Display device and method of manufacturing the same

Abstract

The present invention relates to a display device and, more particularly, to a high-performance display device that ensures high transmittance and enhances efficiency in a manner that uses a mixture of an organic substance and an alkaline earth metal as a metal of a cathode and facilitates patterning.

Description

Technical Field

[0001] The present invention relates to a display device, and more particularly, to a display device and a method for manufacturing the same. Although the present invention is suitable for a wide range of applications, it is particularly suitable for ensuring high transmittance and improving efficiency by facilitating patterning in a manner using a metal containing a mixture of an alkaline earth metal and an organic substance as a cathode. Background Art

[0002] Recently, as the information age has fully arrived, the field of displays that visually display electrically transmitted information signals has been rapidly developed. In response to this, various flat panel display devices having excellent characteristics such as small thickness, low weight and low power consumption have been developed, and these flat panel display devices have rapidly replaced existing cathode ray tubes (CRTs).

[0003] Representative examples of such flat panel display devices may include a liquid crystal display (LCD) device, a plasma display panel (PDP) device, a field emission display (FED) device, an organic light emitting display (OLED) device, a quantum dot display device, and the like.

[0004] Among these devices, a self-luminous display device such as an organic light emitting display device or a quantum dot light emitting display device is regarded as a competitive application because it does not require a separate light source and enables compact device design and vivid color display.

[0005] In addition, the self-luminous display device includes a plurality of pixels on a substrate, and a light emitting diode having an anode electrode and a cathode electrode facing each other in each pixel and a light emitting layer between the anode electrode and the cathode electrode.

[0006] Since the self-luminous display device uses light emitted from a light-emitting diode to realize display, it is important to effectively use the amount of light emitted from the light-emitting diode. Therefore, many efforts are being made to reduce the thickness of the cathode electrode located in the light-emitting direction in order to increase the transmittance and improve the reliability of the cathode electrode and the configuration adjacent to the cathode electrode in terms of performance stability of the device.

[0007] In addition, the demand for a transparent display device capable of displaying an image in such a manner that light can be transmitted through the front and rear without interrupting the field of view is rising.

[0008] The transparent display device aims to obtain both a transparent display and a light-emitting display by making the arrangement of light-emitting diodes in the self-luminous area and the transparent area different.

[0009] However, since the self-luminous region and the transparent region need to give top priority to increase in efficiency of light emission and transmission, respectively, they require different structures due to different purposes, and thus are difficult to implement using a common formation method. Summary of the invention

[0010] Accordingly, the present invention is directed to a display device and a method of manufacturing the same that substantially obviate one or more problems due to limitations and disadvantages of the related art.

[0011] An object of the present invention is to provide a display device, and more particularly, to provide a display device suitable for ensuring high transmittance and improving efficiency by facilitating patterning in a manner using a metal including a mixture of an alkaline earth metal and an organic substance as a metal used as a cathode and a method for manufacturing the same.

[0012] Additional advantages, purposes and features of the present invention will be described in part in the following description, and will become apparent to those skilled in the art after reading the following, or may be learned through practice of the present invention. The purposes and other advantages of the present invention may be realized and obtained through the structures particularly pointed out in the written description and claims and the accompanying drawings.

[0013] The display device of the present invention enables deposition patterning of the cathode by changing the composition of the cathode, thereby ensuring both high transmittance and high efficiency.

[0014] To achieve these objectives and other advantages and in accordance with the purposes of the present invention, as implemented and broadly described herein, a display device according to one embodiment may include: an anode at each of a plurality of light-emitting portions of a substrate; a light-emitting layer disposed above each of the anodes; and a cathode above the light-emitting layer to overlap with the plurality of light-emitting portions of the substrate, the cathode comprising an alkaline earth metal and a fullerene compounded with the alkaline earth metal.

[0015] In another aspect of the present invention, as implemented and broadly described herein, a method for manufacturing a display device according to another embodiment may include the following steps: providing an anode at each of a plurality of light-emitting portions of a substrate; providing a light-emitting layer above each of the anodes; and providing a cathode by depositing a mixture of an alkaline earth metal and fullerene above the light-emitting layer.

[0016] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention.

[0018] Figure 1 FIG. 2 is a diagram showing the layout of a display device according to the present invention.

[0019] Figure 2 FIG. 2 is a diagram showing a layout of pixels of a display device according to a first embodiment of the present invention.

[0020] Figure 3 It is along Figure 2 A cross-sectional view taken along line II'.

[0021] Figure 4 2 is a layout of pixels of a display device according to a second embodiment of the present invention.

[0022] Figure 5 It is along Figure 4 A cross-sectional view taken along line II-II'.

[0023] Fig. 6A The fullerene C that can be used in the cathode of the display device of the present invention is shown in FIG. 60 Schematic diagram of an example of .

[0024] Figure 6B are diagrams showing various examples of fullerenes.

[0025] Figure 7 is a diagram showing fullerene derivatives that can be used in the cathode of the display device of the present invention.

[0026] Fig. 8A , Figure 8B , Figure 8C and Fig.8D : is a diagram showing an example of a complex formed between an alkaline earth metal and fullerene which can be used for a cathode of the display device of the present invention.

[0027] Fig. 9 is a diagram illustrating a method of forming a cathode in a display device according to a first embodiment of the present invention.

[0028] Fig.10 is a diagram illustrating a method of forming a cathode in a display device according to a second embodiment of the present invention.

[0029] Fig.11 The AgMg cathode and Mg-C 60 A graph showing the light emission characteristics of the cathode.

[0030] Fig.12The AgMg cathode and Mg-C cathode with different thickness are shown in FIG. 60 A graph showing the life characteristics of the cathode.

[0031] Fig.13 is a graph showing the JV characteristics of the Mg cathode according to the elapsed time.

[0032] Fig.14 It shows that Mg-C 60 A graph showing the JV characteristics of the cathode according to the elapsed time.

[0033] Fig.15A is a cross-sectional view of a display device according to a seventh test example.

[0034] Fig. 15B is a cross-sectional view of a display device according to an eighth test example.

[0035] Fig. 15C are cross-sectional views of display devices according to ninth to twelfth test examples.

[0036] Fig.16 FIG. 2 is a diagram showing a layout of a display device according to a third embodiment of the present invention.

[0037] Fig.17A and Fig. 17B is a layout of a modified example of the third embodiment of the present invention.

[0038] Fig.18 is a diagram showing the layout of a display device according to a fourth embodiment of the present disclosure.

[0039] Fig.19 It is along Fig.18 A cross-sectional view taken along line III-III'.

[0040] Fig. 20 is a cross-sectional view of a display device according to a fifth embodiment of the present invention.

[0041] Fig.21 is a graph showing the transmittance of the transmission portion at visible light wavelengths depending on the presence or absence of the cathode. DETAILED DESCRIPTION

[0042] Now, a description will be given in detail according to the exemplary embodiments disclosed herein with reference to the accompanying drawings. Throughout the specification, the same reference numerals basically refer to the same components. In the following description, if it is determined that the specific description of the technology or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description should be omitted. In addition, the component names used in the following description are selected in consideration of the convenience of preparing the specification, and may be different from the partial names of the actual product.

[0043] In the accompanying drawings for illustrating exemplary embodiments of the present invention, for example, the illustrated shapes, sizes, ratios, angles and quantities are given by way of example and are therefore not limited to the disclosure of the present invention. Throughout the specification, the same reference numerals designate the same constituent elements. In addition, in the following description of the present invention, when the detailed description of the known functions and configurations incorporated herein would make the subject matter of the present invention quite unclear, the detailed description will be omitted. The terms "comprising", "including" and / or "having" used in this specification do not exclude the presence or addition of other elements unless it is used together with the term "only". Unless the context clearly indicates otherwise, the singular form is intended to also include the plural form.

