Display device

Abstract

A display device includes: a circuit layer on a substrate; a pixel electrode on the circuit layer; an intermediate layer on the pixel electrode, and including a first emission layer, a second emission layer, a third emission layer, and a fourth emission layer; an opposing electrode on the intermediate layer; a color filter layer on the opposing electrode and including a first color filter, a second color filter, and a third color filter; and an optical auxiliary layer between the pixel electrode and the intermediate layer, in which a thickness of each of the plurality of layers included in the intermediate layer and a thickness of each of the plurality of optical auxiliary bodies included in the optical auxiliary layer are optimized.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0096415 filed in the Korean Intellectual Property Office on July 24, 2023, the disclosure of which is incorporated herein in its entirety by reference. Technical Field

[0003] Aspects of one or more embodiments relate to a display device. Background Art

[0004] A display device is a device that displays an image by receiving information about the image. The display device can be used as a display part of a small product such as a mobile phone, or as a display part of a large product such as a television.

[0005] The display device includes a plurality of pixels that receive an electrical signal and emit light to externally display an image. Each pixel includes a light emitting element, and for example, in the case of an organic light emitting display device, each pixel includes an organic light emitting diode as a light emitting element. Generally, in an organic light emitting display device, a thin film transistor and an organic light emitting diode are formed on a substrate, and the organic light emitting diode itself emits light.

[0006] Furthermore, much research is being conducted to improve the light efficiency of these display devices.

[0007] The above information disclosed in this Background section is only for enhancement of understanding of the background technology and therefore, the information discussed in this Background section does not necessarily constitute prior art. Utility Model Content

[0008] Aspects of one or more embodiments relate to a display device, and, for example, to a display device having relatively high light efficiency.

[0009] Aspects of one or more embodiments include a display device having relatively high light efficiency. However, these characteristics are merely illustrative, and the scope of embodiments according to the present disclosure is not limited thereto.

[0010] 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 the presented embodiments of the disclosure.

[0011] According to some embodiments, a display device includes: a circuit layer on a substrate; a pixel electrode on the circuit layer; an intermediate layer on the pixel electrode and including a first emission layer, a second emission layer, a third emission layer and a fourth emission layer, the first emission layer being configured to emit light within a first band, the second emission layer being configured to emit light within a second band, the third emission layer being configured to emit light within a third band, and the fourth emission layer being configured to emit light within the first band; an opposing electrode on the intermediate layer; a color filter layer on the opposing electrode, and the color filter layer including: a first color filter, the light within the second band being transmitted through the first color filter; a second color filter a pixel electrode and the intermediate layer, the optical auxiliary layer comprising a first optical auxiliary body having a first thickness and a second optical auxiliary body parallel to the first optical auxiliary body and having a second thickness, the second thickness being greater than the first thickness, wherein in the plan view, the first optical auxiliary body and the first color filter overlap each other, and in the plan view, the second optical auxiliary body and the third color filter overlap each other.

[0012] According to some embodiments, the intermediate layer may further include a first hole transport layer between the pixel electrode and the first emission layer.

[0013] According to some embodiments, the sum of the optical thickness of the first hole transport layer in the first band and the optical thickness of the second optical auxiliary body in the first band may be consistent with the sum of the optical thickness of the first hole transport layer in the second band and the optical thickness of the first optical auxiliary body in the second band.

[0014] According to some embodiments, the optical thickness of the first hole transport layer within the first wavelength band may be inversely proportional to the optical thickness of the second optical auxiliary body within the first wavelength band.

[0015] According to some embodiments, the portion of the first hole transport layer within the first wavelength band may be replaceable by the portion of the second optical auxiliary body within the first wavelength band.

[0016] According to some embodiments, the optical thickness of the portion of the first hole transport layer within the first wavelength band may be consistent with the optical thickness of the portion of the second optical auxiliary body within the first wavelength band.

[0017] According to some embodiments, the pixel electrode may include a reflective layer on the substrate and a first transparent conductive layer on the reflective layer, and the optical auxiliary layer may be located between the first transparent conductive layer and the intermediate layer.

[0018] According to some embodiments, the pixel electrode may further include a second transparent conductive layer under the reflective layer, and an upper surface of the second transparent conductive layer and a lower surface of the reflective layer may contact each other.

[0019] According to some embodiments, a difference between the second thickness and the first thickness may be greater than a thickness of the first emission layer.

[0020] According to some embodiments, the thickness of the first emission layer may be consistent with the thickness of the fourth emission layer.

[0021] According to some embodiments, the first wavelength band may be based on a blue visible light region, the second wavelength band may be based on a red visible light region, and the third wavelength band may be based on a green visible light region.

[0022] According to some embodiments, a first connection layer may be between the first emission layer and the second emission layer, and a second connection layer may be between the third emission layer and the fourth emission layer.

[0023] According to some embodiments, a thickness of the first connection layer and a thickness of the second connection layer may be greater than a thickness of the first emission layer.

[0024] According to some embodiments, the first connection layer may include a first electron transport layer on the first emission layer, a first charge generation layer on the first electron transport layer, and a second hole transport layer on the first charge generation layer.

[0025] According to some embodiments, the second connection layer may include a second electron transport layer on the third emission layer, a second charge generation layer on the second electron transport layer, and a third hole transport layer on the second charge generation layer.

[0026] According to some embodiments, an upper surface of the second emission layer and a lower surface of the third emission layer may be in contact with each other.

[0027] According to some embodiments, a cover layer may be further between the opposite electrode and the color filter layer.

[0028] According to some embodiments, the difference between the second thickness and the first thickness may be about to about within the range.

[0029] According to some embodiments, the optical auxiliary layer may further include a third optical auxiliary body having a third thickness and arranged side by side with the first optical auxiliary body and the second optical auxiliary body.

[0030] According to some embodiments, the third thickness may be smaller than the first thickness and the second thickness.

[0031] According to some embodiments, the difference between the third thickness and the second thickness may be about to about within the range.

[0032] According to some embodiments, the difference between the second thickness and the third thickness may be six times the difference between the first thickness and the second thickness.

[0033] According to some embodiments, in the plan view, the third optical auxiliary body may overlap with the second color filter.

[0034] According to some embodiments, the thickness of the intermediate layer may be about to about within the range. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and other aspects, features and characteristics of some embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings, in which:

[0036] Figure 1 is a plan view schematically showing a display panel of a display device according to an embodiment;

[0037] Figure 2 yes Figure 1 An equivalent circuit diagram of a pixel of a display panel;

[0038] Figure 3 It is schematically shown Figure 1 A cross-sectional view of a portion of a display panel;

[0039] Figure 4 It is schematically shown Figure 3 Conceptual diagram of a cross section of an intermediate layer;

[0040] Figure 5 It is shown Figure 3 The refractive index of the optical auxiliary layer and Figure 4 A graph of the refractive index of a first hole transport layer;

[0041] Figure 6 It is schematically shown Figure 3 A cross-sectional view of an example of a stacked structure of a pixel electrode, an optical auxiliary layer, an intermediate layer, a cover layer, and a color filter layer;

[0042] Figures 7 to 9 It is shown Figure 6 A view of the light efficiency according to each wavelength band in an example;

[0043] Fig.10 It is schematically shown Figure 3 A cross-sectional view of another example of a stacked structure of a pixel electrode, an optical auxiliary layer, an intermediate layer, a cover layer, and a color filter layer;

[0044] Fig.11 It is schematically shown Figure 3 A cross-sectional view of another example of a stacked structure of a pixel electrode, an optical auxiliary layer, an intermediate layer, a cover layer, and a color filter layer;

[0045] Fig.12 It is schematically shown Figure 3 A cross-sectional view of another example of a stacked structure of a pixel electrode, an optical auxiliary layer, an intermediate layer, a cover layer, and a color filter layer; and

[0046] Fig.13 and Fig.14 is a schematic diagram showing a display device according to a comparative example. Figure 3 A cross-sectional view of an example of a cross-section corresponding to a stacked structure of a pixel electrode, an optical auxiliary layer, an intermediate layer, a cover layer and a color filter layer. DETAILED DESCRIPTION

[0047] Reference will now be made to the aspects of some embodiments in more detail, the examples of these embodiments are shown in the accompanying drawings, wherein the same reference numerals refer to the same elements from time to time. In this regard, the embodiments presented can have different forms and should not be construed as being limited to the description set forth herein. Therefore, the embodiments are described below only by reference to the accompanying drawings to illustrate the aspects of this description. As used in this article, the term "and / or" includes any combination and all combinations of one or more of the relevant listed items. Throughout the disclosure, the statement "at least one (kind / person) of a, b and c" represents only a, only b, only c, both a and b, both a and c, both b and c, all of a, b and c or their variations.

