Electroluminescent display device

Abstract

Disclosed is an electroluminescent display device including 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 in a boundary region between the first and second sub-pixels on the substrate, a light-emitting layer stack provided on the first electrode and the bank, and a second electrode provided on the light-emitting layer stack, wherein the bank includes a first bank and a second bank provided on the first bank, the light-emitting layer stack includes a first layer provided in each of the first and second sub-pixels and a second layer provided on the first layer and continuously provided from the first sub-pixel to the second sub-pixel, and the first bank is provided under the second layer and the second bank is provided on the second layer.

Description

Technical Field

[0001] This disclosure relates to an electroluminescent display device, and more specifically, to an electroluminescent display device manufactured by a solution process. Background Technology

[0002] An electroluminescent display device includes a first electrode, a second electrode, and a light-emitting laminate disposed between the first electrode and the second electrode, wherein the light-emitting laminate emits light through an electric field between the two electrodes, thereby displaying an image.

[0003] The light-emitting stack can include organic materials that emit light when excitons are annihilated due to recombination of electrons and holes. An exciton is an electrically neutral quasi-particle consisting of electrostatically coupled electrons and holes. Excitons can be generated when an organic material absorbs photons with energy higher than its band gap (which can excite electrons from the valence band to the conduction band). When the conduction band electrons in the exciton recombine with valence band holes, the exciton disappears, and its energy can be converted into light. Summary of the Invention

[0004] In some implementations, a vacuum deposition process can be used to form the light-emitting laminate. In this case, a vacuum deposition apparatus may be required, which can increase manufacturing costs, especially in the case of large electroluminescent display devices, where the size of the mask used to form the pattern and the vacuum deposition apparatus may become larger, thereby reducing the productivity of mass production.

[0005] Therefore, in order to reduce manufacturing costs, solution processing using inkjet equipment or similar methods can be used to form light-emitting laminates.

[0006] However, when light-emitting laminates are formed using solution processing, for example, the solution used to form a red light-emitting laminate may flow from the red sub-pixel to the green sub-pixel adjacent to the red sub-pixel, which may degrade the image quality of the green sub-pixel.

[0007] One aspect of this disclosure is to provide an electroluminescent display device manufactured by a solution process and configured to prevent light-emitting layers of any sub-pixel from flowing to another adjacent sub-pixel in the solution process.

[0008] According to one aspect of this disclosure, the above can be achieved by providing an electroluminescent display device, the electroluminescent display device comprising: a substrate including a first sub-pixel and a second sub-pixel arranged in a first direction; a first electrode disposed in each of the first sub-pixel and the second sub-pixel on the substrate; a dam disposed in a boundary region between the first sub-pixel and the second sub-pixel on the substrate; a light-emitting stack disposed on the first electrode; and a second electrode disposed on the light-emitting stack, wherein the dam includes a first dam and a second dam located on the first dam, the light-emitting stack includes a first layer disposed in each of the first sub-pixel and the second sub-pixel and a second layer disposed on the first layer, the second layer extending continuously from the first sub-pixel to the second sub-pixel, and the first dam being disposed below the second layer and the second dam being disposed on the second layer.

[0009] According to another aspect of this disclosure, the above can be achieved by providing an electroluminescent display device, the electroluminescent display device comprising: a substrate including a plurality of first sub-pixels and a plurality of second sub-pixels; a first dam portion disposed in a boundary region between the plurality of first sub-pixels and the plurality of second sub-pixels, a boundary region between each of the plurality of first sub-pixels, and a boundary region between each of the plurality of second sub-pixels; a second dam portion configured as a continuous linear structure along the boundary regions between the plurality of first sub-pixels and the plurality of second sub-pixels; and a third dam portion configured as a discontinuous linear structure in the boundary regions between each of the plurality of first sub-pixels and between each of the plurality of second sub-pixels. Attached Figure Description

[0010] Figure 1 This is a plan view illustrating an electroluminescent display device according to one embodiment of the present disclosure;

[0011] Figure 2 This is a schematic cross-sectional view of an electroluminescent display device according to one embodiment of the present disclosure, which corresponds to Figure 1 A cross-sectional view taken along line AB.

[0012] Figure 3 This is a schematic cross-sectional view of a light-emitting layer according to one embodiment of the present disclosure;

[0013] Figures 4 to 6 This is a schematic cross-sectional view illustrating various embodiments of an electroluminescent display device according to the present disclosure, illustrating a portion of the boundary region between a first sub-pixel and a second sub-pixel;

[0014] Figure 7 This is a schematic cross-sectional view illustrating an electroluminescent display device according to one embodiment of the present disclosure, which corresponds to Figure 1 A cross-sectional view taken along line CD;

[0015] Figure 8 This is a schematic plan view illustrating an electroluminescent display device according to another embodiment of the present disclosure;

[0016] Figure 9 This is a schematic cross-sectional view illustrating an electroluminescent display device according to another embodiment of the present disclosure, which corresponds to Figure 8 A cross-sectional view taken along line EF.

[0017] Figures 10 to 12 This is a schematic plan view illustrating various embodiments of an electroluminescent display device according to the present disclosure. Detailed Implementation

[0018] In the following, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0019] Figure 1 This is a plan view illustrating an electroluminescent display device according to one embodiment of the present disclosure.

[0020] like Figure 1 As shown, an electroluminescent display device according to one embodiment of the present disclosure includes a substrate 100, a plurality of sub-pixels SP1, SP2 and SP3 located on the substrate 100, a first electrode 300 located on each of the plurality of sub-pixels SP1, SP2 and SP3, and embankments 410 and 420 located in the boundary regions between the plurality of sub-pixels SP1, SP2 and SP3.

[0021] Multiple sub-pixels SP1, SP2 and SP3 may include a first sub-pixel SP1, a second sub-pixel SP2 and a third sub-pixel SP3 arranged in a first direction (e.g., in the X-axis direction).

[0022] The first color of light is emitted from the first sub-pixel SP1, the second color of light is emitted from the second sub-pixel SP2, and the third color of light can be emitted from the third sub-pixel SP3.

