Organic Light Emitting Display Panel and Method for manufacturing the same

Abstract

The present invention relates to a method for manufacturing an organic light-emitting display panel that can simplify the process and improve display quality. The organic light-emitting display panel according to the present invention comprises: a first electrode disposed in each sub-pixel area on a substrate in which a plurality of sub-pixel areas are defined; a bank layer disposed on the substrate on the boundary portion of each sub-pixel area and having a side surface that is hydrophilic; a first organic material layer disposed across the bank layer and the first electrode and having a surface on the upper side of the bank layer that is hydrophobic; a second organic material layer disposed on the first organic material layer between the bank layers; a third organic material layer disposed across the second organic material layer and the first organic material layer; and a second electrode disposed on the third organic material layer.

Description

Technology Field

[0001] The present invention relates to an organic light-emitting display panel and a method for manufacturing the same, and in particular to an organic light-emitting display panel capable of improving display quality and a method for manufacturing the same. Background Technology

[0002] An organic light-emitting display device comprises an organic light-emitting display panel having data lines, scan lines, and a plurality of subpixels formed at the intersections of the data lines and scan lines, a gate driving circuit that supplies scan signals to the scan lines, and a data driving circuit that supplies data voltages to the data lines.

[0003] Each subpixel of the above-described organic light-emitting display panel is equipped with an organic light-emitting diode (hereinafter referred to as 'OLED') and a pixel circuit that independently drives the organic light-emitting diode.

[0004] Organic light-emitting diodes have multiple organic compound layers between the azod electrode and the cathode electrode, and recently, multiple organic compound layers are manufactured using an inkjet printing method.

[0005] That is, a first electrode (11) of the light-emitting element is formed in each subpixel area.

[0006] Then, after coating a first bank material having hydrophilicity, the first bank material is patterned to form a first bank at the boundary of each sub-pixel area.

[0007] After forming a second bank having hydrophobicity on top of the first bank, a plurality of organic compound layers are formed on the first electrode using an inkjet printing method.

[0008] However, when the first and second banks are formed as described above, an organic residue film is present on the first electrode, which degrades the characteristics of the organic light-emitting diode, and if UV or plasma treatment is performed to remove the organic residue film, the hydrophobic characteristics of the second bank are degraded, making subsequent inkjet printing impossible. The problem to be solved

[0009] The present invention aims to provide an organic light-emitting display panel and a method for manufacturing the same that can simplify the process and improve display quality. means of solving the problem

[0010] An organic light-emitting display panel according to an embodiment of the present invention for achieving the above-mentioned purpose comprises: a first electrode disposed in each sub-pixel area on a substrate in which a plurality of sub-pixel areas are defined; a bank layer disposed on the substrate on the boundary portion of each sub-pixel area and having a side surface that is hydrophilic; a first organic material layer disposed across the bank layer and the first electrode and having a surface on the upper side of the bank layer that is hydrophobic; a second organic material layer disposed on the first organic material layer between the bank layers; a third organic material layer disposed across the second organic material layer and the first organic material layer; and a second electrode disposed on the third organic material layer. The first organic material layer comprises at least one of a hole injection layer and a hole transport layer, the second organic material layer comprises a light-emitting layer, and the third organic material layer may comprise at least one of an electron transport layer and an electron injection layer.

[0011] Here, to improve the pile-up, the second organic material layer may include a first hole transport layer disposed only on the first organic material layer in the red subpixel region and the green subpixel region between the bank layers, and a light-emitting layer disposed in the red subpixel region, the green subpixel region, and the red subpixel region.

[0012] An organic light-emitting display panel according to an embodiment of the present invention for achieving the above-mentioned purpose comprises: a first electrode disposed in each sub-pixel region on a substrate in which a plurality of sub-pixel regions are defined; a bank layer disposed on the substrate on the boundary portion of each sub-pixel region and having a side surface that is hydrophilic; a first organic material layer disposed on the first electrode of each sub-pixel region between the bank layer; a second organic material layer disposed across the first organic material layer and the bank layer, wherein the upper surface of the bank layer is hydrophobic; a third organic material layer disposed on the second organic material layer between the bank layers; a fourth organic material layer disposed across the third organic material layer and the first organic material layer; and a second electrode disposed on the fourth organic material layer. The first organic material layer includes a first hole transport layer and a first light-emitting layer, the second organic material layer includes a first electron transport layer, an n-type charge generation layer, a p-type charge generation layer, and a hole injection layer, and the third organic material layer includes a second hole transport layer and a second light-emitting layer. The fourth organic material layer may include a second electron transport layer and an electron injection layer.

[0013] To improve fill-up, an organic light-emitting display panel according to an embodiment of the present invention comprises: a first electrode disposed in each subpixel area on a substrate in which a plurality of subpixel areas having red, green, and blue subpixels are defined; a bank layer disposed on the substrate on the boundary portion of each subpixel area and having a side surface that is hydrophilic; a first organic material layer disposed on the first electrode of each subpixel area between the bank layer; a second organic material layer disposed across the first organic material layer and the bank layer, with the upper surface of the bank layer being hydrophobic; a third organic material layer disposed on the second organic material layer between the bank layer; a fourth organic material layer disposed across the third organic material layer and the first organic material layer; and a second electrode disposed on the fourth organic material layer. The third organic material layer comprises a first hole transport layer disposed only on the second organic material layer of the red subpixel area and the green subpixel area between the bank layer, and the red subpixel area, the green subpixel area, and It may include a first light-emitting layer disposed in the above red subpixel area.

[0014] An organic light-emitting display panel according to an embodiment of the present invention for achieving the above-mentioned purpose comprises: a first electrode disposed in each subpixel area on a substrate in which a plurality of subpixel areas having red, green, and blue subpixels are defined; a bank layer disposed on the substrate on the boundary portion of each subpixel area and having a side surface that is hydrophilic; a first organic material layer disposed on the substrate over the bank layer and the first electrode, wherein the surface of the upper side of the bank layer is hydrophobic; a second organic material layer disposed on the first organic material layer in each subpixel area between the bank layer; a third organic material layer disposed over the second organic material layer and the first organic material layer, wherein the surface of the upper side of the bank layer is hydrophobic; a fourth organic material layer disposed on the third organic material layer between the bank layer; a fifth organic material layer disposed over the fourth organic material layer and the third organic material layer; and a second electrode disposed on the fifth organic material layer, wherein the fourth organic material layer is disposed in the red subpixel area between the bank layer and the green It may include a first hole transport layer disposed only on the third organic material layer of the subpixel region, and a first light-emitting layer disposed on the red subpixel region, the green subpixel region, and the red subpixel region.

[0015] In addition, a method for manufacturing an organic light-emitting display panel according to an embodiment of the present invention for achieving the above-mentioned purpose comprises the steps of: forming a first electrode in each sub-pixel area on a substrate in which a plurality of sub-pixel areas are defined; forming a bank layer at the boundary of each sub-pixel area on the substrate; removing an organic residue film on each first electrode of each sub-pixel area and hydrophilizing the side of the bank layer and the upper part of the first electrode by first plasma treatment; forming a first organic material layer across the first electrode and the bank layer by a deposition process; hydrophobizing the upper surface of the first organic material layer above the bank layer by second plasma treatment; forming a second organic material layer on the first organic material layer of each sub-pixel area by an inkjet printing process; and forming a third organic material layer and a second electrode across the first organic material layer and the second organic material layer by a deposition process, wherein the first organic material layer comprises at least one of a hole injection layer and a hole transport layer, the second organic material layer comprises a light-emitting layer, and the third organic material layer It may include at least one of an electron transport layer and an electron injection layer.

[0016] Here, in order to improve the pile-up, the step of forming the second organic material layer may involve forming a second hole transport layer only on the first organic material layer in the red subpixel region and the green subpixel region between the bank layers, and forming a light-emitting layer in each of the red subpixel region, the green subpixel region, and the red subpixel region. Effects of the invention

[0017] The method for manufacturing an organic light-emitting display panel according to the present invention has the following effects.

[0018] First, by making the bank structure a single layer, the organic residue on the first electrode can be removed while simplifying the process.

[0019] Second, since the light-emitting device can be constructed by combining deposition and inkjet printing processes, the materials for each light-emitting layer can be selected in various ways.

[0020] Third, by repeating the deposition and inkjet printing processes multiple times, the light-emitting layer can be configured as a multi-stack, thereby improving the light-emitting characteristics of the light-emitting device.

[0021] Fourth, the present invention can improve fill-up by manufacturing a light-emitting device by combining an inkjet printing process and a deposition process. Brief explanation of the drawing

[0022] FIG. 1 is a plan view of subpixels of an organic light-emitting display panel according to the present invention. FIG. 2 is a structural diagram showing an organic light-emitting diode having a single stack structure and a process for each layer according to a first embodiment of the present invention. FIG. 3 is a cross-sectional view of the structure of an organic light-emitting display panel according to a first embodiment of the present invention. FIGS. 4a to 4g are process cross-sectional views of an organic light-emitting display panel along line II' of FIG. 1 according to a first embodiment of the present invention. FIGS. 5A and 5B are process cross-sectional views of an organic light-emitting display panel along the line II-II' of FIG. 1 according to a first embodiment of the present invention. FIG. 6 is a plan view and a cross-sectional view illustrating a hydrophobization plasma treatment method on the upper side of a bank layer according to an embodiment of the present invention. FIG. 7 is a schematic diagram illustrating the chemical structure of the surface of an organic material layer during hydrophobization plasma treatment according to an embodiment of the present invention. FIG. 8 is a structural diagram showing a process for each layer that can exclude pile-up effects in a light-emitting device having a single stack structure according to a second embodiment of the present invention. FIG. 9 is a cross-sectional view of the structure of an organic light-emitting display panel according to a second embodiment of the present invention. FIGS. 10a to 10i are process cross-sectional views of an organic light-emitting display panel along line II' of FIG. 1 according to a second embodiment of the present invention. FIG. 11 is a structural diagram showing a light-emitting element having a multi-stack structure and a process for each layer according to a third embodiment of the present invention. FIG. 12 is a cross-sectional view of the structure of an organic light-emitting display panel according to a third embodiment of the present invention. FIGS. 13a to 13i are process cross-sectional views of an organic light-emitting display panel along line II' of FIG. 1 according to a third embodiment of the present invention. FIG. 14 is a structural diagram showing a light-emitting element having a multi-stack structure and a process for each layer according to a fourth embodiment of the present invention. FIG. 15 is a cross-sectional view of the structure of an organic light-emitting display panel according to a fourth embodiment of the present invention. FIGS. 16a to 16k are process cross-sectional views of an organic light-emitting display panel along line II' of FIG. 1 according to a fourth embodiment of the present invention. FIG. 17 is a structural diagram showing a light-emitting element having a multi-stack structure and a process for each layer according to the fifth embodiment of the present invention. FIG. 18 is a cross-sectional view of the structure of an organic light-emitting display panel according to a fifth embodiment of the present invention. FIGS. 19a to 19m are process cross-sectional views of an organic light-emitting display panel along line II' of FIG. 1 according to a fifth embodiment of the present invention. Specific details for implementing the invention

[0023] Hereinafter, an organic light-emitting display panel according to a preferred embodiment of the present invention having the above-mentioned features will be described in more detail with reference to the attached drawings.

[0024] Throughout the specification, identical reference numbers refer to substantially identical components.

[0025] FIG. 1 is a plan view of subpixels of an organic light-emitting display panel according to the present invention.

[0026] As illustrated in FIG. 1, an organic light-emitting display panel according to an embodiment of the present invention comprises a plurality of sub-pixel regions (P), a first electrode (11) disposed in each sub-pixel region (P), and a bank layer (20) surrounding each sub-pixel region (P) and forming a grid shape.

[0027] A plurality of subpixels include a red subpixel equipped with an organic light-emitting diode (OLED) that emits red light, a green subpixel equipped with an organic light-emitting diode (OLED) that emits green light, and a blue subpixel equipped with an organic light-emitting diode (OLED) that emits blue light.

