Multilayer electrode, light emitting diode including the same, and display device

Abstract

The utility model relates to a multilayer electrode, a light emitting diode including the same, and a display device. The multilayer electrode includes a first conductive layer including a first base metal and a first additive metal different from the first base metal, a second conductive layer on the first conductive layer and including a single metal material; and a third conductive layer on the second conductive layer and including a second base metal and a second additive metal different from the second base metal.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2021-0117201 filed in the Korean Intellectual Property Office on September 2, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments relate to a multilayer electrode having low driving voltage, high efficiency, and long lifespan, a light emitting diode including the multilayer electrode, and a display device including the light emitting diode. Background Art

[0004] Among display devices, organic light emitting display devices are next-generation display devices not only due to their wide viewing angles and excellent contrast ratios but also due to their fast response speeds.

[0005] In an organic light-emitting display device, a thin film transistor and a light-emitting diode (e.g., an organic light-emitting element) are arranged on a substrate, and the light-emitting diode itself emits light. The organic light-emitting display device is used as a display unit for small products such as mobile phones, and is also used as a display unit for large products such as televisions.

[0006] The light emitting diode may have a structure in which a first electrode (e.g., an anode) is arranged on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode (e.g., a cathode) are sequentially formed on the first electrode. Holes injected from the first electrode move to the emission layer via the hole transport region, and electrons injected from the second electrode move to the emission layer via the electron transport region. Carriers such as holes and electrons recombine in the emission layer region to generate excitons. As these excitons change from an excited state to a ground state, light is generated.

[0007] It should be understood that this background technology section is intended, in part, to provide a useful background for understanding the technology. However, this background technology section may also include ideas, concepts or cognitions that were not known or understood by a person skilled in the relevant art before the corresponding effective filing date of the subject matter disclosed herein. Utility Model Content

[0008] The embodiments include a light emitting diode having low driving voltage, high efficiency and long lifespan and a display device including the light emitting diode. However, the embodiments do not limit the scope of the present disclosure.

[0009] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of embodiments of the disclosure.

[0010] According to an embodiment, a display device may include a first electrode on a substrate, a second electrode facing the first electrode, and an emission layer between the first electrode and the second electrode, wherein the second electrode may include: a first conductive layer including a first base metal and a first additive metal different from the first base metal, a second conductive layer on the first conductive layer and including a single metal material, and a third conductive layer on the second conductive layer and including a second base metal and a second additive metal different from the second base metal.

[0011] In one embodiment, the first base metal may include at least one of Ag, Au, Cu, Al, and Mg. In one embodiment, the first base metal may include a 7 At least one of the metals having an electrical conductivity of S / m.

[0012] In one embodiment, the first additive metal may include at least one of Mg, Ca, Li, Au, Al, Yb, Cu, and Sm. In one embodiment, the first additive metal may include at least one of metals having a work function equal to or less than about 3 eV.

[0013] In one embodiment, the single metal material may include at least one of Ag, Au, Cu, Al, and Mg. In one embodiment, the single metal material may include a 7 At least one of the metals having an electrical conductivity of S / m.

[0014] In one embodiment, the thickness of the first conductive layer may be smaller than the thickness of the second conductive layer.

[0015] In one embodiment, the thickness of the first conductive layer may be about to about within the range.

[0016] In one embodiment, the thickness of the second conductive layer may be about to about within the range.

[0017] In one embodiment, the second electrode may have a plurality of stack structures each including the first conductive layer and the second conductive layer.

[0018] In one embodiment, a volume ratio of the first base metal to the first additive metal may be in a range from about 99:1 to about 1:1.

[0019] In one embodiment, the second base metal may include at least one of Ag, Au, Cu, Al, and Mg. In one embodiment, the second base metal may include a7 At least one of the metals having an electrical conductivity of S / m.

[0020] In one embodiment, the second additive metal may include at least one of Mg, Ca, Li, Au, Al, Yb, Cu, and Sm. In one embodiment, the second additive metal may include at least one of metals having a work function equal to or less than about 3 eV.

[0021] In one embodiment, the third conductive layer may include the same material as the first conductive layer.

[0022] In one embodiment, the thickness of the first conductive layer may be smaller than the thickness of the third conductive layer.

[0023] In one embodiment, the thickness of the third conductive layer may be about to about within the range.

[0024] In one embodiment, a volume ratio of the second base metal to the second additive metal may be in a range of about 99:1 to about 1:1.

[0025] In one embodiment, a thickness ratio of the first conductive layer to the second conductive layer to the third conductive layer may be approximately 1:6:1.

[0026] According to an embodiment, a light emitting diode may include a first electrode, a second electrode facing the first electrode, and an emission layer between the first electrode and the second electrode, wherein the second electrode may include: a first conductive layer including a first base metal and a first additive metal different from the first base metal, a second conductive layer on the first conductive layer and including a single metal material, and a third conductive layer on the second conductive layer and including a second base metal and a second additive metal different from the second base metal.

[0027] In one embodiment, the first base metal may include at least one of Ag, Au, Cu, Al, and Mg. In one embodiment, the first base metal may include a 7 At least one of other metals having an electrical conductivity of 200 000 s / m.

[0028] In one embodiment, the first additive metal may include at least one of Mg, Ca, Li, Au, Al, Yb, Cu, and Sm. In one embodiment, the first additive metal may include at least one of metals having a work function equal to or less than about 3 eV.

[0029] In one embodiment, the thickness of the first conductive layer may be smaller than the thickness of the second conductive layer.

[0030] In one embodiment, a volume ratio of the first base metal to the first additive metal may be in a range from about 99:1 to about 1:1.

[0031] In one embodiment, the second base metal may include at least one of Ag, Au, Cu, Al, and Mg. In one embodiment, the second base metal may include a 7 At least one of the metals having an electrical conductivity of S / m.

[0032] In one embodiment, the second additive metal may include at least one of Mg, Ca, Li, Au, Al, Yb, Cu, and Sm. In one embodiment, the second additive metal may include at least one of metals having a work function equal to or less than about 3 eV.

[0033] In one embodiment, the thickness of the first conductive layer may be smaller than the thickness of the third conductive layer.

[0034] In one embodiment, a volume ratio of the second base metal to the second additive metal may be in a range of about 99:1 to about 1:1.

[0035] In one embodiment, the single metal material may include at least one of Ag, Au, Cu, Al, and Mg. In one embodiment, the single metal material may include a 7 At least one of other metals having an electrical conductivity of 200 000 s / m.

[0036] In one embodiment, a thickness ratio of the first conductive layer to the second conductive layer to the third conductive layer may be approximately 1:6:1.

[0037] According to an embodiment, a multilayer electrode may include: a first conductive layer including a first base metal and a first additive metal different from the first base metal, a second conductive layer on the first conductive layer and including a single metal material, and a third conductive layer on the second conductive layer and including a second base metal and a second additive metal different from the second base metal.

[0038] The above and other aspects, features, and advantages of embodiments of the present disclosure will become more apparent from the following description, drawings, and claims.

[0039] These aspects may be implemented using a system, a method, a computer program, or a combination of specific systems, methods, and computer programs. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and other aspects, features and advantages of the embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0041] Figure 1 is a schematic cross-sectional view of a multilayer electrode structure according to an embodiment;

[0042] Figure 2A and Figure 2B is a schematic plan view illustrating an example of a display device according to an embodiment;

[0043] Figure 3A and Figure 3B is an equivalent circuit diagram of a pixel of a display device according to an embodiment;

[0044] Figure 4 and Figure 5 is a schematic cross-sectional view of a stacked structure of an organic light emitting diode that can be used in a display device according to an embodiment;

[0045] Figure 6 to Figure 7 is a schematic cross-sectional view of a stacked structure of a second electrode according to an embodiment;

[0046] Figure 8 is a schematic cross-sectional view of a portion of a display device according to an embodiment;

[0047] Fig. 9 is a table obtained by measuring the light transmittance, reflectance, and absorptance of the multilayer electrode to which the embodiment of the present disclosure is applied and the multilayer electrode to which the comparative example is applied;

[0048] Fig.10 is a graph obtained by measuring the light transmittance in the comparative example and the embodiment;

[0049] Fig.11 is a graph obtained by measuring the reflectance in Comparative Examples and Examples;

[0050] Fig.12 is a graph obtained by measuring the absorbance in Comparative Examples and Examples;

[0051] Fig.13 is a graph obtained by measuring sheet resistance and high temperature reliability in comparative examples and embodiments;

[0052] Fig.14 A table comparing the pixel efficiency of the comparative example with the pixel efficiency of the embodiment of the present disclosure; and

[0053] Fig.15 The table is a comparison of the pixel efficiency of the comparative example and the pixel efficiency of the embodiment of the present disclosure. DETAILED DESCRIPTION

[0054] The present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. However, the present disclosure may be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. Instead, these embodiments are provided so that the present disclosure will be thorough and complete and will fully convey the scope of the present disclosure to those skilled in the art.

[0055] In the drawings, the size, thickness, ratio, and dimensions of elements may be exaggerated for ease of description and for clarity. The same reference numerals refer to the same elements throughout.

[0056] In the description, it will be understood that when an element (or region, layer, portion, etc.) is referred to as being "on," "connected to," or "coupled to" another element, it may be directly on, connected to, or coupled to the other element, or one or more intervening elements may be present therebetween. In a similar sense, when an element (or region, layer, portion, etc.) is described as "covering" another element, it may directly cover the other element, or one or more intervening elements may be present therebetween.

[0057] In the description, when an element is "directly on," "directly connected to," or "directly coupled to" another element, there are no intervening elements. For example, "directly on" may mean that two layers or two elements are disposed without additional elements, such as adhesive elements, between them.

[0058] As used herein, expressions used in the singular, such as “a”, “an” and “the”, are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0059] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. For example, "A and / or B" may be understood to mean "A, B, or A and B". The terms "and" and "or" may be used in a connecting or disconnecting sense and may be understood to be equivalent to "and / or".

[0060] In the specification and claims, the term "at least one of" is intended to include the meaning of "at least one selected from the group of" for the purpose of its meaning and interpretation. For example, "at least one of A and B" is understood to mean "A, B, or A and B." When following a list of elements, the term "at least one of" modifies the entire list of elements and does not modify the individual elements in the list.

[0061] It will be understood that although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Therefore, the first element may be referred to as the second element without departing from the teaching of the present disclosure. Similarly, the second element may be referred to as the first element without departing from the teaching of the present disclosure.