[0048] Because various modifications and various embodiments of the present disclosure are possible, specific embodiments are shown in the drawings and described in detail in the specific description. The effects and features of the present disclosure and methods for achieving them will be apparent with reference to the embodiments described in detail below in conjunction with the drawings. However, the present disclosure is not limited to the embodiments disclosed herein, but can be implemented in various forms.

[0049] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings, and the same or corresponding components are denoted by the same reference numerals, and the same reference numerals are assigned and redundant descriptions will be omitted.

[0050] In the following embodiments, when a part such as a layer, a film, a region or a plate is on another part, this is not only when the part is on the other part, but also when other elements are placed between the part and the other part. In addition, in the accompanying drawings, the size of the element may be exaggerated or reduced for ease of explanation. For example, because the size and thickness of each component shown in the drawings are arbitrarily indicated for ease of explanation, the present disclosure is not necessarily limited to the drawings.

[0051] In the following embodiments, the x-axis, y-axis, and z-axis are not limited to the three axes on the Cartesian coordinate system, but can be interpreted in a broad sense including the three axes on the Cartesian coordinate system. For example, the x-axis, y-axis, and z-axis can be perpendicular to each other, or can refer to different directions that are not orthogonal to each other.

[0052] Hereinafter, a display device according to some embodiments will be described in detail based on the above description as follows.

[0053] Figure 1 is a plan view schematically illustrating a display panel 10 of a display device according to some embodiments.

[0054] like Figure 1 As shown in , the display device according to some embodiments may include a display panel 10. Such a display device may be any display device including the display panel 10. For example, the display device may be various devices (such as a smart phone, a tablet computer, a laptop computer, a television, or a billboard). Because the display device according to some embodiments includes a thin film transistor and a capacitor, etc., the thin film transistor and the capacitor, etc. may be implemented by a conductive layer and an insulating layer.

[0055] The display panel 10 may include a display area DA and a peripheral area PA outside the display area DA (eg, in the periphery of the display area DA or outside an occupied area of ​​the display area DA). Figure 1 In the embodiment, the display area DA is shown to have a rectangular shape. However, the embodiment is not limited thereto. The display area DA may have various shapes (such as a circular shape, an elliptical shape, other polygonal shapes, and a shape of a specific figure, etc.).

[0056] The display area DA is where an image is displayed, and a plurality of pixels PX may be arranged in the display area DA. Each of the plurality of pixels PX may include a display element (such as an organic light emitting diode). For example, each pixel PX may emit red light, green light, or blue light. The pixel PX may be connected to a pixel circuit including a thin film transistor (TFT) and a storage capacitor, etc. The pixel circuit may be connected to a scan line SL configured to transmit a scan signal, a data line DL intersecting the scan line SL and configured to transmit a data signal therethrough, and a drive voltage line PL configured to supply a drive voltage therethrough. The scan line SL may extend in the x direction (or the second direction), and the data line DL and the drive voltage line PL may extend in the y direction (or the first direction).

[0057] The pixel PX may emit light having a brightness corresponding to an electrical signal from a pixel circuit electrically connected to the pixel PX. In the display area DA, a specific image may be displayed by light emitted from the pixel PX. For reference, as described above, the pixel PX may be defined as a light emitting area in which any one of red light, green light, and blue light is emitted.

[0058] The peripheral area PA may be an area in which the pixels PX are not positioned and the image is not displayed. Power supply wiring for driving the pixels PX may be located in the peripheral area PA. In addition, a plurality of pads may be arranged in the peripheral area PA, and a printed circuit board including a driving circuit unit or an integrated circuit device (such as a driver integrated circuit (IC)) may be arranged to be electrically connected to the plurality of pads.

[0059] For reference, since the display panel 10 includes the substrate 100, the substrate 100 may have a display area DA and a peripheral area PA. A detailed description of the substrate 100 will be described in more detail later.

[0060] In addition, a plurality of transistors may be arranged in the display area DA. Among the plurality of transistors, the first terminal of the transistor may be a source electrode or a drain electrode, and the second terminal of the transistor may be an electrode different from the first terminal, depending on the type (N-type or P-type) of the transistor and / or operating conditions. For example, when the first terminal is a source electrode, the second terminal may be a drain electrode.

[0061] The plurality of transistors may include a driving transistor, a data writing transistor, a compensation transistor, an initialization transistor and / or an emission control transistor, etc. The driving transistor may be connected between the driving voltage line PL and the organic light emitting diode OLED (see Figure 2 ), and the data write transistor may be connected to the data line DL and the driving transistor, and may perform a switching operation for transmitting a data signal through the data line DL.

[0062] The compensation transistor may be turned on in response to a scan signal received through the scan line SL to connect the driving transistor to the organic light emitting diode OLED, thereby compensating for a threshold voltage of the driving transistor.

[0063] The initialization transistor may be turned on in response to a scan signal received through the scan line SL to transmit an initialization voltage to the gate electrode of the driving transistor, thereby initializing the gate electrode of the driving transistor. The scan line connected to the initialization transistor may be a separate scan line different from the scan line connected to the compensation transistor.

[0064] The emission control transistor may be turned on in response to an emission control signal received through the emission control line, and as a result, a driving current may flow through the organic light emitting diode OLED.

[0065] like Figure 2 and Figure 3 As shown in FIG. 1 , the organic light emitting diode OLED may include a pixel electrode (anode) 150 and an opposite electrode (cathode) 170, and a second power voltage ELVSS may be applied to the opposite electrode 170. The organic light emitting diode OLED may receive a driving current from a driving transistor to emit light, thereby displaying an image.

[0066] In the following, an organic light-emitting display device will be described as a display device according to some embodiments, but the display device of the present disclosure is not limited thereto. According to some embodiments, the display device of the present disclosure may be a display device such as an inorganic light-emitting display device, an inorganic electroluminescent (EL) display device, or a quantum dot light-emitting display device. For example, the light-emitting layer of the display element of the display device may include an organic material or an inorganic material. In addition, the display device may include a light-emitting layer and quantum dots located on the path of light emitted from the light-emitting layer.

[0067] Figure 2 yes Figure 1 1 is an equivalent circuit diagram of a pixel PX of the display panel 10.

[0068] Reference Figure 2 , each pixel PX may include a pixel circuit PC connected to the scan line SL and the data line DL and an organic light emitting diode OLED connected to the pixel circuit PC.

[0069] The pixel circuit PC may include a driving thin film transistor Td, a switching thin film transistor Ts, and a storage capacitor Cst. The switching thin film transistor Ts may be connected to the scan line SL and the data line DL, and may transmit a data signal Dm input through the data line DL to the driving thin film transistor Td in response to a scan signal Sn input through the scan line SL.

[0070] The storage capacitor Cst may be connected to the switching thin film transistor Ts and the driving voltage line PL, and may store a voltage corresponding to a difference between a voltage transmitted from the switching thin film transistor Ts and a first power source voltage ELVDD supplied to the driving voltage line PL.

[0071] The second power voltage ELVSS may be a driving voltage having a relatively lower level than the first power voltage ELVDD. The level of the driving voltage supplied to each pixel PX may be a difference between the levels of the first power voltage ELVDD and the second power voltage ELVSS.

[0072] The driving thin film transistor Td may be connected to the driving voltage line PL and the storage capacitor Cst, and may control a driving current flowing from the driving voltage line PL through 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 with a specific brightness by using the driving current.

[0073] although Figure 2 The case where the pixel circuit PC includes two thin film transistors and one storage capacitor is shown, but the embodiment is not limited thereto. The pixel circuit PC may also include two or more storage capacitors. The pixel circuit PC is not limited to the components shown and described above, and according to some embodiments, the pixel circuit PC may include additional components or fewer components without departing from the spirit and scope of the embodiments according to the present disclosure.

[0074] Figure 3 It is schematically shown Figure 1 1 is a cross-sectional view of a portion of the display panel 10 .

[0075] As described above, the substrate 100 may include the display area DA (see Figure 1 ) and the peripheral area PA (see Figure 1 ) corresponding area. The substrate 100 may include various flexible or bendable materials. For example, the substrate 100 may include glass, metal or polymer resin. In addition, the substrate 100 may include a polymer resin (such as polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polyimide, polycarbonate or cellulose acetate propionate). Of course, various modifications are possible, such as, the substrate 100 may have a multilayer structure, which includes two layers containing such a polymer resin and a barrier layer between the two layers, wherein the barrier layer includes an inorganic material (e.g., silicon oxide, silicon nitride, silicon oxynitride, etc.) between the two layers.