[0028] The structure and manufacturing method of an organic light-emitting display panel according to the first embodiment of the present invention are described as follows.

[0029] FIG. 2 is a structural diagram showing an organic light-emitting diode having a single stack structure according to a first embodiment of the present invention and a process for each layer.

[0030] As shown in FIG. 2, a light-emitting device according to the first embodiment of the present invention has a single stack structure in which a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) are stacked in sequence between a first electrode (Anode; ITO) and a second electrode (Cathode; Metal). Here, a hole injection layer may not be formed.

[0031] Here, the hole injection layer (HIL) and the hole transport layer (HTL) are formed by a deposition process, the light-emitting layer (EML) is formed by an inkjet printing process (Soluble process), and the electron transport layer (ETL), the electron injection layer (EIL), and the second electrode can be formed by a deposition process.

[0032] FIG. 3 is a cross-sectional view of the structure of an organic light-emitting display panel according to a first embodiment of the present invention.

[0033] An organic light-emitting display panel according to the first embodiment of the present invention includes thin-film transistors (70) and organic light-emitting elements in a plurality of subpixel regions (P) on a substrate (80), as shown in FIG. 3.

[0034] The substrate (80) may be made of an insulating material, for example, the substrate (80) may be made of a plastic material such as glass, polyimide (PI), etc.

[0035] A buffer layer (81) is disposed on a substrate (80). The buffer layer (81) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx), or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx). However, the buffer layer (81) is not an essential component and may be omitted based on the type and material of the substrate (60), the structure and type of the thin-film transistor (70), etc.

[0036] A thin-film transistor (70) is disposed on a buffer layer (81). The thin-film transistor (70) includes an active layer (71), a gate electrode (72), a source electrode (73), and a drain electrode (74).

[0037] The active layer (71) of the thin-film transistor (70) is placed on the buffer layer (81), and the gate insulating layer (82) is placed on the active layer (71) and the buffer layer (81).

[0038] The active layer (71) can be formed from amorphous silicon (a-Si), polycrystalline silicon (poly-Si), oxide semiconductor, or organic semiconductor.

[0039] The gate insulating layer (62) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto.

[0040] In the gate insulating layer (82), contact holes are formed for the source electrode (73) and the drain electrode (74), respectively, to contact the active layer (71).

[0041] The gate electrode (72) is placed on the gate insulating layer (82) so as to overlap with the active layer (71). The gate electrode (72) may be composed of a conductive metal, for example, copper (Cu), aluminum (Al), molybdenum (Mo), or an alloy thereof, but is not limited thereto.

[0042] An interlayer insulating layer (83) is disposed on the gate electrode (72). The interlayer insulating layer (83) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto. Contact holes may be formed in the interlayer insulating layer (83) to contact the source electrode (73) and the drain electrode (74) to the active layer (71).

[0043] A source electrode (73) and a drain electrode (74) are disposed on the interlayer insulating layer (83). The source electrode (73) and the drain electrode (74) may be composed of a conductive metal, for example, copper (Cu), aluminum (Al), molybdenum (Mo), or an alloy thereof, but are not limited thereto. Each of the source electrode (73) and the drain electrode (74) may be electrically connected to the active layer (71) through a contact hole.

[0044] A passivation layer (84) may be disposed on a thin-film transistor (70). The passivation layer (84) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto.

[0045] A contact hole may be formed in the passivation layer (84) for the first electrode (11) of the light-emitting element (OLED) to be connected to the thin-film transistor (70). The passivation layer (64) is not a necessary component and may be omitted depending on the design of the organic light-emitting display panel.

[0046] A flattening layer (85) is disposed on the passivation layer (84). The flattening layer (85) may be made of an organic material, and a contact hole may be formed in the flattening layer (85) to expose the drain electrode (74) of the thin-film transistor (70).

[0047] A first electrode (11) is disposed in each subpixel area on the flattening layer (85), and a bank layer (20) is disposed on the substrate (10) on the boundary portion of each subpixel area (P) so as to overlap with the edge of the first electrode (11).

[0048] The edges and sides of the upper surface of the bank layer (20) in the vertical direction (first direction) can be hydrophilized, and the upper surface and sides of the bank layer (20) in the horizontal direction (second direction) adjacent to each subpixel area can also be hydrophilized.

[0049] A first organic material layer (51) is formed over the upper surface and side of the bank layer (20) and over the first electrode (11), and the first organic material layer (51) on the upper side of the bank layer (20) is optionally hydrophobic.

[0050] A second organic material layer (53a to 53c) is disposed on the first organic material layer (51) between the bank layers (20), and a third organic material layer (54) is disposed on the first organic material layer (51) above the bank layers (20) and the second organic material layer (53a to 53c).

[0051] And, a second electrode (60) is placed on the third organic material layer (54).

[0052] Here, the first organic material layer may include a hole injection layer (HIL) and a hole transport layer (HTL), the second organic material layer may include an emitting layer (EML), and the third organic material layer may include an electron transport layer (ETL) and an electron injection layer (EIL).

[0053] The method for manufacturing an organic light-emitting display panel according to the first embodiment of the present invention having a structure as shown in FIG. 3 is described as follows.

[0054] FIGS. 4a to 4g are process cross-sectional views of an organic light-emitting display panel along the II' line of FIG. 1 according to a first embodiment of the present invention, and FIGS. 5a to 5b are process cross-sectional views of an organic light-emitting display panel along the II-II' line of FIG. 1 according to a first embodiment of the present invention.

[0055] In FIGS. 4a to 4g and FIGS. 5a to 5b, only the process of the light-emitting element is illustrated without explaining the manufacturing process of the thin-film transistor (70) in the structural cross-sectional view of FIG. 3. Accordingly, the substrate (10) illustrated in FIGS. 4a to 4g and FIGS. 5a to 5b includes the substrate (80), thin-film transistor (7), and planarization layer (85) illustrated in FIG. 3.

[0056] As illustrated in FIGS. 4a and 5a, a plurality of first electrodes (11) are formed in each subpixel region (P) on a substrate (10) that includes a plurality of subpixel regions (P).

[0057] A hydrophobic organic insulating material is coated on a substrate (10) on which a first electrode (11) is formed and selectively removed to form a bank layer (20) in a grid shape at the boundary of each subpixel area so as to overlap with the edge of the first electrode (11).

[0058] When a hydrophobic organic insulating material is selectively removed to form the bank layer (20), an organic residue film (20a) may be present on the surface of the first electrode (11).

[0059] As illustrated in FIGS. 4b and 5b, the upper edge and side of the bank layer (20) in the vertical direction, the upper surface and side of part of the bank layer (2) in the horizontal direction, and the surface of the first electrode (11) are selectively plasma printed to remove the organic residue (20a) remaining on the surface of the first electrode (11) and simultaneously hydrophilize part of the upper surface of the bank layer (20), the edge and side of the upper surface.

[0060] To explain in more detail, it is as follows.

[0061] The above plasma printing process uses O2 / N2 / Ar gas and selectively performs plasma printing using a scanning method. That is, in Fig. 1, the plasma printing direction is indicated as “30”.

[0062] Plasma printing is performed in a scanning manner along vertical subpixels so as to overlap the upper surface edges of two adjacent vertical bank layers (20) among the grid-shaped bank layers (20).

[0063] Accordingly, the upper surface edges of two adjacent vertical bank layers (20) are removed to a predetermined depth to form a step, and as shown in FIG. 5b, the upper surface of the horizontal bank layer (2) adjacent to the subpixel area of ​​the grid-shaped bank layer (20) is also removed to a predetermined depth. Then, the stepped portion of the vertical bank layer (20), the side of the vertical bank layer (20), and the upper surface and side of the horizontal bank layer (2) are hydrophilized.

[0064] As shown in FIG. 4c, a first organic material layer (51) is formed on the front surface of a substrate (10) including the first electrode (11) and the bank layer (20) using a deposition process.

[0065] The first organic material layer (51) may include a hole injection layer (HIL) and a hole transport layer (HTL) as shown in FIG. 2. Of course, a hole injection layer may not be formed.

[0066] Accordingly, in FIG. 4c, the first organic material layer (51) is shown as a single layer, but is not limited thereto, and the first organic material layer (51) may be composed of multiple layers including a hole injection layer (HIL) and a hole transport layer (HTL).

[0067] As shown in FIG. 4d, the surface of the first organic material layer (51) on the upper side of the bank layer (20) is treated with CF4 or SF6 gas plasma to make the surface of the first organic material layer (51) on the upper side of the bank layer (20) hydrophobic.

[0068] To explain in more detail, it is as follows.

[0069] FIG. 6 is a plan view and a cross-sectional view illustrating a method for hydrophobizing plasma treatment on the upper side of a bank layer according to an embodiment of the present invention, and FIG. 7 is a schematic diagram illustrating the chemical structure of the surface of an organic material layer during hydrophobizing plasma treatment according to an embodiment of the present invention.

[0070] As shown in FIG. 6, using a scanning method, CF4 or SF6 gas plasma treatment is selectively applied only to the first organic material layer (51) on the upper side of the bank layer (20) in the vertical direction (first direction) of the grid-shaped bank layer (20).

[0071] As shown in FIG. 7, before CF4 or SF6 gas plasma treatment, the surface of the first organic material layer (51) has a chemical structure in which terminal groups (X) are bonded to carbon (C).

[0072] As described in FIG. 6, if the first organic material layer (51) on the upper part of the bank layer (20) is selectively treated with CF4 or SF6 gas plasma using a scanning method, the surface of the first organic material layer (51) treated with CF4 or SF6 gas plasma has a chemical structure in which the terminal group (X) is substituted with fluorine and bonded to carbon (C).

[0073] Therefore, if only the surface of the first organic material layer (51) on the upper bank layer (20) is selectively treated with CF4 or SF6 gas plasma, the surface of the first organic material layer (51) on the upper bank layer (20) becomes hydrophobic.

[0074] As shown in FIG. 4e, after hydrophobizing the first organic material layer (51) on the upper side of the bank layer (20), a second organic material solution (52a~52c) is dropped onto the first organic material layer (51) of each sub-pixel area (P).

[0075] At this time, the spreading ability of the second organic material solution (52a~52c) is determined by the surface tension of the second organic material solution (52a~52c), the surface energy of the first electrode (11) placed in each subpixel area (P) in contact with the dropped second organic material solution (52a~52c), and the surface energy of the bank layer (20) placed at the boundary of each subpixel area (P).

[0076] That is, the smaller the surface tension of the second organic material solution (52a~52c), the better the spreadability of the second organic material solution (52a~52c), and the larger the surface energy of the surface in contact with the dropped second organic material solution (52a~52c), the better the spreadability.

[0077] Meanwhile, the second organic material solution (52a to 52c) with low surface tension may dry unevenly during the drying process, which can reduce the thickness uniformity of each layer constituting the second organic material solution (52a to 52c). Therefore, the second organic material solution (52a to 52c) with relatively high surface tension can be used.

[0078] Additionally, the dropped second organic material solution (52a to 52c) may be present on the upper surface of the first electrode (11) as well as on the upper surface of the bank layer (20).

[0079] In the organic light-emitting display panel according to the first embodiment of the present invention, the upper surface of the first organic material layer (51) on the upper side of the vertical bank layer (20) has hydrophobic properties, so the surface energy of the first organic material layer (51) on the upper side of the vertical bank layer (20) is reduced.

[0080] Therefore, the second organic material solution (52a to 52c) dropped into each subpixel area (P) can be prevented from mixing with each other with the second organic material solution (52a to 52c) dropped into each adjacent subpixel area (P) in the horizontal direction.

[0081] At this time, since the first organic material layer (51) on the upper side of the bank layer (20) in the horizontal direction is not hydrophobic, the same second organic material solution (52a~52c) can be dropped into each subpixel area adjacent in the vertical direction.