[0062] For ease of description, spatially relative terms such as "below", "under", "down", "above", "upper", etc. may be used herein to describe the relationship between one element or component and another element or component as illustrated in the figure. It will be understood that in addition to the orientation depicted in the figure, the spatially relative terms are intended to cover different orientations of the device in use or operation. For example, in the case where the device illustrated in the figure is flipped, a device located "below" or "below" another device may be placed "above" the other device. Accordingly, the exemplary term "below" may include both a lower position and an upper position. The device may also be oriented in other directions, and therefore the spatially relative terms may be interpreted differently depending on the orientation.

[0063] The term "overlap" or "overlapping" means that a first object can be above or below or to one side of a second object, and vice versa. In addition, the term "overlap" may include layer, stack, facing, extending throughout, covering or partially covering or any other appropriate term that a person of ordinary skill in the art will recognize and understand.

[0064] The term "facing" means that the first element may be directly or indirectly opposite to the second element. In the case where a third element is interposed between the first element and the second element, the first element and the second element may be understood to be indirectly opposite to each other although still facing each other.

[0065] When an element is described as “non-overlapping” another element, it may include the elements being spaced apart from each other, offset from each other, or separated from each other, or any other appropriate terminology that would be recognized and understood by one of ordinary skill in the art.

[0066] The x-axis, y-axis, and z-axis are not limited to the three axes of the rectangular coordinate system and can be interpreted in a broader sense. For example, the x-axis, y-axis, and z-axis can be perpendicular to each other or can represent different directions that are not perpendicular to each other.

[0067] When some embodiments may be implemented differently, a specific process order may be performed differently from the order described. For example, two processes described in succession may be performed substantially simultaneously, or may be performed in an order opposite to the order described.

[0068] As used herein, the term "about" or "approximately" is inclusive of the stated value and means within an acceptable range of deviation from the stated value determined by one of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the stated quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or within ±20%, ±10%, or ±5% of the stated value.

[0069] It should be understood that the terms “includes,” “comprising,” “having,” “containing,” etc. are intended to indicate the presence of the described features, integers, steps, operations, elements, parts, or combinations thereof in the present disclosure, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, or combinations thereof.

[0070] Unless otherwise defined or implied herein, all terms (including technical and scientific terms) used have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an ideal or overly formal sense unless clearly defined in the specification.

[0071] Figure 1 is a schematic cross-sectional view of a multilayer electrode structure according to an embodiment.

[0072] See also Figure 1 , the multilayer electrode 1000 may include a first conductive layer CL1, a second conductive layer CL2, and a third conductive layer CL3 stacked in sequence. The second conductive layer CL2 may be disposed between the first conductive layer CL1 and the third conductive layer CL3.

[0073] The first conductive layer CL1 is a layer including different types of metal materials, and may include a first base metal BM1 and a first additive metal AM1 different from the first base metal BM1. The first conductive layer CL1 including the first base metal BM1 and the first additive metal AM1 may mean that the first conductive layer CL1 may include a material in which the first base metal BM1 and the first additive metal AM1 are alloyed, or may mean that both elements of the first base metal BM1 and elements of the first additive metal AM1 are in the first conductive layer CL1.

[0074] In one embodiment, the first base metal BM1 may include at least one material selected from Ag, Au, Cu, Al, and Mg. In another embodiment, the first base metal BM1 may include a material having a thickness equal to or greater than about 1×10 7In one embodiment, the first additive metal AM1 may include at least one of metals having an electrical conductivity of about 1000 Å / s. In one embodiment, the first additive metal AM1 may include a material selected from at least one of Mg, Ca, Li, Au, Al, Yb, Cu, and Sm. In another embodiment, the first additive metal AM1 may include at least one of metals having a work function equal to or less than about 3 eV. Since the first conductive layer CL1 must include different types of metal materials, the first base metal BM1 and the first additive metal AM1 must be selected from different metal materials.

[0075] In one embodiment, a volume ratio of the first base metal BM1 to the first additive metal AM1 in the first conductive layer CL1 may be in a range of about 99:1 to about 1:1. For example, the volume amount of the first base metal BM1 may be equal to or greater than the volume amount of the first additive metal AM1.

[0076] The first conductive layer CL1 allows metal particles forming the second conductive layer CL2 to be uniformly distributed during an initial formation process of the second conductive layer CL2 as described below, and thus the second conductive layer CL2 may be uniformly formed.

[0077] The second conductive layer CL2 is a highly conductive layer and may include a single metal material SM. The second conductive layer CL2 including the single metal material SM may mean that the second conductive layer CL2 includes a pure single metal element except for inevitable impurities.

[0078] In one embodiment, the single metal material SM may include at least one material selected from Ag, Au, Cu, Al, and Mg. In another embodiment, the single metal material SM may include a material having a carbon content equal to or greater than about 1×10 7 At least one of metals having an electrical conductivity of 200 S / m. For example, the second conductive layer CL2 may include silver (Ag), and the second conductive layer CL2 may be provided as a pure silver (Ag) layer.

[0079] Since the second conductive layer CL2 includes a conductive layer having a thickness equal to or greater than about 1×10 7 The second conductive layer CL2 may be implemented as a high conductive layer. The multilayer electrode 1000 including the second conductive layer CL2 may have low resistance and high conductivity, and may achieve high reflection while reducing light absorption rate, and thus may improve outcoupling.

[0080] The third conductive layer CL3 is a layer including different types of metal materials, and may include a second base metal BM2 and a second additive metal AM2 different from the second base metal BM2. The third conductive layer CL3 including the second base metal BM2 and the second additive metal AM2 may mean that the third conductive layer CL3 may include a material in which the second base metal BM2 and the second additive metal AM2 are alloyed, or may mean that both elements of the second base metal BM2 and elements of the second additive metal AM2 are in the third conductive layer CL3.

[0081] In one embodiment, the second base metal BM2 may include at least one material selected from Ag, Au, Cu, Al, and Mg. In another embodiment, the second base metal BM2 may include a material having a thickness equal to or greater than about 1×10 7 The second additive metal AM2 may include at least one of metals having an electrical conductivity of 1000 Å / s / m. In one embodiment, the second additive metal AM2 may include a material selected from at least one of Mg, Ca, Li, Au, Al, Yb, Cu, and Sm. In another embodiment, the second additive metal AM2 may include at least one of metals having a work function equal to or less than about 3 eV. Since the third conductive layer CL3 must include different types of metal materials, the second base metal BM2 and the second additive metal AM2 must be selected from different metal materials.

[0082] In one embodiment, the volume ratio of the second base metal BM2 to the second additive metal AM2 in the third conductive layer CL3 may be in the range of about 99:1 to about 1:1. For example, the volume amount of the second base metal BM2 may be equal to or greater than the volume amount of the second additive metal AM2.

[0083] The third conductive layer CL3 may ensure thermal and electrical stability of the multilayer electrode 1000 by chemically bonding with atoms (eg, Ag atoms) of the single metal material SM of the second conductive layer CL2 disposed directly under the third conductive layer CL3 .

[0084] The thickness t1 of the first conductive layer CL1 and the thickness t3 of the third conductive layer CL3 may both be smaller than the thickness t2 of the second conductive layer CL2. The thickness t1 of the first conductive layer CL1 may be equal to or different from the thickness t3 of the third conductive layer CL3.

[0085] In one embodiment, the thickness t1 of the first conductive layer CL1 may be about to about In one embodiment, the thickness t3 of the third conductive layer CL3 may be about to about In one embodiment, the thickness t2 of the second conductive layer CL2 may be about to about within the range.

[0086] In one embodiment, the thickness ratio (t1:t2:t3) of the first conductive layer CL1 to the second conductive layer CL2 to the third conductive layer CL3 may be approximately 1:6:1. For example, in order to satisfy the above thickness ratio (t1:t2:t3) of the first conductive layer CL1 to the second conductive layer CL2 to the third conductive layer CL3, the thickness t1 of the first conductive layer CL1 may be approximately The thickness t2 of the second conductive layer CL2 may be approximately The thickness t3 of the third conductive layer CL3 may be about

[0087] The multilayer electrode 1000 may achieve low resistance, high conductivity, and high transmittance by including a second conductive layer CL2 of a single metal material SM having high conductivity, and may ensure thermal and electrical stability of the second conductive layer CL2 by including a first conductive layer CL1 and a third conductive layer CL3 of a first additive metal AM1 and a second additive metal AM2 as dopants, respectively.

[0088] The multilayer electrode 1000 can be used as an electrode (e.g., an anode or cathode) of an organic or inorganic optoelectronic element of a light-emitting device included in a display device. For example, the light-emitting device may include an organic light-emitting diode, an inorganic light-emitting diode, a light-emitting diode, a quantum dot (QD) light-emitting diode, an organic solar cell, a perovskite light-emitting diode, or a perovskite solar cell.

[0089] Hereinafter, the multilayer electrode 1000 is described in detail as a second electrode (eg, Figure 5 An example of a second electrode 230, or cathode).

[0090] Figure 2A and Figure 2B is a schematic plan view illustrating an example of a display device according to an embodiment.

[0091] Figure 2A and Figure 2B The display devices 1 and 1' are shown as examples having a display area DA having a substantially rectangular shape. Figure 2A and Figure 2B In the embodiment, various components may be arranged on a substrate 100 having a major axis and a minor axis. From the user's perspective, Figure 2A A display device 1 is illustrated in which a horizontal direction (eg, an x ​​direction) is a short axis and a vertical direction (eg, a y direction) is a long axis, and Figure 2B A display device 1' is exemplified in which the horizontal direction (eg, x direction) is the long axis and the vertical direction (eg, y direction) is the short axis. In the display devices 1 and 1' according to the embodiments, the printed circuit board PCB may be arranged in the short axis direction of the display device 1, such as Figure 2A As shown, the printed circuit board PCB can be arranged in the short axis direction and the long axis direction of the display device 1 ', as shown Figure 2B In one embodiment, as shown. Figure 2A The illustrated display device 1 can be used in small and medium-sized electronic devices such as mobile phones, smart phones, tablet personal computers (PCs), mobile communication terminals, electronic notebooks, electronic books, portable multimedia players (PMPs), etc., and can be used as Figure 2B The display device 1 ′ in the embodiment can be used in large electronic devices such as televisions, laptop computers, monitors, billboards, etc.

[0092] See also Figure 2A , the display device 1 may be formed by bonding the substrate 100 and the upper substrate 700 to each other using the sealing member 600. The sealing member 600 may be formed to surround the outer edge of the substrate 100 and the outer edge of the upper substrate 700 to bond the substrate 100 and the upper substrate 700 to each other. The upper substrate 700 may be provided with a size slightly smaller than that of the substrate 100 so that the pad portion 30 may be exposed.

[0093] The display device 1 may include a display area DA and a peripheral area PA arranged around the display area DA. The display device 1 may provide a specific image by using light emitted from a pixel P arranged in the display area DA. Hereinafter, the term "pixel P" used herein may refer to a sub-pixel including one organic light emitting diode.