[0023] Multiple first sub-pixels SP1 can be arranged in a second direction (e.g., in the Y-axis direction) intersecting the first direction. Similarly, multiple second sub-pixels SP2 and multiple third sub-pixels SP3 can be arranged in the second direction.

[0024] The arrangement of the multiple sub-pixels SP1, SP2 and SP3 can be changed in various forms known to those skilled in the art.

[0025] The first electrode 300 can be used as the anode of the electroluminescent display device, and the first electrode 300 can be patterned in each of the plurality of sub-pixels SP1, SP2 and SP3, and can be surrounded by embankments 410 and 420.

[0026] Dikes 410 and 420 can be set in the boundary region between multiple sub-pixels SP1, SP2 and SP3, thereby defining the region of each sub-pixel SP1, SP2 and SP3.

[0027] Dike sections 410 and 420 include a first dike section 410 and a second dike section 420.

[0028] The first embankment 410 can be formed in a mesh structure in the boundary region between multiple sub-pixels SP1, SP2 and SP3. Specifically, the first embankment 410 can be formed in the boundary region between each of the first sub-pixels SP1, second sub-pixels SP2 and third sub-pixels SP3 arranged in the first direction, in the boundary region between multiple first sub-pixels SP1 arranged in the second direction, in the boundary region between multiple second sub-pixels SP2 arranged in the second direction, and in the boundary region between multiple third sub-pixels SP3 arranged in the second direction.

[0029] The second embankment 420 can be formed with a different pattern than the first embankment 410. Specifically, the second embankment 420 can be formed in the boundary region between each of the first sub-pixels SP1, second sub-pixels SP2, and third sub-pixels SP3 arranged in the first direction, but it can be excluded from the boundary region between the plurality of first sub-pixels SP1, second sub-pixels SP2, and third sub-pixels SP3 arranged in the second direction. Therefore, the second embankment 420 can extend in the second direction and can be formed as a strip structure spaced apart by a predetermined distance in the first direction.

[0030] Figure 2 This is a schematic cross-sectional view of an electroluminescent display device according to one embodiment of the present disclosure, which corresponds to Figure 1 A cross-sectional view taken along line AB. That is to say, Figure 2 It is a cross-sectional view of the boundary region between each of the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3 that emit different colors of light.

[0031] like Figure 2As shown, an electroluminescent display device according to one embodiment of the present disclosure includes a substrate 100, a circuit element layer 200, a first electrode 300, embankments 410 and 420, a light-emitting layer stack 500, a second electrode 600, an encapsulation layer 700, a color filter 800, a light-shielding layer 850, and a protective layer 900.

[0032] The substrate 100 can be made of glass or transparent plastic, but is not limited to these, and can be made of semiconductor materials such as silicon wafers. If the electroluminescent display device according to one embodiment of the present disclosure is formed as a top-emitting type, opaque materials and transparent materials can be used as materials for the substrate 100. However, if the electroluminescent display device according to one embodiment of the present disclosure is formed as a bottom-emitting type, a transparent material is used as the material for the substrate 100.

[0033] The circuit element layer 200 is formed on the substrate 100.

[0034] The circuit element layer 200 includes driving thin-film transistors.

[0035] The driving thin-film transistor includes an active layer 210 on a substrate 100, a gate insulating film 220 on the active layer 210, a gate electrode 230 on the gate insulating film 220, an interlayer insulating film 240 on the gate electrode 230, and a source electrode 251 and a drain electrode 252 disposed on the interlayer insulating film 240 and connected to the active layer 210 through holes formed in the interlayer insulating film 240 and the gate insulating film 220. Although a top-gate structure driving thin-film transistor in which the gate electrode 230 is disposed above the active layer 210 is shown, this disclosure may include a bottom-gate structure driving thin-film transistor in which the gate electrode 230 is disposed below the active layer 210.

[0036] The circuit element layer 200 may further include a passivation layer 260 and a planarization layer 270 disposed on or above the driving thin-film transistor. The passivation layer 260 is formed on the source electrode 251 and the drain electrode 252, and the planarization layer 270 is formed on the passivation layer 260.

[0037] The passivation layer 260 and the planarization layer 270 may include contact holes, and the first electrode 300 may be connected to the drain electrode 252 through the contact holes. If necessary, the first electrode 300 may be connected to the source electrode 251 through the contact holes.

[0038] The circuit element layer 200 may also include various signal lines including gating lines, data lines, power lines and reference wiring, various thin film transistors including switching thin film transistors and sensing thin film transistors, and capacitors.

[0039] In some cases, the switching thin-film transistor is switched according to a gating signal provided to the gating line, and is configured to provide the data voltage from the data line to the driving thin-film transistor.

[0040] In some cases, the driving thin-film transistor switches according to the data voltage provided from the switching thin-film transistor, generates a data current from the power supply provided from the power line, and provides the data current to the first electrode 300.

[0041] In some cases, the sensing thin-film transistor senses the threshold voltage deviation of the driving thin-film transistor (which may lead to image quality degradation), and in response to a sensing control signal provided from the gate line or a separate sensing line, the current driving the thin-film transistor is supplied to the reference line.

[0042] The capacitor maintains the data voltage supplied to the driving thin-film transistor during a frame and is connected to the gate terminal and source terminal of the driving thin-film transistor, respectively.

[0043] Each of the switching thin-film transistor, the driving thin-film transistor, and the sensing thin-film transistor can be modified into various structures known in the art, such as bottom-gate or top-gate structures.

[0044] In addition, the circuit element layer 200 may also include a passivation layer for protecting the switching thin-film transistor, the driving thin-film transistor, and the sensing thin-film transistor, as well as a planarization layer disposed on the passivation layer.

[0045] A first electrode 300 is formed on the circuit element layer 200 of each sub-pixel SP1, SP2, and SP3. The first electrode 300 can be used as the anode of an electroluminescent display device. When the electroluminescent display device according to the present disclosure is a bottom-emitting type, the first electrode 300 may include a transparent electrode, and when the electroluminescent display device according to the present disclosure is a top-emitting type, the first electrode 300 may include a reflective electrode.

[0046] Dikes 410 and 420 are disposed on the circuit element layer 200, and the dike 410 includes a first dike 410 and a second dike 420.