[0044] In the interpretation of the constituent elements included in the various embodiments of the present invention, the constituent elements are interpreted as including an error range even if it is not explicitly described.

[0045] In the description of various embodiments of the present invention, when describing a positional relationship, for example, when using "on", "above", "below", "beside", etc. to describe the positional relationship between two parts, one or more other parts may be located between the two parts, unless the term "directly" or "closely" is used.

[0046] In the description of various embodiments of the present invention, when describing a time relationship, for example, when using "after", "subsequently", "next", "before", etc. to describe the time relationship between two actions, these actions may not occur continuously unless the terms "directly" or "exactly" are used.

[0047] In the description of various embodiments of the present invention, although terms such as "first" and "second" may be used to describe various elements, these terms are only used to distinguish the same or similar elements from each other. Therefore, in this specification, unless otherwise mentioned, within the technical scope of the present invention, the element modified by "first" may be the same as the element modified by "second".

[0048] The corresponding features of various embodiments of the present invention can be partially or completely connected and combined with each other, and various technical connections and drives thereof are possible. These various embodiments can be performed independently of each other, or can be performed in association with each other.

[0049] The main feature of the display device of the present invention is that a cathode used as one electrode of a light-emitting device is formed in a substrate in the form of a mixture including an alkaline earth metal and fullerene. Since the cathode composed of a mixture of alkaline earth metal and fullerene produces a complex between some carbon atoms of the fullerene and the alkaline earth metal, a metal carbide is produced, thereby enhancing the electrode reliability. In addition, the transmittance that is reduced when a single Mg layer is used can be improved. In addition, considering that the deposition temperature in the alloy structure is as high as more than 500°C, when the cathode deposition temperature of the mixture structure becomes close to the organic deposition temperature, the FMM mask can be used for the deposition process and facilitates patterning.

[0050] Figure 1 FIG. 2 is a diagram showing the layout of a display device according to the present invention.

[0051] Reference Figure 1 , the display device 1000 according to the present invention includes a substrate 100, and the substrate 100 is divided into a display area AA (ie, inside a dotted line area) and a non-display area NA.

[0052] A plurality of pixels P are arranged in the display area AA. Figure 3 or Figure 5 ) and a thin film transistor configured to drive the light emitting device (e.g., Figure 3 or Figure 5 A TFT in the pixel ( ) is formed in each pixel P, whereby display is performed by the operation of the light-emitting device of each pixel.

[0053] The non-display area NA exists outside the display area AA. The pad portion PAD is located in some of the non-display areas and a pad electrode (not shown) is provided to the pad portion PAD, whereby a signal is applied from the outside through connection to a circuit film (not shown) or the like. Link lines extending from wiring provided in the display area AA are provided in the non-display area NA on the side or sides where the pad portion PAD is not formed, and are connected to the pad portion PAD. The circuit film is connected to a circuit board (not shown), whereby an electrical signal is transferred from the circuit board to the pad electrode side. The thin film transistors TFT1, TFT2, and TFT3 may be connected to first and second wirings (not shown) that intersect each other.

[0054] The substrate 100 may be transparent like glass or a transparent plastic film. Alternatively, the substrate 100 may include an opaque metal substrate. Figure 4), the substrate 100 may be formed of a material that is transparent enough for back transmission (e.g., a glass substrate, a transparent plastic film, etc.). Although the substrate 100 generally includes a transparent plastic film for the purpose of permanence or flexibility of the device in use, a glass substrate is suitable in a manner that reduces its own thickness.

[0055] Each pixel P includes one or more light emitting devices (eg, OLEDs), and a cover layer may be formed on the light emitting device (OLED) (see Figure 3 or Figure 5 "170" in the figure) to improve light extraction and protect the light emitting device (OLED).

[0056] In the display device according to the present invention, the cathode 140 is formed in all display areas AA and is formed in some of the non-display areas NA via the display area AA. The cathode 140 of the display device according to the present invention constitutes two electrodes of the light-emitting device (OLED) together with the anode 111. When the display device is used as a top-emitting device, it is important for the cathode 140 of the present invention to maintain the transmission capability. If the cathode 140 contains a metal, it should be a thin film. In addition, as Figure 1 As shown in , since the cathode 140 is formed separately in a manner that completely covers the display area AA, it is important to form a surface with uniform potential rather than deviation in each pixel area. For this purpose, the conductivity of the component constituting the cathode 140 should be higher than a predetermined level, and thus the component used for the cathode configuration is important. The cathode 140 of the present invention is formed in a manner that fullerene or a fullerene derivative is mixed with an alkaline earth metal, thereby aiming to ensure transparency and low resistance.

[0057] In addition, if Figure 1 As shown in FIG. 1 , the encapsulation layer 200 is formed on the display area AA and the non-display area NA except the pad portion PAD, thereby completely covering the cathode 140. The encapsulation layer 200 prevents moisture from penetrating from the outside and protects the array structure (including the thin film transistor) and the light emitting device (OLED) formed on the entire display area AA, and is formed to have a size larger than that of the cathode 140, which is one of the components of the light emitting device (OLED). Therefore, the encapsulation layer 200 can be formed in a manner of covering the top surface and the side surface of the cathode 140 of the light emitting device (OLED).

[0058] In some embodiments, the encapsulation layer 200 may be formed as a stacked layer including an inorganic encapsulation layer, an organic encapsulation layer, and an inorganic encapsulation layer. In addition, a pair of organic / inorganic encapsulation layers may be added. The inorganic encapsulation layer is at least further formed outside the organic encapsulation layer, thereby enabling the inorganic encapsulation layer to prevent external moisture from penetrating. The organic encapsulation layer is configured to cover particle flows or internal particles caused by internal gas according to environmental conditions during processing.

[0059] The cathode 140 has a wiring connected to the pad portion PAD and a prescribed contact portion (not shown) on the substrate 100 , thereby receiving a ground signal or a predetermined voltage signal from the pad portion PAD.

[0060] In contrast to the anode 111 formed separately for each subpixel SP, the cathode 140 is formed in an integrated manner for the entire display area AA. In order to maintain a predetermined potential without difference per area for stable operation of the organic light emitting device (OLED), it is important to keep the cathode 140 low in resistance.

[0061] Hereinafter, according to various embodiments of the present invention, a display device according to a specific embodiment of the present invention is described with reference to cross-sectional views.

[0062] Figure 2 is a diagram showing a layout of pixels of a display device according to a first embodiment of the present invention, and Figure 3 It is along Figure 2 A cross-sectional view taken along line II'.

[0063] Figure 2 and Figure 3 The display device according to the first embodiment of the present invention may include: an anode 111, which is arranged in each of the multiple light-emitting portions E1, E2 and E3 of the substrate 100; a light-emitting layer 132a / 132b / 132c, which is arranged on the corresponding anode 111; and a cathode 140, which contains an alkaline earth metal and a fullerene complexed with the alkaline earth metal on the light-emitting layer in a manner overlapping with the multiple light-emitting portions of the substrate 100.

[0064] The light emitting device OLED is disposed in each of the light emitting parts E1, E2 and E3, thereby emitting light. The type of the light emitting device OLED may include an organic light emitting device OLED or an inorganic light emitting device OLED according to whether the internal light emitting layer is an organic light emitting layer or an inorganic light emitting layer, but the present invention is not limited thereto.