[0076] Alternatively, in order to achieve ultra-high resolution, the substrate 100 may include a semiconductor material, for example, a group IV semiconductor, a group III-V compound semiconductor, or a group II-VI compound semiconductor. The substrate 100 may include a silicon layer. That is, the substrate 100 may be a semiconductor substrate including a semiconductor material. The substrate 100 may be a substrate including a silicon wafer formed by using a semiconductor process. In this case, an active layer may be formed inside the substrate 100 including the silicon wafer, and gate lines, data lines, and transistors may be arranged on the upper surface of the substrate 100. In this way, an organic light emitting diode OLED (see Figure 2 ) may be referred to as an organic light emitting diode on silicon (OLEDoS). For example, in the case of OLEDoS, a complementary metal oxide semiconductor (CMOS) process is required to form fine pixels, and an organic light emitting diode device may be formed on an electrode formed by using a CMOS process. In OLEDoS, in order to realize red (R), green (G), and blue (B), respectively, typically, a white organic light emitting diode may be made, and a color filter may be positioned on the white organic light emitting diode so that R color, G color, and B color may be realized. OLEDoS may be mainly used for extended reality (XR), and may achieve high quality exceeding 8K in a small area of ​​about 1 inch to about 2 inches. When a semiconductor substrate is used, intensive control of pixels arranged at ultra-high resolution is possible. However, one or more embodiments are not limited thereto.

[0077] The buffer layer 101 may be located on the substrate 100. The buffer layer 101 may prevent or reduce diffusion of impurity ions, may prevent or reduce penetration of moisture or external air, and may be used as a barrier layer and / or an isolating layer for planarizing the surface of the substrate 100. The buffer layer 101 may include silicon oxide, silicon nitride, or silicon oxynitride. In addition, the buffer layer 101 may adjust the rate at which heat is provided during a crystallization process for forming the semiconductor layer 110 so that the semiconductor layer 110 may be uniformly crystallized.

[0078] The semiconductor layer 110 may be located on the buffer layer 101. The semiconductor layer 110 may include polycrystalline silicon, and may include a channel region in which impurities are not doped, and a source region and a drain region located at both sides of the channel region and doped with impurities. Here, the impurities may vary according to the type of the thin film transistor, and may be N-type impurities or P-type impurities.

[0079] The gate insulating layer 102 may be located on the semiconductor layer 110. The gate insulating layer 102 may be a component for ensuring the insulating properties between the semiconductor layer 110 and the gate layer 120. The gate insulating layer 102 may include an inorganic material (such as silicon oxide, silicon nitride and / or silicon oxynitride), and may be between the semiconductor layer 110 and the gate layer 120. In addition, the gate insulating layer 102 may have a shape corresponding to the entire surface of the substrate 100, and may have a structure in which a through hole is formed at a preset portion. Similarly, an insulating layer including an inorganic material may be formed on / over the substrate 100 by chemical vapor deposition (CVD) or atomic layer deposition (ALD). This also applies to the following embodiments and modifications thereof.

[0080] The first gate layer 120a may be located on the gate insulating layer 102. The first gate layer 120a may be located at a position where the first gate layer 120a vertically overlaps the semiconductor layer 110, and may include at least one of the group consisting of molybdenum (Mo), aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), titanium (Ti), tungsten (W), and copper (Cu).

[0081] The first interlayer insulating layer 103a may be located on the first gate layer 120a. The first interlayer insulating layer 103a may cover the first gate layer 120a. The first interlayer insulating layer 103a may include an inorganic material. For example, the first interlayer insulating layer 103a may include an inorganic material, and specifically, the inorganic material may include silicon oxide (SiO 2 ), silicon nitride (SiN x ), silicon oxynitride (SiON), aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), Tantalum Oxide (Ta 2 O 5 ), hafnium oxide (HfO 2 ) or zinc oxide (ZnO x , which can be ZnO or ZnO 2 In some embodiments, the first interlayer insulating layer 103a may include SiO x / SiN y or SiN x / SiO y The dual structure.

[0082] The second gate layer 120b may be located on the first interlayer insulating layer 103a. The second gate layer 120b may be located at a position where the second gate layer 120b vertically overlaps the first gate layer 120a, and may include at least one of the group consisting of Mo, Al, Pt, Pd, Ag, Mg, Au, Ni, Nd, Ir, Cr, Li, Ca, Ti, W, and Cu.

[0083] The second gate layer 120b may form an upper surface with the first gate layer 120a. Figure 2 The first gate layer 120a may be one electrode of the storage capacitor Cst, and the second gate layer 120b may be the other electrode of the storage capacitor Cst.

[0084] The second interlayer insulating layer 103b may be located on the second gate layer 120b. The second interlayer insulating layer 103b may cover the second gate layer 120b. The second interlayer insulating layer 103b may include an inorganic material. For example, the second interlayer insulating layer 103b may include an inorganic material, and specifically, the inorganic material may include silicon oxide (SiO 2 ), silicon nitride (SiN x ), silicon oxynitride (SiON), aluminum oxide (Al 2 O 3 ), titanium oxide (TiO 2 ), Tantalum Oxide (Ta 2 O 5 ), hafnium oxide (HfO 2 ) or zinc oxide (ZnO x , which can be ZnO or ZnO 2 In some embodiments, the second interlayer insulating layer 103b may include SiO x / SiN y or SiN x / SiO y The dual structure.

[0085] The first conductive layer 130 may be located on the second interlayer insulating layer 103b. The first conductive layer 130 may be used as an electrode connected to the source region / drain region of the semiconductor layer 110 through the second interlayer insulating layer 103b, the first interlayer insulating layer 103a, and the through hole in the gate insulating layer 102. The first conductive layer 130 may include at least one metal selected from the group consisting of Al, Pt, Pd, Ag, Mg, Au, Ni, Nd, Ir, Cr, Li, Ca, Mo, Ti, W, and Cu. For example, the first conductive layer 130 may include a Ti layer, an Al layer, and / or a Cu layer.

[0086] The first organic insulating layer 104 may be located on the first conductive layer 130. The first organic insulating layer 104 may be an organic insulating layer covering the top of the first conductive layer 130 and having a substantially flat top surface and serving as a planarization layer. The first organic insulating layer 104 may include an organic material such as acryl, benzocyclobutene (BCB), or hexamethyldisiloxane (HMDSO). The first organic insulating layer 104 may be variously modified, such as having a single-layer structure or a multi-layer structure.

[0087] The second conductive layer 140 may be located on the first organic insulating layer 104. The second conductive layer 140 may be used as an electrode connected to the first conductive layer 130 through a through hole in the first organic insulating layer 104 and further connected to the source / drain region of the semiconductor layer 110. The second conductive layer 140 may include at least one metal selected from the group consisting of Al, Pt, Pd, Ag, Mg, Au, Ni, Nd, Ir, Cr, Li, Ca, Mo, Ti, W, and Cu. For example, the second conductive layer 140 may include a Ti layer, an Al layer, and / or a Cu layer.

[0088] The second organic insulating layer 105 may be located on the first conductive layer 130. The second organic insulating layer 105 may be an organic insulating layer covering the top of the second conductive layer 140 and having a substantially flat top surface and serving as a planarization layer. The second organic insulating layer 105 may include an organic material such as acryl, BCB, or HMDSO. The second organic insulating layer 105 may be variously modified, such as having a single-layer structure or a multi-layer structure.

[0089] In addition, according to some embodiments, an additional conductive layer and an additional insulating layer may be between the conductive layer and the pixel electrode 150, and may be applied to various embodiments. In this case, the additional conductive layer may include the same material as the above-mentioned conductive layer and may have the same layer structure. The additional insulating layer may include the same material as the above-mentioned organic insulating layer and may have the same layer structure.

[0090] The pixel electrode 150 may be located on the second organic insulating layer 105. The pixel electrode 150 may be connected to the second conductive layer 140 through a through hole formed in the second organic insulating layer 105. A display element may be located on the pixel electrode 150. An organic light emitting diode OLED may be used as a display element. That is, for example, the organic light emitting diode OLED may be located on the pixel electrode 150. The pixel electrode 150 may include a transparent conductive oxide (such as ITO, In 2 O 3 The pixel electrode 150 may include a transparent conductive layer formed of ITO or IZO and a reflective layer formed of a metal such as Al or Ag. For example, the pixel electrode 150 may have a triple-layer structure of ITO / Ag / ITO.

[0091] The pixel defining layer 106 may be located on the second organic insulating layer 105 and may be arranged to cover the edge of the pixel electrode 150. That is, the pixel defining layer 106 may cover the edge of the pixel electrode 150. The pixel defining layer 106 may have a shape similar to that of the pixel PX (see Figure 1 ) corresponding to the pixel electrode 150, and the opening may be formed so that at least the central portion of the pixel electrode 150 may be exposed. The pixel defining layer 106 may include an organic material (such as polyimide or HMDSO) or an inorganic material (such as a silicon compound (e.g., SiN x 、SiO x wait)).