[0094] The display area DA includes pixels P connected to data lines DL extending in the y direction and scan lines SL extending in the x direction crossing the y direction. Each pixel P is also connected to a driving voltage line PL extending in the y direction.

[0095] Each pixel P may include a display element such as an organic light emitting diode. For example, each pixel P may emit red light, green light, blue light, or white light through an organic light emitting diode. In an embodiment, the color of each pixel P may be realized by the color of light emitted from the organic light emitting diode included in the pixel P and a color filter arranged above the organic light emitting diode.

[0096] Each pixel P may be electrically connected to a built-in circuit disposed in the peripheral area PA. A first power wiring 10, a second power wiring 20, and a pad portion 30 may be disposed in the peripheral area PA.

[0097] The first power wiring 10 may be arranged to correspond to one side of the display area DA. The first power wiring 10 may be connected to a driving voltage line PL that transmits a driving voltage ELVDD (see the following description) to the display area DA. Figure 3A and Figure 3B ) is transmitted to pixel P.

[0098] The second power wiring 20 having a ring shape with one open side may partially surround the display area DA. The second power wiring 20 may supply a common voltage to the second electrode of the pixel P. The second power wiring 20 may be referred to as a common voltage supply wiring.

[0099] The pad portion 30 may include pads 31 and may be arranged on one side of the substrate 100. Each pad 31 may be connected to the first connection wiring 41 connected to the first power wiring 10, the connection wiring CW extending to the display area DA, etc. The pads 31 of the pad portion 30 may be exposed by not being covered by the insulating layer and electrically connected to the printed circuit board PCB. The terminal portion PCB-P of the printed circuit board PCB may be electrically connected to the pad portion 30.

[0100] The printed circuit board PCB may transmit a signal or power of a controller (not shown) to the pad portion 30. The controller may supply a driving voltage ELVDD and a common voltage ELVSS to the first power wiring 10 and the second power wiring 20 through the first connection wiring 41 and the second connection wiring 42 (see the following description). Figure 3A and Figure 3B ).

[0101] The data driving circuit 60 may be electrically connected to the data line DL. The data signal of the data driving circuit 60 may be applied to each pixel P through the connection wiring CW connected to the pad portion 30 and the data line DL connected to the connection wiring CW. Figure 2A The data driving circuit 60 is illustrated as being disposed on the printed circuit board PCB, but in another embodiment, the data driving circuit 60 may be disposed on the substrate 100. For example, the data driving circuit 60 may be disposed between the pad portion 30 and the first power wiring 10.

[0102] The dam portion 70 may be disposed in the peripheral area PA. Figure 8 ) of the organic encapsulation layer 320, the dam portion 70 may prevent the organic material from flowing in the edge direction of the substrate 100, thereby preventing the formation of the edge tail of the organic encapsulation layer 320. The dam portion 70 may be arranged on the peripheral area PA to surround at least a portion of the display area DA. The dam portion 70 may include a dam, and when the dam is arranged, the dams may be formed to be spaced apart from each other. The dam portion 70 may be arranged closer to the display area DA than the sealing member 600 in the peripheral area PA. A built-in drive circuit portion (not shown) for applying a scan signal for each pixel may be further included in the peripheral area PA. In an embodiment, the built-in drive circuit portion and the dam portion 70 may be formed to overlap each other.

[0103] Figure 2B The display device 1' in the above Figure 2A However, despite Figure 2A It is illustrated that one printed circuit board PCB is attached to the pad portion 30, but a plurality of printed circuit boards PCB may be attached to the pad portion 30, such as Figure 2B As shown in Figure 2B In the embodiment, the pad portion 30 may be arranged along both sides of the substrate 100. The pad portion 30 may be provided as a plurality of sub-pad portions 30S, and one printed circuit board PCB may be attached to each sub-pad portion 30S.

[0104] Figure 3A and Figure 3B is an equivalent circuit diagram of a pixel of a display device according to an embodiment.

[0105] See also Figure 3A , each pixel P may be implemented by a pixel circuit PC connected to a scan line SL and a data line DL and an organic light emitting diode OLED connected to the pixel circuit PC. The pixel circuit PC may include a driving thin film transistor T1, a switching thin film transistor T2, and a storage capacitor Cst. The switching thin film transistor T2 may be connected to the scan line SL and the data line DL, and may be configured to transmit a data signal Dm input through the data line DL to the driving thin film transistor T1 in response to a scan signal Sn input through the scan line SL.

[0106] The storage capacitor Cst may be connected to the switching thin film transistor T2 and the driving voltage line PL and may be configured to store a voltage corresponding to a difference between a voltage received from the switching thin film transistor T2 and a driving voltage ELVDD (or a first power source voltage) supplied to the driving voltage line PL.

[0107] The driving thin film transistor T1 may be connected to the driving voltage line PL and the storage capacitor Cst, and may be configured to control a driving current flowing from the driving voltage line PL to the organic light emitting diode OLED in response to a voltage value stored in the storage capacitor Cst. The organic light emitting diode OLED may emit light having a specific brightness according to the driving current.

[0108] Figure 3A The illustrated pixel circuit PC includes two thin film transistors and one storage capacitor, but the embodiment is not limited thereto.

[0109] See also Figure 3B , the pixel circuit PC may include a driving thin film transistor T1 , a switching thin film transistor T2 , a sensing thin film transistor T3 , and a storage capacitor Cst.

[0110] The scan line SL may be connected to the gate electrode G2 of the switching thin film transistor T2 , the data line DL may be connected to the source electrode S2 of the switching thin film transistor T2 , and the first electrode CE1 of the storage capacitor Cst may be connected to the drain electrode D2 of the switching thin film transistor T2 .

[0111] Accordingly, the switching thin film transistor T2 may be configured to supply the data signal Dm of the data line DL to the first node N in response to the scan signal Sn input from the scan line SL of each pixel P.

[0112] The gate electrode G1 of the driving thin film transistor T1 can be connected to the first node N, the source electrode S1 of the driving thin film transistor T1 can be connected to the driving voltage line PL transmitting the driving voltage ELVDD, and the drain electrode D1 of the driving thin film transistor T1 can be connected to the first electrode (e.g., anode) of the organic light emitting diode OLED.

[0113] Accordingly, the driving thin film transistor T1 may be configured to adjust the amount of current flowing through the organic light emitting diode OLED according to a source-gate voltage (Vgs) thereof, for example, a voltage applied between the driving voltage ELVDD and the first node N.

[0114] The sensing control line SSL may be connected to the gate electrode G3 of the sensing thin film transistor T3, the source electrode S3 of the sensing thin film transistor T3 may be connected to the second node S, and the drain electrode D3 of the sensing thin film transistor T3 may be connected to the reference voltage line RL. In one embodiment, the sensing thin film transistor T3 may be controlled by the scan line SL instead of the sensing control line SSL.

[0115] The sensing thin film transistor T3 can sense the potential of the first electrode (e.g., anode) of the organic light emitting diode OLED. The sensing thin film transistor T3 can be configured to supply the precharge voltage Vpre from the reference voltage line RL to the second node S in response to a sensing signal SSn from the sensing control line SSL, or supply the voltage of the first electrode (e.g., anode) of the organic light emitting diode OLED to the reference voltage line RL in a sensing period.

[0116] In the storage capacitor Cst, the first electrode CE1 may be connected to the first node N, and the second electrode CE2 may be connected to the second node S. The storage capacitor Cst may be configured to charge a voltage corresponding to a difference between voltages supplied to the first node N and the second node S to supply the same voltage as the driving voltage of the driving thin film transistor T1. For example, the storage capacitor Cst may be configured to charge a voltage corresponding to a difference between a data signal Dm and a precharge voltage Vpre supplied to the first node N and the second node S, respectively.

[0117] The bias electrode BSM may be formed to correspond to the driving thin film transistor T1 to be connected to the source electrode S3 of the sensing thin film transistor T3. Since the bias electrode BSM is provided with a voltage related to the potential of the source electrode S3 of the sensing thin film transistor T3, the driving thin film transistor T1 may be stabilized. In one embodiment, the bias electrode BSM may not be connected to the source electrode S3 of the sensing thin film transistor T3, but may be connected to a separate bias wiring.

[0118] A second electrode (eg, cathode) of the organic light emitting diode OLED may receive the common voltage ELVSS. The organic light emitting diode OLED may receive a driving current from the driving thin film transistor T1 to emit light.

[0119] Figure 3B Each pixel P is illustrated to include signal lines SL, SSL and DL, reference voltage line RL and driving voltage line PL, but the embodiment is not limited thereto. For example, at least one of the signal lines SL, SSL and DL and / or the reference voltage line RL and driving voltage line PL may be shared by adjacent pixels.

[0120] The pixel circuit PC is not limited to the reference Figure 3A and Figure 3B The number and circuit design of the thin film transistors and storage capacitors are described, and the number and circuit design thereof may be variously changed.

[0121] Figure 4 and Figure 5 FIG. 4 is a schematic cross-sectional view of a stacked structure of an organic light emitting diode (OLED) that can be used in a display device according to an embodiment.

[0122] See also Figure 4 , an organic light emitting diode OLED as a light emitting element may be included in each pixel P (see Figure 2A or Figure 2B ). Figure 3A or Figure 3B In the embodiment, the organic light emitting diode OLED may be electrically connected to the pixel circuit PC, and may receive power or a signal through the pixel circuit PC to control the light emission degree.

[0123] The organic light emitting diode OLED may include a first electrode 210, a second electrode 230, and an intermediate layer 220 between the first electrode 210 and the second electrode 230. The first electrode 210 may be patterned and provided for each organic light emitting diode OLED, and the second electrode 230 may be provided in an integrated form for a plurality of organic light emitting diodes OLED.

[0124] The first common layer 221 may be disposed on the first electrode 210. The first common layer 221 may be used as a hole transport region. The first common layer 221 may include at least one layer selected from a hole injection layer HIL, a hole transport layer HTL, an emission auxiliary layer, and an electron blocking layer. The thicknesses of the hole injection layer HIL, the hole transport layer HTL, the emission auxiliary layer, and the electron blocking layer may be independent of each other.

[0125] For example, the hole transport region may have a single-layer structure including layers containing different materials, or a multilayer structure of hole injection layer / hole transport layer, hole injection layer / hole transport layer / emission auxiliary layer, hole injection layer / emission auxiliary layer, hole transport layer / emission auxiliary layer or hole injection layer / hole transport layer / emission auxiliary layer stacked from the first electrode in the order described in each of them, but is not limited thereto.

[0126] In one embodiment, the Figure 4 The organic light emitting diode OLED in the embodiment includes a hole injection layer HIL and a hole transport layer HTL as a hole transport region. The hole injection layer HIL may be disposed adjacent to the first electrode 210, and the hole transport layer HTL may be disposed on the hole injection layer HIL.