[0065] The light emitting device OLED includes an anode 111, an organic stack EL, and a cathode 140. Anodes of corresponding light emitting portions E1 / E2 / E3 are connected to corresponding thin film transistors TFT1 / TFT2 / TFT3, thereby receiving electrical signals.

[0066] like Figure 2 As shown in FIG. 1 , the pixel P may include a blue light emitting portion E1 , a red light emitting portion E2 , and a green light emitting portion E3 , or alternatively a combination of other colors. The pixel P shown in the figure may be repeated in a matrix in the display area AA of the substrate 100 .

[0067] For example, the light-emitting parts E (i.e., E1, E2, and E3) may be arranged in parallel in the same row. Alternatively, the light-emitting parts E may be arranged in a diagonal direction. Alternatively, the light-emitting parts E may be arranged in a manner having different arrangements in a column. Although the light-emitting parts E have the same size, the present invention is not limited thereto. Alternatively, the light-emitting parts E may have different sizes according to the expected characteristics of the display device to be displayed, which can be changed by weighting or subtracting a specific light-emitting part. The shape of the light-emitting parts E (i.e., E1, E2, and E3) is rectangular in the figure, and the present invention is not limited thereto. Alternatively, the shape of the light-emitting parts E (i.e., E1, E2, and E3) may be polygonal or elliptical, or at least some of the corners of the light-emitting parts E may be rounded. In some cases, the corners of the light-emitting parts E (i.e., E1, E2, and E3) may be arranged in a manner adjacent to each other at a predetermined distance from each other.

[0068] The arrangement of the light-emitting parts E1, E2 and E3 of the light-emitting part E that emit light of different colors may include, for example, the blue, green and red sub-pixels mentioned above, but the present invention is not limited thereto. The light-emitting part E may also include a white light-emitting part WE. The blue / green / red arrangement of the light-emitting part E may be replaced by other arrangements (e.g., cyan / magenta / yellow, etc.). In addition, the light-emitting part E may have an arrangement of other color combinations of the light-emitting part.

[0069] Although the following description is mainly proposed for the case of applying to an organic light-emitting device using an organic light-emitting layer as a light-emitting layer, the case of setting a quantum dot light-emitting device (QLED) to the light-emitting part by changing the organic light-emitting layer into a layer including a quantum dot light-emitting layer is applicable to the display device of the present invention.

[0070] In addition, the region may be defined in such a manner that the bank 150 is provided around the light emitting portion E (ie, E1 , E2 , and E3 ) and the transmission portion T. The bank 150 may partially overlap the edge of the anode 111 .

[0071] The organic stacked EL includes a light-emitting layer 132a / 132b / 132c that generates a large amount of light emission through the recombination of holes and electrons, a hole transport layer (HTL) 131 that transports holes from the anode 111 to the light-emitting layer 132a / 132b / 132c, and an electron transport layer (ETL) that transports electrons from the cathode 140 to the light-emitting layer 132a / 132b / 132c.

[0072] A hole injection layer (not shown) may be further included between the hole transport layer 131 and the anode 111, and an electron injection layer 134 may be included between the electron transport layer 133 and the cathode 140. The electron injection layer 134 may include an inorganic compound such as an alkaline compound or a lanthanide metal without including an organic substance, and may be formed in the process of forming the cathode 140.

[0073] The hole injection layer and the electron injection layer 134 may be omitted. In certain embodiments, each of the hole transport layer 131 and the electron transport layer 133 may be formed as a multilayer by being endowed with different functions.

[0074] The bank 150 is formed in a region of each pixel P where the light emitting parts E1 , E2 , and E3 are not provided. The light emitting parts E1 , E2 , and E3 may be defined as an opening region of the bank 150 .

[0075] In addition, a cover layer 170 is further disposed on the light emitting device OLED to protect and extract light therefrom, and an encapsulation layer 200 is formed on the cover layer 170 to prevent external moisture from penetrating the light emitting device OLED and thin film transistors TFT1, TFT2 and TFT3 and protect them.

[0076] Although the configuration of the light emitting device OLED of each of the light emitting parts E1, E2 and E3 and its optical effect are described from Figure 3 The bank 150 is omitted, but the bank 150 partially overlapping the edge of the anode 111 may be further formed after forming the anode 111 and before forming the organic stack EL to define the light emitting portions E1, E2, and E3.

[0077] Figure 4 is a layout of pixels of a display device according to a second embodiment of the present invention, and Figure 5 It is along Figure 4 A cross-sectional view taken along line II-II'.

[0078] like Figure 4 and Figure 5 As shown in FIG. 1 , the display device according to the second embodiment of the present invention further includes a transmission portion T provided in the pixel P in addition to the light emitting portions E1 , E2 , and E3 , each of which is a sub-pixel. Figure 4 The structure of the pixel P shown in FIG. 1 may be repeatedly arranged in Figure 1 In the display area AA of the substrate 100 shown in FIG.

[0079] In the display device according to the second embodiment of the present invention, as Figure 5 As shown in , the cathode 240 may be patterned in such a manner that the transmission portion T is not included.

[0080] By doing so, since the cathode 240 is not included in the light path traveling in the transmission portion T, an increase in light transmittance occurs due to the amount of light absorption occupied by the metal component included in the cathode 240. In this case, since in the transmission portion T, the components of the thin film transistor TFT, the anode 111, the light emitting layers 132a, 132b and 132c, and the cathode 240 are not included in the light path, and more specifically, an electrode component having reflectivity is not included, light sufficient to be observed from the back side of the substrate 100 passes through the encapsulation layer 200 from the bottom of the substrate 100, as compared with the light emitting portions E1, E2, and E3.

[0081] In the display device according to the second embodiment of the present invention, the configuration of the light emitting sections E (ie, E1 , E2 , and E3 ) is the same as that of the above-mentioned first embodiment, and the description thereof will be omitted.

[0082] Furthermore, since the bank 150 is omitted in the transmission portion T, this helps the transmission capability.

[0083] In the display device according to the second embodiment of the present invention, as Figure 4 As shown in , the bank 150 may be configured to expose and separate the light emitting portion and the transmission portion, respectively.

[0084] according to Figure 2 and Figure 3 A display device according to a first embodiment of the present invention and Figure 4 and Figure 5 The display device of the second embodiment of the present invention may both include a cathode 140 / 240 overlapping with the plurality of light emitting portions E1 , E2 , and E3 of the substrate 100 and including an alkaline earth metal and fullerene composited with the alkaline earth metal.

[0085] Hereinafter, fullerene used for the cathode of the present invention is described.

[0086] Fig. 6A The figure shows the fullerene C that can be contained in the cathode component of the display device of the present invention. 60 , and Figure 6B are diagrams showing various examples of fullerenes. Figure 7 This is a diagram showing fullerene derivatives that can be contained in the cathode component of the display device of the present invention. Fig. 8A , Figure 8B , Figure 8C and Fig.8D : is a diagram showing an example of a complex formed between an alkaline earth metal and fullerene which can be used for a cathode of the display device of the present invention.

[0087] like Fig. 6A and Figure 6BAs shown in , fullerene is an organic compound of carbon and has a three-dimensional shape that forms a stable form in a spherical or oval shape or the like. In fullerene, a pentagonal or hexagonal carbon bonding structure is repeated on a three-dimensional surface, and carbon is located at the position of each vertex of the pentagon or hexagon.

[0088] Fullerene has structural symmetry because its carbon-bonding structure is not unilateral, and also has high stability due to the properties of delocalized π (pi) electrons from spherical or elliptical shapes.