[0092] In addition, a spacer may be located on the pixel defining layer 106. The spacer may be located in the peripheral area PA, but may also be located in the display area DA. The spacer may prevent or reduce the situation where the organic light emitting diode OLED is damaged due to the depression of the mask in the manufacturing process using the mask. The spacer may include an organic insulating material and may have a single-layer structure or a multi-layer structure.

[0093] The optical auxiliary layer 160 may be located on the pixel electrode 150. For example, the optical auxiliary layer 160 may be located in the opening of the pixel defining layer 106. The optical auxiliary layer 160 may be or include SiN x and / or SiO x Inorganic material layer. Figure 6 As described, the optical auxiliary layer 160 may include a plurality of optical auxiliary bodies arranged side by side in a direction parallel to the substrate 100. Each of the plurality of optical auxiliary bodies may be an inorganic structure for optical resonance, and a description thereof will be provided later.

[0094] The intermediate layer 200 and the opposite electrode 170 may be located on the opening of the pixel defining layer 106. The intermediate layer 200 may include a low molecular weight material or a polymer material, and the intermediate layer 200 may include a hole injection layer, a hole transport layer, an emission layer, an electron transport layer, and / or an electron injection layer. Figure 4 A detailed description of the intermediate layer 200 is provided in detail.

[0095] The counter electrode 170 may include a transparent conductive oxide (such as ITO, In 2 O 3 The pixel electrode 150 may be a transparent conductive layer formed of a ZnO or IZO. Alternatively, the opposing electrode 170 may be a conductive layer including Ag and / or Mg. The pixel electrode 150 may be used as an anode, and the opposing electrode 170 may be used as a cathode. Of course, the polarity of the electrodes may be reversed.

[0096] The structure of the intermediate layer 200 is not limited to the above description, and may have various structures. For example, at least one of the layers forming the intermediate layer 200 may be integrally formed like the opposite electrode 170. According to some embodiments, the intermediate layer 200 may include a layer patterned to correspond to each of the plurality of pixel electrodes 150.

[0097] The opposing electrode 170 may be located on top of the intermediate layer 200 and may be located in front of the intermediate layer 200. That is, the opposing electrode 170 may be integrally formed to correspond to a plurality of pixels. The opposing electrode 170 may be in electrical contact with a common power line located in the peripheral area PA. According to some embodiments, the opposing electrode 170 may extend to the blocking wall.

[0098] The capping layer CPL may be formed on the opposite electrode 170 by stacking at least an organic capping layer and an inorganic capping layer. The capping layer CPL may be formed by thermal evaporation deposition or electron beam evaporation deposition. The formation of the capping layer CPL may include performing a deposition process at a relatively higher temperature than a deposition process for forming an emission layer included in the intermediate layer 200. Alternatively, the capping layer CPL may be formed as a multilayer structure in which dielectric thin films having different refractive indices are alternately and repeatedly stacked.

[0099] The color filter layer CFL may be located on the cover layer CPL. The color filter layer CFL, which is a component through which light in a specific wavelength band is transmitted, may be a component through which light in wavelength bands of R color, G color, and B color corresponding to each pixel is transmitted. The color filter layer CFL may include a first color filter CF1 (see Figure 6 ), the second color filter CF2 (see Figure 6 ) and the third color filter CF3 (see Figure 6 ), and a description of each color filter will be provided later.

[0100] According to some embodiments, a light shielding layer for blocking the emission of light generated by the intermediate layer 200 may be located between the color filter layers CFL. The light shielding layer may be a black matrix, and may include various materials that absorb at least a portion of the light. For example, the light shielding layer may include at least one of carbon black, graphite, a chromium-based material, a dye, a metal reflective layer, and a light absorbing layer. The light shielding layer may block external light or prevent or reduce reflection of external light, and may prevent or reduce internal reflection of light generated by the display element.

[0101] According to some embodiments, a thin film encapsulation layer may be located on the opposite electrode 170. In some cases, the thin film encapsulation layer may be located between the opposite electrode 170 and the cover layer CPL, or may be located on the cover layer CPL. The thin film encapsulation layer may completely cover the display area DA, may extend to the peripheral area PA, and may be arranged to cover at least a portion of the peripheral area PA.

[0102] The thin film encapsulation layer may include a first inorganic encapsulation layer, a second inorganic encapsulation layer, and an organic encapsulation layer between the first inorganic encapsulation layer and the second inorganic encapsulation layer. The first inorganic encapsulation layer and the second inorganic encapsulation layer may each include an inorganic material including at least one of aluminum oxide, titanium oxide, tantalum oxide, hafnium oxide, zinc oxide, silicon oxide, silicon nitride, and silicon oxynitride.

[0103] The organic encapsulation layer may include a monomer material or a polymer material. The polymer material may include acrylic resin, epoxy resin, polyimide or polyethylene, etc. According to some embodiments, the organic encapsulation layer may include acrylate.

[0104] The barrier wall may be located in the peripheral area PA of the substrate 100. According to some embodiments, the barrier wall may include a portion of the first organic insulating layer 104, a portion of the second organic insulating layer 105, a portion of the pixel defining layer 106, and a portion of the spacer. However, embodiments are not limited thereto.

[0105] As occasion demands, the barrier wall may be disposed to surround the display area DA, and may prevent or reduce a situation in which a material of an organic encapsulation layer of the thin film encapsulation layer overflows to the outside of the substrate 100 .

[0106] Figure 4 It is schematically shown Figure 3 For reference, the cross-sectional view of the intermediate layer 200 may be omitted. Figure 4 The descriptions given are identical or redundant.

[0107] like Figure 4 As shown in , the intermediate layer 200 may include a first emission layer EML1, a second emission layer EML2, a third emission layer EML3 and a fourth emission layer EML4. The first emission layer EML1, the second emission layer EML2, the third emission layer EML3 and the fourth emission layer EML4 may be vertically stacked layers, and the first emission layer EML1 and the fourth emission layer EML4 may emit light in the same wavelength band.

[0108] In an example, the first emission layer EML1 and the fourth emission layer EML4 may emit blue-based visible light, the second emission layer EML2 may emit red-based visible light, and the third emission layer EML3 may emit green-based visible light.

[0109] In an example, in a plan view, the first emission layer EML1, the second emission layer EML2, the third emission layer EML3 and the fourth emission layer EML4 may overlap each other. In this case, the first emission layer EML1 and the second emission layer EML2 may be spaced apart from each other in the thickness direction of the first emission layer EML1, and the third emission layer EML3 and the fourth emission layer EML4 may be spaced apart from each other in the thickness direction of the first emission layer EML1. The second emission layer EML2 and the third emission layer EML3 may be positioned adjacent to each other.

[0110] The intermediate layer 200 may further include a first hole transport layer 201. The first hole transport layer 201 may be located at the pixel electrode 150 (see Figure 3 ). The first hole transport layer 201 may be configured to transport holes from the organic light emitting diode OLED (see Figure 2 ) and may be an organic material layer into which electron holes may be injected from the pixel electrode 150. For ease of explanation, it may be understood that in this specification, the first hole transport layer 201 includes a hole injection layer.

[0111] The intermediate layer 200 may include a first emission layer EML1 that emits light in the first wavelength band. The first emission layer EML1 may be located on the first hole transport layer 201. The thickness of the first emission layer EML1 may be about 100 Å. to about (Preferably, ). The first emission layer EML1 may be an organic material layer emitting blue-based visible light.

[0112] The intermediate layer 200 may include a second emission layer EML2 that emits light in the second wavelength band. The second emission layer EML2 may be located on the first emission layer EML1. The thickness of the second emission layer EML2 may be about 100 Å. to about (Preferably, ). The second emission layer EML2 may be an organic material layer emitting red-based visible light.

[0113] The intermediate layer 200 may include a third emission layer EML3 that emits light in a third wavelength band. The third emission layer EML3 may be located on the second emission layer EML2. The thickness of the third emission layer EML3 may be about 100 Å. to about (Preferably, ). The third emission layer EML3 may be an organic material layer emitting green-based visible light.

[0114] The intermediate layer 200 may include a fourth emission layer EML4 that emits light in the first wavelength band. The fourth emission layer EML4 may be located on the third emission layer EML3. The thickness of the fourth emission layer EML4 may be about to about (Preferably, ). The fourth emission layer EML4 may be an organic material layer emitting blue-based visible light.

[0115] The intermediate layer 200 may further include a first connection layer 202 between the first emission layer EML1 and the second emission layer EML2. The first connection layer 202 may be an organic material layer including a first electron transport layer 202A, a first charge generation layer 202B, and a second hole transport layer 202C. The thickness of the first connection layer 202 may be about 1000 Å. to about (Preferably, ).