[0127] The hole injection layer HIL may facilitate injection of holes and may include one or more selected from the group consisting of hexaazatriphenylene hexacarbonitrile (HAT-CN), copper phthalocyanine (CuPC), poly(3,4)-ethylenedioxythiophene (PEDOT), polyaniline (PANI), and N,N-dinaphthyl-N,N′-diphenylbenzidine (NPD), but is not limited thereto.

[0128] The hole transport layer HTL may include a triphenylamine derivative having high hole mobility and excellent stability, such as tris(4-carbazol-9-ylphenyl)amine (TCTA), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine) (TPD), or N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB) as a host of the hole transport layer. Figure 4 The example hole transport layer HTL includes a single layer, but the hole transport layer HTL may have a multilayer structure. The hole transport layer HTL may have a multilayer structure including two or more layers of different materials selected from the above materials. For example, the hole transport layer HTL may be provided as two layers including NPB and TCTA, respectively.

[0129] The emission layer 222 may be arranged on the first common layer 221. The emission layer 222 may include an organic material that emits one of red light, blue light, and green light. For example, when the emission layer 222 emits red light, the emission layer 222 may be formed by using, for example, a red dopant in a specific host material. As another example, when the emission layer 222 emits green light, the emission layer 222 may be formed by using, for example, a green dopant in a specific host material. As yet another example, when the emission layer 222 emits blue light, the emission layer 222 may be formed by using, for example, a blue dopant in a specific host material.

[0130] The second common layer 223 may be disposed on the emission layer 222. The second common layer 223 may be used as an electron transport region. The second common layer 223 may include at least one layer selected from a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer ETL, and an electron injection layer EIL. The thicknesses of the buffer layer, the hole blocking layer, the electron control layer, the electron transport layer ETL, and the electron injection layer EIL may be independent of each other.

[0131] For example, the electron transport region may have a single-layer structure including layers containing different materials, or a multilayer structure in which an electron transport layer / electron injection layer, a hole blocking layer / electron transport layer / electron injection layer, an electron control layer / electron transport layer / electron injection layer, or a buffer layer / electron transport layer / electron injection layer are stacked from the emission layer in the order described respectively, but is not limited thereto.

[0132] In one embodiment, the Figure 4 The organic light emitting diode OLED in the embodiment includes an electron injection layer EIL and an electron transport layer ETL as an electron transport region. The electron injection layer EIL may be disposed adjacent to the second electrode 230 , and the electron transport layer ETL may be disposed on the emission layer 222 .

[0133] The electron transport layer ETL may facilitate the transport of electrons and may include a material selected from tris(8-hydroxyquinoline)aluminum (Alq 3 ), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), spiro-PBD, bis(2-methyl-8-hydroxyquinoline)-4-(phenylphenol)aluminum (BAlq), 8-hydroxyquinoline lithium (Liq), BMB-3T, PF-6P, 2,2',2"-(1,3,5-benzenetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi), one or more of the group consisting of COT and SAlq, but not limited thereto.

[0134] The electron injection layer EIL can facilitate the injection of electrons and may include Yb, tris(8-hydroxyquinoline)aluminum (Alq 3), PBD, TAZ, spiro-PBD, BAlq or SAlq, but are not limited thereto.

[0135] Figure 4 The exemplary organic light emitting diode OLED includes all of the hole injection layer HIL, the hole transport layer HTL, the electron transport layer ETL, and the electron injection layer EIL, but the embodiment is not limited thereto. In another embodiment, at least one of the hole injection layer HIL, the hole transport layer HTL, the electron transport layer ETL, and the electron injection layer EIL may be omitted.

[0136] Other layers except the emission layer 222, for example, a hole injection layer HIL, a hole transport layer HTL, an electron transport layer ETL, and an electron injection layer EIL may be provided as one body over the plurality of organic light emitting diodes OLED.

[0137] The organic light emitting diode OLED may have a tandem structure including a stack of m or more emission units, where m is an integer greater than or equal to 2. m-1 number of charge generation layers 224 may be between the stack of emission units.

[0138] See also Figure 5 In one embodiment, the organic light emitting diode OLED may have a stacked series structure including two or more emission units. Figure 5 An organic light emitting diode OLED having a first stack ST1 and a second stack ST2 formed as two emission units is illustrated. A first emission layer 222a and a second emission layer 222b may be disposed in the first stack ST1 and the second stack ST2, respectively. A charge generation layer 224 may be between the first stack ST1 and the second stack ST2.

[0139] Hereinafter, the layers stacked on the first electrode 210 will be described in detail.

[0140] The first common layer 221 may be disposed on the first electrode 210. Figure 4 The first common layer described is the same, and thus a detailed description thereof is omitted.

[0141] The first emission layer 222a may be arranged on the first common layer 221. The first emission layer 222a may include an organic material that emits one of red light, blue light, and green light. For example, when the first emission layer 222a emits red light, the first emission layer 222a may be formed by using, for example, a red dopant in a specific host material. As another example, when the first emission layer 222a emits green light, the first emission layer 222a may be formed by using, for example, a green dopant in a specific host material. As yet another example, when the first emission layer 222a emits blue light, the first emission layer 222a may be formed by using, for example, a blue dopant in a specific host material.

[0142] The electron transport layer ETL may be disposed on the first emission layer 222 a . The electron transport layer ETL disposed on the first emission layer 222 a may perform the same function as the electron transport layer ETL included in the second common layer 223 .

[0143] The charge generation layer 224 may be disposed on the electron transport layer ETL. The charge generation layer 224 may be between the first stack ST1 and the second stack ST2. Figure 5 In the embodiment, the charge generation layer 224 may be between the electron transport layer ETL of the first stack ST1 and the hole transport layer HTL of the second stack ST2.

[0144] In an embodiment, the charge generation layer 224 may include an n-type charge generation layer n-CGL for supplying electrons to the first stack ST1 and a p-type charge generation layer p-CGL for supplying holes to the second stack ST2 .

[0145] The n-type charge generation layer n-CGL may include an n-type dopant material and an n-type host material. In one embodiment, the volume ratio of the n-type host material to the n-type dopant material may be in the range of about 99:1 to about 90:10. The n-type dopant material may include a metal dopant, and the n-type host material may include an organic material, such as an organic semiconductor material.

[0146] The n-type dopant material may be an organic material or a mixture thereof that can inject metals or electrons of Group I elements and Group II elements in the periodic table. For example, the n-type dopant material may include any one of an alkali metal and an alkaline earth metal. For example, the n-type charge generation layer n-CGL may include an organic layer doped with an alkali metal such as lithium (Li), sodium (Na), potassium (K) or cesium (Cs) or an alkaline earth metal such as magnesium (Mg), strontium (Sr), barium (Ba) or radium (Ra), but is not limited thereto. As another example, the n-type dopant material may include a lanthanide. For example, the n-type dopant material may include any one of dysprosium (Dy), europium (Eu), ytterbium (Yb) and samarium (Sm). As the n-type dopant material, a metal having a work function of less than about 3 eV may be used.

[0147] The n-type host material may include a material capable of transporting electrons, such as tris(8-hydroxyquinoline)aluminum (Alq 3), 8-hydroxyquinoline lithium (Liq), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), spiro-PBD, bis(2-methyl-8-hydroxyquinoline)-4-(phenylphenol)aluminum (BAlq), SAlq, 2,2',2"-(1,3,5-benzenetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi), at least one of oxadiazole, triazole, phenanthroline, benzoxazole and benzothiazole, but not limited thereto.

[0148] The p-type charge generation layer p-CGL may include a p-type dopant material and a p-type host material. In one embodiment, the volume ratio of the p-type host material and the p-type dopant material may be in the range of about 99:1 to about 80:20. The p-type host material and the p-type dopant material may include organic materials. For example, the p-type host material may include a first organic semiconductor material, and the p-type dopant material may include a second organic semiconductor material or a metal material.

[0149] The p-type dopant material may include an organic material such as tetrafluoro-tetracyanoquinodimethane (F4-TCNQ), hexaazatriphenylenehexacarbonitrile (HAT-CN), hexaazatriphenylene, or a V 2 O 5 、MoO x , WO 3 The p-type host material may include a material capable of transporting holes, for example, a material including at least one of N,N-dinaphthyl-N,N'-diphenylbenzidine (NPD), N,N'-bis(naphthalene-1-yl)-N,N'-bis(phenyl)-2,2'-dimethylbenzidine, N,N'-bis(3-tolyl)-N,N'-bis(phenyl)-benzidine (TPD), and 4,4',4-tris(N-3-methylphenyl-N-phenyl-amino)-triphenylamine (MTDATA), but is not limited thereto.

[0150] Each of the n-type charge generation layer n-CGL and the p-type charge generation layer p-CGL may be formed to have a thickness of about to about When the thickness of the n-type charge generation layer n-CGL and the thickness of the p-type charge generation layer p-CGL satisfy the above range, satisfactory charge transport characteristics can be obtained without significantly increasing the driving voltage.

[0151] The second stack ST2 may be disposed on the charge generation layer 224. For example, the hole transport layer HTL may be disposed on the p-type charge generation layer p-CGL. The hole transport layer HTL of the second stack ST2 may be the same as the hole transport layer HTL in the first stack ST1.

[0152] The second emission layer 222b may be arranged on the hole transport layer HTL. The second emission layer 222b may include an organic material that emits one of red light, blue light, and green light. For example, when the second emission layer 222b emits red light, the second emission layer 222b may be formed by using, for example, a red dopant in a specific host material. As another example, when the second emission layer 222b emits green light, the second emission layer 222b may be formed by using, for example, a green dopant in a specific host material. As yet another example, when the second emission layer 222b emits blue light, the second emission layer 222b may be formed by using, for example, a blue dopant in a specific host material.

[0153] In one embodiment, the first emission layer 222a and the second emission layer 222b may emit light having the same wavelength, or may emit light having different wavelengths. For example, both the first emission layer 222a and the second emission layer 222b may emit blue light. As another example, the first emission layer 222a may emit blue light, and the second emission layer 222b may emit green light. However, the embodiment is not limited thereto.

[0154] The second common layer 223 may be disposed on the second emission layer 222b. The second common layer 223 may be used as an electron transport region. Figure 4 The second common layer described is the same, and thus a detailed description thereof is omitted.

[0155] refer to Figure 4 and Figure 5 The described organic light emitting diode OLED may include a second electrode 230 on the second common layer 223. Similar to the first common layer 221 and the second common layer 223, the second electrode 230 may be provided as a single body over a plurality of organic light emitting diodes OLED.

