third layer 530 so that the third layer 530 is not continuous between the sub-pixels (SP1, SP2, SP3).

[0069] In detail, the second layer 520 is formed to be continuous in the boundary region between the sub-pixels (SP1, SP2, SP3), but the top surface of the second layer 520 does not have hydrophobic properties. Therefore, if the third layer 530 is formed on the top surface of the second layer 520 by a solution process without further forming the second bank 420, the third layer 530 may flow out into the boundary region between the sub-pixels (SP1, SP2, SP3). In that case, since the third layer 530 is formed to be continuous between the adjacent sub-pixels (SP1, SP2, SP3), a problem of light emission may occur in the boundary region between the sub-pixels (SP1, SP2, SP3).

[0070] Therefore, in one embodiment of the present invention, the second bank 420 is further formed on the upper surface of the second layer 520, and the upper portion of the second bank 420 is made to have hydrophobic properties, so that the third layer 530 does not spread onto the upper surface of the second bank 420 when the third layer 530 is formed by a solution process such as an inkjet process. As a result, it is possible to prevent a problem in which the third layer 530 is patterned in a discontinuous state in the plurality of sub-pixels (SP1, SP2, SP3) and light is emitted in the boundary region between the plurality of sub-pixels (SP1, SP2, SP3).

[0071] The fourth layer 540 may be formed on the third layer 530 by a deposition process such as an evaporation method. The fourth layer 540 may not include an organic light-emitting stack that causes light emission, but may instead include a functional layer that injects or transports electrons. The fourth layer 540 may be formed to be continuous without interruption throughout the internal regions and boundary regions of the plurality of sub-pixels (SP1, SP2, SP3). Thus, the fourth layer 540 in the first sub-pixel (SP1), the fourth layer 540 in the second sub-pixel (SP2), and the fourth layer 540 in the third sub-pixel (SP3) are connected to each other without interruption. In other words, the fourth layer 540 is continuous from the first sub-pixel (SP1) to the third sub-pixel (SP3). The fourth layer 540 may cover the entire top surface of the second bank 420.

[0072] 3 is a schematic cross-sectional view of a light-emitting stack 500 according to an embodiment of the present invention. The light-emitting stack 500 may include multiple layers as well as multiple stacks and sub-stacks that differ from one another. Various embodiments of the light-emitting stack 500 are described below.

[0073] As can be seen from FIG. 3, the light-emitting stack 500 according to one embodiment of the present invention includes a first stack (1 st Stack), which emits light of the second hue, nd The first stack (1 Stack) and a charge generation layer (N-CGL, P-CGL) provided between the first stack and the second stack. st The light of the first hue emitted from the second stack (2 nd The light of the second hue emitted from the light emitting stack 500 may be mixed to emit white light from the light emitting stack 500.

[0074] The first stack (1 st The stack is made up of a hole injection layer (HIL), a first hole transport layer (1 st HTL), 1st luminous stack (1 st EML) and the first electron transport layer (1 st ETL), nd The second hole transport layer (2 nd HTL), 2nd luminous stack (2 nd EML), second electron transport layer (2 nd The layer may comprise a first insulating layer (SIL) and an electron injection layer (EIL).

[0075] The first light-emitting stack (1 st EML) emits blue light and the second emitting stack (2 nd The first light-emitting stack (1 EML) can emit yellow-green light. st EML) emits yellow-green light, and the second emitting stack (2 nd EML) can emit blue light.

[0076] The charge generation layer (N-CGL, P-CGL) comprises an N-type charge generation layer (N-CGL) and a P-type charge generation layer (P-CGL). The N-type charge generation layer (N-CGL) is st Stack), and the first stack (1 st The P-type charge generation layer (P-CGL) is formed on the N-type charge generation layer (N-CGL), and the second stack (2 nd The GaN-GaN Stack provides holes to the GaN-GaN GaN HEMT.

[0077] Referring to FIG. 2, the first layer 510 formed by the solution process is the first stack (1 st In particular, the hole injection layer (HIL), the first hole transport layer (1 st HTL), and the first light-emitting stack (1 st EML).