[0116] As a result of numerical limitation on the thickness of the first connection layer 202, the display device according to some embodiments can realize a more efficient resonance structure compared to the display device according to the comparative example to be described later. As a result, a display device with high light efficiency can be provided.

[0117] The first electron transport layer 202A may be located on the first emission layer EML1. The lower surface of the first electron transport layer 202A may be in contact with the upper surface of the first emission layer EML1. The first electron transport layer 202A may be configured to transport electrons from the organic light emitting diode OLED and may be an organic material layer. For ease of explanation, it may be understood that in this specification, the first electron transport layer 202A includes an electron injection layer.

[0118] The first charge generation layer 202B may be located on the first electron transport layer 202A. The lower surface of the first charge generation layer 202B may contact the upper surface of the first electron transport layer 202A. The first charge generation layer 202B may include a P-type charge generation layer and an N-type charge generation layer. The P-type charge generation layer may include a host material having a hole transport capability, and the N-type charge generation layer may include a host material having an electron transport capability. For example, the N-type charge generation layer may be configured to inject electrons into the first emission layer EML1, and the P-type charge generation layer may be configured to inject holes into the second emission layer EML2.

[0119] The second hole transport layer 202C may be located on the first charge generation layer 202B. The lower surface of the second hole transport layer 202C may be in contact with the upper surface of the first charge generation layer 202B. The second hole transport layer 202C may be configured to transport electron holes from the organic light emitting diode OLED, and may be an organic material layer. For ease of explanation, it is understood that in this specification, the second hole transport layer 202C includes a hole injection layer (HIL) (e.g., a p-doped hole transport layer (HTL) used as a HIL).

[0120] like Figure 4 As shown in FIG. 1 , the intermediate layer 200 may further include a second connection layer 203 between the third emission layer EML3 and the fourth emission layer EML4. The second connection layer 203 may be an organic material layer including a second electron transport layer 203A, a second charge generation layer 203B, and a third hole transport layer 203C. The thickness of the second connection layer 203 may be about to about (Preferably, ).

[0121] As a result of the numerical limitation on the thickness, the display device according to some embodiments can realize a more efficient resonance structure than the display device according to the comparative example to be described later. As a result, a display device with high light efficiency can be provided.

[0122] The second electron transport layer 203A may be located on the third emission layer EML3. The lower surface of the second electron transport layer 203A may be in contact with the upper surface of the third emission layer EML3. The second electron transport layer 203A may be configured to transport electrons from the organic light emitting diode OLED and may be an organic material layer. For ease of explanation, it is understood that in this specification, the second electron transport layer 203A includes an electron injection layer.

[0123] The second charge generation layer 203B may be located on the second electron transport layer 203A. The lower surface of the second charge generation layer 203B may be in contact with the upper surface of the second electron transport layer 203A. The second charge generation layer 203B may include a P-type charge generation layer and an N-type charge generation layer. The P-type charge generation layer may include a host material having a hole transport capability, and the N-type charge generation layer may include a host material having an electron transport capability. For example, the N-type charge generation layer may be configured to inject electrons into the third emission layer EML3, and the P-type charge generation layer may be configured to inject holes into the fourth emission layer EML4.

[0124] The third hole transport layer 203C may be located on the second charge generation layer 203B. The lower surface of the third hole transport layer 203C may be in contact with the upper surface of the second charge generation layer 203B. The third hole transport layer 203C may be configured to transport electron holes from the organic light emitting diode OLED, and may be an organic material layer. For ease of explanation, it is understood that in this specification, the third hole transport layer 203C includes a HIL (e.g., a p-doped HTL used as a HIL).

[0125] like Figure 4 As shown in , the intermediate layer 200 may further include a third electron transport layer 204 located on the fourth emission layer EML4. The third electron transport layer 204 may be located on the fourth emission layer EML4. The lower surface of the third electron transport layer 204 may be in contact with the upper surface of the fourth emission layer EML4. The third electron transport layer 204 may be configured to transport electrons from the organic light emitting diode OLED and may be an organic material layer. For ease of explanation, it is understood that in this specification, the third electron transport layer 204 includes an electron injection layer. The above-mentioned relative electrode 170 (see Figure 3 ) may be located on the third electron transport layer 204 .

[0126] Figure 5 It is shown Figure 3 The refractive index of the optical auxiliary layer 160 and Figure 4 A graph of the refractive index of the first hole transport layer 201 is shown in FIG.

[0127] For reference, you can omit the reference Figure 5 The descriptions given are identical or redundant. Figure 5 The horizontal axis represents the wavelength of light, and Figure 5 The vertical axis represents the refractive index.

[0128] like Figure 5 As shown in FIG. , as comprising SiN x and / or SiO x The optical auxiliary layer 160, which is an inorganic material layer, may have a refractive index of about 1.5, and a change in the refractive index according to the wavelength of light transmitted through the optical auxiliary layer 160 is rarely observed. However, the first hole transport layer 201, which is an organic material layer, may have a refractive index that increases as the wavelength decreases, and the refractive index of the first hole transport layer 201 may be in the range of about 1.6 to about 2.2.

[0129] Therefore, since the optical path passing through the first hole transport layer 201 changes according to the wavelength, the optical thickness of the first hole transport layer 201 may change according to the transmitted light or the wavelength. However, since it may be difficult to change the thickness of the first hole transport layer 201 according to the wavelength, the thickness of each of the plurality of optical auxiliary bodies included in the optical auxiliary layer 160 may be adjusted so that the total length of the optical path through which the wavelength passes (i.e., the length of the path reflecting the refractive index) may be adjusted.

[0130] Figure 6 It is schematically shown Figure 3 2 is a cross-sectional view of an example of a stacked structure of a pixel electrode 150, an optical auxiliary layer 160, an intermediate layer 200, a cover layer CPL, and a color filter layer CFL.

[0131] For reference, you can omit Figure 3 The same description as in the description of , and for the convenience of explanation, illustration of structures such as a pixel defining layer, etc. may be omitted.

[0132] In addition, for reference, although Figure 6 The various layers shown in FIG. 1 are shown to be spaced apart from each other, but this is only for ease of understanding, and Figure 6 Each layer shown in the figure and the precise illustration of multiple layers may not be spaced apart from each other. These layers may contact each other, and different layers may be embedded between these layers as required. This also applies to Figure 6 Other drawings besides .

[0133] like Figure 6 As shown in Figure 3 An example of a stacked structure may include a pixel electrode 150, an optical auxiliary layer 160, an intermediate layer 200, an opposing electrode 170, a cover layer CPL, and a color filter layer CFL. For ease of explanation, it will be described that the components below the pixel electrode 150 include a substrate 100 (see Figure 3 ) and circuit layer.

[0134] For example, as referenced Figure 3 The circuit layer may be located on the substrate 100 and may include at least one thin film transistor. For example, the circuit layer may include at least one of the semiconductor layer 110, the gate insulating layer 102, the first gate layer 120a, the first interlayer insulating layer 103a, the first conductive layer 130 and the first organic insulating layer 104.

[0135] In some cases, the circuit layer may be interpreted as a concept including the semiconductor layer 110, the second conductive layer 140, and the second organic insulating layer 105 covering the second conductive layer 140. However, the scope of the rights of the present disclosure is not limited thereto. For example, the circuit layer may refer to a plurality of layer structures arranged between the substrate 100 and the pixel electrode 150.

[0136] The pixel electrode 150 may include a reflective layer 152. The reflective layer 152 may include a metal material such as Ag or Al. The reflective layer 152 may be a component for reflecting a portion of light emitted from the intermediate layer 200 toward the color filter layer CFL. The thickness of the reflective layer 152 may be about 1000 Å. to about (and preferably, ).

[0137] The pixel electrode 150 may further include a first transparent electrode layer 153 located on the reflective layer 152. The first transparent electrode layer 153 may include a transparent conductive material (such as ITO, etc.). The thickness of the first transparent electrode layer 153 may be less than that of the reflective layer 152. The thickness of the first transparent electrode layer 153 may be about 1000 Å. to about (and preferably, ).