[0082] As illustrated in FIG. 4f, a drying process is carried out on the dropped second organic material solution (52a~52c) to evaporate the solvent of the second organic material solution (52a~52c) and leave only the solute of the second organic material solution (52a~52c) on the first organic material layer (51) to form the second organic material layer (53a~53c) on the first organic material layer (51).

[0083] The second organic material layer (53a to 53c) above may include the light-emitting layer (EML) shown in FIG. 2.

[0084] For example, a red light-emitting material solution (52a), a green light-emitting material solution (52b), and a blue light-emitting material solution (52c) can be dropped onto the first organic material layer (51) of each subpixel area (P) as a second organic material solution (52a~52c) and dried to form a red light-emitting layer (53a), a green light-emitting layer (53b), and a blue light-emitting layer (53c).

[0085] As shown in FIG. 4g, a third organic material layer (54) is formed on a substrate (10) on which the second organic material layer (53a~53c) is formed using a deposition process.

[0086] The third organic material layer (54) may include an electron transport layer (ETL) and an electron injection layer (EIL) as shown in FIG. 2. Accordingly, although the third organic material layer (54) is shown as a single layer in FIG. 5g, it is not limited thereto, and the third organic material layer (54) may be composed of multiple layers.

[0087] Then, a second electrode (60) is formed on the substrate (10) on which the third organic material layer (54) is formed using a deposition process.

[0088] Meanwhile, even in a single-stack structured light-emitting device as described in Fig. 2, the thickness of the hole injection layer and the hole transport layer may differ for each subpixel due to differences in cavity size for red, green, and blue subpixels.

[0089] In addition, in the case of soluble solution processes such as inkjet printing, there is a possibility that the pile-up area will expand as the thickness increases, and in particular, red subpixels with relatively high thickness are significantly affected by the pile-up risk.

[0090] Therefore, the file-up effect can be eliminated by running the inkjet printing process and the deposition process in parallel.

[0091] The organic light-emitting display panel and the method for manufacturing the same according to the second embodiment of the present invention, which can exclude the above-mentioned file-up effect, are described as follows.

[0092] FIG. 8 is a structural diagram showing a process for each layer that can exclude file-up effects in a light-emitting device having a single stack structure according to a second embodiment of the present invention.

[0093] A light-emitting device according to a second embodiment of the present invention has a single stack structure in which a hole injection layer (HIL), a first hole transport layer (HTL1), a second hole transport layer (HTL2), an emission layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) are sequentially stacked between a first electrode (Anode; ITO) and a second electrode (Cathode; Metal), as shown in FIG. 8. Here, a hole injection layer may not be formed.

[0094] Here, the hole injection layer (HIL) and the first hole transport layer (HTL1) are formed by a deposition process, the second hole transport layer (HTL2) and the light-emitting layer (EML) are formed by an inkjet printing process (Soluble process), and the electron transport layer (ETL), the electron injection layer (EIL), and the second electrode can be formed by a deposition process.

[0095] The structure of the organic light-emitting display panel of the second embodiment of the present invention, which can exclude file-up effects in the light-emitting element having the above single stack structure, is as follows.

[0096] FIG. 9 is a cross-sectional view of the structure of an organic light-emitting display panel according to a second embodiment of the present invention.

[0097] An organic light-emitting display panel according to the second embodiment of the present invention includes a thin-film transistor (70) and an organic light-emitting element in red, green, and blue subpixel regions (R, G, B) on a substrate (80), respectively, as shown in FIG. 9.

[0098] The substrate (80) may be made of an insulating material, for example, the substrate (80) may be made of a plastic material such as glass, polyimide (PI), etc.

[0099] A buffer layer (81) is disposed on a substrate (80). The buffer layer (81) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx), or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx). However, the buffer layer (81) is not an essential component and may be omitted based on the type and material of the substrate (60), the structure and type of the thin-film transistor (70), etc.

[0100] A thin-film transistor (70) is disposed on a buffer layer (81). The thin-film transistor (70) includes an active layer (71), a gate electrode (72), a source electrode (73), and a drain electrode (74).

[0101] The active layer (71) of the thin-film transistor (70) is placed on the buffer layer (81), and the gate insulating layer (82) is placed on the active layer (71) and the buffer layer (81).

[0102] The active layer (71) can be formed from amorphous silicon (a-Si), polycrystalline silicon (poly-Si), oxide semiconductor, or organic semiconductor.

[0103] The gate insulating layer (62) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto.

[0104] In the gate insulating layer (82), contact holes are formed for the source electrode (73) and the drain electrode (74), respectively, to contact the active layer (71).

[0105] The gate electrode (72) is placed on the gate insulating layer (82) so as to overlap with the active layer (71). The gate electrode (72) may be composed of a conductive metal, for example, copper (Cu), aluminum (Al), molybdenum (Mo), or an alloy thereof, but is not limited thereto.

[0106] An interlayer insulating layer (83) is disposed on the gate electrode (72). The interlayer insulating layer (83) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto. Contact holes may be formed in the interlayer insulating layer (83) to contact the source electrode (73) and the drain electrode (74) to the active layer (71).

[0107] A source electrode (73) and a drain electrode (74) are disposed on the interlayer insulating layer (83). The source electrode (73) and the drain electrode (74) may be composed of a conductive metal, for example, copper (Cu), aluminum (Al), molybdenum (Mo), or an alloy thereof, but are not limited thereto. Each of the source electrode (73) and the drain electrode (74) may be electrically connected to the active layer (71) through a contact hole.

[0108] A passivation layer (84) may be disposed on a thin-film transistor (70). The passivation layer (84) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto.

[0109] A contact hole may be formed in the passivation layer (84) for the first electrode (11) of the light-emitting element (OLED) to be connected to the thin-film transistor (70). The passivation layer (64) is not a necessary component and may be omitted depending on the design of the organic light-emitting display panel.

[0110] A flattening layer (85) is disposed on the passivation layer (84). The flattening layer (85) may be made of an organic material, and a contact hole may be formed in the flattening layer (85) to expose the drain electrode (74) of the thin-film transistor (70).

[0111] A first electrode (11) is disposed in each subpixel area on a substrate (10) in which a plurality of subpixel areas (P) including red, green, and blue subpixels (R, G, B) are defined on a flattening layer (85), and a bank layer (20) is disposed on the substrate (10) on the boundary portion of each subpixel area (P) so as to overlap with the edge of the first electrode (11).

[0112] The edges and sides of the upper surface of the bank layer (20) in the vertical direction (first direction) can be hydrophilized, and the upper surface and sides of the bank layer (20) in the horizontal direction (second direction) adjacent to each subpixel area can also be hydrophilized.

[0113] A first organic material layer (91) is formed over the upper surface and side of the bank layer (20) and over the first electrode (11), and the first organic material layer (91) on the upper side of the bank layer (20) is optionally hydrophobic.

[0114] On the first organic material layer (91) of the red subpixel region (R) and green subpixel region (G), excluding the bank layer (20), a second hole transport layer (93a, 93b) and a light-emitting layer (95a, 95b) are stacked and arranged, and on the first organic material layer (91) of the red subpixel region (B), only a light-emitting layer (95c) is arranged.

[0115] A third organic material layer (96) is disposed on the first organic material layer (91) above the light-emitting layer (95a~95c)) and the bank layer (20), and a second electrode (60) is disposed on the third organic material layer (96).

[0116] Here, the first organic material layer may include a hole injection layer (HIL) and a first hole transport layer (HTL1), and the third organic material layer may include an electron transport layer (ETL) and an electron injection layer (EIL).

[0117] The method for manufacturing an organic light-emitting display panel according to the second embodiment of the present invention having a structure as shown in FIG. 9 is described as follows.

[0118] FIGS. 10a to 10h are process cross-sectional views of an organic light-emitting display panel on line II' of FIG. 1 according to a second embodiment of the present invention.

[0119] In FIGS. 10a to 10i, only the process of the light-emitting element is illustrated without explaining the manufacturing process of the thin-film transistor (70) in the structural cross-sectional view of FIG. 9. Accordingly, the substrate (10) illustrated in FIGS. 10a to 10i includes the substrate (80), thin-film transistor (7), and planarization layer (85) illustrated in FIG. 9.

[0120] As illustrated in FIG. 10a, a plurality of first electrodes (11) are formed in each subpixel region (P) on a substrate (10) that includes a plurality of subpixel regions (P).

[0121] Then, an insulating material is deposited on a substrate (10) on which the first electrode (11) is formed and selectively removed to form a bank layer (20) in the shape of a grid at the boundary of each subpixel area.

[0122] The bank layer (20) above can be formed of an organic material or an inorganic material.

[0123] Here, when the hydrophobic organic insulating material is selectively removed to form the bank layer (20), an organic residue film (20a) may be present on the surface of the first electrode (11).

[0124] When a hydrophobic organic insulating material is selectively removed to form the bank layer (20), an organic residue film (20a) may be present on the surface of the first electrode (11).

[0125] As illustrated in FIG. 10b and FIG. 5b, the upper edge and side of the bank layer (20) in the vertical direction, the upper surface and side of part of the bank layer (2) in the horizontal direction, and the surface of the first electrode (11) are selectively plasma printed to remove the organic residue (20a) remaining on the surface of the first electrode (11) and simultaneously hydrophilize part of the upper surface, the edge and side of the upper surface of the bank layer (20).

[0126] To explain in more detail, it is as follows.

[0127] The above plasma printing process uses O2 / N2 / Ar gas and selectively performs plasma printing using a scanning method. That is, in Fig. 1, the plasma printing direction is indicated as “30”.

[0128] Plasma printing is performed in a scanning manner along vertical subpixels so as to overlap the upper surface edges of two adjacent vertical bank layers (20) among the grid-shaped bank layers (20).

[0129] Accordingly, the upper surface edges of two adjacent vertical bank layers (20) are removed to a predetermined depth to form a step, and as shown in FIG. 5b, the upper surface of the horizontal bank layer (2) adjacent to the subpixel area of ​​the grid-shaped bank layer (20) is also removed to a predetermined depth. Then, the stepped portion of the vertical bank layer (20), the side of the vertical bank layer (20), and the upper surface and side of the horizontal bank layer (2) are hydrophilized.

[0130] As illustrated in FIG. 10c, a first organic material layer (91) is formed on the front surface of a substrate (10) including the first electrode (11) and the bank layer (20) using a deposition process.

[0131] The first organic material layer (91) may include a hole injection layer (HIL) and a first hole transport layer (HTL1) as shown in FIG. 8. Of course, a hole injection layer may not be formed.

[0132] Accordingly, in FIG. 10c, the first organic material layer (91) is shown as a single layer, but is not limited thereto, and the first organic material layer (91) may be composed of multiple layers including a hole injection layer (HIL) and a first hole transport layer (HTL1).

[0133] As shown in FIG. 10d, the surface of the first organic material layer (51) on the upper side of the bank layer (20) is treated with CF4 or SF6 gas plasma to hydrophobize the surface of the first organic material layer (91) on the upper side of the bank layer (20).

[0134] Here, when the first organic material layer (91) includes a hole injection layer (HIL) and a first hole transport layer (HTL1), the surface of the first hole transport layer (HTL1) above the bank layer (20) is treated with CF4 or SF6 gas plasma to hydrophobize the surface of the first hole transport layer (HTL1).

[0135] A detailed explanation is provided in Figures 6 and 7, so it will be omitted.

[0136] As illustrated in FIG. 10e, assuming each subpixel area (P) is a red subpixel area (R), a green subpixel area (G), and a blue subpixel area (B), a second hole transport material solution (92a, 92b) is dropped onto the first organic material layer (91) of the red subpixel area (R) and the green subpixel area (G), and the second hole transport material solution is not dropped onto the blue subpixel area (B).

[0137] As shown in FIG. 10f, a process of drying the dropped second hole transport material solution (92a, 92b) is carried out.

[0138] That is, the solvent of the second hole transport material solution (92a, 92b) is evaporated so that only the solute of the second hole transport material solution (92a, 92b) remains on the first organic material layer (91).