[0078] The second layer 520 formed by the deposition process is the first stack (1 st The remaining layers of the charge generating layer (N-CGL, P-CGL) and the charge generating layer (N-CGL, P-CGL), in particular the first electron transport layer (1 st The ETL may comprise an N-type charge generation layer (N-CGL) and a P-type charge generation layer (P-CGL).

[0079] The third layer 530 formed by the solution process is nd In particular, the second hole transport layer (2 nd HTL and the second light-emitting stack (2 nd EML).

[0080] The fourth layer 540 formed in the deposition process is the second stack (2 nd The remaining layers of the Stack may comprise, in particular, the second electron transport layer (2 nd The layer may comprise an electron injection layer (ETL) and an electron injection layer (EIL).

[0081] The first light-emitting stack (1 st When the upper layer of the EML is formed by solution processing, the solvent in the solution may cause the first light-emitting stack (1 st Since the first light-emitting stack (1 st The upper layer of the second light-emitting stack (2 nd It may be preferable that the upper layer of the EML also be formed by a deposition process. For this reason, the second layer 520 and the fourth layer 540 may be formed by a deposition process instead of a solution process.

[0082] Referring again to FIG. 2, the second electrode 600 is formed on the light emitting stack 500. The second electrode 600 may be formed continuously without interruption throughout the inner regions and boundary regions of the plurality of sub-pixels (SP1, SP2, SP3). The second electrode 600 may function as a cathode of the electroluminescent display device. The second electrode 600 may be formed as a transparent electrode or a semi-transparent electrode when the electroluminescent display device according to the present invention is a top emission type, and may be formed as a reflective electrode when the electroluminescent display device according to the present invention is a bottom emission type.

[0083] The encapsulation layer 700 is formed on the second electrode 600 and serves to prevent external moisture or oxygen from penetrating into the light emitting stack 500 .

[0084] The color filter 800 and the light-shielding layer 850 may be formed on the encapsulation layer 700. The color filter 800 may include a red (R) color filter provided in a first sub-pixel (SP1), a green (G) color filter provided in a second sub-pixel (SP2), and a blue (B) color filter provided in a third sub-pixel (SP3). The light-shielding layer 850 may be formed in an area between the red (R) color filter, the green (G) color filter, and the blue (B) color filter, i.e., a boundary area between the sub-pixels (SP1, SP2, SP3).

[0085] When the electroluminescence display device according to the embodiment of the present invention is a top emission type, as shown in the drawing, the color filter 800 and the light blocking layer 850 may be formed on the upper surface of the encapsulation layer 700. However, when the electroluminescence display device according to the embodiment of the present invention is a bottom emission type, the color filter 800 and the light blocking layer 850 may be formed below the light emitting stack 500, for example, in the circuit element layer 200.

[0086] The protective layer 900 is formed on the color filter 800 and the light blocking layer 850 and serves to protect the internal components from external impact.

[0087] 4 to 6 are schematic cross-sectional views of electroluminescent displays according to various embodiments of the present invention.

[0088] FIG. 4 differs from the electroluminescent display device of FIG. 2 described above in that the configuration of upper bank layer 411b of first bank 410 is changed.

[0089] 4, a hole (H) is provided on the upper surface of the upper bank layer 411b of the first bank 410. Thus, the second layer 521 of the light-emitting stack 500 formed on the upper bank layer 411b extends along the inner side of the hole (H), and the lower portion of the second bank 421 formed on the second layer 521 is provided to fill the hole (H). The second layer 521 is formed by a deposition process.

[0090] According to the structure of FIG. 4, the anode of this embodiment, which is a conductive layer, can be formed by a deposition process, an organic light-emitting stack can be formed directly on top of it by an inkjet printing process, a second conductive layer can be formed by a deposition process, and a second organic light-emitting stack can be formed directly on top of it by an inkjet printing process.

[0091] According to the structure shown in FIG. 4, the hole (H) formed on the upper surface of the upper bank layer 411b has the advantage that the current path of the second layer 521 of the light-emitting stack 500 is increased, thereby reducing the occurrence of leakage current between the third sub-pixel (SP3) and the second sub-pixel (SP2).