[0089] like Fig. 6A As shown in , a typical example of fullerene is C 60 , the fullerene used as a component of the cathode of the display device of the present invention is not limited thereto. 20 The spherical or oval carbon aggregates with delocalized π electron characteristics can be changed to have different 60 Another structure with the number of carbon atoms. For example, fullerene can be realized as C 20 , C 24 , C 28 , C 32 Such includes carbon forms having 20 or more carbon atoms.

[0090] Figure 6B By making the number of carbon atoms similar to that of fullerene C 60 Different from the C 32 , C 50 , C 70 , C 76 , C 78 , C 84 , C 120 and C 180 Examples of such fullerenes. The number of hexagonal and pentagonal bonding structures that fit the spherical or oval surface of the fullerene can vary as the number of carbon atoms in the fullerene changes. In addition, even the same number of carbon atoms can slightly change the three-dimensional shape of the fullerene, depending on the nature of the orbital bonding.

[0091] Figure 7 A fullerene derivative is shown as an n-type fullerene derivative having high electron mobility.

[0092] Contains PCBM (6,6-phenyl C 61 butyrate) as an isomer and a single C 60 Fullerene derivatives can also be used as a component contained in the cathode of the present invention.

[0093] Thus, forming a cathode by including a fullerene derivative in an alkaline earth metal may have the advantage of increasing the electron injection characteristics in the cathode. In certain embodiments, if the cathode itself contains an organic fullerene derivative and the electron permeability of the fullerene derivative is high, it may be possible to omit Figure 3 or Figure 5 The organic light emitting device is realized in the form of the electron injection layer 134. In this case, the cathode may be in direct contact with the electron transport layer 133.

[0094] In addition, when forming the cathode, the organic fullerene and the alkaline earth metal are co-deposited by containing them in a single crucible. In doing so, the substances are supplied in such a manner that the content of the alkaline earth metal is greater than that of the organic fullerene, and more preferably, the ratio of the alkaline earth metal to the organic fullerene is 10:1 to 20:1. After formation, the fullerene may be contained in a content of 1 vol% to 10 vol% of the total volume of the cathode.

[0095] In the cathode 140, the alkaline earth metal controls the conductivity and reflectivity of the cathode 140 that can cause reflection resonance of a strong cavity characteristic between the anode 111 and the cathode 140 in the light emitting device (OLED), and should be contained more than fullerene or a fullerene derivative when considering the electro-optical function of the cathode 140. Therefore, in the entire structure of the cathode 140, the alkaline earth metal becomes a main component, and the fullerene or a fullerene derivative may be included in the alkaline earth metal as a dopant.

[0096] exist Figures 1 to 5 In the display device according to the present invention, light emitted from the light emitting layer 132a / 132b / 132c is finally projected toward the cathode 140 through resonance and reflection between the anode 111 and the cathode 140. For this purpose, a reflective electrode of Al, Al alloy, Ag, Ag alloy, Mg, Mg alloy, APC (Ag-Pd-Cu), etc. may be included in the anode 111. The cathode 140 contains an alkaline earth metal having a reflective transmission capability to achieve final light transmission.

[0097] In the display device, the alkaline earth metal used for the cathode 140 includes at least one of Mg, Ca, Be, Sr, Ba, and Ra.

[0098] Furthermore, when the alkaline earth metal M and the fullerene are co-deposited to form a layer of the cathode 140, the carbon atoms contained in the fullerene may form a complex with the alkaline earth metal M ( Fig. 8A ) or the in-situ carbon (C) atom can form a complex with the alkaline earth metal M by breaking the double bond ( Figure 8B ). Alternatively, Figure 8C As shown in , when the alkaline earth metal M is located between fullerene monomers, the carbon atoms of the two monomers and the alkaline earth metal M can be combined together. In other configurations, such as Fig.8D As shown in , the alkaline earth metal M enters the three-dimensional structure to form a complex with at least one carbon atom on the surface.

[0099] In some implementations, Figure 7 In the complex of the fullerene derivative and the alkaline earth metal shown in , the functional group of the fullerene derivative and the alkaline earth metal can be complexed together, at least one carbon atom on the surface of the fullerene derivative and the alkaline earth metal can be complexed together, or the alkaline earth metal can enter the three-dimensional structure of the fullerene derivative and then form a complex with the adjacent carbon atom.

[0100] Therefore, according to the display device of the present invention, when the cathode is formed by the compound of fullerene and alkaline earth metal, an alkaline earth metal composite structure is generated in the cathode. Therefore, due to the metal doping effect, the interface resistance is reduced and the conductivity of the cathode is improved. When the carbon of the fullerene is compounded with the alkaline earth metal, it acts as a metal carbide, thereby increasing the conductivity and stabilizing the layer characteristics. Therefore, surface stability and reliability can be enhanced. In addition, since alkaline earth metal is included as the main component of the cathode, the low resistivity of the alkaline earth metal can be maintained. In addition, in the cathode 140, the metal carbide (MC2 or Mg2C3) produced by the compound between the carbon atom and the alkaline earth metal can be changed according to the fullerene content.

[0101] In the display device of the present invention, since each light emitting portion is implemented to have a strong cavity effect, the thicknesses of the corresponding light emitting layers 132a, 132b and 132c between the anode 111 and the cathode 140 may be different from each other for optimal resonance effect.

[0102] In addition, the alkaline earth metal and fullerene or fullerene derivative contained in the cathode of the present invention have similar deposition temperatures below 500°C. In this case, since the alkaline earth metal is a metal but has a low deposition temperature, cathode deposition is possible at the heat-resistant temperature of the FMM mask, and a cathode that can be patterned can be formed during the deposition process. On the other hand, when a cathode containing a metal such as Ag is formed, since the corresponding deposition temperature is 800°C or higher, deformation occurs when using a fine metal mask (FMM). Therefore, patterning is impossible.

[0103] In addition, when forming a cathode including a metal such as Ag, another metal with a low deposition temperature can be used as an additional metal. In this case, since the evaporation points are different, it is impossible to use them in the same source, thereby disadvantageously requiring the use of separate crucibles.

[0104] The cathode of the display device according to the present invention uses alkaline earth metal and organic substance fullerene having similar deposition temperatures below 500° C., thereby enabling the same crucible to be used. Therefore, alkaline earth metal and fullerene can be co-deposited in a manner of being included in the same source as a mixture.

[0105] Hereinafter, a method of forming the cathode of the display device according to the first embodiment is described.

[0106] Fig. 9 is a diagram illustrating a method of forming a cathode in a display device according to a first embodiment of the present invention.

[0107] Reference Fig. 9 In the display device according to the first embodiment, the cathode 140 is formed to cover the light emitting parts E1, E2 and E3 of each sub-pixel P provided in the display area AA. Since the cathode 140 is formed in the entire display area AA, it is not necessary to use an FMM deposition mask. Therefore, by supplying fullerene C from different sources 510 and 520, respectively, 60 By maintaining the evaporation conditions of the sources 510 and 520 the same or similar to those of an alkaline earth metal such as Mg, the cathode material can be completely formed on the substrate 500 .

[0108] Here, reference numeral 600 refers to a stage on which the substrate 500 is fixed within a chamber (not shown), and a deposition process is performed on the stage 600 .

[0109] Fig.10 is a diagram illustrating a method of forming a cathode in a display device according to a second embodiment of the present invention.

[0110] Reference Fig.10 In the display device according to the second embodiment of the present invention, in addition to the light-emitting parts E1, E2 and E3, the pixel P also includes a transmission part T. In order to increase the transmittance of the transmission part, an FMM mask 910 with an area other than the transmission part T as an opening area OP can be used to selectively deposit the cathode material only on the non-transmission part. Here, the reason why the FMM mask 910 can be used is that the fullerene C 60 It has a deposition temperature similar to that of alkaline earth metals (Mg), which is 500°C or lower.