[0139] Accordingly, a second hole transport layer (93a~93b) is formed on the first organic material layer (91) of the red subpixel region (R) and the green subpixel region (G). A second hole transport layer is not formed in the blue subpixel region (B).

[0140] As illustrated in FIG. 10g, a red light-emitting material solution (94a), a green light-emitting material solution (94b), and a blue light-emitting material solution (94c) are dropped into each of the red subpixel area (R), the green subpixel area (G), and the blue subpixel area (B).

[0141] As shown in FIG. 10h, a drying process is carried out on the dropped red light-emitting material solution (94a), green light-emitting material solution (94b), and blue light-emitting material solution (94c).

[0142] That is, the solvents of the red light-emitting material solution (94a), the green light-emitting material solution (94b), and the blue light-emitting material solution (94c) are evaporated, and only the solutes of the red light-emitting material solution (94a), the green light-emitting material solution (94b), and the blue light-emitting material solution (94c) remain in each of the subpixel areas.

[0143] Accordingly, a red light-emitting layer (95a), a green light-emitting layer (95b), and a blue light-emitting layer (95c) are formed in each of the red subpixel area (R), the green subpixel area (G), and the blue subpixel area (B).

[0144] As described in FIGS. 10e to 10h, the red subpixel region (R) and the green subpixel region (G) have the first and second hole transport layers (HTL1, HTL2) formed therein, but the blue subpixel region (B) has only the first hole transport layer (HTL1) formed therein, so the file-up effect can be excluded.

[0145] As shown in FIG. 10i, a third organic material layer (96) is formed on a substrate (10) on which the light-emitting layers (95a to 95c) are formed using a deposition process.

[0146] The third organic material layer (96) may include an electron transport layer (ETL) and an electron injection layer (EIL) as shown in FIG. 8. Accordingly, although the third organic material layer (96) is shown as a single layer in FIG. 10i, it is not limited thereto, and the third organic material layer (96) may be composed of multiple layers.

[0147] Then, a second electrode (60) is formed on the substrate (10) on which the third organic material layer (96) is formed using a deposition process.

[0148] Meanwhile, a multi-stack structured light-emitting device can be manufactured by combining an inkjet printing process and a deposition process.

[0149] FIG. 11 is a structural diagram showing a light-emitting element having a multi-stack structure and a process for each layer according to a third embodiment of the present invention.

[0150] A light-emitting device according to the third embodiment of the present invention has a multi-stack structure in which a first hole transport layer (HTL1), a first light-emitting layer (EML1), a first electron transport layer (ETL1), an n-type charge generation layer (n-CGL), a p-type charge generation layer (p-CGL), a hole injection layer (HIL), a second hole transport layer (HTL2), a second light-emitting layer (EML2), a second electron transport layer (ETL2), and an electron injection layer (EIL) are stacked in sequence between a first electrode (Anode; ITO) and a second electrode (Cathode; Metal), as shown in FIG. 11.

[0151] Here, the first stack (Stack1) is configured to include a first hole transport layer (HTL1), a first light-emitting layer (EML1), and a first electron transport layer (ETL1), and the second stack (Stack2) is configured to include a hole injection layer (HIL), a second hole transport layer (HTL2), a second light-emitting layer (EML2), a second electron transport layer (ETL2), and an electron injection layer (EIL). Accordingly, a charge generation layer is located between the first and second stacks.

[0152] The first hole transport layer (HTL1) and the first light-emitting layer (EML1) can be formed by an inkjet printing process (Soluble process).

[0153] The first electron transport layer (ETL1), n-type charge generation layer (n-CGL), p-type charge generation layer (p-CGL), and hole injection layer (HIL) can be formed by a deposition process.

[0154] The second hole transport layer (HTL2) and the second light-emitting layer (EML2) can be formed by an inkjet printing process (Soluble process).

[0155] The second electron transport layer (ETL2), the electron injection layer (EIL), and the second electrode can be formed by a deposition process.

[0156] The structure of the organic light-emitting display panel of the third embodiment of the present invention having the above multi-stack structure is as follows.

[0157] FIG. 12 is a cross-sectional view of the structure of an organic light-emitting display panel according to a third embodiment of the present invention.

[0158] The structure of an organic light-emitting display panel according to the third embodiment of the present invention includes thin-film transistors (70) and organic light-emitting elements in a plurality of sub-pixel regions (P) on a substrate (80), as shown in FIG. 12.

[0159] The substrate (80) may be made of an insulating material, for example, the substrate (80) may be made of a plastic material such as glass, polyimide (PI), etc.

[0160] A buffer layer (81) is disposed on a substrate (80). The buffer layer (81) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx), or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx). However, the buffer layer (81) is not an essential component and may be omitted based on the type and material of the substrate (60), the structure and type of the thin-film transistor (70), etc.

[0161] A thin-film transistor (70) is disposed on a buffer layer (81). The thin-film transistor (70) includes an active layer (71), a gate electrode (72), a source electrode (73), and a drain electrode (74).

[0162] The active layer (71) of the thin-film transistor (70) is placed on the buffer layer (81), and the gate insulating layer (82) is placed on the active layer (71) and the buffer layer (81).

[0163] The active layer (71) can be formed from amorphous silicon (a-Si), polycrystalline silicon (poly-Si), oxide semiconductor, or organic semiconductor.

[0164] The gate insulating layer (62) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto.

[0165] In the gate insulating layer (82), contact holes are formed for the source electrode (73) and the drain electrode (74), respectively, to contact the active layer (71).

[0166] The gate electrode (72) is placed on the gate insulating layer (82) so as to overlap with the active layer (71). The gate electrode (72) may be composed of a conductive metal, for example, copper (Cu), aluminum (Al), molybdenum (Mo), or an alloy thereof, but is not limited thereto.

[0167] An interlayer insulating layer (83) is disposed on the gate electrode (72). The interlayer insulating layer (83) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto. Contact holes may be formed in the interlayer insulating layer (83) to contact the source electrode (73) and the drain electrode (74) to the active layer (71).

[0168] A source electrode (73) and a drain electrode (74) are disposed on the interlayer insulating layer (83). The source electrode (73) and the drain electrode (74) may be composed of a conductive metal, for example, copper (Cu), aluminum (Al), molybdenum (Mo), or an alloy thereof, but are not limited thereto. Each of the source electrode (73) and the drain electrode (74) may be electrically connected to the active layer (71) through a contact hole.

[0169] A passivation layer (84) may be disposed on a thin-film transistor (70). The passivation layer (84) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto.

[0170] A contact hole may be formed in the passivation layer (84) for the first electrode (11) of the light-emitting element (OLED) to be connected to the thin-film transistor (70). The passivation layer (64) is not a necessary component and may be omitted depending on the design of the organic light-emitting display panel.

[0171] A flattening layer (85) is disposed on the passivation layer (84). The flattening layer (85) may be made of an organic material, and a contact hole may be formed in the flattening layer (85) to expose the drain electrode (74) of the thin-film transistor (70).

[0172] A first electrode (11) is disposed in each subpixel area on the flattening layer (85), and a bank layer (20) is disposed on the substrate (10) on the boundary portion of each subpixel area (P) so as to overlap with the edge of the first electrode (11).

[0173] The edges and sides of the upper surface of the bank layer (20) in the vertical direction (first direction) can be hydrophilized, and the upper surface and sides of the bank layer (20) in the horizontal direction (second direction) adjacent to each subpixel area can also be hydrophilized.

[0174] A first organic material layer (112a to 112c) is disposed on the first electrode (11) between the bank layers (20).

[0175] A second organic material layer (113) is disposed over the first organic material layer (112a~112c) and the bank layer (20), and the second organic material layer (113) on the upper side of the bank layer (20) is optionally hydrophobic.

[0176] A third organic material layer (115a to 115c) is disposed on the second organic material layer (113) between the bank layers (20), and a fourth organic material layer (116) is disposed across the third organic material layer (115a to 115c) and the first organic material layer (51) above the bank layers (20).

[0177] And, a second electrode (60) is placed on the fourth organic material layer (116).

[0178] Here, the first organic material layer (112a to 112c) may include a first hole transport layer (HTL1) and a first light-emitting layer (EML1), and the second organic material layer (113) may include a first electron transport layer (EHL1), an n-type charge generation layer (n-CGL), a p-type charge generation layer (p-CGL), and a hole injection layer (HIL).

[0179] The above third organic material layer (115a to 115c) may include a second hole transport layer (HTL2) and a second light-emitting layer (EML2), and the above fourth organic material layer (116) may include a second electron transport layer (ETL2) and an electron injection layer (EIL).

[0180] The method for manufacturing an organic light-emitting display panel according to the third embodiment of the present invention having a structure as shown in FIG. 12 is described as follows.

[0181] FIGS. 13a to 13i are process cross-sectional views of an organic light-emitting display panel on line II' of FIG. 1 according to a third embodiment of the present invention.

[0182] In FIGS. 13a to 13i, only the process of the light-emitting element is illustrated without explaining the manufacturing process of the thin-film transistor (70) in the structural cross-sectional view of FIG. 12. Accordingly, the substrate (10) illustrated in FIGS. 13a to 13i includes the substrate (80), thin-film transistor (7), and planarization layer (85) illustrated in FIG. 12.

[0183] As illustrated in FIG. 13a, a plurality of first electrodes (11) are formed in each subpixel area (P) on a substrate (10) that includes a plurality of subpixel areas (P).

[0184] Then, a hydrophobic organic insulating material is coated on the substrate (10) on which the first electrode (11) is formed and selectively removed to form a bank layer (20) in the shape of a grid at the boundary of each subpixel area.

[0185] Here, when the hydrophobic organic insulating material is selectively removed to form the bank layer (20), an organic residue film (20a) may be present on the surface of the first electrode (11).

[0186] As illustrated in FIG. 13b and FIG. 5b, the upper edge and side of the bank layer (20) in the vertical direction, the upper surface and side of part of the bank layer (2) in the horizontal direction, and the surface of the first electrode (11) are selectively plasma printed to remove the organic residue (20a) remaining on the surface of the first electrode (11) and simultaneously hydrophilize part of the upper surface of the bank layer (20), the edge and side of the upper surface.

[0187] To explain in more detail, it is as follows.

[0188] The above plasma printing process uses O2 / N2 / Ar gas and selectively performs plasma printing using a scanning method. That is, in Fig. 1, the plasma printing direction is indicated as “30”.

[0189] Plasma printing is performed in a scanning manner along vertical subpixels so as to overlap the upper surface edges of two adjacent vertical bank layers (20) among the grid-shaped bank layers (20).

[0190] Accordingly, the upper surface edges of two adjacent vertical bank layers (20) are removed to a predetermined depth to form a step, and as shown in FIG. 5b, the upper surface of the horizontal bank layer (2) adjacent to the subpixel area of ​​the grid-shaped bank layer (20) is also removed to a predetermined depth. Then, the stepped portion of the vertical bank layer (20), the side of the vertical bank layer (20), and the upper surface and side of the horizontal bank layer (2) are hydrophilized.

[0191] As illustrated in FIG. 13c, a first organic material solution (111a, 111b, 111c) is dropped onto the first electrode (11) of each subpixel area (P) using an inkjet printing method (soluble process).

[0192] At this time, since the upper surface of the bank layer (20) in the vertical direction has hydrophobic properties, the surface energy of the upper surface of the bank layer (20) is reduced, so the first organic material solutions (111a~111c) dropped in each sub-pixel area (P) adjacent in the horizontal direction are not mixed with each other.

[0193] In addition, since the upper side of the bank layer (20) in the horizontal direction is hydrophilized, the same first organic material solution (52a~52c) can be dropped into each subpixel area adjacent in the vertical direction.

[0194] As illustrated in FIG. 13d, a drying process is carried out on the dropped first organic material solutions (111a to 111c) to evaporate the solvent of the first organic material solutions (111a to 111c) and leave only the solute of the first organic material solutions (111a to 111c) on the first electrode (11) to form a first organic material layer (112a to 112c) on the first electrode (11).

