Light Emitting Display Device

Abstract

The light-emitting display device of the present invention can prevent lateral leakage current by having a connection part connected to a cathode and one layer of an internal stack in a non-light-emitting part between light-emitting parts emitting different colors, and can minimize brightness variability due to temperature change by reducing the resistance of the multilayered stack. A light-emitting display device according to one embodiment of the present invention may include a substrate having a plurality of light-emitting parts and a non-light-emitting part between the light-emitting parts, a first electrode each provided in the light-emitting parts and spaced apart from each other, a first stack and a second stack provided on the substrate including the first electrode with a first charge generating layer in between, and a second electrode provided on the second stack and electrically connected to the first charge generating layer in the non-light-emitting part through a connection part.

Description

Technology Field

[0001] The present invention relates to a display device, and more specifically, to a light-emitting display device that improves lateral leakage current and temperature-dependent brightness characteristics by connecting a part of a charge generation layer separating stacks in a structure in which multiple stacks are stacked with a cathode. Background Technology

[0002] With the recent entry into the full-scale information age, the field of displays that visually represent electrical information signals has been rapidly developing, and in response to this, various display devices with excellent performance such as thinness, lightness, and low power consumption are being developed.

[0003] Among these, a light-emitting display device that does not require a separate light source and has a light-emitting element within the display panel for compact device and clear color display is being considered as a competitive application.

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

[0005] Since the common layer is formed across multiple subpixels, in the light-emitting display device, lateral leakage current between subpixels caused by the common layer may occur. The problem to be solved

[0006] The present invention aims to provide an improved light-emitting display device capable of preventing or reducing lateral leakage current and ensuring uniformity of luminance characteristics according to temperature changes by providing a connection portion between a part of the common layer and the cathode. means of solving the problem

[0007] The light-emitting display device of the present invention is provided with a connection part connected to a cathode and one layer of an internal stack in a non-light-emitting part between light-emitting parts emitting different colors, thereby preventing lateral leakage current and reducing the resistance of the multilayered stack, so as to minimize brightness variability due to temperature changes.

[0008] A light-emitting display device according to one embodiment of the present invention may include a substrate having a plurality of light-emitting parts and a non-light-emitting part between the light-emitting parts, a first electrode each provided on the light-emitting parts and spaced apart from each other, a first stack and a second stack provided on the substrate including the first electrode with a first charge generating layer in between, and a second electrode provided on the second stack and electrically connected to the first charge generating layer through a connection part in the non-light-emitting part.

[0009] In addition, a light-emitting display device according to one embodiment of the present invention may include a substrate having a first light-emitting part and a second light-emitting part spaced apart from each other, a first anode and a second anode respectively provided in the first light-emitting part and the second light-emitting part, a first stack and a second stack provided on the substrate including the first anode and the second anode with a charge-generating layer in between, and a cathode provided on the second stack and having a connection part with the charge-generating layer between the first light-emitting part and the second light-emitting part. Effects of the invention

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

[0011] First, in the non-luminous portion between the luminous portions, a connection portion between the common layer within the organic stack between the anode and the cathode and the cathode is provided, thereby preventing an increase in resistance due to an increase in the stack of the organic stack. In a tandem structure with an increased stack, an increase in resistance caused by an increase in the common layer is prevented, and consequently, a decrease in current can be prevented. By supplying a current equal to the current flowing in the first stack to the second electrode, fluctuations in brightness due to temperature changes can be blocked.

[0012] Second, through the connection part, a certain potential is supplied to the common layer of adjacent subpixels in the non-emitting part between adjacent emitting parts, thereby preventing leakage current caused by the difference in turn-on voltage between different emitting parts. In the connection part, a vertical path is formed between the lower charge generation layer and the second electrode of the second stack, and the common layer is removed to prevent lateral leakage current between adjacent emitting parts emitting other colors, and effectively prevent low-gradation leakage light. Brief explanation of the drawing

[0013] FIG. 1 is a plan view showing one form of a light-emitting display device according to one embodiment of the present invention. Figure 2 is a plan view and cross-sectional view of a subpixel of Figure 1. Figures 3a to 3c are graphs showing the IV characteristics when red, green, and blue light-emitting elements are applied as a single stack and multiple stacks, respectively. Figures 4a to 4c are graphs showing the relationship between current density and resistance when red, green, and blue light-emitting elements are applied as a single stack and multiple stacks, respectively. FIG. 5 is a plan view according to a first embodiment of the light-emitting display device of the present invention. Figure 6 is a cross-sectional view along the line II to II' of Figure 5. FIG. 7 is a plan view according to a modified example of the first embodiment of the light-emitting display device of the present invention. FIGS. 8a to 8d are cross-sectional views of light-emitting elements according to the first to fourth experimental examples. FIGS. 9a and 9b are graphs showing the emission spectrum of a blue subpixel during low-gradation driving according to the first and second experimental examples. FIG. 10 is a circuit diagram schematically showing the current flow of a light-emitting element according to the first and second experimental examples. Figure 11 is a graph showing the IV characteristics according to the 5th to 13th experimental examples. FIG. 12 is a plan view according to a second embodiment of the light-emitting display device of the present invention. Figure 13 is a cross-sectional view along the line III to III' of Figure 12. FIG. 14 is a plan view according to a third embodiment of the light-emitting display device of the present invention. FIG. 15 is a cross-sectional view along lines IV to IV' of FIG. 14. Figure 16 is a graph comparing the IV characteristics when applying a tandem structured red light-emitting element to the first experimental example and the second experimental example. Figure 17 is a graph comparing the IV characteristics when applying a green light-emitting diode with a tandem structure to the first and second experimental examples. Figure 18 is a graph comparing the IV characteristics when a tandem structure blue light-emitting diode is applied to the first experimental example and the second experimental example. Specific details for implementing the invention

[0014] Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings. Throughout the specification, identical reference numbers denote substantially identical components. In the following description, if it is determined that a detailed description of a technology or configuration related to the present invention could unnecessarily obscure the essence of the invention, such detailed description is omitted. Furthermore, the component names used in the following description have been selected for ease of drafting the specification and may differ from the actual product part names.

[0015] Shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for describing various embodiments of the present invention are exemplary, and therefore the present invention is not limited to the matters depicted in the drawings. Throughout this specification, the same reference numerals refer to the same components. Furthermore, in describing the present invention, if it is determined that a detailed description of related prior art may unnecessarily obscure the essence of the present invention, such detailed description is omitted. Where terms such as "includes," "has," or "is made up" are used in this specification, other parts may be added unless "only" is used. Where a component is expressed in the singular, it includes cases where it is included in the plural unless specifically stated otherwise.

[0016] In interpreting the components included in various embodiments of the present invention, they are interpreted to include an error range even without separate explicit description.

[0017] In describing various embodiments of the present invention, when describing positional relationships, for example, when the positional relationship between two parts is described using expressions such as 'on', 'on the upper part', 'on the lower part', 'next to', etc., unless 'immediately' or 'directly' is used, one or more other parts may be located between the two parts.

[0018] In describing various embodiments of the present invention, when describing temporal relationships, for example, when describing temporal sequence relationships using 'after', 'following', 'next', 'before', etc., cases that are not continuous may be included unless 'immediately' or 'directly' is used.

[0019] In describing various embodiments of the present invention, terms such as 'first~', 'second~', etc. may be used to describe various components, but these terms are used merely to distinguish between identical or similar components. Accordingly, unless otherwise stated, a component modified by 'first~' in this specification may be identical to a component modified by 'second~' within the technical scope of the present invention.

[0020] Each feature within various embodiments of the present invention may be combined or combined with one another, either partially or wholly, and may technically enable various interlocking and operation. Each of the various embodiments may be implemented independently of one another or may be implemented together in an associated relationship.

[0021] Hereinafter, the light-emitting element of the present invention and the display device including the same will be described with reference to the drawings.

[0022] FIG. 1 is a plan view showing one form of a light-emitting display device according to one embodiment of the present invention. FIG. 2 is a plan view and cross-sectional view showing a subpixel of FIG. 1.

[0023] As shown in FIGS. 1 and 2, the light-emitting display device (1000) of the present invention may include a display panel (1100), a scan driving unit (1200), a flexible film (1400) including a data driving unit, a circuit board (1500), and a timing control unit (1600). The flexible film (1400) may include a drive IC (1300) to function as a data driving unit. As illustrated, the flexible film (1400) may divide a plurality of signal lines provided in the display panel (1100) into several blocks to supply data signals and detect sensing signals, or a single flexible film (1400) may correspond to all signal lines provided in the display panel (1110) to perform the function of a data driving unit. In some cases, the flexible film (1400) and the circuit board (1500) may be formed as a single unit.

[0024] The display panel (1100) may include an array on a single substrate (see 100 in FIG. 2), or may be formed in a bonded form in which a substrate (100) having an array and an opposing substrate are placed facing each other.

[0025] The substrate (100) and the opposing substrate may comprise a substrate of glass or plastic components. The substrate (100) may further comprise a thin-film transistor array, a color filter array, or an optical film configuration. For example, if the substrate (100) and / or the opposing substrate comprise a substrate of plastic components, the plastic forming the substrate may be polyimide, PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or PC (polycarbonate). If the substrate (100) comprises a substrate of plastic components, the light-emitting display device (1000) may be implemented as a flexible display device that can be bent or curved. The opposing substrate may comprise any one of glass, a plastic film, or an encapsulation film. When the opposing substrate is an encapsulation film, the encapsulation film may have a unit structure that alternately includes organic films and inorganic films, and may be formed directly on the substrate (100) without a bonding process with the substrate (100) including the array.