[0156] The second electrode 230 may include a conductive material having a low work function. For example, the second electrode 230 may include a (semi) transparent layer including silver (Ag), Mg, Al, platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), Li, calcium (Ca) or an alloy thereof. As another example, the second electrode 230 may further include a (semi) transparent layer including ITO, IZO, ZnO or In on the (semi) transparent layer including the above materials. 2 O 3 layer.

[0157] The second electrode 230 requires a low sheet resistance to increase power efficiency and reduce IR drop (i.e., voltage drop). However, a trade-off relationship is established in which the light absorption rate of the second electrode 230 increases and the light efficiency of the organic light emitting diode OLED decreases. Therefore, it is necessary to implement a second electrode 230 having a low sheet resistance and a low light absorption rate.

[0158] In one embodiment, the second electrode 230 may have a multi-layer structure and may also be referred to as a multi-layer electrode. The second electrode 230 may include a first conductive layer (ie, Figure 6 The first conductive layer 231 in the embodiment of the present invention and the second conductive layer including a single metal material (ie, Figure 6 The second conductive layer 232 in FIG. 1 ). This will refer to Figure 6 to Figure 7 Describe in detail.

[0159] Figure 6 to Figure 7 is a schematic cross-sectional view of a stacked structure of the second electrode 230 according to an embodiment.

[0160] See also Figure 6 The second electrode 230 may include a first conductive layer 231, a second conductive layer 232, and a third conductive layer 233 stacked in sequence. The first conductive layer 231 may be arranged at Figure 4 or Figure 5 The second conductive layer 232 may be disposed between the first conductive layer 231 and the third conductive layer 233.

[0161] The first conductive layer 231 is a layer including different types of metal materials, and may include a first base metal BM1 and a first additive metal AM1 different from the first base metal BM1. The first conductive layer 231 including the first base metal BM1 and the first additive metal AM1 may mean that the first conductive layer 231 may include a material in which the first base metal BM1 and the first additive metal AM1 are alloyed, or may mean that both an element of the first base metal BM1 and an element of the first additive metal AM1 are in the first conductive layer 231. For example, in order for the first conductive layer 231 to include the first base metal BM1 and the first additive metal AM1, the first conductive layer 231 may be formed by simultaneously spraying a material of the first base metal BM1 and a material of the first additive metal AM1 on a substrate.

[0162] In one embodiment, the first base metal BM1 may include at least one material selected from Ag, Au, Cu, Al, and Mg. In another embodiment, the first base metal BM1 may include a material having a thickness equal to or greater than about 1×10 7S / m. In one embodiment, the first additive metal AM1 may include a material selected from at least one of Mg, Ca, Li, Au, Al, Yb, Cu, and Sm. In another embodiment, the first additive metal AM1 may include at least one of metals having a work function equal to or less than about 3 eV. Because the first conductive layer 231 must include different types of metal materials, the first base metal BM1 and the first additive metal AM1 must be selected from different metal materials.

[0163] In one embodiment, the volume ratio of the first base metal BM1 to the first additive metal AM1 in the first conductive layer 231 may be in the range of about 99:1 to about 1:1. For example, the first conductive layer 231 may include an amount of the first base metal BM1 in the range of about 50% to about 99% by volume and an amount of the first additive metal AM1 in the range of about 1% to about 50% by volume. Therefore, the volume amount of the first base metal BM1 may be equal to or greater than the volume amount of the first additive metal BM1. In one embodiment, the first conductive layer 231 may include Ag as the first base metal BM1 and Mg as the first additive metal AM1, so that the first conductive layer 231 may be a silver-rich layer with a high silver content.

[0164] The first conductive layer 231 allows metal particles forming the second conductive layer 232 to be uniformly distributed during an initial formation process of the second conductive layer 232 as described below, and thus the second conductive layer 232 may be uniformly formed.

[0165] The second conductive layer 232 is a highly conductive layer and may include a single metal material SM. The second conductive layer 232 including the single metal material SM may mean that the second conductive layer 232 includes a pure single metal element except for inevitable impurities.

[0166] In one embodiment, the single metal material SM may include at least one material selected from Ag, Au, Cu, Al, and Mg. In another embodiment, the single metal material SM may include a material having a carbon content equal to or greater than about 1×10 7 At least one of metals having an electrical conductivity of 200 s / m. For example, the second conductive layer 232 may include silver (Ag), and the second conductive layer 232 may be provided as a pure silver (Ag) layer.

[0167] Since the second conductive layer 232 includes a conductive layer having a thickness equal to or greater than about 1×10 7 The second conductive layer 232 may be implemented as a high conductive layer. The second electrode 230 including the second conductive layer 232 may have low resistance and high conductivity, and may achieve high reflection while reducing light absorption, and thus may improve outcoupling.

[0168] The third conductive layer 233 is a layer including different types of metal materials, and may include a second base metal BM2 and a second additive metal AM2 different from the second base metal BM2. The inclusion of the second base metal BM2 and the second additive metal AM2 by the third conductive layer 233 may mean that the third conductive layer 233 may include a material in which the second base metal BM2 and the second additive metal AM2 are alloyed, or may mean that both an element of the second base metal BM2 and an element of the second additive metal AM2 are in the third conductive layer 233. For example, in order for the third conductive layer 233 to include the second base metal BM2 and the second additive metal AM2, the third conductive layer 233 may be formed by simultaneously spraying a material of the second base metal BM2 and a material of the second additive metal AM2 on a substrate.

[0169] In one embodiment, the second base metal BM2 may include at least one material selected from Ag, Au, Cu, Al, and Mg. In another embodiment, the second base metal BM2 may include a material having a thickness equal to or greater than about 1×10 7 The second additive metal AM2 may include at least one of metals having an electrical conductivity of 100 Å / m. In one embodiment, the second additive metal AM2 may include a material selected from at least one of Mg, Ca, Li, Au, Al, Yb, Cu, and Sm. In another embodiment, the second additive metal AM2 may include at least one of metals having a work function equal to or less than about 3 eV. Since the third conductive layer 233 must include different types of metal materials, the second base metal BM2 and the second additive metal AM2 must be selected from different metal materials.

[0170] In one embodiment, the volume ratio of the second base metal BM2 to the second additive metal AM2 in the third conductive layer 233 may be in the range of about 99:1 to about 1:1. For example, the third conductive layer 233 may include an amount of the second base metal BM2 in the range of about 50% to about 99% by volume and an amount of the second additive metal AM2 in the range of about 1% to about 50% by volume. Therefore, the volume amount of the second base metal BM2 may be equal to or greater than the volume amount of the second additive metal AM2. In one embodiment, the third conductive layer 233 may include Ag as the second base metal BM2 and Mg as the second additive metal AM2, so that the third conductive layer 233 may be a silver-rich layer with a high silver content.

[0171] The third conductive layer 233 may ensure thermal and electrical stability of the second electrode 230 by chemically bonding with atoms (eg, Ag atoms) of the single metal material SM of the second conductive layer 232 disposed directly under the third conductive layer 233 .

[0172] In an embodiment, the third conductive layer 233 may be provided as the same layer as the first conductive layer 231. The first conductive layer 231 and the third conductive layer 233 being the same layer may mean that the first base metal BM1 of the first conductive layer 231 and the second base metal BM2 of the third conductive layer 233 include the same material and the first additive metal AM1 of the first conductive layer 231 and the second additive metal AM2 of the third conductive layer 233 may include the same material. However, even in such an embodiment, the volume ratio of the first base metal BM1 to the first additive metal AM1 in the first conductive layer 231 may be equal to or different from the volume ratio of the second base metal BM2 to the second additive metal AM2 in the third conductive layer 233.

[0173] In another embodiment, the third conductive layer 233 may be provided as a different layer from the first conductive layer 231. The first conductive layer 231 and the third conductive layer 233 being different layers may mean that the first base metal BM1 of the first conductive layer 231 and the second base metal BM2 of the third conductive layer 233 include different materials, or the first additive metal AM1 of the first conductive layer 231 and the second additive metal AM2 of the third conductive layer 233 include different materials.

[0174] The thickness t1 of the first conductive layer 231 and the thickness t3 of the third conductive layer 233 may both be smaller than the thickness t2 of the second conductive layer 232. The thickness t1 of the first conductive layer 231 may be equal to or different from the thickness t3 of the third conductive layer 233. In one embodiment, the thickness t1 of the first conductive layer 231 may be smaller than the thickness t3 of the third conductive layer 233.

[0175] In one embodiment, the thickness t1 of the first conductive layer 231 may be about to about In one embodiment, the thickness t3 of the third conductive layer 233 may be about to about When the thickness t1 of the first conductive layer 231 and the thickness t3 of the third conductive layer 233 are both less than When the thickness t1 and t3 exceed t1, it may be difficult to form the first conductive layer 231 and the third conductive layer 233 in the process thereof. When the light transmittance of the first conductive layer 231 and the third conductive layer 233 is reduced, the light transmittance of the first conductive layer 231 and the third conductive layer 233 may be reduced. In one embodiment, the thickness t2 of the second conductive layer 232 may be about to about When the thickness t2 of the second conductive layer 232 is less than When the thickness t2 exceeds When the light absorption rate of the second conductive layer 232 is increased, the efficiency of the organic light emitting diode OLED may be reduced.

[0176] In one embodiment, the thickness ratio (t1:t2:t3) of the first conductive layer 231 to the second conductive layer 232 to the third conductive layer 233 may be about 1:6:1. For example, in order to satisfy the above thickness ratio (t1:t2:t3) of the first conductive layer 231 to the second conductive layer 232 to the third conductive layer 233, the thickness t1 of the first conductive layer 231 may be about The thickness t2 of the second conductive layer 232 may be approximately The thickness t3 of the third conductive layer 233 may be about

[0177] See also Figure 7 The second electrode 230 includes a first conductive layer 231, a second conductive layer 232, and a third conductive layer 233 stacked in sequence, but each of the first conductive layer 231 and the second conductive layer 232 may be provided in plural. Each of the first conductive layer 231 and the second conductive layer 232 may be repeatedly provided in n number, and the third conductive layer 233 may be located at the top. Figure 7 A structure in which the first conductive layer 231, the second conductive layer 232, the first conductive layer 231, the second conductive layer 232, and the third conductive layer 233 are sequentially stacked is illustrated. The characteristics of each of the first conductive layer 231, the second conductive layer 232, and the third conductive layer 233 are the same as those of the above reference Figure 6 Same as those described.

[0178] In this way, through a structure in which n first conductive layers 231 and n second conductive layers 232 (where n is an integer greater than or equal to 2) are alternately stacked and a third conductive layer 233 is stacked on top, a plurality of second conductive layers 232 each including a single metal material SM can be provided, thereby realizing a second electrode 230 with high conductivity.

[0179] Figure 8 is a schematic cross-sectional view of a portion of a display device according to an embodiment.