[0195] Here, the first organic material layers (112a to 112c) may include the first hole transport layer (HTL1) and the first light-emitting layer (EML1) shown in FIG. 11.

[0196] Accordingly, in FIG. 13d, the first organic material layer (112a to 112c) is shown as a single layer, but is not limited thereto, and the first organic material layer (112a to 112c) can be composed of multiple layers.

[0197] If the first organic material layer (112a~112c) includes a first hole (HTL1) and a first light-emitting layer (EML1), the process may proceed as follows.

[0198] As described in FIG. 13c-13d, a hole transport material solution is dropped onto the first electrode (11) of each subpixel region (P) and dried to form a first hole transport layer (HTL1) on the first electrode (11).

[0199] Each subpixel area (P) is assumed to be a red subpixel area (R), a green subpixel area (G), and a blue subpixel area (B).

[0200] As shown in FIG. 13c, a red light-emitting material solution, a green light-emitting material solution, and a blue light-emitting material solution are dropped onto the first positive electrode transport layer of each of the red subpixel region (R), the green subpixel region (G), and the blue subpixel region (B), and as described in FIG. 13d, the dropped red light-emitting material solution, the green light-emitting material solution, and the blue light-emitting material solution are dried to form a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer.

[0201] As shown in FIG. 13e, a second organic material layer (113) is formed on the front surface of a substrate (10) including the first organic material layers (112a~112c) and the bank layer (20) using a deposition process.

[0202] The first organic material layer (51) may include the first electron transport layer (ETL1), n-type charge generation layer (n-CGL), p-type charge generation layer (p-CGL), and hole injection layer (HIL) as shown in FIG. 11.

[0203] That is, a first electron transport layer (ETL1), an n-type charge generation layer (n-CGL), a p-type charge generation layer (p-CGL), and a hole injection layer (HIL) are deposited sequentially on the front surface of a substrate (10) including the first organic material layers (112a~112c) and a bank layer (20).

[0204] Accordingly, in FIG. 13e, the second organic material layer (113) is shown as a single layer, but is not limited thereto, and the second organic material layer (113) may be composed of multiple layers including a first electron transport layer (ETL1), an n-type charge generation layer (n-CGL), a p-type charge generation layer (p-CGL), and a hole injection layer (HIL).

[0205] As shown in FIG. 13f, the surface of the second organic material layer (113) above the bank layer (20) is treated with CF4 or SF6 gas plasma to make the surface of the second organic material layer (113) above the bank layer (20) hydrophobic.

[0206] That is, the surface of the hole injection layer (HIL) located above the bank layer (20) among the hole injection layers (HIL) formed at the uppermost side of the second organic material layer (113) is treated with CF4 or SF6 gas plasma to hydrophobize the surface of the hole injection layer (HIL) above the bank layer (20).

[0207] A more specific method for hydrophobization plasma treatment is described in Figures 6 and 7, so it is omitted here.

[0208] As illustrated in Fig. 13g, a third organic material solution (114a to 114c) is dropped onto the second organic material layer (113) of each subpixel area (P).

[0209] At this time, since the second organic material layer (113) on the upper side of the bank layer (20) has hydrophobic properties, the surface energy of the second organic material layer (113) on the upper side of the bank layer (20) is reduced, thereby preventing the third organic material solutions (114a~114c) dropped into each sub-pixel area (P) from mixing with each other.

[0210] As illustrated in FIG. 13h, a drying process is carried out on the dropped third organic material solution (114a to 114c) to evaporate the solvent of the third organic material solution (114a to 114c) and leave only the solute of the third organic material solution (114a to 114c) on the second organic material layer (113) to form the second organic material layer (115a to 115c) on the second organic material layer (113).

[0211] The above third organic material layers (115a to 115c) may include the second hole transport layer (HTL2) and the second light-emitting layer (EML2) shown in FIG. 10.

[0212] For example, a second hole transport material solution is dropped as a third organic material solution (114a to 114c) onto the second organic material layer (113) of each subpixel area (P) and dried to form a second hole transport layer (HTL2).

[0213] And, a red light-emitting material solution, a green light-emitting material solution, and a blue light-emitting material solution can be dropped and dried as a third organic material solution (114a~114c) onto the second hole transport layer (HTL2) of each red subpixel area (R), green subpixel area (G), and blue subpixel area (B) to form a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer.

[0214] As shown in FIG. 13i, a fourth organic material layer (116) is formed on a substrate (10) on which the third organic material layers (115a to 115c) are formed using a deposition process.

[0215] The fourth organic material layer (116) may include the second electron transport layer (ETL2) and the electron injection layer (EIL) shown in FIG. 11. Accordingly, although the fourth organic material layer (116) is shown as a single layer in FIG. 13i, it is not limited thereto, and the fourth organic material layer (116) may be composed of multiple layers.

[0216] Then, a second electrode (60) is formed on the substrate (10) on which the fourth organic material layer (116) is formed using a deposition process.

[0217] Meanwhile, in a light-emitting device with a multi-stack structure, the file-up effect can be eliminated by performing an inkjet printing process and a deposition process in parallel. Below, a manufacturing method that can eliminate the file-up effect in a multi-stack structure is described as follows.

[0218] FIG. 14 is a structural diagram showing a light-emitting element having a multi-stack structure and a process for each layer according to the fourth embodiment of the present invention.

[0219] A light-emitting device according to the fourth embodiment of the present invention has a multi-stack structure in which a first hole transport layer (HTL1), a first light-emitting layer (EML1), a first electron transport layer (ETL1), an n-type charge generation layer (n-CGL), a p-type charge generation layer (p-CGL), a second hole transport layer (HTL2), a third hole transport layer (HTL3), a second light-emitting layer (EML2), a second electron transport layer (ETL2), and an electron injection layer (EIL) are stacked in sequence between a first electrode (Anode; ITO) and a second electrode (Cathode; Metal), as shown in FIG. 14.

[0220] Here, the first stack (Stack1) is configured to include a first hole transport layer (HTL1), a first light-emitting layer (EML1), and a first electron transport layer (ETL1), and the second stack (Stack2) is configured to include a second hole transport layer (HTL2), a third hole transport layer (HTL3), a second light-emitting layer (EML2), a second electron transport layer (ETL2), and an electron injection layer (EIL). Accordingly, a charge generation layer is located between the first and second stacks.

[0221] The first hole transport layer (HTL1) and the first light-emitting layer (EML1) can be formed by an inkjet printing process (Soluble process).

[0222] The first electron transport layer (ETL1), n-type charge generation layer (n-CGL), p-type charge generation layer (p-CGL), and second hole transport layer (HTL2) can be formed by a deposition process.

[0223] The third hole transport layer (HTL3) and the second light-emitting layer (EML2) can be formed by an inkjet printing process (Soluble process).

[0224] The second electron transport layer (ETL2), the electron injection layer (EIL), and the second electrode can be formed by a deposition process.

[0225] The structure of the organic light-emitting display panel of the fourth embodiment of the present invention, which can exclude file-up effects in a light-emitting element having a multi-stack structure as described above, is as follows.

[0226] FIG. 15 is a cross-sectional view of the structure of an organic light-emitting display panel according to a fourth embodiment of the present invention.

[0227] An organic light-emitting display panel according to the fourth embodiment of the present invention includes thin-film transistors (70) and organic light-emitting elements in a plurality of sub-pixel regions (P) on a substrate (80), as shown in FIG. 15.

[0228] The substrate (80) may be made of an insulating material, for example, the substrate (80) may be made of a plastic material such as glass, polyimide (PI), etc.

[0229] A buffer layer (81) is disposed on a substrate (80). The buffer layer (81) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx), or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx). However, the buffer layer (81) is not an essential component and may be omitted based on the type and material of the substrate (60), the structure and type of the thin-film transistor (70), etc.

[0230] A thin-film transistor (70) is disposed on a buffer layer (81). The thin-film transistor (70) includes an active layer (71), a gate electrode (72), a source electrode (73), and a drain electrode (74).

[0231] The active layer (71) of the thin-film transistor (70) is placed on the buffer layer (81), and the gate insulating layer (82) is placed on the active layer (71) and the buffer layer (81).

[0232] The active layer (71) can be formed from amorphous silicon (a-Si), polycrystalline silicon (poly-Si), oxide semiconductor, or organic semiconductor.

[0233] The gate insulating layer (62) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto.

[0234] In the gate insulating layer (82), contact holes are formed for the source electrode (73) and the drain electrode (74), respectively, to contact the active layer (71).

[0235] The gate electrode (72) is placed on the gate insulating layer (82) so as to overlap with the active layer (71). The gate electrode (72) may be composed of a conductive metal, for example, copper (Cu), aluminum (Al), molybdenum (Mo), or an alloy thereof, but is not limited thereto.

[0236] An interlayer insulating layer (83) is disposed on the gate electrode (72). The interlayer insulating layer (83) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto. Contact holes may be formed in the interlayer insulating layer (83) to contact the source electrode (73) and the drain electrode (74) to the active layer (71).

[0237] A source electrode (73) and a drain electrode (74) are disposed on the interlayer insulating layer (83). The source electrode (73) and the drain electrode (74) may be composed of a conductive metal, for example, copper (Cu), aluminum (Al), molybdenum (Mo), or an alloy thereof, but are not limited thereto. Each of the source electrode (73) and the drain electrode (74) may be electrically connected to the active layer (71) through a contact hole.

[0238] A passivation layer (84) may be disposed on a thin-film transistor (70). The passivation layer (84) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto.

[0239] A contact hole may be formed in the passivation layer (84) for the first electrode (11) of the light-emitting element (OLED) to be connected to the thin-film transistor (70). The passivation layer (64) is not a necessary component and may be omitted depending on the design of the organic light-emitting display panel.

[0240] A flattening layer (85) is disposed on the passivation layer (84). The flattening layer (85) may be made of an organic material, and a contact hole may be formed in the flattening layer (85) to expose the drain electrode (74) of the thin-film transistor (70).

[0241] A first electrode (11) is disposed in each subpixel area on the flattening layer (85), and a bank layer (20) is disposed on the substrate (10) on the boundary portion of each subpixel area (P) so as to overlap with the edge of the first electrode (11).

[0242] The edges and sides of the upper surface of the bank layer (20) in the vertical direction (first direction) can be hydrophilized, and the upper surface and sides of the bank layer (20) in the horizontal direction (second direction) adjacent to each subpixel area can also be hydrophilized.

[0243] A first organic material layer (132a to 132c) is disposed on the first electrode (11) between the bank layers (20).

[0244] A second organic material layer (133) is disposed over the first organic material layer (132a~132c) and the bank layer (20), and the second organic material layer (133) on the upper side of the bank layer (20) is optionally hydrophobic.

[0245] A third organic material layer (135a~135b, 137a~137c) is disposed on the second organic material layer (133) between the bank layers (20), and a fourth organic material layer (138) is disposed across the third organic material layer (135a~135b, 137a~137c) and the first organic material layer (133) above the bank layers (20).

[0246] And, a second electrode (60) is placed on the fourth organic material layer (138).

[0247] Here, the first organic material layer (132a to 132c) may include a first hole transport layer (HTL1) and a first light-emitting layer (EML1), and the second organic material layer (133) may include a first electron transport layer (EHL1), an n-type charge generation layer (n-CGL), a p-type charge generation layer (p-CGL), and a second hole transport layer (HTL2).

[0248] The above third organic material layers (135a~135b, 137a~137c) may include a third hole transport layer (135a~135b) formed only in the red subpixel region (R) and the green subpixel region (G), and a red light-emitting layer (137a), a green light-emitting layer (137b), and a blue light-emitting layer (137c) formed in the red subpixel region (R), the green subpixel region (G), and the blue subpixel region (B).

[0249] The above-mentioned fourth organic material layer (116) may include a second electron transport layer (ETL2) and an electron injection layer (EIL).

[0250] The method for manufacturing a light-emitting element of the fourth embodiment of the present invention, which can exclude file-up effects in a light-emitting element having a multi-stack structure as described above, is explained as follows.