[0026] The substrate (100) is a thin film transistor substrate on which thin film transistors are formed.

[0027] Scan lines, signal lines, and subpixels (SP) are formed on one side of the substrate (100). The subpixels (SP) may be provided in an area defined by the intersection structure of the scan lines and signal lines. Each scan line is connected to a scan driver (1200), and the signal lines are connected to a data driver (1400). Additionally, the scan driver (1200) may be provided by being directly embedded in the non-display area (NDA) of the array substrate (1110) as illustrated, or it may be connected to the non-display area (NDA) on the array substrate (1110) by a separate drive IC or printed circuit film.

[0028] As shown in FIG. 1, the display panel (1100) can be divided into a display area (DA) where subpixels (SP) are formed to display an image and a non-display area (NDA) surrounding the display area (DA). Scan lines, signal lines, and subpixels (SP) can be formed in the display area (DA). A scan driving unit (1200), pads, and link lines connecting the signal lines and pads can be formed in the non-display area (NDA).

[0029] A subpixel (SP) may be provided with a light-emitting part (E) where light is emitted and a non-light-emitting part (NE) outside the light-emitting part. As shown in FIG. 2, the light-emitting part (E) may be provided in an area where a bank (115) is not formed.

[0030] And, the subpixel (SP) may include at least one thin-film transistor (T).

[0031] Figure 2 shows one subpixel of Figure 1, with a plan view and cross-sectional view of the entire area of ​​the subpixel (SP) on the left and an enlarged cross-sectional view of a portion corresponding to the connection part (CT) on the right.

[0032] As shown in FIG. 1 and FIG. 2, a light-emitting display device according to one embodiment of the present invention comprises a substrate (100) having a plurality of light-emitting parts (E) and a non-light-emitting part (NE) between the light-emitting parts, a first electrode (121) provided on each of the light-emitting parts and spaced apart from each other, a first stack (S1) and a second stack (S2) provided on the substrate including the first electrode with a charge generation layer (CGL) in between, and provided on the second stack (S2). Additionally, it may include a second electrode (CTD) (130) that is electrically connected to the charge generation layer (CGL) and a connection part (CT) in the non-light-emitting part (NE).

[0033] A second electrode (130) formed integrally across a plurality of light-emitting parts (E) and non-light-emitting parts (NE) of a substrate (100) is connected to a charge generation layer (CGL) of the non-light-emitting part (NE), so that the second stack (S2) and the charge generation layer (CGL) in the non-light-emitting part (NE) can have a common potential with the second electrode (130). Accordingly, lateral leakage current generated in the layer formed in common to the light-emitting parts (E) and non-light-emitting parts (NE) in the charge generation layer (CGL) and the second stack (S2) can be prevented.

[0034] The display device can emit different colors to adjacent light-emitting parts (E), and the light-emitting color emitted from the light-emitting part (E) can be adjusted in the light-emitting wavelength range by varying the components of the host and dopant of the light-emitting layers (EML1, EML2) within the first and second stacks (S1, S2). For example, the light-emitting layers (EML1, EML2) included in the first and second stacks (S1, S2) superimposed in the same light-emitting part (E) can emit the same color. When another light-emitting part having a light-emitting layer emitting a second color different from the first color is provided around a light-emitting part including a light-emitting layer (EML1, EML2) emitting a first color, there is a difference in turn-on voltage between the light-emitting part emitting the first color and the light-emitting part emitting the second color. For example, the light-emitting part emitting a short wavelength light-emitting color may have a higher turn-on voltage than the light-emitting part emitting a long wavelength light-emitting color. In this case, when only the light-emitting part with a high turn-on voltage is selectively turned on in a low grayscale, the adjacent light-emitting part with a low turn-on voltage may be weakly turned on by leakage current. The light-emitting display device of the present invention is provided with a connection part (CT) between the second electrode (130) and the charge generation layer (CGL) between adjacent light-emitting parts (E), so that when driving in a low grayscale, the charge generation layer (CGL), the second stack (S2), and the second electrode (130) have the same potential, thereby preventing leakage light from the light-emitting part having a low turn-on voltage even if the light-emitting part with a high turn-on voltage is selectively turned on.

[0035] The example illustrated in FIG. 2 shows a configuration in which a connection part (CT) is formed on both the left and right non-light-emitting parts (NE) spaced apart from a single light-emitting part (E). This is not limited to this configuration, and the connection part (NE) may be located on both the upper and lower sides relative to the light-emitting part (E), or may be provided on all sides (left, right, upper, and lower). Furthermore, it is more effective to have the connection part (NE) located between light-emitting parts (E) that emit different light colors to prevent leakage light caused by lateral leakage current.

[0036] While the light-emitting portion (E) is defined as an opening of the bank (BNK) (115) and is spaced apart from each other, the non-light-emitting portion (NE) fills the space between the light-emitting portions (E) and the entire shape is connected in a matrix shape, and the non-light-emitting portion (NE) may be integral on the substrate (100). Additionally, the non-light-emitting portion (NE) may be a region where the bank (BNK) (115) is formed.

[0037] The first electrode (121) and the second electrode (130) are also referred to as an anode and a cathode, respectively. In some cases, the first electrode (121) is formed separately for each subpixel (SP), whereas the second electrode (130) is formed commonly for the subpixels (SP) provided on the substrate (100), so it is also referred to as a 'common electrode'. The first electrode (121) is connected to a thin-film transistor (T) and can be selectively driven for each subpixel, and a constant voltage or ground voltage is applied to the second electrode (130).

[0038] The light-emitting display device of the present invention can make the potential of the charge-generating layer (CGL) and the second stack (S2) in the non-light-emitting part equal to the common voltage applied to the second electrode (130) by connecting the second electrode (130) to the charge-generating layer (CGL) in the connection part (CT).

[0039] Each of the light-emitting part (E) is provided with a first electrode (121), a first stack (S1), a charge generating layer (CGL), a second stack (S2), and a second electrode (130). The entire stack (S) between the first electrode (121) and the second electrode (130) may be made of organic material.

[0040] A hole injection layer (HIL), a first hole transport layer (HTL1), a first light-emitting layer (EML1), and a first electron transport layer (ETL1) may be formed in sequence in the first stack (S1), and a second hole transport layer (HTL2), a second light-emitting layer (EML2), and a second electron transport layer (ETL2) may be provided in the second stack (S2).

[0041] The entire stack (S), including the first stack (S1), charge generation layer (CGL), and second stack (S2) between the first electrode (121) and the second electrode (130), may be composed of organic layers having organic compounds as the basic composition, and may include inorganic materials in some of the organic layers for luminescence characteristics and hole and electron transport characteristics. In some cases, the first stack (S1), charge generation layer (CGL), and second stack (S2) may further include inorganic layers containing inorganic compounds.

[0042] The hole injection layer (HIL) and the first and second hole transport layers (HTL1, HTL2) are located below the first and second light-emitting layers (EML1, EML2) in each stack (S1, S2) and perform functions related to hole injection and hole transport. Specifically, the hole injection layer (HIL) functions to inject holes into the stack from the first electrode (121) toward the second electrode (130). The first and second hole transport layers (HTL1, HTL2) are provided to transfer holes supplied from the hole injection layer (HIL) and the charge generation layer (CGL) to the first and second light-emitting layers (EML1, EML2).

[0043] The first and second electron transport layers (ETL1, ETL2) are each located on top of the first and first light-emitting layers (EML1, EML2) and perform functions related to electron transport. Specifically, the first and second electron transport layers (ETL1, ETL2) are a charge generation layer (CGL) and a second electrode (CTD) (130). It is provided to transfer electrons supplied from to the first and second light-emitting layers (EML1, EML2).

[0044] In some cases, at least one of the hole injection layer (HIL), the first and second hole transport layers (HTL1, HTL2), the first and second light-emitting layers (EML1, EML2), and the first and second electron transport layers (ETL1, ETL2) may be a plurality of layers.

[0045] Also, as shown in FIG. 2, the first and second light-emitting layers (EML1, EML2) may not be formed in a part of the non-light-emitting portion (NE). The first and second light-emitting layers (EML1, EML2) may be formed with an area larger than that of the light-emitting portion (E) and positioned at the edges of the non-light-emitting portion (NE). When providing light-emitting layers that emit different colors for each light-emitting portion (E), the first and second light-emitting layers (EML1, EML2) may be formed through a fine metal mask. The fine metal mask has an opening corresponding to each light-emitting portion, and the size of the opening may become smaller as the resolution increases. Since the first and second light-emitting layers (EML1, EML2) must be sufficiently formed in the light-emitting portion (E) exposed by the bank (115), the opening may be formed by considering the alignment margin or scan alignment margin of the fine metal mask during the deposition process.

[0046] Additionally, an electron injection layer may be further included between the second stack (S2) and the second electrode (140). The electron injection layer may also be included inside the second stack (S2).

[0047] The electron injection layer may include an inorganic compound containing a metal or a halogen element to improve interface characteristics with the second electrode (130) or to improve reliability in a specific environment. When the electron injection layer is made of an inorganic material or an inorganic compound, the second electrode (130) may be formed in multiple layers, and the lower layer may be used.

[0048] The first stack (S1), the charge generating layer (CGL), and the second stack (S2) included in the entire stack (S) provided between the first electrode (121) and the second electrode (130) may be organic layers having organic compounds as their main components.

[0049] The first electrode (121) and the second electrode (130) may each include a reflective electrode and the other may be a transparent electrode or a semi-transparent electrode. The transparent electrode may include at least one of ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), and ITZO (Indium Tin Zinc Oxide). The reflective electrode may be a reflective metal such as aluminum (Al), silver (Ag), magnesium (Mg), or ytterbium (Yb), or a reflective alloy containing at least one reflective metal material. The semi-transparent electrode may have both transmittance and reflectivity by making the thickness of the reflective electrode thin.