[0047] The first embankment 410 is formed at both ends of the first electrode 300 on the circuit element layer 200, and is formed in the boundary region between the plurality of sub-pixels SP1, SP2 and SP3.

[0048] The first embankment 410 can be formed as a double-layer structure of a lower embankment layer 410a and an upper embankment layer 410b.

[0049] The lower dam layer 410a may be formed to contact the first electrode 300 and the circuit element layer 200. The lower dam layer 410a may be thinner and wider than the upper dam layer 410b. The lower dam layer 410a may be formed of a hydrophilic material, but is not limited thereto. The lower dam layer 410a may be made of a hydrophobic material.

[0050] The upper embankment layer 410b is patterned on the lower embankment layer 410a. The upper embankment layer 410b may be formed in the boundary region between the first sub-pixel SP1 and the second sub-pixel SP2 and the boundary region between the second sub-pixel SP2 and the third sub-pixel SP3, but may not be formed in the boundary regions between multiple first sub-pixels SP1, multiple second sub-pixels SP2 and multiple third sub-pixels SP3.

[0051] The upper embankment layer 410b can be formed by applying a solution obtained by mixing a hydrophobic material such as fluorine to a hydrophilic organic insulating material and forming a pattern by photolithography. The hydrophobic material, such as fluorine, can be moved to the top of the upper embankment layer 410b by light irradiation during the photolithography process, thereby making the top of the upper embankment layer 410b hydrophobic and another portion hydrophilic. That is, the portion of the upper embankment layer 410b that contacts the lower embankment layer 410a can be hydrophilic, and the upper part of the upper embankment layer 410b can be hydrophobic, but is not limited thereto. The entire portion of the upper embankment layer 410b can be hydrophobic. As described above, because the upper embankment layer 410b is hydrophobic, the solution can be prevented from diffusing into the light-emitting stack 500, and more specifically, the solution can be prevented from diffusing and mixing between adjacent sub-pixels SP1, SP2, and SP3.

[0052] The second dam 420 is formed above the first dam 410 in the boundary region between the plurality of sub-pixels SP1, SP2, and SP3. The second layer 520 of the light-emitting stack 500 is disposed between the second dam 420 and the first dam 410, such that the second dam 420 does not contact the first dam 410. The width of the second dam 420 may be smaller than the width of the first dam 410, but is not limited thereto. The light-emitting stack 500 may include multiple layers made of different materials, some of which emit light and some of which do not, but facilitate the emission of light from other layers in the light-emitting stack 500. For example, the light-emitting stack 500 may include one or more organic light-emitting stacks, and further include one or more layers of the following: a hole injection layer, a hole transport layer, a charge generation layer, an electron transport layer, and / or an electron injection layer.

[0053] The second dam portion 420 can be formed from the same material as the upper dam layer 410b using the same process, thereby allowing the lower part of the second dam portion 420 to be hydrophilic and the upper part of the second dam portion 420 to be hydrophobic. Furthermore, the entire portion of the second dam portion 420 can be hydrophobic. As described above, because the upper part of the second dam portion 420 is hydrophobic, it prevents the solution used to form the third layer 530 of the light-emitting laminate 500 from diffusing to and mixing with the adjacent sub-pixels SP1, SP2, and SP3.

[0054] The light-emitting laminate 500 is formed on the first electrode 300 and the embankments 410 and 420. The light-emitting laminate 500 includes a first layer 510, a second layer 520, a third layer 530 and a fourth layer 540 stacked sequentially.

[0055] The first layer 510 is formed using a solution process with an inkjet device on the first electrode 300. The first layer 510 includes a light-emitting layer of organic material that can cause light emission.

[0056] The first layer 510 is patterned in multiple sub-pixels SP1, SP2, and SP3, and is disconnected in multiple sub-pixels SP1, SP2, and 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 disconnected rather than connected to each other, thereby preventing light emission in the boundary region between sub-pixels SP1, SP2, and SP3.

[0057] Since the upper part of the upper embankment layer 410b is hydrophobic, the first layer 510 does not diffuse to the upper part of the upper embankment layer 410b, and is patterned in each of the plurality of sub-pixels SP1, SP2 and SP3 as an open state in the plurality of sub-pixels SP1, SP2 and SP3.

[0058] The first layer 510 may be formed to contact the lower embankment layer 410a of the first embankment 410. Although not shown in detail, the first layer 510 may extend to the upper embankment layer 410b of the first embankment 410 and may contact the side surface of the upper embankment layer 410b.

[0059] The second layer 520 can be formed on the first layer 510 by a deposition process such as evaporation. The second layer 520 may include a functional layer for injecting or transporting electrons or a functional layer for generating charges, without including the light-emitting organic material in the light-emitting stack.

[0060] The second layer 520 can be formed continuously without being broken from the entire boundary region between the multiple sub-pixels SP1, SP2, and SP3, or from within the multiple sub-pixels SP1, SP2, and SP3. 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 being broken. In other words, the second layer 520 is continuous from the first sub-pixel SP1 to the third sub-pixel SP3. The entire upper surface of the first embankment 410 can be covered by the second layer 520.

[0061] A third layer 530 is formed on the second layer 520 using a solution process with an inkjet printer. The third layer 530 includes a light-emitting layer of organic material that induces light emission.

[0062] The third layer 530 is patterned in each of the plurality of sub-pixels SP1, SP2, and SP3, and is disconnected in the plurality of sub-pixels SP1, SP2, and 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 disconnected without being connected to each other, thereby preventing light emission in the boundary region between sub-pixels SP1, SP2, and SP3.

[0063] According to one embodiment of the present disclosure, before forming the third layer 530, a second embankment 420 is additionally formed on the upper surface of the second layer 520, thereby disconnecting the third layer 530 from the plurality of sub-pixels SP1, SP2 and SP3 when there is no connection among the plurality of sub-pixels SP1, SP2 and SP3.