[0138] The pixel electrode 150 may further include a second transparent electrode layer 151 located below the reflective layer 152. Therefore, the reflective layer 152 may be between the first transparent electrode layer 153 and the second transparent electrode layer 151. The second transparent electrode layer 151 may include a transparent conductive material (such as ITO, etc.). The thickness of the second transparent electrode layer 151 may be less than that of the reflective layer 152. The thickness of the second transparent electrode layer 151 may be about to about and preferably The upper surface of the second transparent electrode layer 151 and the lower surface of the reflective layer 152 may be in contact with each other. Figure 6 As shown in , the optical auxiliary layer 160 may include a first optical auxiliary body 160A having a first thickness Ta and a second optical auxiliary body 160C having a second thickness Tc. The second thickness Tc may be greater than the first thickness Ta, and the first optical auxiliary body 160A and the second optical auxiliary body 160C may be arranged side by side. The optical auxiliary layer 160 may include SiN as described above. x and / or SiO x The optical auxiliary layer 160 may be between the first transparent electrode layer 153 and the intermediate layer 200 .

[0139] As a result of the numerical limitation on the thickness, the display device according to some embodiments can realize a more efficient resonance structure than the display device according to the comparative example to be described later. As a result, a display device with high light efficiency can be provided.

[0140] like Figure 6As shown in FIG. 1 , the pixel electrode 150 including the first transparent electrode layer 153, the second transparent electrode layer 151 and the reflective layer 152 may have a pixel PX (see FIG. 1 ). Figure 1 ) divided structure. In addition, one pixel PX may correspond to one of the first color filter CF1, the second color filter CF2, and the third color filter CF3 to be described later. In addition, the optical auxiliary layer 160 may include an optical auxiliary body corresponding to one pixel PX.

[0141] For example, the first optical auxiliary body 160A may correspond to one pixel PX, and may correspond to the first color filter CF1. For example, in a plan view, the first optical auxiliary body 160A may overlap with the first color filter CF1.

[0142] For example, the second optical auxiliary body 160C may correspond to another pixel and may correspond to the third color filter CF3. For example, in a plan view, the second optical auxiliary body 160C may overlap with the third color filter CF3.

[0143] The intermediate layer 200 may be located on the optical auxiliary layer 160. The intermediate layer 200 may include a first hole transport layer 201, a first emission layer EML1, a first connection layer 202, a second emission layer EML2, a third emission layer EML3, a second connection layer 203, a fourth emission layer EML4, and a third electron transport layer 204.

[0144] For example, the first connection layer 202 may be located between the first emission layer EML1 and the second emission layer EML2, and the second connection layer 203 may be located between the third emission layer EML3 and the fourth emission layer EML4. The thickness of the first connection layer 202 and the second connection layer 203 may be greater than the thickness of the first emission layer EML1.

[0145] For example, the sum of the optical thickness of the first hole transport layer 201 in the first band and the optical thickness of the second optical auxiliary body 160C in the first band may be consistent with the sum of the optical thickness of the first hole transport layer 201 in the second band and the optical thickness of the first optical auxiliary body 160A in the second band. In this case, the consistency of the sum of thicknesses may refer to consistency within the range of errors that may occur in measurement or micro-processing.

[0146] Optical thickness may mean a value obtained by multiplying the thickness of a specific layer by the refractive index of the specific layer. The optical thickness of the first hole transport layer 201 within the first band may be a value obtained by multiplying the thickness of the first hole transport layer 201 by the refractive index of the first hole transport layer 201 at about 460 nm (an example of a representative value within the first band). Similarly, the optical thickness of the second optical auxiliary body 160C within the first band may be a value obtained by multiplying the thickness of the second optical auxiliary body 160C by the refractive index of the second optical auxiliary body 160C at about 460 nm (an example of a representative value within the first band).

[0147] For example, the optical thickness of the first hole transport layer 201 in the first wavelength band may be inversely proportional to the optical thickness of the second optical auxiliary body 160C in the first wavelength band. Because the sum of the optical thickness of the first hole transport layer 201 in the first wavelength band and the optical thickness of the second optical auxiliary body 160C in the first wavelength band needs to be constant, the optical thickness of the second optical auxiliary body 160C in the first wavelength band needs to increase the amount of reduction of the optical thickness of the first hole transport layer 201 in the first wavelength band. Therefore, the inverse relationship can be expressed as the following equation 1.

[0148] Equation 1

[0149] Reduction of T1 × n 201 =Increase in Tc × n 160

[0150] n 201 is the refractive index of the first hole transport layer 201 in the first wavelength band, n 160 is the refractive index of the second optical auxiliary body 160C in the first wavelength band, T1 is the thickness of the first hole transport layer 201, and Tc is the thickness of the second optical auxiliary body 160C.

[0151] Therefore, according to the above equation, the portion of the first hole transport layer 201 within the first band can be replaced by the portion of the second optical auxiliary body 160C within the first band. In this case, the optical thickness of the portion of the first hole transport layer 201 within the first band can be consistent with the optical thickness of the portion of the second optical auxiliary body 160C within the first band.

[0152] As a result of the numerical limitation on the thickness, the display device according to some embodiments can realize a more efficient resonance structure than the display device according to the comparative example to be described later. As a result, a display device with high light efficiency can be provided.

[0153] For example, the first emission layer EML1 may be an organic material layer that emits light within the first wavelength band. The thickness of the first emission layer EML1 may be less than the difference between the second thickness Tc of the second optical auxiliary body 160C and the first thickness Ta of the first optical auxiliary body 160A. The difference between the second thickness Tc of the second optical auxiliary body 160C and the first thickness Ta of the first optical auxiliary body 160A may be greater than the thickness of the first emission layer EML1. For example, the fourth emission layer EML4 may be an organic material layer that emits light within the first wavelength band like the first emission layer EML1, and the thickness of the fourth emission layer EML4 may be consistent with the thickness of the first emission layer EML1.

[0154] For example, the first wavelength band may be a blue-based visible light region, the second wavelength band may be a red-based visible light region, and the third wavelength band may be a green-based visible light region.

[0155] like Figure 6 As shown in , the opposing electrode 170 may be located on the third electron transport layer 204, the cover layer CPL may be located on the opposing electrode 170, and the color filter layer CFL may be located on the cover layer CPL. The color filter layer CFL may include a first color filter CF1 through which light in the second band is transmitted, a second color filter CF2 positioned side by side with the first color filter CF1 and through which light in the third band is transmitted, and a third color filter CF3 positioned side by side with the second color filter CF2 and through which light in the first band is transmitted. That is, light in the first band may be transmitted through the third color filter CF3, light in the second band may be transmitted through the first color filter CF1, and light in the third band may be transmitted through the second color filter CF2.

[0156] In this case, the first optical auxiliary body 160A and the first color filter CF1 may overlap each other in a plan view, and the second optical auxiliary body 160C and the third color filter CF3 may overlap each other in a plan view.

[0157] Examples including detailed numerical values ​​are as follows.

[0158] For example, the difference between the first thickness Ta of the first optical auxiliary body 160A and the second thickness Tc of the second optical auxiliary body 160C may be approximately to about (Preferably, ).

[0159] For example, the thickness of the intermediate layer 200 may be about to about (Preferably, ).

[0160] exist Figure 6 , not shown having a third thickness Tb (see Fig.10 ) of the third optical auxiliary body 160B (see Fig.10 ), and this means that the third thickness Tb may be 0. In this case, the difference between the third thickness Tb and the first thickness Ta may be approximately to about (Preferably, ). Since the third thickness Tb is 0, the difference between the third thickness Tb and the first thickness Ta is the same as the first thickness Ta.

[0161] For example, the thickness of the first hole transport layer 201 may be greater than the thickness of the first connection layer 202. In addition, the thickness of the first connection layer 202 may be greater than the thickness of the second connection layer 203. The thickness of the first emission layer EML1 and the thickness of the fourth emission layer EML4 may be consistent with each other. The thickness of the second emission layer EML2 may be less than the thickness of the third emission layer EML3. The thickness of the third emission layer EML3 may be greater than the thickness of the fourth emission layer EML4.

[0162] As a result of the numerical limitation on the thickness, the display device according to some embodiments can realize a more efficient resonance structure than the display device according to the comparative example to be described later. As a result, a display device with high light efficiency can be provided.

[0163] Figures 7 to 9 It is shown Figure 6 . For reference, the color coordinates may include Rx, Ry, Gx, Gy, Bx, By. For example, Rx is the x-axis coordinate for red in the color coordinates, By is the y-axis coordinate for blue in the color coordinates, and Gx is the x-axis coordinate for green in the color coordinates.

[0164] Reference Figure 6 and Figure 7 , when the first thickness Ta of the first optical auxiliary body 160A is about And the distance T2 between the second emission layer EML2 and the optical auxiliary layer 160 (ie, the distance between the lower surface of the second emission layer EML2 and the lower surface of the first hole transport layer 201) is about to about When the first thickness Ta is about And the distance T2 between the second emission layer EML2 and the optical auxiliary layer 160 is about When the light efficiency is relatively high, the light efficiency based on red visible light can be relatively high.