[0050] Depending on whether one of the first electrode (121) and the second electrode (130) includes a reflective electrode, light is emitted to the opposite side of the reflective electrode, and the direction of light emission can be determined. In some cases, when both the first electrode (121) and the second electrode (130) include a transparent electrode, the light-emitting display device can function as a transparent light-emitting display device.

[0051] When a reflective electrode is included on either side of the first electrode (121) and the second electrode (130), the reflective electrode is formed in a laminated structure in contact with a transparent electrode, thereby allowing adjustment of the resonance distance of light coming from each subpixel or adjustment of the interface characteristics between the first electrode (121) and the second electrode (130) and the adjacent internal organic layer.

[0052] On the upper side of the second electrode (130), a capping layer (140) (CPL) may be further included to increase the emission efficiency of light emitted by the first and second light-emitting layers (EML1, EML2) and to protect the second electrode (130) and the internal organic layer. The capping layer (140) may be made of an inorganic compound or an organic compound having a refractive index similar to that of the organic layer between the first electrode (121) and the second electrode (130).

[0053] In addition, in a light-emitting display device according to one embodiment of the present invention, as shown in FIG. 2, a connection portion (CT) penetrates the second hole transport layer (HTL2) and the second electron transport layer (ETL2) of the second stack (S2), and the second electrode (130) can be directly connected to the charge generation layer (CGL) through the connection portion (CT). The width of the connection portion (CT) can have various shapes and various widths as long as it does not encroach upon the light-emitting portion (E).

[0054] The charge generation layer (CGL) may include an n-type charge generation layer (NCGL) near the first stack (S1) and a p-type charge generation layer (PCGL) near the second stack (S2). The n-type charge generation layer (NCGL) supplies electrons to the first stack (S1), and the p-type charge generation layer (PCGL) supplies holes to the second stack (S2).

[0055] In FIG. 2, the connection portion (CT) is formed by removing the common layer of the second stack (S2) in a layered structure. The common layer of the second stack (S2) includes a second hole transport layer (HTL2) and a second electron transport layer (ETL2). Depending on the case, the second stack (S2) may further include an electron blocking layer between the second hole transport layer (HTL2) and the second light-emitting layer (EML2) and / or a hole blocking layer between the second light-emitting layer (EML2) and the second electron transport layer (ETL2). A removal portion is provided in the portion corresponding to the connection portion (CT) in the added common layer within the second stack (S2) so that the charge generation layer (CGL) and the second electrode (130) can be directly connected.

[0056] In addition, the removal of the connection portion (CT) from the common layer can be done after the common layer is formed, but it can also be formed by depositing the common layer through a fine metal mask having a blocking portion corresponding to the connection portion during the formation of each common layer. That is, during the deposition process, a fine metal mask is provided having a blocking portion corresponding to the connection portion and an opening in the remaining area, and a common layer forming material is deposited through the opening of the fine metal mask, leaving the area corresponding to the connection portion empty and forming the common layer in the remaining area. In the case of the structure of FIG. 2, a fine metal mask can be used in the deposition process of each layer when forming the second hole transport layer (HTL2) and the second electron transport layer (ETL2) of the second stack (S2). FIG. 2 shows that the second electron transport layer (ETL2) is formed covering the side of the second hole transport layer (HTL2). This means that the second electron transport layer (ETL2) has a smaller area of ​​connection than the second hole transport layer (HTL2). This is possible by reducing the area of ​​the blocking portion of the fine metal mask when forming the second electron transport layer (ETL2) relative to the area of ​​the blocking portion of the fine metal mask for forming the second hole transport layer (HTL2) and increasing the opening to increase the deposition area. This is not limited to this, and when forming the second hole transport layer (HTL2) and the second electron transport layer (ETL2), the same fine metal mask may be used or provided in a form having the same opening and the same blocking portion to have the same connection portion (CT).

[0057] As shown in FIG. 2, the common layer of the second stack (S2), that is, the second hole transport layer (HTL2) and the second electron transport layer (ETL2), can be side-connected with the second electrode (130) that has entered the connection part (CT) and the second hole transport layer (HTL2) and the second electron transport layer (ETL2) located on the side of the connection part (CT) because no deposited material is formed in the connection part (CT).

[0058] In some cases, when the charge generation layer (CGL) includes a two-layer structure of an n-type charge generation layer and a p-type charge generation layer, a removal portion of the p-type charge generation layer (PCGL) may be further included as a connection portion (CT) to directly connect the second electrode (130) and the n-type charge generation (NCGL). In this case, the common layer of the p-type charge generation layer (pCGL) and the second stack (S2) is laterally connected to the second electrode (140) at the connection portion.

[0059] Meanwhile, the first electrode (121) of the light-emitting part (E) can be connected to a thin-film transistor (T) and turned on.

[0060] For example, as shown in FIG. 2, a thin-film transistor (T) may include a gate electrode (101) on a substrate (100), a semiconductor layer (104) that overlaps with the gate electrode (101) and has a channel in the region overlapping with the gate electrode (101), and source electrodes (106a) and drain electrodes (106b) connected to both sides of the semiconductor layer (104). A gate insulating film (102) may be provided between the gate electrode (101) and the semiconductor layer (104), and an interlayer insulating film (105) may be further provided between the channel of the semiconductor layer and the source / drain electrode layers (106a / 106b).

[0061] A flattening layer (107) may be further included between the first electrode (121) and the thin-film transistor (T), excluding a contact hole that is electrically connected to each other. The first electrode (121) may be connected to the thin-film transistor (T) through the contact hole, and the first electrode (121) may be provided on the flattening layer (107).

[0062] The example of the thin-film transistor described above is merely an example, and its shape is not limited to the structure of FIG. 2. As another example, it is also possible to change the position so that the gate electrode (101) is located on the upper side relative to the semiconductor layer (104).

[0063] Meanwhile, the connection part (CT) may be provided in a part of the non-luminous part (NE) as shown in FIG. 2. It may be provided corresponding to a part of the upper portion of the bank (115). The connection part (CT) may be located in the non-luminous part (NE) spaced apart from the luminous part (E) in an island shape on a plane. Accordingly, the common layer of the second stack (S2) in the non-luminous part (NE) between adjacent luminous parts (E) can be cut off, thereby preventing leakage current flow caused by the common layer.

[0064] A connection part (CT) may be provided for each non-light-emitting part (NE) between light-emitting parts (E). Additionally, a connection part (CT) may be provided in a non-light-emitting part (NE) surrounding a light-emitting part that emits a specific color. In some cases, a number of connection parts (CT) may be provided in multiple rows or columns spaced apart from each other between two adjacent light-emitting parts (E).

[0065] The reason why the common layer of the second stack (S2) is removed and the connection part (CT) is provided in the light-emitting display device of the present invention is as follows.

[0066] A tandem structure that includes multiple light-emitting layers emitting the same color in a stack has the advantage of increasing the efficiency of each light-emitting layer.

[0067] However, in a tandem structure, common layers such as a hole transport layer and an electron transport layer are provided in addition to the light-emitting layer in each stack. Compared to a single-stack structure that includes a single light-emitting layer between the anode and the cathode, the tandem structure has more than twice the number of common layers, resulting in a large internal resistance to current flow between the anode and the cathode. Meanwhile, the light-emitting display device can be placed in various environments and must have uniform reliability against temperature changes.

[0068] Table 1 below shows the change in luminance by temperature when the temperature is changed from 15°C to 35°C in a single stack structure and a tandem structure. In the experiment of Table 1, both the single stack and the tandem structure did not have a connection between the second electrode (cathode) and another common layer.

[0069] structure Luminance change by temperature (Luminance change % / ℃) Single stack 1.53 Tandem (equipped with 2 stacks) 2.37

[0070] As shown in Table 1, it can be confirmed that the tandem structure exhibits large fluctuations in internal luminance as the temperature changes, as the internal resistance between the first and second electrodes is high. This is understood to be a result of the increased internal resistance in the vertical direction due to the increase in the common layer compared to the single-stack structure. In other words, since the tandem structure has higher vertical resistance in the organic layers located between the first and second electrodes compared to the single-stack structure, when current is supplied by applying the same voltage difference between the first and second electrodes, a smaller reference current value is supplied in the tandem structure compared to the single-stack structure at an initial temperature of 15°C. Consequently, the tandem structure has a smaller reference current value compared to the single-stack structure, and the fluctuation in the current relative to the reference current value as the temperature changes in the tandem structure is greater than the fluctuation in the current relative to the reference voltage value as the temperature changes in the single structure; consequently, the luminance variability with respect to temperature changes in the tandem structure becomes significant.

[0071] The light-emitting display device of the present invention blocks the cause of increased resistance caused by the second stack by connecting a charge generating layer provided between the first stack and the second stack to the second electrode in the non-light-emitting part, thereby making the charge generating layer, the second stack, and the second electrode have a common potential in the non-light-emitting part.

[0072] Below, we examine the changes in voltage characteristics and resistance characteristics under the same current conditions when applying red, green, and blue light-emitting diodes, respectively, in a single stack and a tandem structure (2 stacks). In this experiment, the changes in the single stack and tandem structure were examined without the provision of a connection part.

[0073] Figures 3a to 3c are graphs showing the IV characteristics when applying a single stack and a tandem structure (multiple stacks) to red, green, and blue light-emitting elements, respectively.