[0111] In addition, due to the fullerene C 60 The deposition temperature of the fullerene substance and the alkaline earth metal (Mg) are close to each other, so the fullerene substance and the alkaline earth metal are supplied in a divided manner in the same source 930, evaporated by the same crucible supplying heat to the same source, and deposited on the opening area OP in the FMM mask 910, thereby the cathode (see Figure 5”240” in FIG. 2 may be formed in a region other than the transmission portion T. In this case, as Figure 4 As shown in the layout of FIG. 1 , the cathode 240 is integrated at least in the display area ( Figure 1 AA in the .

[0112] Regarding the display device according to the second embodiment of the present invention, Fig.10 As shown in , when the cathode is formed of a mixture of an alkaline earth metal and fullerene or a mixture of an alkaline earth metal and a fullerene derivative, since the deposition temperature is as low as the temperature at which the light emitting layer or the common layer is deposited, a deposition chamber can be used in common and process convenience can be ensured.

[0113] Hereinafter, the characteristics of the mixed structure of the alkaline earth metal and the fullerene derivative used for the cathode of the present invention are described by tests.

[0114] In the test, for example, magnesium was representatively used as an exemplary alkaline earth metal and fullerene C was used. 60 As an exemplary fullerene.

[0115] First, the first test case applies a thickness of The AgMg alloy was used as the cathode, and the second test example applied a thickness of AgMg alloy as the cathode. 60 For cathode, 5 vol% C 60 Doping is performed and the thickness is divided into and The driving voltage, efficiency and time T95 until the luminance drops to 95% of the initial value are respectively compared with the values ​​of the first test example. The shift voltage ΔV is a value obtained by implementing the cathode according to each test example and measuring the change by keeping it at 100° C. for 240 hours.

[0116] [Table 1]

[0117]

[0118] Fig.11 The AgMg cathode and Mg-C 60 A graph of the luminescent characteristics of the cathode, and Fig.12 The AgMg cathode and Mg-C cathode with different thickness are shown in FIG. 60 A graph showing the life characteristics of the cathode.

[0119] As shown in Table 1, since high-conductivity Ag is not used, the efficiency of the third to sixth test cases is reduced by about 10% compared with the first test case. However, it can be observed that the third to sixth test cases have a level close to that of the second test case in which the thickness of AgMg is thinned. In addition, it can be confirmed that the lifespan or the level of the shift voltage of the third to fifth test cases is close to that of the first test case.

[0120] like Fig.11 As shown in , it can be confirmed that the brightness spectra in the first test case and the fourth test case are equal or similar. Fig.12 As shown in , it can be observed that the lifespans are almost equal in the first test case and the third to fifth test cases.

[0121] That is, like the cathode of the present invention, when a mixed structure of an alkaline earth metal and a fullerene derivative is used, the efficiency, life and shift voltage characteristics are similar to those of the first test example. Therefore, it can be obtained that the functional level of the AgMg cathode is similar to that of a metal alloy using an alloy including an organic substance and an alkaline earth metal rather than an alloy including an alkaline earth metal and other metals.

[0122] In the following tests, the cathode of a single alkaline earth metal layer and the alkaline earth metal and C were examined by referring to the lifetime characteristics. 60 High temperature reliability of the cathode in the hybrid structure. Fig.13 and Fig.14 In the test, the JV characteristics were examined by keeping the cathode at 100°C for 250 hours.

[0123] Fig.13 is a graph showing JV characteristics according to the elapsed time of the Mg cathode, and Fig.14 It is shown that according to Mg-C 60 A graph showing the JV characteristics of the cathode over time.

[0124] Reference Fig.13 , when a single-layer Mg cathode is used, even for the same current density of 10 mA / cm 2 , after 50 hours, the shift voltage was also 8.9 V or higher, which means that normal operation is impossible. That is, this means that in the case of applying the Mg single layer, the interface uniformity on the organic stacked EL is reduced due to weak bonding force.

[0125] On the other hand, referring to Fig.14 When using Mg-C 60 At the cathode, the shift voltage was equal to or lower than 0.4 V after 0 h, 50 h, or 250 h, indicating that the Mg-C 60In the case of the hybrid cathode, high temperature reliability is significantly enhanced.

[0126] Table 2 below shows the FIG. 15A to FIG. 15C Transparency, sheet resistance, lifespan, and high-temperature reliability in the structures of various test examples of the transparent display device configured in FIG.

[0127] Fig.15A is a cross-sectional view of a display device according to a seventh test example, Fig. 15B is a cross-sectional view of a display device according to an eighth test example, and Fig. 15C are cross-sectional views of display devices according to ninth to twelfth test examples.

[0128] Together, according to Fig.15A The display device of the seventh test example shown in Fig. 15B The display device of the eighth test example shown in Fig. 15C The display devices of the ninth to twelfth test examples shown in the figure have the same stacked structure, which consists of an anode 111, an organic stacked EL, a cathode 40a / 40b / 140, an electron injection layer 34 / 134, a covering layer 170, and a three-layer stack including a first inorganic encapsulation layer 201, an organic encapsulation layer 202, and a second inorganic encapsulation layer 203.

[0129] Here, as in the test case Fig.15A The display device of the seventh test example has a thickness of The electron injection layer 34 is formed of Yb:LiF. In the eighth to twelfth test examples, only the same thickness Yb forms the electron injection layer 134 .

[0130] In the cathode 40a / 40b / 140, the respective test cases are different from each other. Fig.15A In the seventh test case, only the thickness AgMg forms cathode 40a. Fig. 15B In the eighth test example, only the thickness The cathode 40b is formed by Mg. Fig. 15C The ninth test example, the tenth test example, and the twelfth test example commonly set the thickness Mg:C 60 , but C 60 The doping amounts of C are respectively 3 vol%, 5 vol% and 8 vol%. 60 The doping amount is set to 5 vol%, and Mg:C 60 The thickness is set to

[0131] The display devices of the seventh to twelfth test examples have the same configuration except for the cathode 40 a / 40 b / 140 and the electron injection layer 134 .

[0132] [Table 2]

[0133]

[0134] Referring to Table 2, since the AgMg of the seventh test example becomes thick The Mg cathode of the eighth test example or the Mg:C cathode of the twelfth test example having a relatively low deposition temperature contains Ag which requires high temperature deposition, so it is impossible to apply the FMM mask. 60 The cathode can be Figure 4 In this way, it is deposited and realized in a manner that no cathode is provided for the transmission portion T. Thus, it can be seen that the aperture ratio is ensured according to the aperture ratio of the transmission portion.

[0135] Referring to Table 2, in the case of the Mg single-layer cathode of the eighth test example, Fig.13 In the inspection, since the shift voltage ΔV is 8.9 V, high temperature reliability cannot be ensured.

[0136] On the contrary, as in the display device of the present invention, when the fullerene C of the ninth to twelfth test examples is applied 60 When the cathode is a mixture with Mg, FMM patterning can be used for each of the cathodes, and a considerable opening ratio can be ensured for the transmission part by the cathode patterning in the transmission part, a lifespan exceeding 90% of the seventh test case can be ensured, and the shift voltage ΔV is equal to or less than 0.5V in the ninth to twelfth test cases, so that the high temperature stability can have a level similar to that of the AgMg thin layer (seventh test case).