[0165] When the second thickness Tc of the second optical auxiliary body 160C is about And the distance T1 between the first emission layer EML1 and the optical auxiliary layer 160 (ie, the distance between the lower surface of the first emission layer EML1 and the lower surface of the first hole transport layer 201) is about to about When the second thickness Tc is about And the distance T1 between the first emission layer EML1 and the optical auxiliary layer 160 is about When the optical efficiency is relatively high, the optical efficiency based on blue visible light can be relatively high.

[0166] Reference Figure 6 and Figure 8 , when the third thickness Tb of the third optical auxiliary body 160B is about And the distance T3 between the third emission layer EML3 and the optical auxiliary layer 160 (ie, the distance between the lower surface of the third emission layer EML3 and the lower surface of the first hole transport layer 201) is about to about When the third thickness Tb is about And the distance T3 between the third emission layer EML3 and the optical auxiliary layer 160 is about When the light efficiency is relatively high, the light efficiency based on green visible light can be relatively high.

[0167] When the second thickness Tc of the second optical auxiliary body 160C is about And the distance T4 between the fourth emission layer EML4 and the optical auxiliary layer 160 (ie, the distance between the lower surface of the fourth emission layer EML4 and the lower surface of the first hole transport layer 201) is about to about When the second thickness Tc is about And the distance T4 between the fourth emission layer EML4 and the optical auxiliary layer 160 is about When the optical efficiency is relatively high, the optical efficiency based on blue visible light can be relatively high.

[0168] Reference Figure 6 and Fig. 9 ,exist Figure 6 In the example, when the following conditions are met, the light efficiency based on white visible light can be the highest.

[0169] (1) The distance between the first emission layer EML1 and the optical auxiliary layer 160 is about

[0170] (2) The distance between the second emission layer EML2 and the optical auxiliary layer 160 is approximately

[0171] (3) The distance between the third emission layer EML3 and the optical auxiliary layer 160 is about

[0172] (4) The distance between the fourth emission layer EML4 and the optical auxiliary layer 160 is about

[0173] (5) The first thickness Ta is about

[0174] (6) The second thickness Tc is about

[0175] (7) The third thickness Tb is about

[0176] As a result of the numerical limitation on the thickness, the display device according to some embodiments can realize a more efficient resonance structure than the display device according to the comparative example to be described later. As a result, a display device with high light efficiency can be provided.

[0177] Fig.10 It is schematically shown Figure 3 1 is a cross-sectional view of another example of a stacked structure of a pixel electrode 150, an optical auxiliary layer 160, an intermediate layer 200, a cover layer CPL, and a color filter layer CFL. For reference, the reference Figure 3 and Figure 6 The descriptions given are identical or redundant.

[0178] like Fig.10 As shown in , the optical auxiliary layer 160 may further include a third optical auxiliary body 160B having a third thickness Tb and positioned side by side with the first optical auxiliary body 160A and the second optical auxiliary body 160C. In this case, the third thickness Tb may be less than the first thickness Ta and the second thickness Tc.

[0179] For example, the difference between the third thickness Tb and the second thickness Tc may be approximately to about For example, the difference between the second thickness Tc and the third thickness Tb may be six times the difference between the first thickness Ta and the second thickness Tc. For example, in a plan view, the third optical auxiliary body 160B may overlap with the second color filter CF2.

[0180] like Fig.10As shown in , the thickness of the first hole transport layer 201 may be smaller than the thickness of the first connection layer 202. In addition, the thickness of the first hole transport layer 201 may be greater than the thickness of the second connection layer 203.

[0181] Examples including detailed numerical values ​​are as follows.

[0182] For example, the difference between the first thickness Ta of the first optical auxiliary body 160A and the second thickness Tc of the second optical auxiliary body 160C may be approximately to about (Preferably, ). The difference between the second thickness Tc of the second optical auxiliary body 160C and the third thickness Tb of the third optical auxiliary body 160B may be approximately to about (Preferably, For example, the thickness of the intermediate layer 200 may be about to about (Preferably, ).

[0183] The first thickness Ta may be approximately to about (Preferably, ). The second thickness Tc may be about to about (Preferably, ). The third thickness Tb may be about to about (Preferably, In this case, the thickness of the first hole transport layer 201 may be about to about (Preferably, ).

[0184] Figure 6 Examples and Fig.10 The examples are compared with each other as follows.

[0185] Figure 6 The thickness of the first hole transport layer 201 may be about and Fig.10 The thickness of the first hole transport layer 201 may be about therefore, Fig.10 The thickness of the first hole transport layer 201 may be relative to Figure 6 The thickness of the first hole transport layer 201 is reduced by about exist Fig.10 In the embodiment, as the thickness of the first hole transport layer 201 decreases, the second thickness Tc of the second optical auxiliary body 160C needs to increase.

[0186] Figure 6 The second thickness Tc may be about and Fig.10 The second thickness Tc may be about therefore, Fig.10 The second thickness Tc increases by about When considering that the optical refractive index of the optical auxiliary layer 160 is about 1.5 and the optical refractive index of the first hole transport layer 201 at about 460 nm is about 1.9, the reduction amount of the thickness of the first hole transport layer 201 and the increase amount of the second thickness Tc may satisfy the above [Equation 1].

[0187] As a result of the numerical limitation on the thickness, the display device according to some embodiments can realize a more efficient resonance structure than the display device according to the comparative example to be described later. As a result, a display device with high light efficiency can be provided.

[0188] Fig.11 It is schematically shown Figure 3 1 is a cross-sectional view of another example of a stacked structure of a pixel electrode 150, an optical auxiliary layer 160, an intermediate layer 200, a cover layer CPL, and a color filter layer CFL. For reference, the reference Figure 3 , Figure 6 and Fig.10 The descriptions given are identical or redundant.

[0189] like Fig.11 As shown in , the optical auxiliary layer may further include a third optical auxiliary body 160B having a third thickness Tb and positioned side by side with the first optical auxiliary body 160A and the second optical auxiliary body 160C. In this case, the third thickness Tb may be less than the first thickness Ta and the second thickness Tc.

[0190] For example, the difference between the third thickness Tb and the second thickness Tc may be approximately to about For example, the difference between the second thickness Tc and the third thickness Tb may be six times the difference between the first thickness Ta and the second thickness Tc. For example, in a plan view, the third optical auxiliary body 160B may overlap with the second color filter CF2.

[0191] like Fig.11 As shown in , the thickness of the first hole transport layer 201 may be smaller than the thickness of the first connection layer 202. In addition, the thickness of the first hole transport layer 201 may be greater than the thickness of the second connection layer 203.

[0192] Examples including detailed numerical values ​​are as follows.

[0193] For example, the difference between the first thickness Ta of the first optical auxiliary body 160A and the second thickness Tc of the second optical auxiliary body 160C may be approximately to about (Preferably, ). The difference between the second thickness Tc of the second optical auxiliary body 160C and the third thickness Tb of the third optical auxiliary body 160B may be approximately to about (Preferably, For example, the thickness of the intermediate layer 200 may be about to about (Preferably, ).

[0194] The first thickness Ta may be approximately to about (Preferably, ). The second thickness Tc may be about to about (Preferably, ). The third thickness Tb may be about to about (Preferably, In this case, the thickness of the first hole transport layer 201 may be about to about (Preferably, ).

[0195] Fig.10 Examples and Fig.11 The examples are compared with each other as follows.

[0196] Fig.10 The thickness of the first hole transport layer 201 may be about and Fig.11 The thickness of the first hole transport layer 201 may be about therefore, Fig.11 The thickness of the first hole transport layer 201 may be relative to Fig.10 The thickness of the first hole transport layer 201 is reduced by about exist Fig.11 In the embodiment, as the thickness of the first hole transport layer 201 decreases, the second thickness Tc of the second optical auxiliary body 160C needs to increase.

[0197] Fig.10 The second thickness Tc may be about and Fig.11 The second thickness Tc may be about therefore, Fig.11 The second thickness Tc increases by about When considering that the optical refractive index of the optical auxiliary layer is about 1.5 and the optical refractive index of the first hole transport layer 201 at about 460 nm is about 1.9, the reduction amount of the thickness of the first hole transport layer 201 and the increase amount of the second thickness Tc may satisfy the above [Equation 1].

[0198] As a result of the numerical limitation on the thickness, the display device according to some embodiments can realize a more efficient resonance structure than the display device according to the comparative example to be described later. As a result, a display device with high light efficiency can be provided.

[0199] Fig.12 It is schematically shown Figure 3 1 is a cross-sectional view of another example of a stacked structure of a pixel electrode 150, an optical auxiliary layer 160, an intermediate layer 200, a cover layer CPL, and a color filter layer CFL. For reference, the reference Figure 3 , Figure 6 , Fig.10 and Fig.11 The descriptions given are identical or redundant.