[0074] As shown in FIGS. 3a to 3c, it can be seen that the driving voltage required in a tandem structure is greater than that required in a single stack to exhibit the same current density in red, green, and blue light-emitting elements.

[0075] FIGS. 4a to 4c are graphs showing the relationship between current density and resistance when applying red, green, and blue light-emitting elements in a single stack and a tandem structure (multiple stacks), respectively.

[0076] As shown in FIGS. 4a to 4c, when examining the resistance for the same current density in red, green, and blue light-emitting elements, it can be seen that the resistance value is larger in the tandem structure than in the single stack.

[0077] As described above, it is understood that the reason a higher driving voltage is applied and resistance is higher in a tandem device than in a single stack is that the resistance increases due to the large number of organic layers provided between the first electrode and the second electrode of the tandem device, and accordingly, the required driving voltage is also large.

[0078] The light-emitting display device of the present invention is provided with a connection part (CT) that connects a charge generating layer provided between a first stack and a second stack to a second electrode in a non-light-emitting part, thereby making the charge generating layer, the second stack, and the second electrode have a common potential in the non-light-emitting part, thereby blocking the cause of increased resistance caused by the second stack.

[0079] Hereinafter, the light-emitting display device of the present invention will be described with reference to drawings showing various examples of connection parts in a light-emitting display device equipped with light-emitting parts of different colors.

[0080] FIG. 5 is a plan view according to a first embodiment of the light-emitting display device of the present invention, and FIG. 6 is a cross-sectional view along lines I to I' of FIG. 5.

[0081] As shown in FIGS. 5 and 6, a first embodiment of the light-emitting display device of the present invention shows an example in which a connection part (CT) is provided around a red light-emitting part (RE).

[0082] The example presented in FIG. 5 is an example of the arrangement of a red light-emitting part (RE), a green light-emitting part (GE), and a blue light-emitting part (BE). In this arrangement, the green light-emitting part (GE) and the red light-emitting part (RE) alternately repeat along the first diagonal, and the blue light-emitting part (BE) and the green light-emitting part (GE) alternately repeat along the second diagonal that is parallel to and adjacent to the first diagonal. Additionally, the illustrated example shows that the sizes are arranged in the order of the blue light-emitting part (BE), the green light-emitting part (GE), and the red light-emitting part (RE). When the area of ​​the blue light-emitting part (BE) is relatively larger compared to the other color light-emitting parts (GE, RE), the low visibility of blue can be compensated. Furthermore, since green has the highest efficiency among red, green, and blue when representing white luminance in a light-emitting display device, white efficiency can be increased at the same driving voltage by having more green light-emitting parts (GE) than other color light-emitting parts (BE, RE).

[0083] The red light-emitting part (RE) is depicted as circular, but is not limited to this and can be changed to a polygonal or circular shape.

[0084] Additionally, the green light-emitting part (GE) may be an elongated ellipse along the first and second diagonal directions, or an elongated ellipse along the diagonal direction intersecting the first and second diagonals, as shown in FIG. 5. In this case, the green light-emitting parts (GE) arranged in an intersecting manner may have the effect of compensating for the viewing angle in a different direction. However, the shape of the green light-emitting part (GE) is not limited to this and may be changed to a polygon or circle of a shape different from FIG. 5.

[0085] The blue light-emitting part (BE) may be in the shape of a rhombus with rounded corners, as illustrated. However, it is not limited to this, and the blue light-emitting part (BE) may be changed to other shapes such as a polygon, circle, or ellipse.

[0086] The light-emitting display device of the present invention is not limited to the arrangement and shape of the light-emitting parts shown in FIG. 5, and can be varied in various ways as long as it has a connection part (CT) of the charge generating layer and a second electrode of the non-light-emitting part around the light-emitting part.

[0087] The light-emitting display device of the present invention according to the first embodiment is provided with a connection part (CT) between a red light-emitting part (RE) and a green light-emitting part (GE) adjacent to the red light-emitting part.

[0088] A light-emitting display device according to the first embodiment of the present invention further includes a bank (115) in a non-light-emitting portion between light-emitting portions (RE, GE, BE) as shown in FIGS. 5 and 6, wherein the bank (115) covers the edges of the first electrodes (ANDR, ANDG, ANDB) of each light-emitting portion (RE, GE, BE) and may include the first stack (S1), a charge generating layer (CGL), the second stack (S2), and the second electrode (CTD) on the bank (115).

[0089] Compared to the first stack (S1) and the second stack (S2) on the bank (115) located in the non-emissive portion (NE), at least the emitting portion (RE, GE, BE) may further include an emitting layer (REML1 / REML2, GEML1 / GEML2, BEML1 / BEML2).

[0090] The second stack (S2) is removed from the connection part (CT), and the second hole transport layer (HTL2) and the second electron transport layer (ETL2) of the second stack (S2) are laterally connected to the second electrode (CTD), and the upper part of the charge generation layer (CGL) exposed from the connection part (CT) can be directly connected to the second electrode (CTD). The light-emitting display device according to the first embodiment of the present invention connects the charge generation layer (CGL) located at the bottom and the second electrode (CTD) located at the top in the connection part (CT) within the non-light-emitting part, so that the current flowing between the first electrode (ANDR, ANDG, ANDB) and the second electrode (CTD) in the connection part (CT) flows directly to the second electrode (CTD) from the charge generation layer (CGL) without passing through the second stack (S2). Accordingly, the second stack (S2), which is a major cause of brightness change due to temperature change in the connection part (CT) of the non-luminous part, is not passed through, thereby reducing resistance and thereby supplying current between the first electrode (ANDR, ANDG, ANDB) and the second electrode (CTD) at a level having only a single stack. Accordingly, a light-emitting display device with a tandem structure having a charge generation layer and a connection part with the second electrode in the non-luminous part can reduce brightness change due to temperature change to the level of a light-emitting display device with a single stack.

[0091] In addition, the light-emitting display device according to the first embodiment of the present invention is provided with a connection part (CT) in a non-light-emitting part surrounding a red light-emitting part (RE), and the second hole transport layer (HTL2) and the second electron transport layer (ETL2) are cut off at the portion of the common layer of the second stack (S2) facing the red light-emitting part (RE) toward the surrounding light-emitting part, thereby blocking or reducing lateral leakage current flowing between the red light-emitting part (RE) and the green light-emitting part (GE) and between the red light-emitting part (RE) and the blue light-emitting part (GE). Accordingly, when a light-emitting part of a specific color is turned on, the phenomenon in which a light-emitting part of another color emits light due to lateral leakage current can be prevented.

[0092] In addition, by providing a connection part (CT) that connects the charge generation layer as a common layer to the second electrode (CTD), lateral leakage current caused by the common layer can also be prevented.

[0093] Accordingly, the light-emitting display device according to the first embodiment of the present invention is provided with a connection portion around a red light-emitting portion, so that even if the turn-on voltage of the red light-emitting portion is lower than the turn-on voltage of each of the blue light-emitting portion and the green light-emitting portion, the phenomenon in which an adjacent red light-emitting portion is turned on when the blue light-emitting portion is selectively turned on or the green light-emitting portion is selectively turned on can be prevented. That is, when a light-emitting portion of a different color other than the red light-emitting portion is turned on, leakage light other than red can be prevented.

[0094] Referring to Fig. 6, we examine the structure of the red light-emitting element provided in the red light-emitting part (RE).

[0095] The red light-emitting element comprises a first electrode (ANDR) provided on a substrate (100) corresponding to at least a region of a red light-emitting part (RE), at least two first and second stacks (S1, S2) on the first electrode (ANDR), a charge generating layer (CGL) between the first and second stacks (S1, S2), and a second electrode (CTD) on the second stack (S2).

[0096] Similarly, the green light-emitting element comprises a first electrode (ANDG) provided on a substrate (100) corresponding to at least a region of a green light-emitting portion (GE), at least two first and second stacks (S1, S2) on the first electrode (ANDG), a charge generating layer (CGL) between the first and second stacks (S1, S2), and a second electrode (CTD) on the second stack (S2).

[0097] And, the blue light-emitting element includes a first electrode (ANDB) provided on a substrate (100) corresponding to at least a region of a blue light-emitting part (BE), at least two first and second stacks (S1, S2) on the first electrode (ANDB), a charge generating layer (CGL) between the first and second stacks (S1, S2), and a second electrode (CTD) on the second stack (S2).

[0098] In the red emitting part (RE), green emitting part (GE), and blue emitting part (BE), the first stack (S1) comprises a hole injection layer (HIL), a first hole transport layer (HTL1), a first emitting layer (REML1, GEML1, BEML1), and a first electron transport layer (ETL1), and the second stack (S2) comprises a second hole transport layer (HTL2), a second emitting layer (REML2, GEML2, BEML2), and a second electron transport layer (ETL2). The red emitting part (RE), green emitting part (GE), and blue emitting part (BE) may be defined as openings of the bank (115), and the bank (115) may be configured to cover the edges of the first electrodes (ANDR, ANDG, ANDB) provided in the red emitting part (RE), green emitting part (GE), and blue emitting part (BE). The non-emissive portion between the emitting portions (RE, GE, BE) may partially overlap the first and second emitting layers (REML1 / REML2, GEML1 / GEML2, BEML1 / BEML2). In the red emitting portion (RE), the first red emitting layer (REML1) of the first stack (S1) and the second red emitting layer (REML2) of the second stack (S2) may overlap. In the green emitting portion (GE), the first green emitting layer (GEML1) of the first stack (S1) and the second green emitting layer (GEML2) of the second stack (S2) may overlap. In the blue emitting portion (BE), the first blue emitting layer (BEML1) of the first stack (S1) and the second blue emitting layer (BEML2) of the second stack (S2) may overlap.