[0064] More specifically, the second layer 520 is formed to be continuous in the boundary regions between the multiple sub-pixels SP1, SP2, and SP3, and the upper surface of the second layer 520 is not hydrophobic. Therefore, when a third layer 530 is formed on the upper surface of the second layer 520 by a solution process without forming a second embankment 420, the third layer 530 may flow into the boundary regions between the multiple sub-pixels SP1, SP2, and SP3. In this case, since the third layer 530 is formed to be continuous between adjacent sub-pixels SP1, SP2, and SP3, light emission problems may occur in the boundary regions between the multiple sub-pixels SP1, SP2, and SP3.

[0065] Therefore, in one embodiment of this disclosure, a second dam 420 is additionally formed on the upper surface of the second layer 520, and the upper portion of the second dam 420 is hydrophobic, preventing the third layer 530 from diffusing onto the upper surface of the second dam 420 when the third layer 530 is formed by a solution process (such as inkjet printing). Thus, the third layer 530 is patterned in a discontinuous state without being continuous among the plurality of sub-pixels SP1, SP2, and SP3, thereby preventing light emission problems in the boundary regions between the plurality of sub-pixels SP1, SP2, and SP3.

[0066] A fourth layer 540 can be formed on the third layer 530 using a deposition process such as evaporation. The fourth layer 540 may include a functional layer for injecting or transporting electrons, rather than a light-emitting stack comprising organic materials that cause light emission. The fourth layer 540 can be formed continuously without being broken throughout the boundary regions between the multiple sub-pixels SP1, SP2, and SP3, or within the interiors of the multiple sub-pixels SP1, SP2, and SP3. Therefore, 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 being broken. In other words, the fourth layer 540 is continuous from the first sub-pixel SP1 to the third sub-pixel SP3. The entire upper surface of the second embankment 420 can be covered by the fourth layer 540.

[0067] Figure 3 This is a schematic cross-sectional view of a light-emitting laminate 500 according to one embodiment of the present disclosure. The light-emitting laminate 500 may consist of multiple layers and multiple different laminates and sub-laminates. Various embodiments of the light-emitting laminate 500 will be described herein.

[0068] like Figure 3 As shown, a light-emitting laminate 500 according to one embodiment of the present disclosure includes a first laminate 1 for emitting light of a first color. st Stack, second layer stack 2 for emitting a second color of light nd Stack and set in the first layer of stack 1 st Stack and second layer 2 nd Charge generation layers N-CGL and P-CGL between stacks. From the first stack 1 st The first color of light emitted from Stack and from the second stack 2 nd The second color of light emitted by the stack can be mixed to emit white light in the light-emitting stack 500.

[0069] First layer of stacked components 1 st Stack includes a hole injection layer (HIL) and a first hole transport layer (1).st HTL, First Light-Emitting Layer 1 st EML and the first electron transport layer 1 st ETL. Second layer stack 2 nd Stack includes a second hole transport layer 2 nd HTL, Second Light-Emitting Layer 2 nd EML, Second Electron Transport Layer 2 nd ETL and electron injection layer EIL.

[0070] In some cases, the first light-emitting laminate 1 st EML emits blue light, second light-emitting laminate 2 nd EML emits a yellow-green light. Alternatively, the first light-emitting layer 1 st EML emits yellow-green light, and the second light-emitting layer 2 nd EML emits a blue light.

[0071] The charge generation layers N-CGL and P-CGL include 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 formed in the first layer stack 1. st On the Stack and configured to stack to the first layer 1 st Stack provides electrons, and a P-type charge generation layer P-CGL is formed on an N-type charge generation layer N-CGL and configured to extend to the second stack 2. nd Stack provides holes.

[0072] Reference Figure 2 The first layer 510 formed by solution processing may include a first layer stack 1 st Some layers of the stack. More specifically, the first layer 510 may include a hole injection layer HIL, a first hole transport layer 1, and so on. st HTL and first light-emitting laminate 1 st EML.

[0073] The second layer 520 formed by the deposition process may include the first layer stack 1 st The remaining layers of the stack, as well as the charge generation layers N-CGL and P-CGL. More specifically, the second layer 520 may include a first electron transport layer 1. st ETL, N-type charge generation layer N-CGL, and P-type charge generation layer P-CGL.

[0074] The third layer 530 formed by solution processing may include the second layer stack 2. nd Some layers of the stack. More specifically, the third layer 530 may include the second hole transport layer 2. ndHTL and second light-emitting laminate 2 nd EML.

[0075] The fourth layer 540, which can be formed by a deposition process, may include the second layer stack 2. nd The remaining layers of the stack. More specifically, the fourth layer 540 may include a second electron transport layer 2. nd ETL and electron injection layer EIL.

[0076] When the first light-emitting laminate is formed by solution processing 1 st When the upper layer of EML is used, the first light-emitting layer 1 st EML may be adversely affected by the solvent in the solution, therefore the first light-emitting laminate 1 st The upper layer of the EML can preferably be formed by a deposition process. Similarly, it is desirable to form the second light-emitting layer stack 2 by a deposition process. nd The upper layer of EML. For this purpose, the second layer 520 and the fourth layer 540 can be formed by deposition process instead of solution process.

[0077] Refer again Figure 2 The second electrode 600 is formed on the light-emitting laminate 500. The second electrode 600 can be formed continuously, without being interrupted throughout the boundary region between the plurality of sub-pixels SP1, SP2, and SP3, or within the plurality of sub-pixels SP1, SP2, and SP3. The second electrode 600 can serve as the cathode of the electroluminescent display device. When the electroluminescent display device according to this disclosure is a top-emitting type, the second electrode 600 can be formed of a transparent electrode or a translucent electrode, and when the electroluminescent display device according to this disclosure is a bottom-emitting type, the second electrode 600 can be formed of a reflective electrode.

[0078] An encapsulation layer 700 is formed on the second electrode 600 and is configured to prevent external moisture or oxygen from penetrating into the light-emitting stack 500.

[0079] Color filter 800 and light-shielding layer 850 can be formed on encapsulation layer 700. Color filter 800 may include a red R color filter disposed in first sub-pixel SP1, a green G color filter disposed in second sub-pixel SP2, and a blue B color filter disposed in third sub-pixel SP3. Light-shielding layer 850 may be formed in the boundary region between the red R color filter, green G color filter, and blue B color filter (i.e., the boundary region between multiple sub-pixels SP1, SP2, and SP3).