[0092] FIG. 5 differs from the electroluminescence display device according to FIG. 4 described above in that the structure of the groove (H) formed on the upper surface of the upper bank layer 412b is changed.

[0093] According to FIG. 4 described above, the hole (H) formed on the upper surface of the upper bank layer 411b is formed without penetrating the upper bank layer 411b, so that the second layer 521 of the light-emitting stack 500 only contacts the upper bank layer 411b in the area corresponding to the hole (H), and does not contact the lower bank layer 410a therebelow.

[0094] In contrast, according to FIG. 5, the hole (H) formed on the upper surface of the upper bank layer 412b is formed to penetrate the upper bank layer 412b, so that the second layer 522 of the light-emitting stack 500 contacts the lower bank layer 410a in the area corresponding to the hole (H), and the lower part of the second bank 422 formed on the second layer 522 is provided to fill the hole (H).

[0095] Compared with the structure of FIG. 4, the structure of FIG. 5 has the advantage that the current path of the second layer 522 of the light-emitting stack 500 in the home (H) region is increased, and the occurrence of leakage current between the third sub-pixel (SP3) and the second sub-pixel (SP2) is reduced.

[0096] FIG. 6 differs from the electroluminescent display device according to FIG. 5 described above in that the structure of the second bank 423 is changed.

[0097] According to FIG. 5 described above, the upper surface of second bank 422 is higher than the upper surface of second layer 522 .

[0098] 6, the upper surface of second bank 423 is at the same height as the upper surface of second layer 522. Even if the upper surface of second bank 423 is at the same height as the upper surface of second layer 522, since the upper surface of second bank 423 has hydrophobic properties, when third layer 530 is formed by a solution process, third layer 530 can be discontinuous at the upper surface of second bank 423.

[0099] Fig. 7 is a schematic cross-sectional view of an electroluminescence display device according to an embodiment of the present invention, which corresponds to a cross-section along line CD in Fig. 1. That is, Fig. 7 is a cross-sectional view including a boundary region between one first sub-pixel (SP1) and another adjacent first sub-pixel (SP1) emitting light of the same color.

[0100] As can be seen from FIG. 7, an electroluminescent display device according to one embodiment of the present invention includes a substrate 100, a circuit element layer 200, a first electrode 300, a lower bank layer 410a, a light-emitting stack 500, a second electrode 600, an encapsulating layer 700, a color filter 800, a light-shielding layer 850, and a protective layer 900.

[0101] The configurations of the substrate 100, the circuit element layer 200, the first electrode 300, the second electrode 600, the sealing layer 700, the color filter 800, the light-shielding layer 850, and the protective layer 900 are the same as those in FIG. 2 described above, so repeated explanations will be omitted.

[0102] According to one embodiment of the present invention, only the lower bank layer 410a of the first bank 410 is formed in the boundary region between one first subpixel (SP1) and another adjacent first subpixel (SP1), and the upper bank layer 410b of the first bank 410 and the second bank 420 are not formed.

[0103] Since one first subpixel (SP1) and another adjacent first subpixel (SP1) emit light of the same hue, even if the first layer 510 of the light-emitting stack 500 and the third layer 530 of the light-emitting stack 500 are continuous between the one first subpixel (SP1) and the other first subpixel (SP1), there is no significant adverse effect on image quality. Therefore, the upper bank layer 410b and the second bank 420 can be omitted in the boundary region between the one first subpixel (SP1) and the other adjacent first subpixel (SP1).

[0104] As a result, in the boundary region between one first sub-pixel (SP1) and another first sub-pixel (SP1), the second layer 520 of the light-emitting stack 500 contacts the entire upper surface of the lower bank layer 410a. Also, in the boundary region between one first sub-pixel (SP1) and another first sub-pixel (SP1), the fourth layer 540 of the light-emitting stack 500 contacts the upper surface of the second layer 520 of the light-emitting stack 500. The fourth layer 540 can be formed by a deposition process such as sputtering.