[0099] In the first and second stacks (S1, S2), between the hole transport layer (HTL1, HTL2) and the electron transport layer (ETL1, ETL2), respectively, the red emitting part (RE) is provided with first and second red emitting layers (REML1, REML2) that emit red light, the green emitting part (GE) is provided with first and second green emitting layers (GEML1, GEML2) that emit green light, and the blue emitting part (BE) is provided with first and second blue emitting layers (BEML1, BEML2) that emit blue light.

[0100] A light-emitting display device according to the first embodiment of the present invention may have an edge portion spaced apart from the connection portion (CT) of the first and second red light-emitting layers (REML1, REML2) provided in the red light-emitting portions (RE). In this case, the opening of the fine metal mask forming the first and second red light-emitting layers (REML1, REML2) is made non-overlapping with the connection portion (CT), and connection between the second electrode (CTD) and the charge generating layer (CGL) at the connection portion is made easy.

[0101] In the first and second stacks (S1, S2), the hole injection layer (HIL), the first and second hole transport layers (HTL1, HTL2), the first and second electron transport layers (ETL1, ETL2), and the charge generation layer (CGL) are provided in common to the emitting part and the non-emitting part, excluding the first and second red emitting layers (REML1, REML2), the first and second green emitting layers (GEML1, GEML2), and the first and second blue emitting layers (BEML1, BEML2). The light-emitting display device according to the first embodiment of the present invention is characterized in that the second hole transport layer (HTL2) and the second electron transport layer (ETL2), which are common layers of the second stack (S2), are removed in a partial area around the red emitting part (RE) among the non-emitting parts, so that the second electrode (CTD) and the charge generation layer (CGL) are directly connected.

[0102] The example illustrated in FIG. 6 shows an example in which two stacks are included between the first and second electrodes (ANDR, CTD), but is not limited thereto, three or more stacks may be further included between the first and second electrodes (ANDR, CTD) as charge generating layers.

[0103] When three or more stacks are provided between the first and second electrodes (ANDR, CTD), the connection portion (CT) may be further provided by penetrating two or more stacks up to the lowest charge generation layer.

[0104] Meanwhile, on the second electrode (CTD), a capping layer (140) (CPL) is further provided to protect the light-emitting elements provided in each light-emitting part (RE, GE, BE) and to increase the light emission efficiency.

[0105] On the upper portion of the capping layer (140), an encapsulation layer (200) may be further provided to protect subpixels (SP) provided on the substrate (100) and to block external moisture. The encapsulation layer (200) may include, for example, an alternating stacked structure of one or more pairs of organic layers and inorganic layers.

[0106] Meanwhile, as shown in FIG. 2, a thin-film transistor (T) is provided between the substrate (100) and the light-emitting element of each light-emitting part so that the light-emitting element can receive an electrical signal.

[0107] FIG. 7 is a plan view according to a modified example of the first embodiment of the light-emitting display device of the present invention.

[0108] As shown in FIG. 7, in a light-emitting display device according to a modified embodiment of the first embodiment of the present invention, the connection portion (CT_A) between the second electrode and the charge generation layer may be a closed ring shape that surrounds any one of the light-emitting portions (GE, BE, or RE). FIG. 7 illustrates a connection portion (CT_A) in the shape of a closed ring surrounding a green light-emitting portion (GE), but is not limited thereto, and the connection portion (CT_A) may be a closed ring shape that surrounds a blue light-emitting portion (BE) or a red light-emitting portion (RE). The connection portion (CT_A) in the shape of a closed ring maintains a spaced-away state from each adjacent light-emitting portion (GE, BE, RE) so as not to degrade the light-emitting characteristics of the light-emitting portions (GE, RE, RE).

[0109] Below, we examine the IV characteristics according to the structure by changing the layers within the second stack between the charge generation layer and the second electrode.

[0110] FIGS. 8a to 8d are cross-sectional views of light-emitting elements according to the first to fourth experimental examples.

[0111] As shown in FIG. 8a, the light-emitting element (D1) of the first experimental example is formed by sequentially forming a first stack of a first hole transport layer (HTL1), a first light-emitting layer (EML1), and a first electron transport layer (ETL1), a charge-generating layer of an n-type charge-generating layer (NCGL) and a p-type charge-generating layer (PCGL), and a second stack of a second hole transport layer (HTL2), a second light-emitting layer (EML2), and a second electron transport layer (ETL2) between the first electrode (AND) and the second electrode (CTD). The second light-emitting layer (EML2) is formed in a selective light-emitting portion through an opening of the mask and is formed on the front surface and is located in a smaller area than the second hole transport layer (HTL2) and the second electron transport layer (ETL2) located at the bottom and top, and the second electron transport layer (ETL2) covers the side of the second light-emitting layer (EML2) and can come into contact with the second hole transport layer (HTL2) on the bottom side.

[0112] The light-emitting element (D2) according to the second experimental example of FIG. 8b has a second electrode (CTD) in contact with a charge generation layer, similar to the light-emitting display device of the present invention, and the stacked configuration of the first experimental example, the first stack, and the charge generation layer is identical to the light-emitting element according to the first experimental example described in FIG. 8a. In the light-emitting element according to the second experimental example, the upper surface of the upper p-type charge generation layer (PCGL) among the charge generation layers having a two-layer structure of an n-type charge generation layer (NCGL) and a p-type charge generation layer (PCGL) is connected to the second electrode (CTD), and the second hole transport layer (HTL2) and the second electron transport layer (ETL2) of the second stack are removed from the connection portion, respectively, so that there is a direct connection between the second electrode (CTD) and the p-type charge generation layer (PCGL).

[0113] In the light-emitting element (D3) according to the third experimental example of FIG. 8c, only the second hole transport layer (HTL2) is patterned within the second stack, and the second electron transport layer (ETL2) is formed across the entire surface, so that the second electron transport layer (ETL2) has electrical connection with the p-type charge generation layer (PCGL).

[0114] In the light-emitting element (D4) according to the fourth experimental example of FIG. 8d, only the second electron transport layer (ETL2) is patterned within the second stack, and the second hole transport layer (HTL2) is formed across the entire surface. The connection between the second hole transport layer (HTL2) and the p-type charge generation layer (PCGL) is the same as that of the light-emitting element (D1) of the first experimental example, and the second electrode (CTD) is electrically connected to the second hole transport layer (HTL).

[0115] The light-emitting elements according to the first to fourth experimental examples further have a capping layer (CPL) in common on the second electrode (CTD).

[0116] FIGS. 9a and 9b are graphs showing the emission spectrum of a blue subpixel during low-gradation driving according to the first and second experimental examples.

[0117] In the case of the light-emitting element (D1) of the first experimental example according to FIG. 8a, which has the common layer (HTL2, ETL2) in the second stack without change, when the blue light-emitting part is driven to a low grayscale, leakage light is generated in the green light-emitting part and the red light-emitting part, which have a relatively lower turn-on voltage than the blue light-emitting part, so that even when blue light is emitted, the emission of green light and red light appears as in FIG. 9a.

[0118] On the other hand, as shown in FIG. 8b, in the case of the light-emitting element (D2) of the second experimental example, in which each of the common layers (HTL2, ETL2) has a through-hole shape with a removed connection part and is electrically connected to the second electrode (CTD) and the p-type charge generation layer (PCGL), a break in the common layer of the second stack between the blue light-emitting part and the surrounding green light-emitting part and red light-emitting part occurs, and no lateral leakage current occurs in the common layers (HTL2, ETL2) of the second stack between the light-emitting parts emitting different colors, so as shown in FIG. 9b, the occurrence of leakage light of other colors caused by lateral leakage current can be significantly prevented even during low-gradation blue light emission. In addition, the light-emitting element (D2) of the second experimental example, having a connection between the second electrode and the charge generation layer, can prevent the influence of the resistance of the second stack and reduce changes in brightness due to temperature changes.

[0119] The light-emitting element according to the third experimental example of FIG. 8c and the light-emitting element according to the fourth experimental example of FIG. 8d each have only a portion of the common layer within the second stack removed, and when emitting low-gradation blue light under the same conditions, the leakage light is smaller than that of the first experimental example and larger than that of the second experimental example. Specifically, this will be examined together in the following 5th to 13th experimental examples.

[0120] FIG. 10 is a circuit diagram schematically showing the current flow of a light-emitting element according to the first and second experimental examples.

[0121] As shown in FIG. 10, the light-emitting element (D1) according to the first experimental example has a first stack (S1) and a second stack (S2) connected in series, each having a light-emitting function between the first electrode (AND) and the second electrode (CTD). Circuit-wise, the first stack (S1) between the first electrode (AND) and the charge generation layer (CGL) acts as the first resistor (R_S1), and the second stack (S2) between the charge generation layer (CGL) and the second electrode (CTD) acts as the second resistor (R_S2). In this case, in the light-emitting element (D1) according to the first experimental example, the current passing through the first resistor (R_S1) of the first stack (S1) in the vertical direction to i0 in the charge generating layer (CGL) passes through the second stack (S2) and the second resistor (R_S2) and is transferred to the second electrode (CTD) to i2, which is smaller than i0.

[0122] On the other hand, in the light-emitting element (D2) according to the second experimental example, the first stack (S1) acts as the first resistor (R_S1) in the same way as in the first experimental example (D1), but the charge generation layer (CGL) and the second electrode (CTD) are directly connected so that the resistance of the second stack does not affect the vertical direction, so the current i0 that passes through the first stack (S1) and is delivered to the charge generation layer (CGL) is delivered to the second electrode (CTD), thereby preventing the current reduction phenomenon caused by the second stack.