[0080] When the electroluminescent display device according to one embodiment of the present disclosure is a top-emitting type, as shown in the figure, the color filter 800 and the light-shielding layer 850 can be formed on the upper surface of the encapsulation layer 700. However, when the electroluminescent display device according to one embodiment of the present disclosure is a bottom-emitting type, the color filter 800 and the light-shielding layer 850 can be formed below the light-emitting layer stack 500, and more specifically, in the circuit element layer 200.

[0081] A protective layer 900 can be formed on the color filter 800 and the light-shielding layer 850 to protect the internal components from external impacts.

[0082] Figures 4 to 6 This is a schematic cross-sectional view of an electroluminescent display device according to various embodiments of the present disclosure.

[0083] Figure 4 Electroluminescent display devices and Figure 2 The difference of the electroluminescent display device is that the configuration of the upper embankment layer 411b of the first embankment 410 is changed.

[0084] like Figure 4 As shown, a groove H is formed on the upper dam layer 411b of the first dam portion 410. Therefore, the second layer 521 of the light-emitting laminate 500 formed on the upper dam layer 411b extends along the inner surface of the groove H, and the lower part of the second dam layer 421 formed on the second layer 521 is configured to fill the groove H. The second layer 521 is formed by a deposition process.

[0085] therefore, Figure 4 The structure provides a structure having a conductive layer 300 (an anode in this example) formed by a deposition process, and a first layer 510 formed directly on top of it by an inkjet printing step, then a second layer 521 formed directly on top of the first layer 510, and then a third layer 530 formed directly on top of the second layer 521 by an inkjet printing process.

[0086] according to Figure 4 In the structure shown, the current path of the second layer 521 of the light-emitting stack 500 is increased by the groove H formed on the upper surface of the upper embankment layer 411b, which makes it possible to reduce the occurrence of leakage current between the third sub-pixel SP3 (e.g., including one of a plurality of sub-pixels SP3) and the second sub-pixel SP2 (e.g., including one of a plurality of sub-pixels SP2).

[0087] Figure 5 Electroluminescent display devices and Figure 4 The difference of the electroluminescent display device is that the structure of the groove H formed on the upper surface of the upper embankment 412b has been changed.

[0088] Reference Figure 4 The groove H formed on the upper surface of the upper embankment layer 411b is formed so as not to penetrate the upper embankment layer 411b, so that the second layer 521 of the light-emitting laminate 500 contacts the upper embankment layer 411b in the portion corresponding to the groove H, and does not contact the lower embankment layer 410a disposed below it.

[0089] In addition, refer to Figure 5 The groove H formed on the upper surface of the upper embankment layer 412b penetrates the upper embankment layer 412b, thereby the second layer 522 of the light-emitting laminate 500 contacts the lower embankment layer 410a in the portion corresponding to the groove H, and the lower portion of the second embankment portion 422 formed on the second layer 522 is configured to fill the groove H.

[0090] and Figure 4 Compared to the structure, Figure 5 The structure can increase the current path of the second layer 522 of the light-emitting stack 500 in the portion of the groove H, thereby reducing the occurrence of leakage current between the third sub-pixel SP3 (e.g., including one of a plurality of sub-pixels SP3) and the second sub-pixel SP2 (e.g., including one of a plurality of sub-pixels SP2).

[0091] Figure 6 Electroluminescent display devices and Figure 5 The difference in the electroluminescent display device is that the structure of the second embankment 423 is changed.

[0092] Reference Figure 5 The upper surface of the second embankment 422 is formed at a height higher than that of the second layer 522.

[0093] In addition, refer to Figure 6 The upper surface of the second dam 423 is formed at the same height as the upper surface of the second layer 522. Even though the upper surface of the second dam 423 is formed at the same height as the upper surface of the second layer 522, the third layer 530 can be broken on the upper surface of the second dam 423 because the upper surface of the second dam 423 is hydrophobic for solution processes.

[0094] Figure 7 This is a schematic cross-sectional view illustrating an electroluminescent display device according to one embodiment of the present disclosure, which corresponds to Figure 1 A cross-sectional view taken along line CD. That is to say, Figure 7 It is a cross-sectional view of the boundary region between a first sub-pixel SP1 that emits light of the same color and another adjacent first sub-pixel SP1.

[0095] like Figure 7As shown, an electroluminescent display device according to one embodiment of the present disclosure includes a substrate 100, a circuit element layer 200, a first electrode 300, a lower embankment layer 410a, a light-emitting layer stack 500, a second electrode 600, an encapsulation layer 700, a color filter 800, a light-shielding layer 850, and a protective layer 900.

[0096] Because the substrate 100, circuit element layer 200, first electrode 300, second electrode 600, encapsulation layer 700, color filter 800, light-shielding layer 850 and protective layer 900 are structurally similar to... Figure 2 Since they are the same, their detailed description can be omitted.

[0097] According to one embodiment of the present disclosure, the lower dam layer 410a of the first dam portion 410 is formed in the boundary region between a first sub-pixel SP1 and another adjacent first sub-pixel SP1, and the upper dam layer 410b and the second dam portion 420 of the first dam portion 410 are not formed therein.

[0098] Light of the same color is emitted from one first sub-pixel SP1 and another first sub-pixel SP1 adjacent to it. Therefore, even if the first layer 510 and the third layer 530 of the light-emitting stack 500 are continuous between one first sub-pixel SP1 and another first sub-pixel SP1, it does not adversely affect the image quality. Therefore, the upper embankment layer 410b and the second embankment 420 can be omitted in the boundary region between one first sub-pixel SP1 and another first sub-pixel SP1 adjacent to it.

[0099] Therefore, the second layer 520 of the light-emitting stack 500 contacts the upper surface of the lower embankment layer 410a in the boundary region between a first sub-pixel SP1 and another adjacent first sub-pixel SP1. Furthermore, 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 in the boundary region between a first sub-pixel SP1 and another adjacent first sub-pixel SP1. The fourth layer 540 is formed by a deposition process such as sputtering, as described elsewhere herein.