[0105] 8 is a schematic plan view of an electroluminescence display device according to another embodiment of the present invention, which is similar to the electroluminescence display device according to FIG. 1 except that a third bank 430 is further included, and therefore, only the different configurations will be described below.

[0106] 8, the third bank 430 is formed in a boundary region between one first sub-pixel (SP1) and another adjacent first sub-pixel (SP1) that emit light of the same hue. The third bank 430 is also formed in a boundary region between one second sub-pixel (SP2) and another adjacent second sub-pixel (SP2) that emit light of the same hue. The third bank 430 is also formed in a boundary region between one third sub-pixel (SP3) and another adjacent third sub-pixel (SP3) that emit light of the same hue.

[0107] Therefore, the third bank 430 has a linear structure extending in the first direction, for example, in the X-axis direction. Here, the third bank 430 does not have a linear structure that is continuous in the first direction, but has a linear structure that is discontinuous in the first direction. That is, the third bank 430 provided at the boundary between two adjacent first sub-pixels (SP1) is not connected to the third bank 430 provided at the boundary between two adjacent second sub-pixels (SP2). The third bank 430 may be discontinuous, including one part and another part that are separated from each other. This example can be understood from FIGS. 8 to 12.

[0108] In addition, the third bank 430 is not connected to the second bank 420. Thus, the third bank 430 is separated from the second bank 420 on one side (e.g., the left side) and the other side (e.g., the right side) of the third bank 430 with a predetermined space (S1) therebetween. In other words, the third bank 430 is formed in a region between two second banks 420 on one side and the other side, excluding the predetermined space (S1), in a boundary region between two adjacent first sub-pixels (SP1).

[0109] The third bank 430 may be made of the same material as the second bank 420, but is not limited thereto, and may be made of a different material than the second bank 420.

[0110] Fig. 9 is a schematic cross-sectional view of an electroluminescence display device according to another embodiment of the present invention, which corresponds to a cross-section taken along line EF in Fig. 8. That is, Fig. 9 is a cross-sectional view including a boundary region between one first sub-pixel SP1 and another first sub-pixel SP1 adjacent thereto, which emit light of the same color.

[0111] As can be seen from FIG. 9, an electroluminescent display device according to another embodiment of the present invention includes a substrate 100, a circuit element layer 200, a first electrode 300, a lower bank layer 410a, a third bank 430, a light-emitting stack 500, a second electrode 600, an encapsulating layer 700, a color filter 800, a light-shielding layer 850, and a protective layer 900.

[0112] The configurations of the substrate 100, the circuit element layer 200, the first electrode 300, the second electrode 600, the sealing layer 700, the color filter 800, the light-shielding layer 850, and the protective layer 900 are the same as those in FIG. 7 described above, so repeated explanations will be omitted.

[0113] According to another embodiment of the present invention, a lower bank layer 410a of the first bank 410 and a third bank 430 are formed in a boundary region between one first sub-pixel (SP1) and another adjacent first sub-pixel (SP1).

[0114] Here, the third bank 430 is disposed between the second layer 520 and the fourth layer 540 of the light-emitting stack 500, similar to the second bank 420 described above.

[0115] As a result, in the boundary region between one first subpixel (SP1) and its adjacent another first subpixel (SP1), the second layer 520 of the light-emitting stack 500 contacts the entire top surface of the lower bank layer 410a. Also, in the boundary region between one first subpixel (SP1) and its adjacent another first subpixel (SP1), the fourth layer 540 of the light-emitting stack 500 contacts the top surface of the third bank 430.

[0116] Therefore, the third layer 530 of the light-emitting stack 500 formed in one first sub-pixel (SP1) can be prevented from spreading to another adjacent first sub-pixel (SP1) by the third bank 430. To this end, the upper surface of the third bank 430 may have hydrophobic properties. However, the upper surface of the third bank 430 may also be formed to have hydrophilic properties.

[0117] Referring again to FIG. 8, according to another embodiment of the present invention, the third bank 430 is configured to be separated from the second bank 420 by a predetermined space (S1), which is because during a solution process for forming the third layer 530 of the light-emitting stack 500, the solution can move smoothly through the predetermined space (S1), thereby preventing the formation of mottle.