[0123] Table 2 shows the light-emitting devices of the 5th to 13th experimental examples (DOE1~DOE9), and the experiment was conducted with the same first stack (S1) consisting of a first electrode (AND), a first hole transport layer (HTL1), a first light-emitting layer (EML1), and a first electron transport layer (ETL1), a charge generation layer stacked with an n-type charge generation layer (NCGL) and a p-type charge generation layer (PCGL), a second electrode (CTD), and a capping layer (CPL).

[0124] The 5th to 13th experimental examples (DOE1 to DOE9) differ in that they are configured within the second stack. In the 5th experimental example (DOE1), the second hole transport layer (HTL2) is provided with a first thickness (H1), the second light-emitting layer (EML2) is provided, and the second electron transport layer (ETL2) is provided with a second thickness (H2).

[0125] composition DOE1 DOE2 DOE3 DOE4 DOE5 DOE6 DOE7 DOE8 DOE9 CPL you you you you you you you you you CTD you you you you you you you you you ETL2 H2 radish H2 H2 / 2 H2 / 4 radish H2 radish H2 / 2 EML2 you radish radish radish radish radish radish radish radish HTL2 H1 radish H1 H1 / 2 H1 / 4 H1 radish H1 / 2 radish PCGL you NCGL you ETL1 you EML1 you HTL1 you

[0126] The light-emitting element (DOE2) of the 6th experimental example is identical to the stack configuration of the light-emitting element (D2) of the 2nd experimental example of FIG. 8b described above, and compared to the 5th experimental example (DOE1), it has a direct connection portion between the second electrode (CTD) and the p-type charge generation layer (PCGL), and the second hole transport layer (HTL2), the second light-emitting layer (EML2), and the second electron transport layer (ETL2) are removed from the direct connection portion. The light-emitting element (DOE3) of the 7th experimental example is identical to the stack configuration of the light-emitting element (D1) of the 1st experimental example of FIG. 8b described above, and has a portion in which the second light-emitting layer (EML2) is patterned and removed, and the second hole transport layer (HTL2) of the second stack is provided with a first thickness (H1), and the second electron transport layer (ETL2) is provided with a second thickness (H2).

[0127] The light-emitting element (DOE4) of the 8th experimental example has a thickness of the common layer in the second stack reduced by half compared to the light-emitting element (DOE3) of the 7th experimental example, and has a portion of the second light-emitting layer (EML2) that has been patterned and removed, and the second hole transport layer (HTL2) of the second stack is provided with a first thickness x 0.5 (H1 / 2), and the second electron transport layer (ETL2) is provided with a second thickness x 0.5 (H2 / 2).

[0128] The light-emitting element (DOE5) of the 9th experimental example has a thickness of the common layer in the second stack reduced by 1 / 4 compared to the light-emitting element (DOE3) of the 7th experimental example, and has a patterned and removed portion of the second light-emitting layer (EML2), and the second hole transport layer (HTL2) of the second stack is provided with a first thickness x 0.25 (H1 / 4), and the second electron transport layer (ETL2) is provided with a second thickness x 0.25 (H2 / 4).

[0129] The light-emitting element (DOE6) of the 10th experimental example is the same as the light-emitting element (D4) of the 4th experimental example in FIG. 8d, and in the second stack, the second light-emitting layer (EML2) has a patterned and removed portion, and the second hole transport layer (HTL2) of the second stack has a first thickness (H1), and also the second electron transport layer (ETL2) has a removed portion and is connected to the second electrode (CTD) and the second hole transport layer (HTL2).

[0130] The light-emitting element (DOE7) of the 11th experimental example is identical to the light-emitting element (D3) of the 3rd experimental example in FIG. 8c, wherein in the second stack, the second light-emitting layer (EML2) has a patterned and removed portion, the second hole transport layer (HTL2) of the second stack is removed, and the second electron transport layer (ETL2) is maintained at a second thickness (H2). In the light-emitting element (DOE7) of the 11th experimental example, the second light-emitting layer (EML2) and the second hole transport layer (HTL2) are removed, and the second electron transport layer (ETL2) has a connection portion with the p-type charge generation layer (PCGL).

[0131] The light-emitting element (DOE8) of the 12th experimental example is a modified example of the 10th experimental example (DOE6), wherein in the second stack, the second light-emitting layer (EML2) has a patterned and removed portion, the second hole transport layer (HTL2) of the second stack is provided with a first thickness x 0.5 (H1 / 2), and also the second electron transport layer (ETL2) has a removed portion and is connected to the second electrode (CTD) and the thin second hole transport layer (HTL2).

[0132] The light-emitting element (DOE9) of the 13th experimental example is a modified example of the 11th experimental example (DOE7), wherein in the second stack, the second light-emitting layer (EML2) has a patterned and removed portion, the second hole transport layer (HTL2) of the second stack is removed, and the second electron transport layer (ETL2) is provided with a second thickness x 0.5 (H2 / 2). In this case, the light-emitting element (DOE9) of the 13th experimental example has the second light-emitting layer (EML2) and the second hole transport layer (HTL2) removed, and the thin second electron transport layer (ETL2) has a connection portion with the p-type charge generation layer (PCGL).

[0133] Figure 11 is a graph showing the IV characteristics according to the 5th to 13th experimental examples.

[0134] When comparing the 5th experimental example (DOE1) and the 6th experimental example (DOE2), it can be confirmed that the turn-on driving voltage is reduced in the 6th experimental example (DOE2) due to the reduction in resistance caused by the removal of the common layer of the 2nd stack.

[0135] In addition, when comparing the 5th experimental example (DOE1) with the 7th to 9th experimental examples (DOE3, DOE4, DOE5), it can be seen that there is a slight improvement in the IV curve due to the reduction in resistance caused by the removal of the second light-emitting layer (EML2) in the 7th to 9th experimental examples (DOE3, DOE4, DOE5), and that there is an improvement in current density in the 7th to 9th experimental examples (DOE3, DOE4, DOE5) in turn at the same driving voltage.

[0136] It can be confirmed that removing the entire second electron transport layer (ETL2) or the entire thickness of the second hole transport layer (HTL2), as in the 10th experimental example (DOE6) and the 11th experimental example (DOE7), is more effective in reducing the driving voltage than leaving all or part of the thickness of the second hole transport layer (HTL2) and the second electron transport layer (ETL2) in the 7th to 9th experimental examples (DOE3, DOE4, DOE5).

[0137] In addition, when comparing the 12th experimental example (DOE8) and the 13th experimental example (DOE9), it can be confirmed that the 13th experimental example (DOE9), which has a thin second electron transport layer (ETL2) in the second stack (S2), is more effective in improving the IV curve characteristics compared to the 12th experimental example (DOE8), which has a thin second hole transport layer (HTL2).

[0138] In the case where both the common layer (HTL2, ETL2) and the light-emitting layer (EML2) of the second stack are removed, as in Experiment 6 (DOE6), which is the most effective among the experimental examples, the node of the charge generation layer (CGL) and the node of the second electrode (CTD) are connected as in the current path of the D2 element in FIG. 10, so that the resistance attributable to the second stack (S2) does not affect the current transmitted to the second electrode (CTD), and the current (i0) transmitted to the charge generation layer (CGL) can be transmitted to the second electrode (CTD) as is. Therefore, when the light-emitting display device of the present invention has a connection between the second electrode and the charge generation layer by removing the common layer from the second stack, the resistance in the vertical direction is reduced, thereby blocking the cause of the increase in resistance due to the increase in the common layer, and thus reducing the change in brightness due to temperature change, thereby improving the reliability of the light-emitting element and the light-emitting display device.

[0139] Hereinafter, a light-emitting display device according to another embodiment of the present invention will be examined.

[0140] FIG. 12 is a plan view according to a second embodiment of the light-emitting display device of the present invention, and FIG. 13 is a cross-sectional view along lines III to III' of FIG. 12.

[0141] As shown in FIG. 12 and FIG. 13, the light-emitting display device according to the second embodiment of the present invention is provided with a connection part (CT) in a non-light-emitting part surrounding a green light-emitting part (GE), and the second hole transport layer (HTL2) and the second electron transport layer (ETL2) are cut off at the portion facing the green light-emitting part (GE) toward the surrounding light-emitting part as a common layer of the second stack (S2), so that side leakage current flowing between the green light-emitting part (GE) and the red light-emitting part (RE) and between the green light-emitting part (GE) and the blue light-emitting part (BE) can be blocked or reduced.

[0142] In addition, by providing a connection part (CT) that connects the charge generation layer (CGL) as a common layer to the second electrode (CTD), lateral leakage current caused by the common layer (HTL2, ETL2) in the second stack (S2) can also be prevented.

[0143] Accordingly, the light-emitting display device according to the second embodiment of the present invention is provided with a connection part (CT) in a non-light-emitting part spaced apart from the green light-emitting part (GE) around the green light-emitting part (GE), so that even if the turn-on voltage of the red light-emitting part is lower than the turn-on voltage of each of the blue light-emitting part and the green light-emitting part, the phenomenon in which the adjacent red light-emitting part is turned on when the blue light-emitting part is selectively turned on or the green light-emitting part is selectively turned on can be prevented. That is, when turning on a light-emitting part of a different color (RE, BE) other than the green light-emitting part (GE), leakage light other than green (GE) can be prevented.