[0100] Figure 8 This is a plan view of an electroluminescent display device according to another embodiment of the present disclosure. Figure 8 In addition to providing a third dam 430, the electroluminescent display device is also compatible with... Figure 1 It is the same as the electroluminescent display device.

[0101] like Figure 8As shown, a third dam 430 is formed in the boundary region between a first sub-pixel SP1 emitting light of the same color and another adjacent first sub-pixel SP1. Furthermore, the third dam 430 is formed in the boundary region between a second sub-pixel SP2 emitting light of the same color and another adjacent second sub-pixel SP2. Additionally, the third dam 430 is formed in the boundary region between a third sub-pixel SP3 emitting light of the same color and another adjacent third sub-pixel SP3.

[0102] Therefore, the third dike portion 430 has a linear structure extending in the first direction (e.g., the X-axis direction). At this time, the third dike portion 430 is not formed as a continuous linear structure in the first direction, but rather as a discontinuous linear structure. That is, the third dike portion 430 disposed in the boundary region between two adjacent first sub-pixels SP1 is not connected to the third dike portion 430 disposed in the boundary region between two adjacent second sub-pixels SP2. The third dike portion has some parts that are separated from the other parts, and is therefore discontinuous.

[0103] As described in this article, examples can be found in Figure 8 , Figure 9 , Figure 10 , Figure 11 and Figure 12 I saw it in the middle.

[0104] The third dike portion 430 is not connected to the second dike portion 420. Therefore, the third dike portion 430 is spaced apart from the second dike portion 420 on one side (e.g., the left side) and the other side (e.g., the right side), with a predetermined space S1 between them. In other words, the third dike portion 430 is formed in the portion other than the predetermined space S1 (which corresponds to the portion between the two second dike portions 420 on the two lateral sides of the third dike portion 430 and the portion in the boundary region between two adjacent first sub-pixels SP1).

[0105] The third dike section 430 may be formed of the same material as the second dike section 420, but is not limited thereto. The third dike section 430 may also be formed of a different material than the second dike section 420.

[0106] Figure 9 This is a schematic cross-sectional view of an electroluminescent display device according to another embodiment of the present disclosure, which corresponds to Figure 8 A cross-sectional view taken along line EF. That is to say, Figure 9 It is a cross-sectional view of the boundary region between a first sub-pixel SP1 that emits light of the same color and another adjacent first sub-pixel SP1.

[0107] like Figure 9As shown, another embodiment of the electroluminescent display device disclosed herein includes a substrate 100, a circuit element layer 200, a first electrode 300, a lower embankment layer 410a, a third embankment 430, a light-emitting layer stack 500, a second electrode 600, an encapsulation layer 700, a color filter 800, a light-shielding layer 850, and a protective layer 900.

[0108] Because the substrate 100, circuit element layer 200, first electrode 300, second electrode 600, encapsulation layer 700, color filter 800, light-shielding layer 850 and protective layer 900 are structurally similar to... Figure 7 Since they are the same, their detailed descriptions can be omitted.

[0109] According to another embodiment of the present disclosure, the lower embankment layer 410a of the first embankment 410 and the third embankment 430 is formed in the boundary region between a first sub-pixel SP1 and another first sub-pixel SP1 adjacent thereto.

[0110] In this case, the third dam 430 is disposed between the second layer 520 and the fourth layer 540 of the light-emitting laminate 500 in the same manner as the second dam 420 described above.

[0111] Therefore, the second layer 520 of the light-emitting stack 500 contacts the entire upper surface of the lower embankment layer 410a in the boundary region between a first sub-pixel SP1 and another adjacent first sub-pixel SP1. Furthermore, the fourth layer 540 of the light-emitting stack 500 contacts the upper surface of the third embankment portion 430 in the boundary region between a first sub-pixel SP1 and another adjacent first sub-pixel SP1.

[0112] Therefore, the third dam 430 can prevent the third layer 530 of the light-emitting stack 500 formed in one first sub-pixel SP1 from diffusing to another adjacent first sub-pixel SP1. For this purpose, the upper surface of the third dam 430 can be hydrophobic. However, the upper surface of the third dam 430 can be formed to be hydrophilic.

[0113] Refer again Figure 8 According to another embodiment of this disclosure, the third dam portion 430 and the second dam portion 420 are spaced apart by a predetermined space S1. For the solution process of forming the third layer 530 of the light-emitting laminate 500, the solution moves smoothly through the predetermined space S1, thereby preventing contamination.

[0114] More specifically, according to the formed third dam 430, the third layer 530 of the light-emitting laminate 500 can be separated between two adjacent first sub-pixels SP1. In this case, if the third dam 430 is formed as a continuous straight line structure in the first direction while in contact with the second dam 420, the solution used to form the third layer 530 of the light-emitting laminate 500 is trapped in each first sub-pixel SP1, thereby preventing the solution from moving between adjacent first sub-pixels SP1. In this situation, when the amount of solution ejected from the inkjet printer is not precisely adjusted, the amount of solution in a particular first sub-pixel SP1 may be greater than or less than a predetermined reference value, potentially leading to stains.

[0115] In another embodiment of this disclosure, since the third dike portion 430 is spaced apart from the second dike portion 420 with a predetermined space S1 between them, the problem of stain formation can be prevented. Specifically, even if the amount of solution ejected from the inkjet printer is not precisely adjusted, the solution can move between adjacent first sub-pixels SP1 through the predetermined space S1, thereby solving the problem related to the amount of solution ejected that is not precisely adjusted, and thus preventing the problem of stain formation.

[0116] Figures 10 to 12 This is a schematic plan view of an electroluminescent display device according to various embodiments of the present disclosure. Figures 10 to 12 Electroluminescent display devices and Figure 8 The difference between the electroluminescent display device and the one mentioned above is that the structure of the third embankment (430) and the predetermined space S2 is changed.

[0117] With Figure 8 In the same way, such as Figures 10 to 12 As shown, the third dike 430 is formed in the portion other than the predetermined space S2 (which corresponds to the portion between the two second dikes 420 on the two lateral sides of the third dike 430 and to the portion in the boundary region between two adjacent first sub-pixels SP1).