[0137] However, when increasing the fullerene C in alkaline earth metals such as Mg 60 In the case of a doping amount of , the sheet resistance tends to increase. If the yield is also considered, the fullerene C used for the cathode of the present invention 60 The doping amount is preferably equal to or less than 10 vol%. In order to solve the problem of reduced high temperature reliability in the case of using a Mg single layer, about 1 vol% or more of fullerene should be contained in the cathode because sufficient fullerene needs to be contained to have a predetermined degree of recombination with Mg.

[0138] That is, in the display device of the present invention, with respect to the cathode formed of a mixture of an alkaline earth metal and fullerene, the content of fullerene may be roughly in the range between 1 vol% and 10 vol%.

[0139] In addition, through the above-mentioned test, it was confirmed that the display device of the present invention has an absolute advantage that patterning can be performed using an FMM mask, which is impossible for the thin film cathode of the seventh test example.

[0140] Hereinafter, an example in which the shapes of the light emitting section and the transmission section in the display device of the present invention are different from those in the second embodiment is described.

[0141] Fig.16 is a diagram showing a layout of a display device according to a third embodiment of the present invention, and Fig.17A and Fig. 17B is a layout of a modified example of the third embodiment of the present invention.

[0142] Reference Fig.16 In the display device according to the third embodiment of the present invention, the transmission portion T may be configured in an octagonal shape having 8 sides in such a manner that each corner of the virtual rectangular shape of the transmission portion T is cut. The first light emitting portion E1 may be adjacent to two of the four sides inclined with respect to the X-axis (not shown), and the third light emitting portion E3 may be adjacent to the rest.

[0143] In addition, the second light emitting portion E2 may be located between the first light emitting portion E1 and the third light emitting portion E3 in a manner adjacent to the flat side of the transmission portion T in parallel with the X-axis direction.

[0144] The first light-emitting portion E1, the second light-emitting portion E2, and the third light-emitting portion E3 located around the transmission portion T may emit light of different colors, respectively. The size of each of the first light-emitting portion E1 and the third light-emitting portion E3 is relatively larger than the size of the second light-emitting portion E2. If there is a light-emitting color with a certain weight in the color expression pursued by the display device, each of the first light-emitting portion E1 and the third light-emitting portion E3 may be set as a light-emitting portion with a larger size. Each of the first light-emitting portion E1 and the third light-emitting portion E3 may be hexagonal, and the second light-emitting portion E2 may be rectangular.

[0145] The bank 150 may be provided between the first, second, and third light emitting portions E1, E2, and E3 and between the transmission portion T and the first, second, and third light emitting portions E1, E2, and E3.

[0146] In the third embodiment of the present invention, the cathode 240 is disposed in a manner not to overlap with the size of the transmission portion T.

[0147] In this case, the cathode 240 may have the same transmittance according to the size of the aperture ratio of the transmission portion T to the substrate 100 .

[0148] Reference Fig.17A and Fig. 17B, illustrates a display device according to a modification of the third embodiment of the present invention. The cathode 240a / 240b is configured to partially overlap the transmission portion T in the X / Y axis direction. In this case, part of the width of the transmission portion T is left as an opening area in the cathode 240a. Fig.17A The example shown in exemplifies that the cathode 240a is formed as a strip extending in the X-axis direction in such a manner as to have the same length as the first light emitting portion E1 or the third light emitting portion E3. Fig. 17B The example shown in FIG. 2 shows a strip extending in the Y-axis direction in a manner having the same width as the first light emitting portion E1 or the third light emitting portion E3. These are merely exemplary, and the conductivity of the cathode can be adjusted by controlling the overlap width between the transmissive portion and the cathode.

[0149] [Table 3]

[0150]

[0151] Referring to Table 3, in the case of the AgMg thin film cathode, since the deposition temperature of Ag is high as described above, complete deposition using the FMM mask is difficult. Therefore, when the cathode is completely deposited and overlapped in the transmission area, in the case where the aperture ratio of the transmission part of the panel is 55% or 65%, the transmittance of the transmission part should consider the transmittance of the single layer occupied by the cathode on the light path. If the corresponding thickness increases, the transparency decreases. On the other hand, in the case of a cathode thin layer comprising a mixture of fullerene and alkaline earth metal according to the present invention, when Fig.16 When the cathodes do not overlap in the entire area of ​​the transmission portion of the third embodiment shown in FIG. 1 , the transmittance of the transmission portion can follow the aperture ratio of the transmission portion of the panel.

[0152] like Fig.17A or Fig. 17B As shown in , in the case where the conductivity of the entire cathode size is overlapped with the predetermined width of the transmission part in consideration of the conductivity of the entire cathode size, when 70% or more of the size of the transmission part does not overlap with the cathode, it can be confirmed that the panel transparency is high compared with the case of overlapping with the entire AgMg cathode film. In particular, due to Figures 16 to 17B The thickness shown in The AgMg cathode realized by the thin film has improved conductivity compared with the case where the transmission portion is provided to the cathode, so the third embodiment of the present invention and its modified example have advantages of enhanced device efficiency and enhanced transparency.

[0153] like Fig.17A and Fig. 17BAs shown in , in a modification of the third embodiment, the inventors of the present invention have confirmed excellent transparency when the cathode 240a / 240b is overlapped with the transmission portion in such a manner that the size of the cathode 240a / 240b is 1 / 4 or less of the total size of the transmission portion on the substrate.

[0154] Hereinafter, in the display device according to the present invention, examples in which patterning of the cathode is applied in various ways are described.

[0155] Fig.18 is a diagram showing a layout of a display device according to a fourth embodiment of the present invention, and Fig.19 It is along Fig.18 A cross-sectional view taken along line III-III'.

[0156] Reference Fig.18 and Fig.19 , the display device according to the fourth embodiment of the present invention shows an example in which the camera 700 is located below the substrate 100. In this case, in order to improve the camera recognition rate in the area where the camera 700 is located, it is intended to omit the configuration for absorbing light from the configuration of the camera top.

[0157] That is, for this purpose, the cathode 440 is patterned in such a manner as to be spaced apart from the camera area CA by a predetermined distance.

[0158] A back plate 660 may be further disposed under the substrate 100 for backside protection.

[0159] In the display device according to the fourth embodiment of the present invention, the cathode 440 formed of a mixture of fullerene and alkaline earth metal can be patterned due to its low deposition temperature. In addition, the cathode 440 may be configured in a manner of being spaced apart from the region of the camera 700.

[0160] Here, the camera 700 includes a camera lens CLZ, a camera module MD supporting and protecting the camera lens CLZ, and a camera circuit board CCB on which the camera module MD is mounted.

[0161] The camera circuit board CCB may be disposed under the back plate 600 by extending around the camera module MD.

[0162] A blank area BZ having a predetermined distance may be provided between the camera area CA and the light emitting portion E. The winding wire 107a passing by avoiding the camera area CA may be partially arranged in the blank area BZ.

[0163] A buffer layer 105 , a thin film transistor TFT and an interlayer insulating layer 108 / 109 are formed on the substrate 100 in an area corresponding to the light emitting portion E, the anode 111 is arranged to be connected to the thin film transistor TFT, and the embankment 150 is arranged to overlap with an edge of the anode 111 .

[0164] A hole transport layer 131, a light emitting layer 132a / 132b, an electron transport layer 133, and a cathode 440 are sequentially formed on the anode 111, thereby constituting a light emitting device (OLED).

[0165] Here, the hole transport layer 131 and the electron transport layer 133 without using the FMM mask may be formed in such a manner as to extend to the blank area BZ and the camera area CA.

[0166] As described above, the cathode 440 may be patterned in such a manner as to be spaced apart from the camera area CA.

[0167] The capping layer 170 is formed on the cathode 440, thereby protecting the light emitting device (OLED) and enhancing light projection characteristics.