[0180] See also Figure 8, the first to third pixels Pr, Pg, and Pb may be arranged on the substrate 100. The first to third pixels Pr, Pg, and Pb include first to third organic light emitting diodes OLED1, OLED2, and OLED3 and a pixel circuit PC, respectively, and each of the first to third organic light emitting diodes OLED1, OLED2, and OLED3 is electrically connected to the pixel circuit PC, so that light emission can be controlled. In the following description, the pixel circuit PC included in the first to third pixels Pr, Pg, and Pb has the same structure, and therefore the stacked structure will be described for one pixel.

[0181] The substrate 100 may include a glass material or a polymer resin. In one embodiment, the substrate 100 may include a sublayer. The sublayer may have a structure in which an organic layer and an inorganic layer are alternately stacked. In the case where the substrate 100 includes a polymer resin, the substrate 100 may include polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, or cellulose acetate propionate.

[0182] The display layer 200 including a display element such as an organic light emitting diode and a thin film encapsulation layer (not shown) covering the display layer may be disposed on the substrate 100. Hereinafter, the display layer will be described in detail.

[0183] The buffer layer 201 may be formed on the substrate 100 to prevent impurities from penetrating into the semiconductor layer Act of the thin film transistor TFT. The buffer layer 201 may include an inorganic insulating material such as silicon nitride, silicon oxide, and silicon oxynitride, and may include a single layer or multiple layers including the inorganic insulating material.

[0184] The pixel circuit PC may be disposed on the buffer layer 201. The pixel circuit PC may be disposed to correspond to each pixel P. The pixel circuit PC includes a thin film transistor TFT and a storage capacitor Cst. The thin film transistor TFT may include a semiconductor layer Act, a gate electrode GE, a source electrode SE, and a drain electrode DE.

[0185] Despite Figure 8 Although not shown in the figure, the data line DL of the pixel circuit PC may be electrically connected to the switching thin film transistor included in the pixel circuit PC. Figure 8 The embodiment illustrates a top gate type thin film transistor TFT in which the gate electrode GE is disposed on the semiconductor layer Act with the gate insulating layer 203 therebetween, but in another embodiment, the thin film transistor TFT may include a bottom gate type thin film transistor.

[0186] In one embodiment, the semiconductor layer Act may include an oxide semiconductor. In another embodiment, the semiconductor layer Act may include amorphous silicon, polycrystalline silicon, an organic semiconductor, etc.

[0187] The gate electrode GE may include a low resistance metal material. The gate electrode GE may include a conductive material including molybdenum (Mo), aluminum (Al), copper (Cu), or titanium (Ti), and may include a single layer or multiple layers including the above materials.

[0188] The gate insulating layer 203 between the semiconductor layer Act and the gate electrode GE may include an inorganic insulating material such as silicon oxide, silicon oxynitride, silicon nitride, aluminum oxide, titanium oxide, tantalum oxide, and hafnium oxide. The gate insulating layer 203 may be a single layer or multiple layers including the above materials.

[0189] The source electrode SE and the drain electrode DE may be located on the same layer as the data line DL and may include the same material. The source electrode SE, the drain electrode DE, and the data line DL may include a material having excellent conductivity. The source electrode SE and the drain electrode DE may each include a conductive material including Mo, Al, Cu, or Ti, and may include a single layer or multiple layers including the above materials. For example, the source electrode SE, the drain electrode DE, and the data line DL may each include a multilayer of Ti / Al / Ti.

[0190] The storage capacitor Cst may include a first electrode CE1 and a second electrode CE2 overlapping each other with a first intermediate insulating layer 205 therebetween. The storage capacitor Cst may overlap with the thin film transistor TFT. In this regard, Figure 8 The gate electrode GE of the exemplary thin film transistor TFT is used as the first electrode CE1 of the storage capacitor Cst. In another embodiment, the storage capacitor Cst may not overlap with the thin film transistor TFT. The storage capacitor Cst may be covered by the second intermediate insulating layer 207. The second electrode CE2 of the storage capacitor Cst may include a conductive material including Mo, Al, Cu or Ti, and may include a single layer or multiple layers including the above materials.

[0191] The first intermediate insulating layer 205 and the second intermediate insulating layer 207 may each include an inorganic insulating material such as silicon oxide, silicon oxynitride, silicon nitride, aluminum oxide, titanium oxide, tantalum oxide, or hafnium oxide. The first intermediate insulating layer 205 and the second intermediate insulating layer 207 may each include a single layer or multiple layers including the above materials.

[0192] The pixel circuit PC including the thin film transistor TFT and the storage capacitor Cst may be covered by the first planarization insulating layer 208. An upper surface of the first planarization insulating layer 208 may include a substantially flat surface.

[0193] Although not shown, a third intermediate insulating layer (not shown) may be further disposed under the first planarization insulating layer 208. The third intermediate insulating layer may include an inorganic insulating material such as silicon oxide, silicon nitride, or silicon oxynitride.

[0194] The pixel circuit PC may be electrically connected to the first electrode 210. Figure 5 As shown in FIG, the contact metal layer CM (see Figure 8 ) may be between the thin film transistor TFT and the first electrode 210. The contact metal layer CM may be electrically connected to the thin film transistor TFT through a contact hole formed in the first planarization insulating layer 208, and the first electrode 210 may be electrically connected to the contact metal layer CM through a contact hole formed in the second planarization insulating layer 209 on the contact metal layer CM. The contact metal layer CM may include a conductive material including Mo, Al, Cu, or Ti, and may include a single layer or multiple layers including the above materials. In one embodiment, the contact metal layer CM may include multiple layers of Ti / Al / Ti.

[0195] The first planarization insulating layer 208 and the second planarization insulating layer 209 may both include an organic insulating material, such as a general polymer such as polymethyl methacrylate (PMMA) or polystyrene (PS), a polymer derivative having a phenolic group, an acrylic polymer, an imide polymer, an aryl ether polymer, an amide polymer, a fluorine polymer, a paraxylene polymer, a vinyl alcohol polymer, or a blend thereof. In one embodiment, the first planarization insulating layer 208 and the second planarization insulating layer 209 may both include polyimide.

[0196] The first to third organic light emitting diodes OLED1, OLED2, and OLED3 may be disposed on the second planarization insulating layer 209. As an example, each of the first to third organic light emitting diodes OLED1, OLED2, and OLED3 may have a Figure 5 Described in series structure.

[0197] Each of the first to third organic light emitting diodes OLED1, OLED2, and OLED3 may include a first electrode 210, a first common layer 221, a first emission layer 222a, a charge generation layer 224, a second emission layer 222b, a second common layer 223, and a second electrode 230 (see FIG. Figure 5 ). In the first to third organic light emitting diodes OLED1, OLED2, and OLED3, the first electrode 210, the first emission layer 222a, and the second emission layer 222b are patterned and provided for each pixel, and the first common layer 221, the second common layer 223, the charge generation layer 224, and the second electrode 230 may all be provided as one body in the display area.

[0198] exist Figure 8 In Figure 5The first to third organic light emitting diodes OLED1, OLED2 and OLED3 of the above-mentioned stacked structure of the organic light emitting diode are used as an example. For the first to third organic light emitting diodes OLED1, OLED2 and OLED3, it is also possible to use Figure 6 or Figure 7 The stacked structure of the second electrode 230 is shown in FIG.

[0199] The first electrode 210 may include a conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In 2 O 3 ), indium gallium oxide (IGO) or aluminum zinc oxide (AZO). In another embodiment, the first electrode 210 may include a reflective film including Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr or a compound thereof. In yet another embodiment, the first electrode 210 may further include a reflective film including ITO, IZO, ZnO or In on and / or below the reflective film. 2 O 3 membrane.

[0200] The pixel defining layer 215 may be formed on the first electrode 210. The pixel defining layer 215 may include an opening exposing the upper surface of the first electrode 210, and may cover the edge of the first electrode 210. In one embodiment, the pixel defining layer 215 may include an organic insulating material. In another embodiment, the pixel defining layer 215 may include an inorganic insulating material such as silicon nitride, silicon oxynitride, or silicon oxide. In yet another embodiment, the pixel defining layer 215 may include an organic insulating material and an inorganic insulating material.

[0201] See also Figure 5 The intermediate layer 220 includes two or more emission layers (eg, a first emission layer 222a and a second emission layer 222b). Each of the first emission layer 222a and the second emission layer 222b may include a polymer organic material or a low molecular weight organic material that emits light having a specific color.

[0202] The intermediate layer 220 may include a first common layer 221 between the first emission layer 222 a and the first electrode 210 and / or a second common layer 223 between the second emission layer 222 b and the second electrode 230 .

[0203] The first common layer 221 may include a single layer or multiple layers. For example, when the first common layer 221 includes a polymer material, the first common layer 221 may include a hole transport layer HTL having a single layer structure, and may include PEDOT or polyaniline (PAN). When the first common layer 221 includes a low molecular weight material, the first common layer 221 may include a hole injection layer HIL and a hole transport layer HTL.

[0204] The second common layer 223 may be omitted. For example, when the first common layer 221, the first emission layer 222a, and the second emission layer 222b include a polymer material, the second common layer 223 may be formed. The second common layer 223 may include a single layer or multiple layers. The second common layer 223 may include an electron transport layer ETL and / or an electron injection layer EIL.

[0205] The charge generation layer 224 may be between the first emission layer 222a and the second emission layer 222b. The charge generation layer 224 may include an n-type charge generation layer n-CGL and a p-type charge generation layer p-CGL (see Figure 5 ).

[0206] The second electrode 230 may include a first conductive layer 231, a second conductive layer 232, and a third conductive layer 233 stacked in sequence. The first conductive layer 231 may be disposed on the second common layer 223, for example, Figure 4 or Figure 5 The second conductive layer 232 may be disposed between the first conductive layer 231 and the third conductive layer 233 .

[0207] The first conductive layer 231, the second conductive layer 232, and the third conductive layer 233 may be provided as a whole on the first to third organic light emitting diodes OLED1, OLED2, and OLED3. The first common layer 221, the second common layer 223, and the second electrode 230 may each be formed on the front surface of the substrate 100 by using a thermal deposition method.

[0208] Figure 8 For example, see the reference above Figure 6 The second electrode 230 described includes a first conductive layer 231, a second conductive layer 232, and a third conductive layer 233. However, Figure 8 The structure can have Figure 7 The first conductive layer 231, the second conductive layer 232 and the third conductive layer 233 may each be the same as the structure of the second electrode 230 illustrated in FIG. Figure 6 Same as those described.

[0209] In one embodiment, the capping layer 240 may be located on the second electrode 230. For example, the capping layer 240 may include a single layer or multiple layers including a material selected from an organic material, an inorganic material, and a mixture thereof. In another embodiment, a lithium fluoride (LiF) layer may be located on the capping layer 240.