[0118] In this case, refer to Figure 10 The third dike portion 430a on one side (e.g., the left side) extends from the second dike portion 420 on one side (e.g., the left side) in another direction (e.g., the right direction), and the third dike portion 430b on the other side (e.g., the right side) extends from the second dike portion 420 on the other side (e.g., the right side) in one direction (e.g., the left direction), and the third dike portion 430a on one side and the third dike portion 430b on the other side are spaced apart by a predetermined space S2.

[0119] Reference Figure 11Multiple third dike sections 430 are spaced apart from each other and have a predetermined space S3 therebetween. The third dike section 430 arranged to be closest to one side (e.g., the left side) and the third dike section 430 arranged to be closest to the other side (e.g., the right side) are spaced apart from the second dike section 420 and have a predetermined space S4 therebetween.

[0120] Reference Figure 12 The third dike 430 extends from one side (e.g., the left side) of the second dike 420 to the other side (e.g., to the right), and the third dike 430 is not connected to the second dike 420 on the other side (e.g., the right side) and is spaced apart from the second dike 420, with a predetermined space S5 therebetween.

[0121] As described above, the positions of the predetermined spaces S1, S2, S3, S4 and S5 can be varied differently in the boundary region between two adjacent first sub-pixels SP1.

[0122] Therefore, this disclosure may have the following advantages.

[0123] According to one embodiment of the present disclosure, a first layer of a light-emitting stack that needs to be separated for each sub-pixel is formed by a solution process such as inkjet printing, and the first layer of the light-emitting stack is disconnected for each sub-pixel by a first dam, such that the first layer of the light-emitting stack is discontinuous for each sub-pixel.

[0124] According to one embodiment of this disclosure, the second and fourth layers of the light-emitting stack, which do not require separation for each sub-pixel, can be formed without a mask by a vacuum deposition method such as an evaporation method.

[0125] According to one embodiment of the present disclosure, a second dam is additionally formed on the second layer of the light-emitting stack, such that the third layer of the light-emitting stack that needs to be separated for each sub-pixel is formed by a solution process such as inkjet printing, and is broken by the second dam while being discontinuous for each adjacent sub-pixel.

[0126] According to another embodiment of this disclosure, a third embankment is formed in the boundary region between a sub-pixel emitting light of the same color and another adjacent sub-pixel, and ensures a predetermined space for ink movement, thereby improving the flowability of the light-emitting laminate and preventing stains from appearing in a particular sub-pixel.

[0127] It will be apparent to those skilled in the art that various substitutions, modifications and changes can be made within the scope of this disclosure without departing from its spirit and scope.

[0128] The various embodiments described above can be combined to provide further embodiments. All U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referenced and / or listed in the application data sheets are incorporated herein by reference in their entirety. If necessary, aspects of the embodiments can be modified to incorporate concepts from various patents, applications and publications to provide additional embodiments.

[0129] In view of the above detailed description, these and other changes may be made to the embodiments. 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 interpreted to include all possible embodiments and the full scope of equivalents conferred by these claims. Therefore, the claims are not limited to this disclosure.

[0130] Cross-reference to related applications

[0131] This application claims the benefit and priority of Korean Patent Application No. 10-2021-0186757, filed on December 24, 2021, the entire contents of which are incorporated herein by reference.

Claims

1. An electroluminescent display device, the electroluminescent display device comprising: A substrate, the substrate including a first sub-pixel and a second sub-pixel arranged in a first direction; A first electrode is disposed in each of the first sub-pixel and the second sub-pixel on the substrate; A dam portion is disposed in the boundary region between the first sub-pixel and the second sub-pixel on the substrate; A light-emitting stack, wherein the light-emitting stack is disposed on the first electrode; as well as The second electrode is disposed on the light-emitting laminate. The embankment includes a first embankment and a second embankment located on the first embankment. The light-emitting stack includes a first layer disposed in each of the first sub-pixel and the second sub-pixel, and a second layer disposed on the first layer, the second layer extending continuously from the first sub-pixel to the second sub-pixel. The first embankment is located below the second layer, and the second embankment is located on the second layer. The substrate further includes a separate first sub-pixel, which is arranged adjacent to the first sub-pixel in a second direction and configured to emit light of the same color as the first sub-pixel. The third dike is attached to the boundary region between the first sub-pixel and the individual first sub-pixel, and The third embankment is located in the portion of the boundary region between the first sub-pixel and the individual first sub-pixel, excluding the predetermined space.

2. The electroluminescent display device according to claim 1, wherein, The first and second embankments are spaced apart vertically without contacting each other, and the second layer is inserted between the first and second embankments.

3. The electroluminescent display device according to claim 1, wherein, The light-emitting stack further includes a third layer and a fourth layer. The third layer is disposed on the second layer and in each of the first sub-pixel and the second sub-pixel, and the fourth layer is disposed on the third layer and is continuously disposed from the first sub-pixel to the second sub-pixel.

4. The electroluminescent display device according to claim 3, wherein, The first layer disposed in the first sub-pixel and the first layer disposed in the second sub-pixel are disconnected from each other, and the first embankment is inserted between the first layer disposed in the first sub-pixel and the first layer disposed in the second sub-pixel. The third layer disposed in the first sub-pixel and the third layer disposed in the second sub-pixel are disconnected from each other, and the second embankment is inserted between the third layer disposed in the first sub-pixel and the third layer disposed in the second sub-pixel.

5. The electroluminescent display device according to claim 3, wherein, The second layer and the fourth layer are spaced apart vertically without contacting each other, and the second embankment is inserted between the second layer and the fourth layer.

6. The electroluminescent display device according to claim 3, wherein, The light-emitting laminate includes a first laminate for emitting light of a first color, a second laminate for emitting light of a second color, and a charge-generating layer disposed between the first laminate and the second laminate. The first layer of the stack includes the first layer, and The second layer includes the third layer.

7. The electroluminescent display device according to claim 6, wherein, The first stacked layer includes a hole injection layer, a first hole transport layer, a first light-emitting layer stack, and a first electron transport layer. The second stacked assembly includes a second hole transport layer, a second light-emitting layer stack, a second electron transport layer, and an electron injection layer. The charge generation layer includes an N-type charge generation layer and a P-type charge generation layer. The first layer includes the hole injection layer, the first hole transport layer, and the first light-emitting layer stack. The second layer includes the first electron transport layer, the N-type charge generation layer, and the P-type charge generation layer. The third layer includes the second hole transport layer and the second light-emitting layer stack, and The fourth layer includes the second electron transport layer and the electron injection layer.