[0168] The capping layer 170 may be formed to protect the cathode 440 in the blank region BZ.

[0169] The structure of the encapsulation layer 300 may be formed on the capping layer 170 in such a manner that the first inorganic encapsulation layer 301 , the organic encapsulation layer 302 , and the second inorganic encapsulation layer 303 are sequentially deposited.

[0170] Here, in the encapsulation layer 300 , the organic encapsulation layer 302 may be partially omitted from the bezel area BZ and the camera area CA in order to achieve moisture permeability stability of the thinned camera area CA.

[0171] In this case, since the first and second inorganic encapsulation layers 301 and 303 are formed on the cover layer 170 , the top and side surfaces of the cathode 440 around the camera area CA may be protected by the cover layer 170 , the first and second inorganic encapsulation layers 301 and 303 .

[0172] In some implementations, a protective film 750 may be further disposed on the top surface of the display device. A polarizer 740 is adhered to the inner surface of the protective film 750 through an adhesive layer 745, thereby protecting external light reflection.

[0173] A touch functional layer or an optical functional layer 800 may be further included between the polarizing plate 740 and the second inorganic encapsulation layer 303 .

[0174] The touch function layer or the optical function layer 800 is formed to cover the camera area CA and the bezel area BZ.

[0175] Fig. 20 is a cross-sectional view of a display device according to a fifth embodiment of the present invention.

[0176] In some embodiments, as a modification of the display device according to the fourth embodiment, the camera 700 may be inserted with a predetermined thickness by removing a portion of the thickness of the substrate 100 .

[0177] Reference Fig. 20 The display device according to the fifth embodiment of the present invention is configured in such a manner that a hole 100a is formed in the substrate 100 and a camera is inserted into the hole 100a. The hole 100a is provided in the back plate 600 and the substrate 400. In this case, the cathode 440 can be patterned while being deposited with a mixture of an alkaline earth metal and fullerene.

[0178] The electron transport layer 133 and the hole transport layer 131 as elements of the light emitting device under the cathode may be omitted from the camera area CA and the bezel area BZ to prevent the risk of moisture penetration due to light exposure in the camera area CA.

[0179] Hereinafter, in the display device of the present invention, the transmittance for visible light wavelengths depending on the presence or absence of a cathode in a transmission portion is described.

[0180] [Table 4]

[0181]

[0182] Fig.21 is a graph showing the transmittance of the transmission portion at visible light wavelengths depending on the presence or absence of the cathode.

[0183] In Table 4, when the cathode is removed from the transmission portion, the transmittance increases by 30% or more at all visible light wavelengths. Fig.21 The transmittance shown in is increased by up to 97% relative to the transmittance of the transmission portion and high transmittance is maintained in all wavelength bands, so there is almost no transmittance difference between wavelengths, thereby making it possible to advantageously prevent color shift.

[0184] As mentioned in the foregoing description, when a mixture of an alkaline earth metal and fullerene is applied as the cathode of the present invention, patterning is facilitated to enable high transmittance to be achieved and to enable a light emitting device to operate stably.

[0185] In addition, when an alkaline earth metal and fullerene are mixed together, the inventors of the present invention confirmed that the formation of an oxide layer due to a reaction between a monolayer of the alkaline earth metal and oxygen is reduced.

[0186] In the process of forming a single Mg layer and Mg and fullerene C 60After the mixed layer of MgO, the bonding energy of each layer was measured. In the single Mg layer, it was confirmed that the MgO peak became dominant. However, in the case of Mg and fullerene C 60 In the mixed layer, it was confirmed that the peak of pure Mg was dominant, thereby improving the oxidation resistance.

[0187] In addition, since the cathode needs to be implemented as a thin film to maintain the transmittance, a transition metal such as Ag causes a problem in that a polymerization effect occurs due to forming a single layer, whereby the surface characteristics become irregular. Therefore, it is difficult to directly apply such a cathode to a display device.

[0188] In order to ensure high transmittance and low resistivity of the cathode, the display device of the present invention proposes to form the cathode 140 with a mixture of some carbon atoms in fullerene and alkaline earth metal instead of a single metal material, and more specifically, utilizes the advantage that the transmission portion patterning can be performed due to the low deposition temperature of these materials.

[0189] Therefore, the display device and the method for manufacturing the same according to the present invention have the following effects and / or advantages.

[0190] First, a cathode is formed using a mixture of an alkaline earth metal and fullerene or a mixture of an alkaline earth metal and a fullerene derivative. In this case, since the deposition temperature is low, cathode deposition can be performed at the heat-resistant temperature of the FMM mask, thereby forming a cathode that can be patterned during the deposition process.

[0191] Second, when a cathode is formed using a mixture comprising or containing an alkaline earth metal and fullerene or a mixture comprising or containing an alkaline earth metal and a fullerene derivative, since the deposition temperature is as low as the temperature used to deposit the light-emitting layer or the common layer, a deposition chamber can be used in common and help ensure processability.

[0192] Third, the mixture of alkaline earth metal and fullerene imparts oxidation resistance to the alkaline earth metal, which can enhance the high temperature and high humidity reliability of the cathode.

[0193] Fourthly, since the cathode of the transmission part can be omitted by the patterned cathode, the transmittance of the transmission part can be improved, which is advantageously applicable to a transparent display device.

[0194] Fifth, since the cathode with the selectively overlapped portion is disposed in the transmission part, the transmission efficiency of the panel can be controlled. In this case, since the cathode can have a low resistivity due to the area overlapping with the transmission part, the voltage drop of the cathode can be prevented and the transmission efficiency can be improved.

[0195] Sixth, when n-type high electron mobility fullerene is used as the fullerene isomer, efficiency is expected to be improved because of improvement in electron injectability.

[0196] To this end, a display device according to one embodiment of the present invention may include an anode at each of a plurality of light-emitting portions of a substrate, a light-emitting layer arranged above each anode, and a cathode above the light-emitting layer to overlap with the plurality of light-emitting portions of the substrate, the cathode including an alkaline earth metal and fullerene compounded with the alkaline earth metal.

[0197] The substrate further includes a transmission portion between the plurality of light emitting portions, and the cathode may include a region that does not overlap with the transmission portion.

[0198] The cathode may overlap the transmission portion by an amount equal to or less than 1 / 4 of the total size of the transmission portion in the substrate.

[0199] The display device may further include a camera under the substrate to correspond to a portion of the area of ​​the transmission portion.

[0200] The cathode may be spaced apart from the camera corresponding region of the substrate by a predetermined distance.

[0201] Fullerenes may include carbon polymers of C20 or higher.

[0202] Fullerenes can have a spherical or ellipsoidal shape.

[0203] The alkaline earth metal is located in a spherical or ellipsoidal shape and can form a complex with one or more carbon atoms of the fullerene.

[0204] The alkaline earth metal is located outside the fullerene and may form a complex with one or more carbon atoms of the fullerene.

[0205] The fullerene of the cathode may be contained in the cathode at less than 10 vol%.

[0206] The display device may further include an electron injection layer between the light emitting layer and the cathode, and the electron injection layer may include or contain lanthanum metal.

[0207] The alkaline earth metal may include at least one of Mg, Ca, Be, Sr, Ba, and Ra.

[0208] The display device may further include a cover layer and an encapsulation layer over the cathode.

[0209] The substrate may include a hole, and the cathode may be spaced apart from the hole by a predetermined distance.

[0210] A capping layer and an inorganic encapsulation layer may be sequentially disposed on a top surface and a side surface of the cathode spaced apart from the hole.