[0210] Since the first to third organic light emitting diodes OLED1, OLED2, and OLED3 may be damaged by external moisture or oxygen, the thin film encapsulation layer 300 may cover and protect the first to third organic light emitting diodes OLED1, OLED2, and OLED3. The thin film encapsulation layer 300 may cover the display area DA and may extend to the non-display area outside the display area DA. The thin film encapsulation layer 300 may include at least one organic encapsulation layer and at least one inorganic encapsulation layer. For example, the thin film encapsulation layer 300 may include a first inorganic encapsulation layer 310, an organic encapsulation layer 320, and a second inorganic encapsulation layer 330.

[0211] The first inorganic encapsulation layer 310 may cover the second electrode 230 and may include silicon oxide, silicon nitride and / or silicon oxynitride. Because the first inorganic encapsulation layer 310 is formed along the structure below it, the upper surface of the first inorganic encapsulation layer 310 may be uneven. The organic encapsulation layer 320 may cover the first inorganic encapsulation layer 310. Unlike the first inorganic encapsulation layer 310, the upper surface of the organic encapsulation layer 320 may be substantially flat. In one embodiment, the upper surface of the organic encapsulation layer 320 may be substantially flat in a portion corresponding to the display area DA. The organic encapsulation layer 320 may include one or more materials selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, hexamethyldisiloxane and acrylic resin (e.g., polymethyl methacrylate, polyacrylic acid, etc.). The second inorganic encapsulation layer 330 may cover the organic encapsulation layer 320 and may include silicon oxide, silicon nitride and / or silicon oxynitride.

[0212] Even in the case where the thin film encapsulation layer 300 is cracked, the above-described multi-layer structure of the thin film encapsulation layer 300 can prevent the crack from being connected between the first inorganic encapsulation layer 310 and the organic encapsulation layer 320 or between the organic encapsulation layer 320 and the second inorganic encapsulation layer 330. Therefore, the formation of a channel through which external moisture or oxygen penetrates into the display area DA can be prevented or minimized.

[0213] The filler 610 may be disposed on the thin film encapsulation layer 300. The filler 610 may be used as a buffer against external pressure, etc. The filler 610 may include an organic material such as methylsiloxane, phenylsiloxane, or polyimide. However, the embodiment is not limited thereto, and the filler 610 may include an organic sealant such as a urethane resin, an epoxy resin, or an acrylic resin, or an inorganic sealant such as silicon.

[0214] The light shielding layer 620 may be disposed on the thin film encapsulation layer 300. The light shielding layer 620 may be disposed directly on the second inorganic encapsulation layer 330 of the thin film encapsulation layer 300. The light shielding layer 620 may be disposed to correspond to a black matrix 510 to be described below, and may include a light shielding material that may be used in the black matrix 510.

[0215] The anti-reflection layer 500 may be provided under the upper substrate 700 and arranged to face the substrate 100 with the filler 610 therebetween. The anti-reflection layer 500 may include a black matrix 510, color filters 520R, 520G, and 520B, first and second color conversion layers QD1 and QD2, a transmission layer TL, and a partition wall 530.

[0216] Each of the first color conversion layer QD1 and the second color conversion layer QD2 may include a quantum dot. The quantum dot exhibits excitation and emission characteristics according to the material and size, and thus may convert incident light into light having a specific color. Various materials may be used as the quantum dot.

[0217] In one embodiment, the quantum dot may have a core-shell structure, which includes a core comprising a nanocrystal and a shell surrounding the core. The core of the quantum dot may be selected from a group consisting of a II-VI compound, a III-V compound, a IV-VI compound, a Group IV element, a Group IV compound, and a combination thereof.

[0218] The II-VI Group compound may be selected from the group consisting of: a binary compound selected from the group consisting of CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS and mixtures thereof; a binary compound selected from the group consisting of AgInS, CuInS, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, C Ternary compounds selected from the group consisting of CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS and mixtures thereof; and quaternary compounds selected from the group consisting of HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe and mixtures thereof.

[0219] The III-V compounds may be selected from the group consisting of: binary compounds selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb and mixtures thereof; ternary compounds selected from the group consisting of GaNPs, GaNAs, GaNSb, GaPAs, GaPSb, AlNPs, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InNAs, InNSb, InPAs, InPSb and mixtures thereof; and quaternary compounds selected from the group consisting of GaAlNPs, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb and mixtures thereof.

[0220] The IV-VI group compound may be selected from the group consisting of: a binary compound selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe and mixtures thereof; a ternary compound selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe and mixtures thereof; and a quaternary compound selected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe and mixtures thereof. The IV group element may be selected from the group consisting of Si, Ge and mixtures thereof. The IV group compound may be selected from the binary compound selected from the group consisting of SiC, SiGe and mixtures thereof.

[0221] The binary, ternary or quaternary compound may be present in the particle in a uniform concentration or may be present in the particle in a state where the concentration distribution is divided into parts that are different. The quantum dot may have a core-shell structure in which one quantum dot surrounds another quantum dot. The interface between the core and the shell may have a concentration gradient in which the concentration of the element in the shell gradually decreases toward the center.

[0222] The shell of the quantum dot can be used as a protective layer to maintain the semiconductor properties by preventing chemical transformation of the core, and / or can be used as a charging layer for imparting electrophoretic properties to the quantum dot. The shell can include a single layer or multiple layers. The interface between the core and the shell can have a concentration gradient, wherein the concentration of elements in the shell gradually decreases toward the center. Examples of the shell of the quantum dot can include metal oxides, non-metal oxides, semiconductor compounds, or combinations thereof.

[0223] For example, examples of metal oxides or non-metal oxides may include SiO 2 、Al 2 O3 、TiO 2 、ZnO、MnO、Mn 2 O 3 , Mn 3 O 4 , CuO, FeO, Fe 2 O 3 , Fe 3 O 4 , CoO, Co 3 O 4 , NiO, etc.; or binary compounds such as MgAl 2 O 4 、CoFe 2 O 4 、NiFe 2 O 4 、CoMn 2 O 4 The invention also can be used as a ternary compound of the invention, but the embodiment is not limited thereto.

[0224] Examples of semiconductor compounds may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, etc., but embodiments are not limited thereto.

[0225] The quantum dots may have a full width at half maximum (FWHM) of an emission wavelength spectrum equal to or less than about 45 nm. For example, the quantum dots may have a FWHM of an emission wavelength spectrum equal to or less than about 40 nm. For example, the quantum dots may have a FWHM of an emission wavelength spectrum equal to or less than about 30 nm. Color purity or color reproducibility may be improved within these ranges. Light emitted by these quantum dots may be emitted in all directions, and thus the optical field of view may be improved.

[0226] The form of quantum dots is not limited to the form used in the art. For example, quantum dots may have the form of spherical, pyramidal, multi-armed or cubic nanoparticles, nanotubes, nanowires, nanofibers or nanoplate-like particles.

[0227] Quantum dots can adjust the color of emitted light according to their particle size, and thus quantum dots can have various emission colors such as blue, red, green, etc.

[0228] The core of the quantum dot may have a diameter in the range of about 2 nm to about 10 nm, and when the quantum dot is exposed to light, the quantum dot may emit light having a specific wavelength according to the size of the particle and the type of material. Therefore, the average size of the quantum dots included in the first color conversion layer QD1 may be different from the average size of the quantum dots included in the second color conversion layer QD2. For example, as the size of the quantum dot increases, color light having a longer wavelength may be emitted. Accordingly, the size of the quantum dot may be selected according to the color of the first pixel Pr and the second pixel Pg.

[0229] In addition to quantum dots, the first color conversion layer QD1 and the second color conversion layer QD2 may further include various materials to mix and properly disperse the quantum dots. For example, the first color conversion layer QD1 and the second color conversion layer QD2 may further include scattering particles, solvents, photoinitiators, binder polymers, dispersants, and the like.

[0230] The color conversion layer may not be provided in the emission area EA of the third pixel Pb accordingly, but the transmission layer TL may be arranged therein. The transmission layer TL may be provided as an organic material, through which light may be emitted without converting the wavelength of light emitted from the third organic light emitting diode OLED3 of the third pixel Pb. The transmission layer TL may include scattering particles for uniform color dispersion. In one embodiment, the scattering particles may have a diameter in the range of about 200 nm to about 400 nm.

[0231] exist Figure 8 In the embodiment illustrated in the figure, the first organic light emitting diode OLED1 and the second organic light emitting diode OLED2 respectively included in the first pixel Pr and the second pixel Pg may emit light having the same wavelength, and the colors of the first pixel Pr and the second pixel Pg may be determined as the colors of light emitted by the quantum dots of the first color conversion layer QD1 and the quantum dots of the second color conversion layer QD2.

[0232] A color conversion layer is not provided to correspond to the emission area EA of the third pixel Pb, and thus the color of the third pixel Pb may be determined as the color of light emitted by the third organic light emitting diode OLED3. For example, the first pixel Pr may realize red light, the second pixel Pg may realize green light, and the third pixel Pb may realize blue light.

[0233] The partition wall 530 may be between the first color conversion layer QD1 and the second color conversion layer QD2 and between the second color conversion layer QD2 and the transmissive layer TL to correspond to the non-emission area NEA. For example, the partition wall 530 may be between the first color conversion layer QD1 and the second color conversion layer QD2 and between the second color conversion layer QD2 and the transmissive layer TL.

[0234] In one embodiment, the partition wall 530 may include an organic material and a material for controlling optical density, such as CR or CrO. x 、Cr / CrO x 、Cr / CrO x / CrN y , resin (carbon pigment, RGB mixed pigment, etc.), graphite or non-Cr-based materials. In another embodiment, the partition wall 530 may include a pigment having red, green or yellow. The partition wall 530 may be used as a black matrix to prevent color mixing and improve visibility.

[0235] First to third color filters 520R, 520G, and 520B and a black matrix 510 may be provided between the upper substrate 700 and the first and second color conversion layers QD1 and QD2 and the transmissive layer TL.

[0236] The first to third color filters 520R, 520G, and 520B may be included to realize a full-color image and improve color purity and outdoor visibility. The first to third color filters 520R, 520G, and 520B may absorb stray light (e.g., lower light that has not been color-converted by quantum dots) that has passed through the first color conversion layer QD1 and the second color conversion layer QD2 without changing its wavelength in the first color conversion layer QD1 and the second color conversion layer QD2, and transmit only light having a desired wavelength. For example, the light that has passed through the first color filter 520R may be red light, the light that has passed through the second color filter 520G may be green light, and the light that has passed through the third color filter 520B may be blue light.