[0251] FIGS. 16a to 16k are process cross-sectional views of an organic light-emitting display panel on line II' of FIG. 1 according to a fourth embodiment of the present invention.

[0252] In FIGS. 16a to 16k, only the process of the light-emitting element is illustrated without explaining the manufacturing process of the thin-film transistor (70) in the structural cross-sectional view of FIG. 15. Accordingly, the substrate (10) illustrated in FIGS. 16a to 16k includes the substrate (80), thin-film transistor (7), and planarization layer (85) illustrated in FIG. 15.

[0253] As illustrated in FIG. 16a, a plurality of first electrodes (11) are formed in each subpixel area (P) on a substrate (10) that includes a plurality of subpixel areas (P).

[0254] Then, a hydrophobic organic insulating material is coated on the substrate (10) on which the first electrode (11) is formed and selectively removed to form a bank layer (20) in the shape of a grid at the boundary of each subpixel area.

[0255] Here, when the hydrophobic organic insulating material is selectively removed to form the bank layer (20), an organic residue film (20a) may be present on the surface of the first electrode (11).

[0256] As illustrated in FIG. 16b and FIG. 5b, the upper edge and side of the bank layer (20) in the vertical direction, the upper surface and side of part of the bank layer (2) in the horizontal direction, and the surface of the first electrode (11) are selectively plasma printed to remove the organic residue (20a) remaining on the surface of the first electrode (11) and simultaneously hydrophilize part of the upper surface of the bank layer (20), the edge and side of the upper surface.

[0257] To explain in more detail, it is as follows.

[0258] The above plasma printing process uses O2 / N2 / Ar gas and selectively performs plasma printing using a scanning method. That is, in Fig. 1, the plasma printing direction is indicated as “30”.

[0259] Plasma printing is performed in a scanning manner along vertical subpixels so as to overlap the upper surface edges of two adjacent vertical bank layers (20) among the grid-shaped bank layers (20).

[0260] Accordingly, the upper surface edges of two adjacent vertical bank layers (20) are removed to a predetermined depth to form a step, and as shown in FIG. 5b, the upper surface of the horizontal bank layer (2) adjacent to the subpixel area of ​​the grid-shaped bank layer (20) is also removed to a predetermined depth. Then, the stepped portion of the vertical bank layer (20), the side of the vertical bank layer (20), and the upper surface and side of the horizontal bank layer (2) are hydrophilized.

[0261] As illustrated in FIG. 16c, a first organic material solution (131a, 131b, 131c) is dropped onto the first electrode (11) of each subpixel area (P) using an inkjet printing method (soluble process).

[0262] At this time, since the upper surface of the bank layer (20) has hydrophobic properties, the surface energy of the upper surface of the bank layer (20) is reduced, so that the first organic material solutions (131a~131c) dropped into each sub-pixel area (P) can be prevented from mixing with each other.

[0263] At this time, since the upper surface of the bank layer (20) in the vertical direction has hydrophobic properties, the surface energy of the upper surface of the bank layer (20) is reduced, so the first organic material solutions (131a~131c) dropped in each sub-pixel area (P) adjacent in the horizontal direction are not mixed with each other.

[0264] In addition, since the upper side of the bank layer (20) in the horizontal direction is hydrophilized, the same first organic material solution (131a~131c) can be dropped into each subpixel area adjacent in the vertical direction.

[0265] As illustrated in FIG. 16d, a drying process is carried out on the dropped first organic material solution (131a to 131c) to evaporate the solvent of the first organic material solution (131a to 131c) and leave only the solute of the first organic material solution (131a to 131c) on the first electrode (11) to form a first organic material layer (132a to 132c) on the first electrode (11).

[0266] Here, the first organic material layers (132a to 132c) may include the first hole transport layer (HTL1) and the first light-emitting layer (EML1) shown in FIG. 14.

[0267] Accordingly, in FIG. 16d, the first organic material layer (132a to 132c) is shown as a single layer, but is not limited thereto, and the first organic material layer (132a to 132c) may be composed of multiple layers.

[0268] If the first organic material layer (132a~132c) includes a first hole (HTL1) and a first light-emitting layer (EML1), the process may proceed as follows.

[0269] As described in FIG. 16c-16d, a hole transport material solution is dropped onto the first electrode (11) of each subpixel region (P) and dried to form a first hole transport layer (HTL1) on the first electrode (11).

[0270] Assuming each subpixel area (P) is a red subpixel area (R), a green subpixel area (G), and a blue subpixel area (B), a red light-emitting material solution, a green light-emitting material solution, and a blue light-emitting material solution are dropped onto the first positive electrode transport layer (HTL1) of each of the red subpixel area (R), the green subpixel area (G), and the blue subpixel area (B), and the dropped red light-emitting material solution, the green light-emitting material solution, and the blue light-emitting material solution are dried to form a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer.

[0271] As shown in FIG. 16e, a second organic material layer (133) is formed on the front surface of a substrate (10) including the first organic material layers (132a~132c) and the bank layer (20) using a deposition process.

[0272] The second organic material layer (133) may include the first electron transport layer (ETL1), n-type charge generation layer (n-CGL), p-type charge generation layer (p-CGL), and second hole transport layer (HTL2) as shown in FIG. 14.

[0273] That is, a first electron transport layer (ETL1), an n-type charge generation layer (n-CGL), a p-type charge generation layer (p-CGL), and a second hole transport layer (HTL2) are deposited sequentially on the front surface of a substrate (10) including the first organic material layer (132a~132c) and the bank layer (20).

[0274] Accordingly, in FIG. 16e, the second organic material layer (133) is shown as a single layer, but is not limited thereto, and the second organic material layer (133) may be composed of multiple layers including a first electron transport layer (ETL1), an n-type charge generation layer (n-CGL), a p-type charge generation layer (p-CGL), and a second hole transport layer (HTL2).

[0275] As shown in FIG. 16f, the surface of the second organic material layer (133) above the bank layer (20) is treated with CF4 or SF6 gas plasma to make the surface of the second organic material layer (133) above the bank layer (20) hydrophobic.

[0276] That is, the surface of the second hole transport layer (HTL2) located above the bank layer (20) among the second hole transport layers (HTL2) formed at the uppermost side of the second organic material layer (133) is treated with CF4 or SF6 gas plasma to hydrophobize the surface of the second hole transport layer (HTL2) above the bank layer (20).

[0277] A more specific method for hydrophobization plasma treatment is described in Figures 6 and 7, so it is omitted here.

[0278] As illustrated in FIG. 16g, if each subpixel area (P) is assumed to be a red subpixel area (R), a green subpixel area (G), and a blue subpixel area (B), the third hole transport material solution (134a, 134b) is dropped only on the second organic material layer (133) of the red subpixel area (R) and the green subpixel area (G), and the third hole transport material solution is not dropped on the blue subpixel area (B).

[0279] As shown in FIG. 16h, a process of drying the dropped third hole transport material solution (134a, 134b) is carried out.

[0280] That is, the solvent of the third hole transport material solution (134a, 134b) is evaporated so that only the solute of the third hole transport material solution (134a, 134b) remains on the second organic material layer (133).

[0281] Accordingly, a third hole transport layer (135a~135b) is formed on the second organic material layer (133) of the red subpixel region (R) and the green subpixel region (G). A third hole transport layer is not formed in the blue subpixel region (B).

[0282] As shown in FIG. 16i, a red light-emitting material solution (136a), a green light-emitting material solution (136b), and a blue light-emitting material solution (136c) are dropped into the red subpixel area (R), the green subpixel area (G), and the blue subpixel area (B), respectively.

[0283] As illustrated in FIG. 16j, a drying process is performed on the dropped red light-emitting material solution (136a), green light-emitting material solution (136b), and blue light-emitting material solution (136c) to form a red light-emitting layer (137a), a green light-emitting layer (137b), and a blue light-emitting layer (137c) in the red subpixel area (R), the green subpixel area (G), and the blue subpixel area (B), respectively.

[0284] Here, the third hole transport layer (135a~135b) and the red light-emitting layer (137a), green light-emitting layer (137b) and blue light-emitting layer (137c) are referred to as the third organic material layer.

[0285] Accordingly, as described in FIGS. 16e to 16j, the red subpixel region (R) and the green subpixel region (G) have the second and third hole transport layers (HTL2, HTL3) formed, but the blue subpixel region (B) has only the third hole transport layer (HTL1) formed, so the file-up effect can be excluded.

[0286] As illustrated in FIG. 16k, a fourth organic material layer (138) is formed on a substrate (10) on which the red light-emitting layer (137a), green light-emitting layer (137b), and blue light-emitting layer (137c) are formed using a deposition process.

[0287] The fourth organic material layer (138) may include the second electron transport layer (ETL2) and the electron injection layer (EIL) shown in FIG. 14. Accordingly, although the fourth organic material layer (138) is shown as a single layer in FIG. 16k, it is not limited thereto, and the fourth organic material layer (138) may be composed of multiple layers.

[0288] Then, a second electrode (60) is formed on the substrate (10) on which the fourth organic material layer (138) is formed using a deposition process.

[0289] Meanwhile, in a multi-stack structured light-emitting device, the file-up effect can be eliminated by performing the inkjet printing process and the deposition process in parallel, but by changing the order of the inkjet printing process and the deposition process. Below, the structure and manufacturing method of an organic light-emitting display panel that can eliminate the file-up effect by changing the order of the inkjet printing process and the deposition process are described as follows.

[0290] FIG. 17 is a structural diagram showing a light-emitting element having a multi-stack structure and a process for each layer according to the fifth embodiment of the present invention.

[0291] A light-emitting device according to the fifth embodiment of the present invention has a multi-stack structure in which a first hole transport layer (HTL1), a first light-emitting layer (EML1), a first electron transport layer (ETL1), an n-type charge generation layer (n-CGL), a p-type charge generation layer (p-CGL), a second hole transport layer (HTL2), a third hole transport layer (HTL3), a second light-emitting layer (EML2), a second electron transport layer (ETL2), and an electron injection layer (EIL) are stacked in sequence between a first electrode (Anode; ITO) and a second electrode (Cathode; Metal), as shown in FIG. 17.

[0292] Here, the first stack (Stack1) is configured to include a first hole transport layer (HTL1), a first light-emitting layer (EML1), and a first electron transport layer (ETL1), and the second stack (Stack2) is configured to include a second hole transport layer (HTL2), a third hole transport layer (HTL3), a second light-emitting layer (EML2), a second electron transport layer (ETL2), and an electron injection layer (EIL). Accordingly, a charge generation layer is located between the first and second stacks.

[0293] The first hole transport layer (HTL1) is formed by a deposition process, and the first light-emitting layer (EML1) can be formed by an inkjet printing process (Soluble process).

[0294] The first electron transport layer (ETL1), n-type charge generation layer (n-CGL), p-type charge generation layer (p-CGL), and second hole transport layer (HTL2) can be formed by a deposition process.

[0295] The third hole transport layer (HTL3) and the second light-emitting layer (EML2) can be formed by an inkjet printing process (Soluble process).

[0296] The second electron transport layer (ETL2), the electron injection layer (EIL), and the second electrode can be formed by a deposition process.

[0297] The structure of the organic light-emitting display panel of the fifth embodiment of the present invention, which can exclude file-up effects in a light-emitting element having a multi-stack structure as described above, is as follows.

[0298] FIG. 18 is a cross-sectional view of the structure of an organic light-emitting display panel according to the fifth embodiment of the present invention.

[0299] The structure of an organic light-emitting display panel according to the fifth embodiment of the present invention includes thin-film transistors (70) and organic light-emitting elements in a plurality of sub-pixel regions (P) on a substrate (80), as shown in FIG. 18.

[0300] The substrate (80) may be made of an insulating material, for example, the substrate (80) may be made of a plastic material such as glass, polyimide (PI), etc.

[0301] A buffer layer (81) is disposed on a substrate (80). The buffer layer (81) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx), or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx). However, the buffer layer (81) is not an essential component and may be omitted based on the type and material of the substrate (60), the structure and type of the thin-film transistor (70), etc.