[0118] More specifically, by forming the third bank 430, the third layer 530 of the light-emitting stack 500 can be separated between two adjacent first sub-pixels (SP1). Here, if the third bank 430 is formed in a linear structure that is continuous in the first direction while contacting the second bank 420, the solution for forming the third layer 530 of the light-emitting stack 500 is confined within each first sub-pixel (SP1) and cannot move between adjacent first sub-pixels (SP1). In this case, if the amount of solution ejected from the inkjet cannot be precisely adjusted, the amount of solution may be too much or too little in a particular first sub-pixel (SP1), resulting in spotting.

[0119] In another embodiment of the present invention, the third bank 430 is configured to be separated from the second bank 420 with a predetermined space (S1) therebetween, thereby preventing the problem of mottle generation. In particular, even if the amount of solution ejected by inkjet cannot be accurately adjusted, the solution can move between the adjacent first sub-pixels (SP1) through the predetermined space (S1), thereby eliminating the problem of the amount of solution being too much or too little in a particular first sub-pixel (SP1), thereby preventing the problem of mottle generation.

[0120] 10 to 12 are schematic plan views of electroluminescent display devices according to various embodiments of the present invention, which differ from the electroluminescent display device according to FIG. 8 described above in that the configuration of the third bank 430 and the predetermined space (S2) is changed.

[0121] As in the above-mentioned FIG. 8, in the cases of FIG. 10 to FIG. 12, the third bank 430 is formed in the area between two second banks 420 on one side and the other side, but in the area excluding a certain space (S2) in the boundary area between two adjacent first sub-pixels (SP1).

[0122] Here, according to FIG. 10, the third bank 430a on one side (e.g., the left side) extends from the second bank 420 on one side (e.g., the left side) toward the other side (e.g., the right side), and the third bank 430b on the other side (e.g., the right side) extends from the second bank 420 on the other side (e.g., the right side) toward one side (e.g., the left side), and the third bank 430a on the one side is separated from the third bank 430b on the other side by a predetermined space (S).

[0123] According to FIG. 11, multiple third banks 430 are spaced apart from each other with a predetermined space (S3) therebetween, and the third banks 430 arranged on the furthest side (e.g., the left side) and the furthest side (e.g., the right side) are spaced apart from the second banks 420 with a predetermined space (S4) therebetween.

[0124] Referring to FIG. 12, the third bank 430 extends from the second bank 420 on one side (e.g., the left side) toward the other side (e.g., the right side), and the third bank 430 is not connected to the second bank 420 on the other side (e.g., the right side) but is separated from it by a predetermined space (S5).

[0125] As described above, the positions of the predetermined spaces (S1, S2, S3, S4, S5) in the boundary region between two adjacent first sub-pixels (SP1) can be changed in various ways.

[0126] Although the embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the scope of the technical idea of ​​the present invention. Therefore, the embodiments disclosed in the present invention are for the purpose of illustrating, not limiting, the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention is not limited by these embodiments. Therefore, it should be understood that the above-described embodiments are illustrative and not limiting in all respects. The scope of protection of the present invention should be interpreted according to the claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0127] 100: Substrate 200: Circuit element layer 300: 1st electrode 410: First Bank 420: 2nd Bank 430: 3rd Bank 500: Luminous stack 510, 520, 530, 540: 1st, 2nd, 3rd, 4th layer 600: 2nd electrode 700: Sealing layer 800: Color filter 850: Light blocking layer 900: Protective layer

Claims

1. a substrate including a plurality of first sub-pixels and a plurality of second sub-pixels; a first electrode provided on the substrate for each of the first sub-pixels and the second sub-pixels, and a light-emitting stack provided on the first electrode; a second electrode disposed on the light emitting stack; first banks provided at boundaries between the first sub-pixels and the second sub-pixels, at boundaries between the first sub-pixels, and at boundaries between the second sub-pixels; a second bank provided on the first bank along a boundary between the first sub-pixels and the second sub-pixels; a third bank provided in a discontinuous linear structure at boundaries between the first sub-pixels and boundaries between the second sub-pixels; the light-emitting stack includes a first layer provided on each of the first sub-pixels and the second sub-pixels, and a second layer provided on the first layer and continuous from the first sub-pixel to the adjacent second sub-pixel; The first bank is provided below the second layer, and the second bank is provided above the second layer.