[0237] The black matrix 510 may be between the first to third color filters 520R, 520G, and 520B to correspond to the non-emission area NEA. The black matrix 510 may improve color sharpness and contrast. The black matrix 510 may include at least one of a black pigment, a black dye, and black particles. In an embodiment, the black matrix 510 may include a Cr or CrO X 、Cr / CrO X 、Cr / CrO X / CrN Y , resin (carbon pigment, RGB mixed pigment), graphite or non-Cr materials.

[0238] The color filters arranged adjacent to each other among the first to third color filters 520R, 520G, and 520B may be arranged to overlap each other in the non-emission area NEA. Since color filters having different colors are provided to overlap each other, the light blocking rate may be improved. In an embodiment, the color filters 520R, 520G, and 520B and the black matrix 510 may be omitted.

[0239] Fig. 9is a table obtained by measuring the transmittance, reflectance, and absorptance of the multilayer electrode to which the embodiment of the present disclosure is applied and the multilayer electrode to which the comparative example is applied, Fig.10 is a graph obtained by measuring the light transmittance in the comparative example and the embodiment, Fig.11 is a graph obtained by measuring the reflectance in Comparative Examples and Examples, Fig.12 is a graph obtained by measuring the absorbance in the comparative example and the example, and Fig.13 It is a graph obtained by measuring the sheet resistance and high temperature reliability in the comparative example and the embodiment.

[0240] exist Figures 9 to 13 In the present invention, a sample to which a single-layer electrode structure or a multi-layer electrode structure is applied after an electron transport layer ETL and an electron injection layer EIL are sequentially stacked on a glass substrate is used for evaluation. Figures 9 to 13 In the figure, the symbol of “X1:X2” indicates “base metal:additive metal.” In the case of the comparative example, a single layer of Ag:Mg was deposited and evaluated, and in the case of Examples 1 to 3, a multilayer structure of Ag:Mg / Ag / Ag:Mg was deposited and evaluated.

[0241] The comparative example discloses that the thickness of the single layer is An electrode layer comprising an Ag:Mg alloy.

[0242] Embodiments 1, 2 and 3 are embodiments of applying a multilayer electrode structure according to an embodiment of the present disclosure, and disclose the following structure: a first conductive layer including an Ag:Mg alloy, a second conductive layer including pure silver (Ag), and a third conductive layer including an Ag:Mg alloy are stacked. Embodiments 1 to 3 all represent the case where the first base metal, the second base metal and the single metal material are Ag, and the first additive metal and the second additive metal are Mg. In Embodiments 1 to 3, the thickness of the first conductive layer is equal to the thickness of the third conductive layer, but the thickness of the second conductive layer is different from the thickness of the first conductive layer and the thickness of the third conductive layer. In Embodiment 1, the thickness of the first conductive layer, the thickness of the second conductive layer, and the thickness of the third conductive layer are respectively and (Total thickness ). In Example 2, the thickness of the first conductive layer, the thickness of the second conductive layer and the thickness of the third conductive layer are respectively and (Total thickness ). In Example 3, the thickness of the first conductive layer, the thickness of the second conductive layer and the thickness of the third conductive layer are respectively and (Total thickness ).

[0243] Fig. 9 The table shows results obtained by respectively measuring the transmittance (T), reflectance (R), and absorbance (A) in different wavelength ranges (eg, 450 nm, 550 nm, and 650 nm).

[0244] See also Fig. 9 and Fig.10 , in terms of light transmittance (T), Examples 1 and 2 showed results at a level almost equal to that of the Comparative Example, or improved results in the short wavelength region.

[0245] See also Fig. 9 and Fig.11 , it can be confirmed that the reflectance (R) of Examples 1 to 3 increased by up to 10% compared with the comparative example.

[0246] See also Fig. 9 and Fig.12 It can be confirmed that the absorbance (A) of Examples 1 to 3, all of which use a multilayer structure, is reduced by up to -2.1% compared to the absorbance of the comparative example using a single-layer structure including Mg as a whole. This is because Mg corresponding to the first additive metal and the second additive metal has the property of absorbing light.

[0247] Thus, in the case of Examples 1 to 3 to which the multilayer structure according to the embodiment of the present disclosure is applied, the absorptivity (A) is reduced and the reflectivity (R) is increased compared to the comparative example, and accordingly, the outcoupling efficiency may be increased.

[0248] See also Fig. 9 and Fig.13 , the average value of the sheet resistance before heat treatment and the average value of the sheet resistance after heat treatment of the comparative example and embodiments 1 to 3 were measured. In the case of the comparative example, the deviation of the sheet resistance before and after heat treatment was 1.8, indicating that the sheet resistance after heat treatment increased significantly compared with that before heat treatment. On the other hand, in the case of embodiment 1, the deviation of the sheet resistance before and after heat treatment was 0.6, and in the case of embodiments 2 and 3, the deviation of the sheet resistance before and after heat treatment was 0.3. In the case of embodiments 1 to 3, it can be confirmed that the deviation of the sheet resistance before and after heat treatment is very small. The sheet resistance deviation in embodiments 1 to 3 is about 1 / 3 or less of the sheet resistance deviation in the comparative example, and therefore, it can be determined that the multilayer electrodes of embodiments 1 to 3 have better thermal stability than the single-layer electrodes of the comparative example.

[0249] Fig.14 is a table comparing the pixel efficiency of the comparative example with the pixel efficiency of the embodiment of the present disclosure, and Fig.15 The table is a comparison of the pixel efficiency of the comparative example and the pixel efficiency of the embodiment of the present disclosure.

[0250] Fig.14The table shows pixel efficiencies of red sub-pixels (R), green sub-pixels (G), and blue sub-pixels (B) regarding Comparative Example and Embodiments 1 to 5 and values ​​obtained by summing the pixel efficiencies. Fig.14 The comparative example, embodiment 1, embodiment 2 and embodiment 3 are respectively compared with the reference Fig. 9 The described comparative example, embodiment 1, embodiment 2 and embodiment 3 are the same. Embodiments 4 and 5 are different from embodiments 1 to 3 in the thickness of the second conductive layer including pure silver (Ag). The second conductive layer in embodiments 1 to 5 is formed to have different thicknesses, which are respectively and

[0251] The pixel efficiency of the comparative example is 53.4, and compared with this, the pixel efficiency of Example 1 increases by +3.2%, the pixel efficiency of Example 2 increases by +3.6%, the pixel efficiency of Example 3 increases by +2.8%, and the pixel efficiency of Example 4 increases by +0.7%. The pixel efficiency of Example 5 is at the same level as that of the comparative example. By this, it can be determined that when the thickness of the second conductive layer including a single metal material exceeds When the light transmittance of the multilayer electrode (ie, the cathode or the second electrode) is reduced, the pixel efficiency is reduced.

[0252] See also Fig.15 , showing the pixel efficiencies of Comparative Examples 1 to 4 and the pixel efficiencies of Examples 2 and 3. Fig.15 Examples 2 and 3 in the reference Fig. 9 Embodiments 2 and 3 described are identical.

[0253] In Comparative Example 1, as a single layer including an Ag:Mg alloy, an Ag-rich electrode was formed by adding 95% by volume of Ag and 5% of Mg, and in Comparative Example 2, as a single layer including an Mg:Ag alloy, a Mg-rich electrode was formed by adding 10% by volume of Ag and 90% by volume of Mg. Comparative Examples 3 and 4 each have a multilayer structure in which a first conductive layer including an Mg:Ag alloy, a second conductive layer including pure Ag, and a third conductive layer including an Mg:Ag alloy are stacked, and the multilayer structure is manufactured to have a Mg-rich characteristic. Comparative Examples 3 and 4 were evaluated by replacing the Ag:Mg of the first conductive layer and the third conductive layer in Examples 2 and 3 with Mg:Ag.

[0254] When the pixel efficiency of Comparative Example 1 is 53.4, compared with this, the pixel efficiency of Example 2 increases by +3.6%, and the pixel efficiency of Example 3 increases by +2.8%. On the other hand, the pixel efficiency of Comparative Example 2 including the magnesium-rich layer decreases by -4.5%, the pixel efficiency of Comparative Example 3 decreases by -0.4%, and the pixel efficiency of Comparative Example 4 decreases by -1.7%.

[0255] based on Fig.15 From the experimental results, as in Comparative Examples 2 to 4, it can be determined that when the volume amount of the additive metal is greater than the volume amount of the base metal (for example, when the electrode structure includes a magnesium-rich layer), the pixel efficiency is lower than that of Comparative Example 1, and is much lower than that of Examples 2 and 3.

[0256] According to the embodiments as described above, a light emitting diode having low driving voltage, high efficiency and long life and a display device including the same can be realized. However, the present disclosure is not limited by these effects.

[0257] Embodiments have been disclosed herein, and although terms are employed, they are used and interpreted in a general and descriptive sense only and not for purposes of limitation. In some cases, as will be appreciated by one of ordinary skill in the art, features, characteristics, and / or elements described in conjunction with one embodiment may be used alone or in combination with features, characteristics, and / or elements described in conjunction with other embodiments, unless specifically indicated otherwise. Accordingly, one of ordinary skill in the art will appreciate that various changes in form and detail may be made without departing from the spirit and scope of the present disclosure as set forth in the claims.

Claims

1. A multilayer electrode, characterized in that: The multilayer electrode comprises: a first conductive layer comprising a first base metal and a first additive metal different from the first base metal; a second conductive layer on the first conductive layer and comprising a single metallic material; and a third conductive layer on the second conductive layer and including a second base metal and a second additive metal different from the second base metal, The first conductive layer and the third conductive layer are only Mg:Ag alloy or Ag:Mg alloy, and the single metal material is Ag, Au, Cu, Al or Mg.

2. The multilayer electrode according to claim 1, characterized in that Each of a thickness of the first conductive layer and a thickness of the third conductive layer is smaller than a thickness of the second conductive layer.

3. The multilayer electrode according to claim 1, characterized in that Each of the thickness of the first conductive layer and the thickness of the third conductive layer is to within the range.

4. The multilayer electrode according to claim 1, characterized in that The thickness of the second conductive layer is to within the range.

5. The multilayer electrode according to claim 1, characterized in that The multilayer electrode has a plurality of stack structures each including the first conductive layer and the second conductive layer.

6. The multilayer electrode according to claim 1, characterized in that The thickness ratio of the first conductive layer to the second conductive layer to the third conductive layer is 1:6:

1.

7. A light emitting diode, comprising: a first electrode; a second electrode facing the first electrode; as well as an emitting layer between the first electrode and the second electrode, Characterized in that the second electrode is a multilayer electrode according to any one of claims 1-6.

8. A display device comprising: a first electrode on the substrate; a second electrode facing the first electrode; as well as an emitting layer between the first electrode and the second electrode, Characterized in that the second electrode is a multilayer electrode according to any one of claims 1-6.

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