[0211] The alkaline earth metal and the fullerene may be co-deposited in such a manner as to be included in the same source as a mixture.

[0212] The content of alkaline earth metals may be greater than that of fullerenes.

[0213] The ratio of alkaline earth metal to fullerene may be from 10:1 to 20:1.

[0214] The alkaline earth metal may be complexed with one or more carbon atoms of the fullerene derivative.

[0215] The fullerene content of the cathode may be higher than 1% of the total volume of the cathode.

[0216] The thickness of the light emitting layer corresponding to each light emitting portion between the anode and the cathode may be different from each other.

[0217] A method for manufacturing a display device according to an embodiment of the present invention may include the following steps: providing an anode at each of a plurality of light-emitting portions of a substrate, providing a light-emitting layer above the anode, and providing a cathode by depositing a mixture of alkaline earth metal and fullerene above the substrate including the light-emitting layer.

[0218] The method may further comprise the step of providing a bank overlapping an edge of the anode after the step of providing the anode.

[0219] In the step of providing the bank, the first opening region may be defined as a light emitting portion, and the second opening region may be defined as a transmissive portion.

[0220] The step of providing the cathode electrode may include the step of using a deposition mask having a shielding portion corresponding to the transmission portion.

[0221] The method may further include the step of positioning a camera below the substrate.

[0222] The step of providing the cathode may include the step of performing patterning so as to be spaced a distance from the camera.

[0223] The base plate may include a hole for inserting the camera.

[0224] Although the embodiments of the present invention have been described in detail above with reference to the accompanying drawings, it will be apparent to those skilled in the art that the above-mentioned invention is not limited to the above-mentioned embodiments, and various alternative forms, modified forms and changed forms can be conceived within the spirit and scope of the present invention. Therefore, the various embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by the embodiments. Therefore, the disclosed embodiments are provided for descriptive purposes and are not intended to limit the technical scope of the present disclosure, and the technical scope of the present disclosure is not limited by the embodiments. The scope of the present disclosure should be interpreted based on the attached claims, and all technical ideas that fall within the equivalent scope of the claims should be understood to belong to the scope of the present disclosure.

[0225] CROSS-REFERENCE TO RELATED APPLICATIONS

[0226] This application claims the benefit of Korean Patent Application No. 10-2019-0180194, filed on Dec. 31, 2019, which is hereby incorporated by reference as if fully set forth herein.

Claims

1. A display device, comprising: a substrate including a plurality of light-emitting portions and a transmission portion between the plurality of light-emitting portions; an anode at each of the plurality of light emitting portions of the substrate; a light-emitting layer, the light-emitting layer being above the anode; a cathode, the cathode being above the light-emitting layer to overlap the plurality of light-emitting portions of the substrate, the cathode comprising an alkaline earth metal and a fullerene or a fullerene derivative composited with the alkaline earth metal; A hole transport layer and an electron transport layer located between the anode and the light-emitting layer, and an electron injection layer located between the light-emitting layer and the cathode; a covering layer, the covering layer being located above the cathode at the plurality of light emitting portions and the transmission portion; an encapsulation layer, the encapsulation layer comprising a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer sequentially disposed on the cover layer; and a camera located below the substrate to correspond to a portion of the area of ​​the transmission portion, wherein the hole transport layer, the electron transport layer and the electron injection layer extend to the transmission portion, wherein the cathode is patterned to include an area that does not overlap with the transmission portion, and the cathode is horizontally spaced apart from the camera by a predetermined distance, wherein the cover layer protrudes from the cathode at the transmission portion, wherein the cover layer contacts the top surface and side surfaces of the patterned cathode and contacts the electron injection layer at the transmission portion, and The organic encapsulation layer is omitted in a region corresponding to the camera and the predetermined distance at which the cathode is horizontally spaced from the camera.

2. The display device according to claim 1, wherein: The cathode electrode overlaps the transmission portion by an amount equal to or smaller than 1 / 4 of a total size of the transmission portion in the substrate.

3. The display device according to claim 1, wherein: The fullerene derivative includes a carbon polymer having 20 or more carbon atoms and the fullerene derivative is an n-type fullerene derivative.

4. The display device according to claim 1, wherein: The fullerene or fullerene derivative has a spherical or elliptical shape.

5. The display device according to claim 4, wherein: The alkaline earth metal is located within the spherical shape or the elliptical shape, and is combined with one or more carbon atoms of the fullerene or the fullerene derivative.

6. The display device according to claim 1, wherein: The alkaline earth metal is located outside the fullerene and is complexed with one or more carbon atoms of the fullerene or the fullerene derivative.

7. The display device according to claim 1, wherein: The cathode has a content of the fullerene or fullerene derivative of less than 10% of the total volume of the cathode.

8. The display device according to claim 1, wherein: The electron injection layer includes lanthanum metal.

9. The display device according to claim 1, wherein: The alkaline earth metal includes at least one selected from the group consisting of Mg, Ca, Be, Sr, Ba, and Ra.

10. The display device according to claim 1, wherein: The substrate includes a hole at an area corresponding to the camera.

11. The display device according to claim 1, wherein: The alkaline earth metal and the fullerene are co-deposited in such a manner as to be included in the same source as a mixture.

12. The display device according to claim 1, wherein: The content of the alkaline earth metal is greater than that of the fullerene.

13. The display device according to claim 12, wherein: The ratio of the alkaline earth metal to the fullerene is 10:1 to 20:

1.

14. The display device according to claim 1, wherein: The alkaline earth metal is complexed with one or more carbon atoms of the fullerene derivative.

15. The display device according to claim 1, wherein: The cathode has a content of the fullerene greater than 1% of the total volume of the cathode.

16. The display device according to claim 1, wherein: The thicknesses of the light emitting layers corresponding to each light emitting portion between the anode and the cathode are different from each other.

17. A method for manufacturing a display device, the method comprising the following steps: providing a substrate including a plurality of light emitting portions and a transmission portion between the plurality of light emitting portions; providing an anode at each of the plurality of light emitting portions of the substrate; Disposing a hole transport layer above the plurality of light emitting portions and the transmission portion; Disposing a light-emitting layer above the anode; Disposing an electron transport layer and an electron injection layer above the plurality of light emitting portions and the transmission portion; Disposing a cathode by depositing a mixture of alkaline earth metal and fullerene in an opening area of ​​a deposition mask on the light emitting layer; providing a cover layer over the cathode at the plurality of light emitting portions and the cover layer protruding from the cathode at the transmission portion; providing an encapsulation layer, the encapsulation layer comprising a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer sequentially provided on the cover layer; and providing a camera, the camera being located below the substrate to correspond to a portion of the area of ​​the transmission portion, wherein the cathode is patterned to overlap with the plurality of light emitting portions and includes a region that does not overlap with the transmission portion and a region that overlaps with the transmission portion to be horizontally spaced a predetermined distance from the camera, wherein the cover layer contacts the top surface and the side surface of the patterned cathode, and the cover layer protruding from the cathode contacts the electron injection layer at the transmission portion, The organic encapsulation layer is omitted in a region corresponding to the camera and the predetermined distance at which the cathode is horizontally spaced from the camera.

18. The method according to claim 17, further comprising the step of providing a bank overlapping an edge of the anode after the step of providing the anode at each of the plurality of light emitting portions of the substrate, in, In the step of providing a bank overlapping an edge of the anode, the first opening region and the second opening region are defined as a light emitting portion and a transmission portion, respectively.

19. The method according to claim 17, wherein: The deposition mask has a shielding portion corresponding to the transmission portion.

20. The method according to claim 17, wherein: The base plate includes a hole for inserting a camera.

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