2. The electroluminescence display device of claim 1 , wherein the third bank is provided in a region excluding a predetermined space in a boundary region between the first sub-pixels.

3. The electroluminescent display device of claim 2 , wherein the third bank is spaced apart from the second bank with the predetermined space therebetween.

4. The electroluminescent display device of claim 2 , wherein the third bank is in contact with the second bank and extends from the second bank.

5. a light-emitting stack including a first layer, a second layer, a third layer, and a fourth layer stacked in sequence; the first layer and the third layer are provided so as to be discontinuous in each of the first sub-pixels and the second sub-pixels, The electroluminescent display device according to claim 1 , wherein the second layer and the fourth layer are provided continuously from the first sub-pixels to the second sub-pixels.

6. the first bank and the second bank are spaced apart from each other above and below the second layer, The electroluminescent display device of claim 5 , wherein the first bank and the third bank are spaced apart from each other above and below the second layer.

7. a substrate including first and second sub-pixels arranged in a first direction; a first electrode provided on the substrate in each of the first sub-pixel and the second sub-pixel; a first portion of a first light-emitting stack disposed on the first electrode; a second portion of the first light-emitting stack spaced apart from the first portion of the first light-emitting stack in a first direction and disposed on the first electrode; a first bank disposed between a first portion of the first light-emitting stack and a second portion of the first light-emitting stack; a conductive layer disposed on the first bank, the first portion of the first light emitting stack, and the second portion of the first light emitting stack; a first portion of a second light emitting stack disposed on the conductive layer; a second portion of the second light-emitting stack spaced apart from the first portion of the second light-emitting stack in the first direction and disposed on the conductive layer; the first and second portions of the first light-emitting stack overlap the first and second portions of the second light-emitting stack; a third portion of the first and second light emitting stacks spaced apart in a second direction from the first portions of the first and second light emitting stacks and disposed on the conductive layer; a second bank disposed on the conductive layer and disposed between the first portion of the second light-emitting stack and the second portion of the second light-emitting stack; a third bank provided in a region excluding a predetermined space in a boundary region between the first portion of the second light-emitting stack and the third portion of the second light-emitting stack; a second electrode disposed on the first to third portions of the second light-emitting stack; a first portion of the second light-emitting stack is associated with a first sub-pixel, and a third portion of the second light-emitting stack is associated with another first sub-pixel that emits light of the same hue as the first sub-pixel; The third bank is provided in a region excluding a predetermined space in a boundary region between the first sub-pixel and the another first sub-pixel.

8. The electroluminescent display device of claim 7 , wherein the conductive layer is a charge generating layer.

9. 8. The electroluminescent display device of claim 7, wherein a first portion of the first light-emitting stack is associated with the first sub-pixel and a second portion of the first light-emitting stack is associated with a second sub-pixel.

10. a first color filter disposed on a first portion of the first light-emitting stack; The electroluminescent display device of claim 7 , further comprising: a second color filter disposed on the second portion of the first light-emitting stack.

11. The electroluminescent display device according to claim 7 , wherein the second bank is provided on the conductive layer.

12. The electroluminescent display device of claim 7 , wherein a height of the first bank is greater than a height of the first portion of the first light-emitting stack.

13. The electroluminescent display device of claim 7 , wherein the first bank includes a hole, and the conductive layer extends along an inner surface of the hole.

14. The electroluminescent display device of claim 7 , further comprising a thin film transistor disposed on the substrate, the first portion of the first light-emitting stack being disposed on the thin film transistor.

15. The electroluminescent display device of claim 7 , wherein the first bank includes one of an insulating material and a hydrophobic material.

16. 8. The electroluminescent display device of claim 7, wherein the first portion of the first light-emitting stack is disposed within the first sub-pixel, and the second portion of the first light-emitting stack is disposed within a second sub-pixel spaced apart from the first sub-pixel.

Images