[0144] The second stack (S2) is removed from the connection part (CT), and the second hole transport layer (HTL2) and the second electron transport layer (ETL2) of the second stack (S2) are laterally connected to the second electrode (CTD), and the upper part of the charge generation layer (CGL) exposed from the connection part (CT) can be directly connected to the second electrode (CTD). The light-emitting display device according to the second embodiment of the present invention connects the charge generation layer (CGL) located at the bottom and the second electrode (CTD) located at the top in the connection part (CT) within the non-light-emitting part, so that the current flowing between the first electrode (ANDR, ANDG, ANDB) and the second electrode (CTD) in the connection part (CT) flows directly to the second electrode (CTD) from the charge generation layer (CGL) without passing through the second stack (S2). Accordingly, the second stack (S2), which is a major cause of brightness change due to temperature change in the connection part (CT) of the non-luminous part, is not passed through, thereby reducing resistance and thereby supplying current between the first electrode (ANDR, ANDG, ANDB) and the second electrode (CTD) at a level having only a single stack. Accordingly, a light-emitting display device with a tandem structure having a charge generation layer and a connection part with the second electrode in the non-luminous part can reduce brightness change due to temperature change to the level of a light-emitting display device with a single stack.

[0145] In addition, the light-emitting display device according to the second embodiment of the present invention is provided with a connection part (CT) in a non-light-emitting part surrounding a green light-emitting part (GE), and the second hole transport layer (HTL2) and the second electron transport layer (ETL2) are cut off at the portion of the common layer of the second stack (S2) facing the green light-emitting part (GE) toward the surrounding light-emitting part, thereby blocking or reducing lateral leakage current flowing between the green light-emitting part (GE) and the red light-emitting part (RE) and between the green light-emitting part (GE) and the blue light-emitting part (BE). Accordingly, when a light-emitting part of a specific color is turned on, the phenomenon in which a light-emitting part of another color emits light due to lateral leakage current can be prevented.

[0146] The plan view of FIG. 11 showing a light-emitting display device according to the second embodiment of the present invention has the same arrangement of red light-emitting part, green light-emitting part, and blue light-emitting part as FIG. 5, so the description thereof is omitted.

[0147] However, the light-emitting display device according to the second embodiment of the present invention is not limited to the arrangement shape shown in FIG. 11, and can, of course, be applied in a structure where a red light-emitting part, a green light-emitting part, and a blue light-emitting part are arranged in a stripe shape, or where one red light-emitting part and one green light-emitting part are arranged in a first direction, and a blue light-emitting part adjacent to one red light-emitting part and one green light-emitting part is arranged adjacently in parallel to the first direction. In addition, it can be applied in various arrangements of red, green, and blue light-emitting parts in a form having a connection part (CT) of a second electrode and a charge generation layer around the green light-emitting part.

[0148] FIG. 14 is a plan view according to a third embodiment of the light-emitting display device of the present invention, and FIG. 15 is a cross-sectional view along lines IV to IV' of FIG. 14.

[0149] As shown in FIGS. 14 and 15, the light-emitting display device according to the third embodiment of the present invention is provided with a connection part (CT) in a non-light-emitting part surrounding a blue light-emitting part (BE), and the second hole transport layer (HTL2) and the second electron transport layer (ETL2) are cut off at the portion of the blue light-emitting part (BE) facing the surrounding light-emitting part as a common layer of the second stack (S2), so that side leakage current flowing between the blue light-emitting part (BE) and the red light-emitting part (RE) and between the blue light-emitting part (BE) and the green light-emitting part (GE) can be blocked or reduced.

[0150] In addition, by providing a connection part (CT) that connects the charge generation layer (CGL) as a common layer to the second electrode (CTD), lateral leakage current caused by the common layer (HTL2, ETL2) in the second stack (S2) can also be prevented.

[0151] Accordingly, the light-emitting display device according to the third embodiment of the present invention is provided with a connection part (CT) in a non-light-emitting part spaced apart from the blue light-emitting part (BE) around the blue light-emitting part (BE), so that even if the turn-on voltage of the red light-emitting part is lower than the turn-on voltage of each of the blue light-emitting part and the green light-emitting part, the phenomenon in which the adjacent red light-emitting part is turned on when the blue light-emitting part is selectively turned on or the green light-emitting part is selectively turned on can be prevented. That is, when turning on light-emitting parts of other colors (RE, GE) different from the blue light-emitting part (BE), leakage light other than blue (BE) can be prevented.

[0152] The second stack (S2) is removed from the connection part (CT), and the second hole transport layer (HTL2) and the second electron transport layer (ETL2) of the second stack (S2) are laterally connected to the second electrode (CTD), and the upper part of the charge generation layer (CGL) exposed from the connection part (CT) can be directly connected to the second electrode (CTD). The light-emitting display device according to the second embodiment of the present invention connects the charge generation layer (CGL) located at the bottom and the second electrode (CTD) located at the top in the connection part (CT) within the non-light-emitting part, so that the current flowing between the first electrode (ANDR, ANDG, ANDB) and the second electrode (CTD) in the connection part (CT) flows directly to the second electrode (CTD) from the charge generation layer (CGL) without passing through the second stack (S2). Accordingly, the second stack (S2), which is a major cause of brightness change due to temperature change in the connection part (CT) of the non-luminous part, is not passed through, thereby reducing resistance and thereby supplying current between the first electrode (ANDR, ANDG, ANDB) and the second electrode (CTD) at a level having only a single stack. Accordingly, a light-emitting display device with a tandem structure having a charge generation layer and a connection part with the second electrode in the non-luminous part can reduce brightness change due to temperature change to the level of a light-emitting display device with a single stack.

[0153] In addition, the light-emitting display device according to the third embodiment of the present invention is provided with a connection part (CT) in a non-light-emitting part surrounding a blue light-emitting part (BE), and the second hole transport layer (HTL2) and the second electron transport layer (ETL2) are cut off at the portion facing the green light-emitting part (GE) toward the surrounding light-emitting part as a common layer of the second stack (S2), so that side leakage current flowing between the blue light-emitting part (BE) and the red light-emitting part (RE) and between the blue light-emitting part (BE) and the green light-emitting part (GE) can be blocked or reduced. Accordingly, when a light-emitting part of a specific color is turned on, the phenomenon in which a light-emitting part of another color emits light due to side leakage current can be prevented.

[0154] The plan view of FIG. 13 showing a light-emitting display device according to the third embodiment of the present invention has a red light-emitting part, a green light-emitting part, and a blue light-emitting part arranged similarly to FIG. 5, so the description thereof is omitted.

[0155] However, the light-emitting display device according to the third embodiment of the present invention is not limited to the arrangement shape shown in FIG. 13, and can, of course, be applied in a structure where a red light-emitting part, a green light-emitting part, and a blue light-emitting part are arranged in a stripe shape, or where one red light-emitting part and one green light-emitting part are arranged in a first direction, and a blue light-emitting part adjacent to one red light-emitting part and one green light-emitting part is arranged adjacently in parallel to the first direction. In addition, it can be applied in various arrangements of red, green, and blue light-emitting parts in a form having a connection part (CT) of a second electrode and a charge generation layer around the blue light-emitting part.

[0156] As shown in FIGS. 6, 13 and 15, in the light-emitting display device of the present invention, the red light-emitting element comprises a first electrode (ANDR) provided on a substrate (100) corresponding to at least a region of a red light-emitting part (RE), at least two first and second stacks (S1, S2) on the first electrode (ANDR), a charge generating layer (CGL) between the first and second stacks (S1, S2), and a second electrode (CTD) on the second stack (S2).

[0157] Similarly, the green light-emitting element comprises a first electrode (ANDG) provided on a substrate (100) corresponding to at least a region of a green light-emitting portion (GE), at least two first and second stacks (S1, S2) on the first electrode (ANDG), a charge generating layer (CGL) between the first and second stacks (S1, S2), and a second electrode (CTD) on the second stack (S2).

[0158] And, the blue light-emitting element includes a first electrode (ANDB) provided on a substrate (100) corresponding to at least a region of a blue light-emitting part (BE), at least two first and second stacks (S1, S2) on the first electrode (ANDB), a charge generating layer (CGL) between the first and second stacks (S1, S2), and a second electrode (CTD) on the second stack (S2).

[0159] The light-emitting display device of the present invention is applicable not only to the arrangement of red, green, and blue light-emitting parts described in the first to third embodiments, but also to light-emitting display devices in which white is implemented through other combinations. For example, cyan, magenta, and yellow light-emitting parts may have a stripe, pentile, or diagonal arrangement, and a light-emitting layer of the same color may be provided in a different stack in each light-emitting part and have an overlapping form. In the non-light-emitting part between the light-emitting parts emitting different colors, a connection part between a second electrode (cathode) and a charge generation layer may be provided, thereby preventing low-gradation leakage light due to the prevention of lateral leakage current described in the light-emitting display device described above, and in a multiple stack structure, when the temperature changes, the phenomenon of brightness change can be reduced or prevented by blocking the influence of the resistance of the second stack.

[0160] Figure 16 is a graph comparing the IV characteristics when a tandem structured red light-emitting element is applied to the first and second experimental examples, Figure 17 is a graph comparing the IV characteristics when a tandem structured green light-emitting element is applied to the first and second experimental examples, and Figure 18 is a graph comparing the IV characteristics when a tandem structured blue light-emitting element is applied to the first and second experimental examples.

[0161] As shown in FIGS. 16 to 18, in a tandem device with two or more stacks, such as in the second experimental example (DR2, DG2, DB2), the influence of resistance caused by the stack between the connected second electrodes is blocked, thereby preventing a decrease in the current supplied to the second electrodes and preventing a decrease in current caused by an increase in resistance, thereby improving the IV curve characteristics and having the effect of reducing the turn-on voltage compared to the first experimental example (DR1, DG1, DB1) which does not have a connection.