[0302] A thin-film transistor (70) is disposed on a buffer layer (81). The thin-film transistor (70) includes an active layer (71), a gate electrode (72), a source electrode (73), and a drain electrode (74).

[0303] The active layer (71) of the thin-film transistor (70) is placed on the buffer layer (81), and the gate insulating layer (82) is placed on the active layer (71) and the buffer layer (81).

[0304] The active layer (71) can be formed from amorphous silicon (a-Si), polycrystalline silicon (poly-Si), oxide semiconductor, or organic semiconductor.

[0305] The gate insulating layer (62) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto.

[0306] In the gate insulating layer (82), contact holes are formed for the source electrode (73) and the drain electrode (74), respectively, to contact the active layer (71).

[0307] The gate electrode (72) is placed on the gate insulating layer (82) so as to overlap with the active layer (71). The gate electrode (72) may be composed of a conductive metal, for example, copper (Cu), aluminum (Al), molybdenum (Mo), or an alloy thereof, but is not limited thereto.

[0308] An interlayer insulating layer (83) is disposed on the gate electrode (72). The interlayer insulating layer (83) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto. Contact holes may be formed in the interlayer insulating layer (83) to contact the source electrode (73) and the drain electrode (74) to the active layer (71).

[0309] A source electrode (73) and a drain electrode (74) are disposed on the interlayer insulating layer (83). The source electrode (73) and the drain electrode (74) may be composed of a conductive metal, for example, copper (Cu), aluminum (Al), molybdenum (Mo), or an alloy thereof, but are not limited thereto. Each of the source electrode (73) and the drain electrode (74) may be electrically connected to the active layer (71) through a contact hole.

[0310] A passivation layer (84) may be disposed on a thin-film transistor (70). The passivation layer (84) may be composed of a single layer of inorganic silicon nitride (SiNx) or silicon oxide (SiOx) or a multilayer of silicon nitride (SiNx) and silicon oxide (SiOx), but is not limited thereto.

[0311] A contact hole may be formed in the passivation layer (84) for the first electrode (11) of the light-emitting element (OLED) to be connected to the thin-film transistor (70). The passivation layer (64) is not a necessary component and may be omitted depending on the design of the organic light-emitting display panel.

[0312] A flattening layer (85) is disposed on the passivation layer (84). The flattening layer (85) may be made of an organic material, and a contact hole may be formed in the flattening layer (85) to expose the drain electrode (74) of the thin-film transistor (70).

[0313] A first electrode (11) is disposed in each subpixel area on the flattening layer (85), and a bank layer (20) is disposed on the substrate (10) on the boundary portion of each subpixel area (P) so as to overlap with the edge of the first electrode (11).

[0314] A first organic material layer (151) is disposed on a substrate over the bank layer (20) and the first electrode (11), and the first organic material layer (151) on the upper side of the bank layer (20) is optionally hydrophobic.

[0315] A second organic material layer (153a to 153c) is disposed on the first organic material layer (151) between the bank layers (20).

[0316] A third organic material layer (154) is disposed over the second organic material layer (153a~153c) and the first organic material layer (151), and the third organic material layer (154) on the upper part of the bank layer (20) is optionally hydrophobic.

[0317] A fourth organic material layer (156a~156b, 158a~158c) is disposed on a third organic material layer (154) between the bank layers (20), and a fifth organic material layer (159) is disposed across the fourth organic material layer (156a~156b, 158a~158c) and the third organic material layer (154) above the bank layers (20).

[0318] And, a second electrode (60) is placed on the fifth organic material layer (159).

[0319] Here, the first organic material layer (151) includes a first hole transport layer (HTL1), and the second organic material layers (153a to 153c) may include a first light-emitting layer (EML1).

[0320] The above third organic material layer (154) may include a first electron transport layer (EHL1), an n-type charge generation layer (n-CGL), a p-type charge generation layer (p-CGL), and a second hole transport layer (HTL2).

[0321] The above-mentioned fourth organic material layer (156a~156b, 158a~158c) may include a third hole transport layer (135a~135b) formed only in the red subpixel region (R) and the green subpixel region (G), and a second light-emitting layer having a red light-emitting layer (158a), a green light-emitting layer (158b), and a blue light-emitting layer (158c) formed in the red subpixel region (R), the green subpixel region (G), and the blue subpixel region (B).

[0322] The above fifth organic material layer (159) may include a second electron transport layer (ETL2) and an electron injection layer (EIL).

[0323] The method for manufacturing a light-emitting element of the fifth embodiment of the present invention, which can exclude file-up effects in a light-emitting element having a multi-stack structure as described above, is explained as follows.

[0324] FIGS. 19a to 19m are process cross-sectional views of an organic light-emitting display panel along line II' of FIG. 1 according to a fifth embodiment of the present invention.

[0325] In FIGS. 19a to 19m, only the process of the light-emitting element is illustrated without explaining the manufacturing process of the thin-film transistor (70) in the structural cross-sectional view of FIG. 18. Accordingly, the substrate (10) illustrated in FIGS. 19a to 19m includes the substrate (80), thin-film transistor (7), and planarization layer (85) illustrated in FIG. 18.

[0326] As illustrated in FIG. 19a, a plurality of first electrodes (11) are formed in each subpixel region (P) on a substrate (10) that includes a plurality of subpixel regions (P).

[0327] Then, a hydrophobic organic insulating material is coated on the substrate (10) on which the first electrode (11) is formed and selectively removed to form a bank layer (20) in the shape of a grid at the boundary of each subpixel area.

[0328] Here, when the hydrophobic organic insulating material is selectively removed to form the bank layer (20), an organic residue film (20a) may be present on the surface of the first electrode (11).

[0329] As illustrated in FIG. 19b and FIG. 5b, the upper edge and side of the bank layer (20) in the vertical direction, the upper surface and side of part of the bank layer (2) in the horizontal direction, and the surface of the first electrode (11) are selectively plasma printed to remove the organic residue (20a) remaining on the surface of the first electrode (11) and simultaneously hydrophilize part of the upper surface of the bank layer (20), the edge and side of the upper surface.

[0330] To explain in more detail, it is as follows.

[0331] The above plasma printing process uses O2 / N2 / Ar gas and selectively performs plasma printing using a scanning method. That is, in Fig. 1, the plasma printing direction is indicated as “30”.

[0332] Plasma printing is performed in a scanning manner along vertical subpixels so as to overlap the upper surface edges of two adjacent vertical bank layers (20) among the grid-shaped bank layers (20).

[0333] Accordingly, the upper surface edges of two adjacent vertical bank layers (20) are removed to a predetermined depth to form a step, and as shown in FIG. 5b, the upper surface of the horizontal bank layer (2) adjacent to the subpixel area of ​​the grid-shaped bank layer (20) is also removed to a predetermined depth. Then, the stepped portion of the vertical bank layer (20), the side of the vertical bank layer (20), and the upper surface and side of the horizontal bank layer (2) are hydrophilized.

[0334] As illustrated in FIG. 19c, a first organic material layer (151) is formed on the front surface of a substrate (10) including the first electrode (11) and the bank layer (20) using a deposition process.

[0335] The first organic material layer (151) may include the first electron transport layer (ETL1) shown in FIG. 17.

[0336] As shown in FIG. 19d, the surface of the first organic material layer (151) on the upper side of the bank layer (20) is treated with CF4 or SF6 gas plasma to make the surface of the first organic material layer (151) on the upper side of the bank layer (20) hydrophobic.

[0337] A more specific method for hydrophobization plasma treatment is described in Figures 6 and 7, so it is omitted here.

[0338] As illustrated in FIG. 19e, a red light-emitting material solution (152a), a green light-emitting material solution (152b), and a blue light-emitting material solution (152c) are dropped onto the first organic material layer (151) of the red subpixel area (R), the green subpixel area (G), and the blue subpixel area (B) using an inkjet printing method (soluble process).

[0339] At this time, since the upper surface of the first organic material layer (151) on the upper side of the vertical bank layer (20) has hydrophobic properties, the red light-emitting material solution (152a), green light-emitting material solution (152b), and blue light-emitting material solution (152c) dropped in each sub-pixel area (P) adjacent in the horizontal direction are not mixed with each other.

[0340] Additionally, since the upper surface of the first organic material layer (151) above the bank layer (20) in the horizontal direction is not hydrophobic, the same red light-emitting material solution (152a), green light-emitting material solution (152b), and blue light-emitting material solution (152c) can be dropped into each subpixel area adjacent in the vertical direction.

[0341] As illustrated in FIG. 19f, a drying process is carried out on the dropped red light-emitting material solution (152a), green light-emitting material solution (152b), and blue light-emitting material solution (152c).

[0342] That is, the solvents of the red light-emitting material solution (152a), the green light-emitting material solution (152b), and the blue light-emitting material solution (152c) are evaporated, and only the solutes of the red light-emitting material solution (152a), the green light-emitting material solution (152b), and the blue light-emitting material solution (152c) remain on the first organic material layer (151).

[0343] Accordingly, a red light-emitting layer (153a), a green light-emitting layer (153b), and a blue light-emitting layer (153c) are formed on the first organic material layer (151).

[0344] Here, the red light-emitting layer (153a), the green light-emitting layer (153b), and the blue light-emitting layer (153c) are referred to as the second organic material layer.

[0345] As illustrated in FIG. 19g, a third organic material layer (154) is formed on the entire surface of a substrate (10) including the second organic material layer (153a~153c) and the first organic material layer (151) using a deposition process.

[0346] The third organic material layer (154) may include the first electron transport layer (ETL1), n-type charge generation layer (n-CGL), p-type charge generation layer (p-CGL), and second hole transport layer (HTL2) as shown in FIG. 17.

[0347] That is, a first electron transport layer (ETL1), an n-type charge generation layer (n-CGL), a p-type charge generation layer (p-CGL), and a second hole transport layer (HTL2) are deposited sequentially on the front surface of a substrate (10) including the first organic material layer (151) and the second organic material layers (153a to 153c).

[0348] Accordingly, although the third organic material layer (154) is shown as a single layer in FIG. 19g, it is not limited thereto, and the third organic material layer (154) may be composed of multiple layers including a first electron transport layer (ETL1), an n-type charge generation layer (n-CGL), a p-type charge generation layer (p-CGL), and a second hole transport layer (HTL2).

[0349] As shown in FIG. 19h, the surface of the third organic material layer (154) above the bank layer (20) is treated with CF4 or SF6 gas plasma to make the surface of the third organic material layer (154) above the bank layer (20) hydrophobic.

[0350] That is, the surface of the second hole transport layer (HTL2) located above the bank layer (20) among the second hole transport layers (HTL2) formed at the uppermost side of the third organic material layer (154) is treated with CF4 or SF6 gas plasma to make the surface of the second hole transport layer (HTL2) above the bank layer (20) hydrophobic.

[0351] A more specific method for hydrophobization plasma treatment is described in Figures 6 and 7, so it is omitted here.

[0352] As illustrated in FIG. 19i, among each subpixel area (P), red subpixel area (R), green subpixel area (G) and blue subpixel area (B), the third hole transport material solution (155a, 155b) is dropped only on the third organic material layer (154) of the red subpixel area (R) and green subpixel area (G), and the third hole transport material solution is not dropped on the blue subpixel area (B).

[0353] As illustrated in FIG. 19j, a process of drying the dropped third hole transport material solution (155a, 155b) is performed to form a third hole transport layer (156a~156b) on the second organic material layer (133) of the red subpixel region (R) and the green subpixel region (G). A third hole transport layer is not formed in the blue subpixel region (B).

[0354] As illustrated in FIG. 19k, a red light-emitting material solution (157a), a green light-emitting material solution (157b), and a blue light-emitting material solution (157c) are dropped into each of the red subpixel area (R), the green subpixel area (G), and the blue subpixel area (B).