8. The electroluminescent display device according to claim 1, wherein, The lower part of the first embankment is hydrophilic, and The upper surfaces of the first embankment and the second embankment are hydrophobic.

9. The electroluminescent display device according to claim 1, wherein, A groove is provided on the upper surface of the first dam, and the second layer extends along the inner surface of the groove, and the second dam is configured to fill the groove.

10. The electroluminescent display device according to claim 1, wherein, The height of the upper surface of the second embankment is higher than the height of the upper surface of the second layer.

11. The electroluminescent display device according to claim 1, wherein, The light-emitting stack further includes a third layer and a fourth layer. The third layer is disposed on the second layer and in each of the first sub-pixel and the second sub-pixel. The fourth layer is disposed on the third layer and is continuously disposed from the first sub-pixel to the second sub-pixel. The third layer disposed in the first sub-pixel and the third layer disposed in the individual first sub-pixel are disconnected from each other, and the third embankment is inserted between the third layer disposed in the first sub-pixel and the third layer disposed in the individual first sub-pixel. The second layer and the fourth layer are spaced apart vertically without touching each other, and the third embankment is inserted between the second layer and the fourth layer.

12. The electroluminescent display device according to claim 1, wherein, The first embankment is attached to the boundary region between the first sub-pixel and the individual first sub-pixel. The first embankment, located in the boundary region between the first sub-pixel and the second sub-pixel, includes a lower embankment layer and an upper embankment layer, and The first embankment, located in the boundary region between the first sub-pixel and the individual first sub-pixel, comprises only the lower embankment layer.

13. An electroluminescent display device, the electroluminescent display device comprising: A substrate, the substrate comprising a plurality of first sub-pixels and a plurality of second sub-pixels; A first embankment is disposed in the boundary region between the plurality of first sub-pixels and the plurality of second sub-pixels, the boundary region between each of the plurality of first sub-pixels, and the boundary region between each of the plurality of second sub-pixels; A second embankment is disposed on the first embankment and along the boundary region between the plurality of first sub-pixels and the plurality of second sub-pixels; as well as A third embankment is provided in a discontinuous linear structure in the boundary regions between each of the plurality of first sub-pixels and between each of the plurality of second sub-pixels. The electroluminescent display device further includes a light-emitting stack, which comprises a first layer, a second layer, a third layer, and a fourth layer stacked sequentially. The first embankment and the second embankment are spaced apart from each other in the vertical direction, and the second layer is inserted between the first embankment and the second embankment.

14. The electroluminescent display device according to claim 13, wherein, The third embankment is located in the portion of the boundary region between each of the plurality of first sub-pixels, excluding the predetermined space.

15. The electroluminescent display device according to claim 14, wherein, The third embankment is spaced apart from the second embankment, and there is a predetermined space between the third embankment and the second embankment.

16. The electroluminescent display device according to claim 14, wherein, The third dike extends from the second dike while contacting it.

17. The electroluminescent display device according to claim 13, wherein, The first layer and the third layer are configured to be disconnected in the plurality of first sub-pixels and the plurality of second sub-pixels, and The second layer and the fourth layer are successively disposed from the plurality of first sub-pixels to the plurality of second sub-pixels.

18. The electroluminescent display device according to claim 13, wherein, The first embankment and the third embankment are spaced apart from each other in the vertical direction, and the second layer is inserted between the first embankment and the third embankment.

19. An electroluminescent display device, the electroluminescent display device comprising: The first portion of the first light-emitting stack is disposed above the substrate; The second part of the first light-emitting stack is disposed above the substrate, and the first part of the first light-emitting stack is disconnected from the second part of the first light-emitting stack. A first embankment is disposed between the first portion of the first light-emitting laminate and the second portion of the first light-emitting laminate. A conductive layer is disposed above the first embankment, the first portion of the first light-emitting layer stack, and the second portion of the first light-emitting layer stack. The first portion of the second light-emitting stack is disposed above the conductive layer; The second portion of the second light-emitting stack is disposed above the conductive layer, and the first portion of the second light-emitting stack is disconnected from the second portion of the second light-emitting stack. as well as A second dam portion is disposed on the conductive layer and located between the first portion and the second portion of the second light-emitting layer stack. The substrate further includes a separate first sub-pixel, which is arranged adjacent to the first sub-pixel and configured to emit light of the same color as the first sub-pixel. Both the first sub-pixel and the separate first sub-pixel are associated with the first portion of the first light-emitting stack. The third dike is attached to the boundary region between the first sub-pixel and the individual first sub-pixel, and The third embankment is located in the portion of the boundary region between the first sub-pixel and the individual first sub-pixel, excluding the predetermined space.

20. The electroluminescent display device according to claim 19, wherein, The conductive layer is a charge generation layer.

21. The electroluminescent display device according to claim 19, wherein, The second portion of the first light-emitting stack is associated with the second sub-pixel.

22. The electroluminescent display device according to claim 19, further comprising: A first color filter is disposed above the first portion of the first light-emitting layer; as well as A second color filter is disposed above the second portion of the first light-emitting layer.

23. The electroluminescent display device according to claim 19, wherein, The height of the first embankment is greater than the height of the first portion of the first light-emitting laminate.

24. The electroluminescent display device according to claim 19, wherein, The first dam includes a groove, and the conductive layer extends along the inner surface of the groove.

25. The electroluminescent display device according to claim 19, further comprising: A thin-film transistor, wherein the thin-film transistor is disposed above the substrate, and the first portion of the first light-emitting stack is disposed above the thin-film transistor.

26. The electroluminescent display device according to claim 19, wherein, The first embankment is made of either an insulating material or a hydrophobic material.

27. The electroluminescent display device according to claim 19, wherein, The first portion of the first light-emitting stack is located in a first sub-pixel, and the second portion of the first light-emitting stack is located in a second sub-pixel spaced apart from the first sub-pixel.

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