[0162] Accordingly, the light-emitting display device of the present invention can prevent an increase in resistance caused by an increase in the common layer in a tandem structure with an increased stack, thereby preventing a decrease in current, and can block fluctuations in brightness due to temperature changes by supplying a current equal to the current flowing in the first stack to the second electrode. In addition, at the connection part, a vertical path is formed between the second stack and the lower charge generation layer and the second electrode, and the common layer is removed to prevent lateral leakage current between adjacent light-emitting parts emitting other colors, and can effectively prevent low-gradation leakage light.

[0163] A light-emitting display device according to one embodiment of the present invention may include a substrate having a plurality of light-emitting parts and a non-light-emitting part between the light-emitting parts, a first electrode each provided on the light-emitting parts and spaced apart from each other, a first stack and a second stack provided on the substrate including the first electrode with a first charge generating layer in between, and a second electrode provided on the second stack and electrically connected to the first charge generating layer through a connection part in the non-light-emitting part.

[0164] A light-emitting display device according to one embodiment of the present invention comprises, wherein the first stack and the second stack each include a hole transport layer, a light-emitting layer, and an electron transport layer, and the connection portion penetrates the hole transport layer and the electron transport layer of the second stack, and the second electrode can be directly connected to the first charge generating layer through the connection portion.

[0165] A light-emitting display device according to one embodiment of the present invention further includes a bank in the non-light-emitting part, wherein the bank covers the edge of the first electrode and, among the first stack, the first charge generating layer, the second stack, and the second electrode on the bank, the second stack may be removed from the connection part.

[0166] In addition, in a light-emitting display device according to one embodiment of the present invention, the common layer of the second stack at the connection part can be laterally connected with the second electrode.

[0167] A light-emitting display device according to one embodiment of the present invention may include a common layer of the second stack, the common layer of the second stack may include a first common layer provided on the lower side of the light-emitting layer provided in the second stack and a second common layer provided on the upper side of the light-emitting layer provided in the second stack.

[0168] In a light-emitting display device according to one embodiment of the present invention, the light-emitting layer provided in the light-emitting parts may have an edge portion spaced apart from the connection portion.

[0169] A light-emitting display device according to one embodiment of the present invention may further include one or more stacks between the first charge generating layer and the second stack, and may further include a second charge generating layer between the one or more stacks included between the first charge generating layer and the second stack and the second stack.

[0170] In a light-emitting display device according to one embodiment of the present invention, the connection portion between the second electrode and the first charge generating layer may be island-shaped between adjacent light-emitting portions.

[0171] In a light-emitting display device according to one embodiment of the present invention, the connection portion between the second electrode and the first charge generating layer may be in the shape of a closed ring surrounding one of the light-emitting portions.

[0172] In addition, a light-emitting display device according to one embodiment of the present invention may include a substrate having a first light-emitting part and a second light-emitting part spaced apart from each other, a first anode and a second anode respectively provided in the first light-emitting part and the second light-emitting part, a first stack and a second stack provided on the substrate including the first anode and the second anode with a charge-generating layer in between, and a cathode provided on the second stack and having a connection part with the charge-generating layer between the first light-emitting part and the second light-emitting part.

[0173] A light-emitting display device according to one embodiment of the present invention further includes a bank between the first and second light-emitting parts, wherein the bank covers the edges of each of the spaced-apart first anode and second anode, and on the bank, the second stack among the first stack, the charge generating layer, the second stack, and the second electrode may be removed from the connection part.

[0174] In a light-emitting display device according to one embodiment of the present invention, the connecting part may be provided in an island shape, spaced apart from the first light-emitting part and the second light-emitting part, respectively.

[0175] A light-emitting display device according to one embodiment of the present invention may include, wherein the first light-emitting part comprises a first light-emitting layer that emits a first color in the first stack and the second stack, and the second light-emitting part may include a second light-emitting layer that emits a second color different from the first color in the first stack and the second stack.

[0176] In a light-emitting display device according to one embodiment of the present invention, the first light-emitting layer and the second light-emitting layer may be spaced apart from the connection part.

[0177] A light-emitting display device according to one embodiment of the present invention may further include, on the substrate, a first common layer below the first light-emitting layer and the second light-emitting layer, and a second common layer above the first light-emitting layer and the second light-emitting layer, extending across the region between the first light-emitting part and the second light-emitting part and the first and second light-emitting parts.

[0178] In a light-emitting display device according to one embodiment of the present invention, the first common layer and the second common layer of the second stack are removed from the connection portion, and the cathode can be directly connected to the charge generating layer through the connection portion.

[0179] In a light-emitting display device according to one embodiment of the present invention, the first common layer and the second common layer of the second stack at the connection portion can be laterally connected with the second electrode.

[0180] Meanwhile, it will be obvious to those skilled in the art that the present invention described above is not limited to the embodiments and attached drawings described above, and that various substitutions, modifications, and changes are possible within the scope of the technical concept of the present invention. Explanation of the symbols

[0181] 100: Substrate 107: Planarization layer 115, BNK: Bank HIL: Hole injection layer 121, AND, ANDR, ANDG, ANDR: First electrode HTL1: First hole transport layer EML1: First emissive layer ETL1: 1st electron transport layer S: Entire stack S1: 1st stack CGL: Charge generation layer NCGL: n-type charge generation layer PCGL: p-type charge generation layer HTL2: Second hole transport layer EML2: Second emissive layer ETL2: Second electron transport layer S2: Second stack 130, CTD: Second electrode 140, CPL: Capping layer 200: Bag layer

Claims

Claim 1 A light-emitting display device comprising: a substrate having a plurality of light-emitting parts and a non-light-emitting part between the light-emitting parts; a first electrode provided on each of the light-emitting parts and spaced apart from each other; a first stack and a second stack provided on the substrate including the first electrode with a first charge generating layer in between; and a second electrode provided on the second stack and electrically connected to the first charge generating layer through a connection part at the non-light-emitting part, wherein the first charge generating layer extends continuously across two adjacent light-emitting parts among the plurality of light-emitting parts. Claim 2 A light-emitting display device according to claim 1, wherein the first stack and the second stack each include a hole transport layer, a light-emitting layer, and an electron transport layer, the connection portion penetrates the hole transport layer and the electron transport layer of the second stack, and the second electrode is directly connected to the first charge generating layer through the connection portion. Claim 3 In claim 1, the light-emitting display device further comprises a bank in the non-luminous portion, wherein the bank covers the edge of the first electrode, and among the first stack, the first charge generating layer, the second stack, and the second electrode on the bank, the second stack is removed from the connection portion. Claim 4 In claim 1, the common layer of the second stack in the connection portion is a light-emitting display device that is laterally connected to the second electrode. Claim 5 In claim 4, the common layer of the second stack comprises a first common layer provided on the lower side of the light-emitting layer provided in the second stack and a second common layer provided on the upper side of the light-emitting layer provided in the second stack, forming a light-emitting display device. Claim 6 In claim 1, the light-emitting layer provided in the light-emitting parts is a light-emitting display device having an edge portion spaced apart from the connection portion. Claim 7 A light-emitting display device according to claim 1, further comprising one or more stacks between the first charge generating layer and the second stack, and further comprising a second charge generating layer between the one or more stacks included between the first charge generating layer and the second stack and the second stack. Claim 8 In claim 1, the connection portion between the second electrode and the first charge generating layer is an island-shaped light-emitting display device between adjacent light-emitting portions. Claim 9 In claim 1, the connection portion between the second electrode and the first charge generating layer is a light-emitting display device in the shape of a closed ring surrounding one of the light-emitting portions. Claim 10 A light-emitting display device comprising: a substrate having a first light-emitting part and a second light-emitting part spaced apart from each other; a first anode and a second anode respectively provided in the first light-emitting part and the second light-emitting part; a first stack and a second stack provided on the substrate including the first anode and the second anode, with a charge-generating layer in between; and a cathode provided on the second stack and having a connection portion with the charge-generating layer between the first light-emitting part and the second light-emitting part, wherein the charge-generating layer extends continuously across the first light-emitting part and the second light-emitting part. Claim 11 In claim 10, the light-emitting display device further comprises a bank between the first and second light-emitting parts, wherein the bank covers the edges of the spaced-apart first anode and second anode, respectively, and the first stack, the charge generating layer, the second stack, and the cathode on the bank, wherein the second stack is removed from the connection part. Claim 12 In claim 10, the connection part is a light-emitting display device provided in an island shape, spaced apart from the first light-emitting part and the second light-emitting part, respectively. Claim 13 In claim 10, the connection portion between the cathode and the charge generation layer is a light-emitting display device in the shape of a closed ring surrounding one of the light-emitting portions. Claim 14 A light-emitting display device according to claim 10, wherein the first light-emitting part comprises a first light-emitting layer emitting a first color in the first stack and the second stack, and the second light-emitting part comprises a second light-emitting layer emitting a second color different from the first color in the first stack and the second stack. Claim 15 In claim 14, the first light-emitting layer and the second light-emitting layer are a light-emitting display device spaced apart from the connection part. Claim 16 A light-emitting display device according to claim 14, further comprising, on the substrate, a first common layer below the first light-emitting layer and the second light-emitting layer and a second common layer above the first light-emitting layer and the second light-emitting layer, extending across the region between the first light-emitting part and the second light-emitting part and the first and second light-emitting parts. Claim 17 In claim 16, the first common layer and the second common layer of the second stack are removed from the connection portion, and the cathode is directly connected to the charge generating layer through the connection portion, in a light-emitting display device. Claim 18 In claim 17, the first common layer and the second common layer of the second stack at the connection portion are laterally connected to the cathode in a light-emitting display device.

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