[0355] As illustrated in FIG. 19, a drying process is performed on the dropped red light-emitting material solution (157a), green light-emitting material solution (157b), and blue light-emitting material solution (157c) to form a red light-emitting layer (158a), a green light-emitting layer (158b), and a blue light-emitting layer (158c) in the red subpixel area (R), the green subpixel area (G), and the blue subpixel area (B), respectively.

[0356] Here, the third hole transport layer (156a~156b) and the red light-emitting layer (158a), green light-emitting layer (158b), and blue light-emitting layer (158c) are referred to as the fourth organic material layer.

[0357] Accordingly, as described in FIGS. 19i to 19l, the second and third hole transport layers (HTL2, HTL3) are formed in the red subpixel region (R) and the green subpixel region (G), but only the second hole transport layer (HTL2) is formed in the blue subpixel region (B), so the file-up effect can be excluded.

[0358] As illustrated in FIG. 19m, a fifth organic material layer (159) is formed on the front surface of a substrate (10) on which the red light-emitting layer (137a), green light-emitting layer (137b), and blue light-emitting layer (137c) are formed using a deposition process.

[0359] The fifth organic material layer (159) may include the second electron transport layer (ETL2) and the electron injection layer (EIL) shown in FIG. 17. Accordingly, although the fifth organic material layer (159) is shown as a single layer in FIG. 19m, it is not limited thereto, and the fifth organic material layer (159) may be composed of multiple layers.

[0360] Then, a second electrode (60) is formed on the substrate (10) on which the fifth organic material layer (159) is formed using a deposition process.

[0361] Meanwhile, in the manufacturing method of the fifth embodiment of the present invention, if the pile-up effect is accepted, the third hole transport layer (156a~156b) process described in FIG. 19i and FIG. 19j may be omitted.

[0362] As explained above, the method of manufacturing an organic light-emitting display panel according to an embodiment of the present invention can form a multi-stack of light-emitting layers by repeating the deposition and inkjet printing processes multiple times, thereby improving the light-emitting characteristics of the light-emitting element.

[0363] In addition, as in the second and fourth-fifth embodiments, the present invention manufactures a light-emitting device by performing an inkjet printing process and a deposition process in parallel, thereby eliminating the effect of pile-up.

[0364] The above description is merely illustrative of the present invention, and various modifications may be made by those skilled in the art without departing from the technical spirit of the present invention. Accordingly, the embodiments disclosed in the specification of the present invention are not intended to limit the present invention. The scope of the present invention should be interpreted by the claims below, and all technologies within the equivalent scope should also be interpreted as being included within the scope of the present invention. Explanation of the symbols

[0365] 10: Substrate 11: First electrode 20: Bank layer 60: Second electrode 40a~40c, 52a~52c, 92a~92c, 111a~111c, 114a~114c, 131a~131c, 75a~75c: Organic material solutions 94a, 136a, 152a, 157a: Red luminescent material solution 94b, 136b, 152b, 157b: Green luminescent material solution 94c, 136c, 152c, 157c: Blue luminescent material solution 95a, 137a, 153a, 158a: Red light-emitting layer 95b, 137b, 153b, 158b: Green light-emitting layer 95c, 137c, 153c, 158c: Blue emissive layer 134a~134b, 155a~155b: Third hole transport material solution 135a~135b, 156a~156b: Third hole transport layer 51, 53a~53c, 54, 91, 93a~93c, 96, 112a~112c, 113, 115a~115c, 116, 132a~132c, 133, 138, 151, 154, 159: Organic material layer

Claims

Claim 1 delete Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 An organic light-emitting display panel comprising: a first electrode disposed in each subpixel area on a substrate in which a plurality of subpixel areas are defined; a bank layer disposed on the substrate on the boundary portion of each subpixel area and having a side surface that is hydrophilic; a first organic material layer disposed on the first electrode in each subpixel area between the bank layers; a second organic material layer disposed across the first organic material layer and the bank layer, wherein the upper surface of the bank layer is hydrophobic; a third organic material layer disposed on the second organic material layer between the bank layers; a fourth organic material layer disposed across the third organic material layer and the second organic material layer; and a second electrode disposed on the fourth organic material layer. Claim 6 An organic light-emitting display panel according to claim 5, wherein the first organic material layer comprises a first hole transport layer and a first light-emitting layer, the second organic material layer comprises a first electron transport layer, an n-type charge generation layer, a p-type charge generation layer, and a hole injection layer, the third organic material layer comprises a second hole transport layer and a second light-emitting layer, and the fourth organic material layer comprises a second electron transport layer and an electron injection layer. Claim 7 An organic light-emitting display panel comprising: a first electrode disposed in each subpixel area on a substrate having a plurality of subpixel areas defined therein having red, green, and blue subpixels; a bank layer disposed on the substrate on the boundary portion of each subpixel area and having a side surface that is hydrophilic; a first organic material layer disposed on the first electrode of each subpixel area between the bank layer; a second organic material layer disposed across the first organic material layer and the bank layer, with the upper surface of the bank layer being hydrophobic; a third organic material layer disposed on the second organic material layer between the bank layer; a fourth organic material layer disposed across the third organic material layer and the second organic material layer; and a second electrode disposed on the fourth organic material layer, wherein the third organic material layer comprises a third hole transport layer disposed only on the second organic material layer of the red subpixel area and the green subpixel area between the bank layer, and a second light-emitting layer disposed in the red subpixel area, the green subpixel area, and the blue subpixel area. Claim 8 An organic light-emitting display panel according to claim 7, wherein the first organic material layer comprises a first hole transport layer and a first light-emitting layer, the second organic material layer comprises a first electron transport layer, an n-type charge generation layer, a p-type charge generation layer, and a second hole transport layer, and the fourth organic material layer comprises a second electron transport layer and an electron injection layer. Claim 9 A first electrode disposed in each subpixel area on a substrate in which a plurality of subpixel areas having red, green, and blue subpixels are defined; a bank layer disposed on the substrate on the boundary portion of each subpixel area and having a side surface that is hydrophilic; a first organic material layer disposed on the substrate over the bank layer and the first electrode, wherein the upper surface of the bank layer is hydrophobic; a second organic material layer disposed on the first organic material layer in each subpixel area between the bank layers; a third organic material layer disposed over the second organic material layer and the first organic material layer, wherein the upper surface of the bank layer is hydrophobic; a fourth organic material layer disposed on the third organic material layer between the bank layers; and a fifth organic material layer disposed over the fourth organic material layer and the third organic material layer. An organic light-emitting display panel comprising a second electrode disposed on the fifth organic material layer, wherein the fourth organic material layer comprises a third hole transport layer disposed only on the third organic material layer of the red subpixel region and the green subpixel region between the bank layers, and a second light-emitting layer disposed on the red subpixel region, the green subpixel region, and the blue subpixel region. Claim 10 An organic light-emitting display panel according to claim 9, wherein the first organic material layer comprises a first hole transport layer, the second organic material layer comprises a first light-emitting layer, the third organic material layer comprises a first electron transport layer, an n-type charge generation layer, a p-type charge generation layer, and a second hole transport layer, and the fifth organic material layer comprises a second electron transport layer and an electron injection layer. Claim 11 delete Claim 12 delete Claim 13 delete Claim 14 delete Claim 15 A method for manufacturing an organic light-emitting display panel comprising: a step of forming a first electrode in each sub-pixel area on a substrate in which a plurality of sub-pixel areas are defined; a step of forming a bank layer at the boundary of each sub-pixel area on the substrate; a step of removing an organic residue film on each first electrode of each sub-pixel area and hydrophilizing the side of the bank layer by first plasma treatment of the side of the bank layer and the top of the first electrode; a step of forming a first organic material layer on the first electrode of each sub-pixel area between the bank layers by an inkjet printing process; a step of forming a second organic material layer across the first organic material layer and the bank layer by a deposition process; a step of hydrophobizing the upper surface of the second organic material layer above the bank layer by second plasma treatment; a step of forming a third organic material layer on the second organic material layer between the bank layers by an inkjet printing process; and a step of forming a fourth organic material layer and a second electrode across the third organic material layer and the second organic material layer by a deposition process. Claim 16 A method for manufacturing an organic light-emitting display panel according to claim 15, wherein the first organic material layer comprises a first hole transport layer and a first light-emitting layer, the second organic material layer comprises a first electron transport layer, an n-type charge generation layer, a p-type charge generation layer, and a hole injection layer, the third organic material layer comprises a second hole transport layer and a second light-emitting layer, and the fourth organic material layer comprises a second electron transport layer and an electron injection layer. Claim 17 A method for manufacturing an organic light-emitting display panel according to claim 15, wherein the plurality of subpixel regions comprises red, green, and blue subpixel regions, the first organic material layer comprises a first hole transport layer and a first light-emitting layer, the second organic material layer comprises a first electron transport layer, an n-type charge generation layer, a p-type charge generation layer, and a second hole transport layer, the fourth organic material layer comprises a second electron transport layer and an electron injection layer, and the step of forming the third organic material layer comprises the step of forming a third hole transport layer only on the second organic material layer of the red subpixel region and the green subpixel region between the bank layers, and the step of forming a second light-emitting layer on the red subpixel region, the green subpixel region, and the blue subpixel region. Claim 18 A step of forming a first electrode in each subpixel area on a substrate in which a plurality of subpixel areas are defined; a step of forming a bank layer at the boundary of each subpixel area on the substrate; a step of removing organic residue on each first electrode of each subpixel area and hydrophilizing the side of the bank layer and the top of the first electrode by first plasma treatment; a step of forming a first organic material layer on the substrate over the bank layer and the top of the first electrode by a deposition process; a step of hydrophobizing the upper surface of the first organic material layer on the top of the bank layer by second plasma treatment; a step of forming a second organic material layer on the first organic material layer in each subpixel area between the bank layers by an inkjet process; a step of forming a third organic material layer over the second organic material layer and the first organic material layer by a deposition process; a step of hydrophobizing the upper surface of the third organic material layer on the top of the bank layer by second plasma treatment; a step of forming a fourth organic material layer on the third organic material layer between the bank layers by an inkjet process. A method for manufacturing an organic light-emitting display panel comprising the step of forming a fifth organic material layer and a second electrode over the fourth organic material layer and the third organic material layer by a deposition process. Claim 19 A method for manufacturing an organic light-emitting display panel according to claim 18, wherein the first organic material layer comprises a first hole transport layer, the second organic material layer comprises a first light-emitting layer, the third organic material layer comprises a first electron transport layer, an n-type charge generation layer, a p-type charge generation layer, and a second hole transport layer, the fourth organic material layer comprises a second light-emitting layer, and the fifth organic material layer comprises a second electron transport layer and an electron injection layer. Claim 20 A method for manufacturing an organic light-emitting display panel according to claim 18, wherein the plurality of subpixel regions comprises red, green, and blue subpixel regions, the first organic material layer comprises a first hole transport layer, the second organic material layer comprises a first light-emitting layer, the third organic material layer comprises a first electron transport layer, an n-type charge generation layer, a p-type charge generation layer, and a second hole transport layer, and the step of forming the fourth organic material layer comprises the step of forming a third hole transport layer only on the third organic material layer of the red subpixel region and the green subpixel region between the bank layers, and the step of forming a second light-emitting layer on the red subpixel region, the green subpixel region, and the blue subpixel region. Claim 21 A method for manufacturing an organic light-emitting display panel according to any one of claims 15 to 20, wherein the first plasma treatment is performed using O2 / N2 / Ar gas in a first direction, scanning a portion of the upper surface and side of two adjacent bank layers and the upper surface of the first electrode, thereby removing a portion of the upper surface of the bank layers to form a step portion in the bank layers and hydrophilizing the step portion and the side. Claim 22 A method for manufacturing an organic light-emitting display panel according to any one of claims 15 to 20, wherein the second plasma treatment selectively treats only the organic material layer on the upper side of the first direction bank layer among the grid-shaped bank layers using a scanning method with CF4 or SF6 gas plasma. Claim 23 A method for manufacturing an organic light-emitting display panel according to any one of claims 15 to 20, wherein the bank layer is formed of a hydrophobic photosensitive organic material.

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