[0200] like Fig.12 As shown in , the optical auxiliary layer may further include a third optical auxiliary body 160B having a third thickness Tb and positioned side by side with the first optical auxiliary body 160A and the second optical auxiliary body 160C. In this case, the third thickness Tb may be less than the first thickness Ta and the second thickness Tc.

[0201] For example, the difference between the third thickness Tb and the second thickness Tc may be approximately to about For example, the difference between the second thickness Tc and the third thickness Tb may be six times the difference between the first thickness Ta and the second thickness Tc. For example, in a plan view, the third optical auxiliary body 160B may overlap with the second color filter CF2.

[0202] like Fig.12 As shown in , the thickness of the first hole transport layer 201 may be smaller than the thickness of the first connection layer 202. In addition, the thickness of the first hole transport layer 201 may be smaller than the thickness of the second connection layer 203.

[0203] Examples including detailed numerical values ​​are as follows.

[0204] For example, the difference between the first thickness Ta of the first optical auxiliary body 160A and the second thickness Tc of the second optical auxiliary body 160C may be approximately to about (Preferably, ). The difference between the second thickness Tc of the second optical auxiliary body 160C and the third thickness Tb of the third optical auxiliary body 160B may be approximately to about (Preferably, For example, the thickness of the intermediate layer 200 may be about to about (Preferably, ).

[0205] The first thickness Ta may be approximately to about (Preferably, ). The second thickness Tc may be about to about (Preferably, ). The third thickness Tb may be about to about (Preferably, In this case, the thickness of the first hole transport layer 201 may be about to about (Preferably, ).

[0206] Fig.11 Examples and Fig.12 The examples are compared with each other as follows.

[0207] Fig.11 The thickness of the first hole transport layer 201 may be about and Fig.12 The thickness of the first hole transport layer 201 may be about therefore, Fig.12 The thickness of the first hole transport layer 201 may be relative to Fig.11 The thickness of the first hole transport layer 201 is reduced by about exist Fig.12 In the embodiment, as the thickness of the first hole transport layer 201 decreases, the second thickness Tc of the second optical auxiliary body 160C needs to increase.

[0208] Fig.11 The second thickness Tc may be about and Fig.12 The second thickness Tc may be about therefore, Fig.11 The second thickness Tc increases by about When considering that the optical refractive index of the optical auxiliary layer is about 1.5 and the optical refractive index of the first hole transport layer 201 at about 460 nm is about 1.9, the reduction amount of the thickness of the first hole transport layer 201 and the increase amount of the second thickness Tc may approximately satisfy the above [Equation 1].

[0209] As a result of the numerical limitation on the thickness, the display device according to some embodiments can realize a more efficient resonance structure than the display device according to the comparative example to be described later. As a result, a display device with high light efficiency can be provided.

[0210] Fig.13 and Fig.14 is a schematic diagram showing a display device according to a comparative example. Figure 3 1 is a cross-sectional view of an example of a cross section corresponding to a stacked structure of a pixel electrode 150, an optical auxiliary layer 160, an intermediate layer 200, a cover layer CPL, and a color filter layer CFL.

[0211] like Fig.13 As shown in FIG. 1 , in the display device according to the comparative example, the thickness of the second connection layer 203 is greater than the thickness of the first connection layer 202, and the thickness of the intermediate layer 200 is significantly greater than that of the display device according to the example of the present disclosure. Figure 6 , Fig.10 , Fig.11 and Fig.12 The thickness of the intermediate layer 200 may significantly reduce the light efficiency. Fig.13 In the structure, the first thickness Ta is greater than the second thickness Tc, and according to the example of the present disclosure Figure 6 , Fig.10 , Fig.11 and Fig.12 The arrangement of these optical auxiliary bodies may be disadvantageous in terms of the resonant structure compared to the arrangement of optical auxiliary bodies.

[0212] like Fig.14 As shown in , in a display device according to another comparative example, the green-based emission layer EML4a and the red-based emission layer EML3a are not located between the blue-based emission layers EML1a and EML2a. In this case, the characteristics of the blue-based visible light are greatly reduced, and the output of the blue-based visible light needs to be increased, so that the life of the organic material emitting the blue-based visible light may be reduced. In addition, in Fig.14 In the structure, the first thickness Ta is greater than the second thickness Tc, and according to the example of the present disclosure Figure 6 , Fig.10 , Fig.11 and Fig.12 The arrangement of these optical auxiliary bodies may be disadvantageous in terms of the resonant structure compared to the arrangement of optical auxiliary bodies.

[0213] According to some embodiments having the above configuration, a display device having relatively high light efficiency may be realized. Of course, the scope of the present disclosure is not limited by these effects.

[0214] It should be understood that the embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. The description of features or aspects within each embodiment should generally be considered applicable to other similar features or aspects in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the appended claims and their equivalents.

Claims

1. A display device, characterized in that: The display device comprises: a circuit layer, on the substrate; A pixel electrode, on the circuit layer; an intermediate layer, on the pixel electrode, the intermediate layer comprising a first emission layer, a second emission layer, a third emission layer and a fourth emission layer, the first emission layer is configured to emit light within a first wavelength band, the second emission layer is configured to emit light within a second wavelength band, the third emission layer is configured to emit light within a third wavelength band, and the fourth emission layer is configured to emit light within the first wavelength band, wherein in a plan view, the first emission layer to the fourth emission layer overlap each other; a counter electrode on the intermediate layer; a color filter layer on the opposite electrode, and the color filter layer includes: a first color filter, through which the light in the second wavelength band is transmitted; a second color filter, side by side with the first color filter, through which the light in the third wavelength band is transmitted; and a third color filter, side by side with the second color filter, through which the light in the first wavelength band is transmitted; and An optical auxiliary layer, between the pixel electrode and the intermediate layer, the optical auxiliary layer includes a first optical auxiliary body having a first thickness and a second optical auxiliary body parallel to the first optical auxiliary body and having a second thickness, the second thickness being greater than the first thickness, wherein in the plan view, the first optical auxiliary body and the first color filter overlap each other, and in the plan view, the second optical auxiliary body and the third color filter overlap each other.

2. The display device according to claim 1, characterized in that The intermediate layer further includes a first hole transport layer between the pixel electrode and the first emission layer, The first wavelength band is based on a blue visible light region, the second wavelength band is based on a red visible light region, and the third wavelength band is based on a green visible light region.

3. The display device according to claim 2, characterized in that The sum of the optical thickness of the first hole transport layer in the first band and the optical thickness of the second optical auxiliary body in the first band is consistent with the sum of the optical thickness of the first hole transport layer in the second band and the optical thickness of the first optical auxiliary body in the second band.

4. The display device according to claim 2, characterized in that The optical thickness of the first hole transport layer in the first wavelength band is inversely proportional to the optical thickness of the second optical auxiliary body in the first wavelength band.

5. The display device according to claim 2, characterized in that The optical thickness of the portion of the first hole transport layer within the first band is consistent with the optical thickness of the portion of the second optical auxiliary body within the first band, and the portion of the first hole transport layer within the first band can be replaced by the portion of the second optical auxiliary body within the first band.

6. The display device according to claim 1, characterized in that The pixel electrode includes a reflective layer on the substrate and a first transparent conductive layer on the reflective layer, the pixel electrode also includes a second transparent conductive layer below the reflective layer, the optical auxiliary layer is between the first transparent conductive layer and the intermediate layer, and the upper surface of the second transparent conductive layer and the lower surface of the reflective layer are in contact with each other.

7. The display device according to claim 1, characterized in that A difference between the second thickness and the first thickness is greater than a thickness of the first emission layer, and the thickness of the first emission layer is consistent with a thickness of the fourth emission layer.

8. The display device according to claim 1, characterized in that A first connecting layer is between the first emitting layer and the second emitting layer, and a second connecting layer is between the third emitting layer and the fourth emitting layer.

9. The display device according to claim 8, characterized in that The thickness of the first connection layer and the thickness of the second connection layer are greater than the thickness of the first emission layer.

10. The display device according to claim 8, characterized in that The first connecting layer includes a first electron transport layer on the first emission layer, a first charge generation layer on the first electron transport layer, and a second hole transport layer on the first charge generation layer, and the second connecting layer includes a second electron transport layer on the third emission layer, a second charge generation layer on the second electron transport layer, and a third hole transport layer on the second charge generation layer.

11. The display device according to claim 8, characterized in that An upper surface of the second emission layer and a lower surface of the third emission layer contact each other.

12. The display device according to claim 1, characterized in that A cover layer is further between the counter electrode and the color filter layer.

13. The display device according to claim 1, characterized in that The difference between the second thickness and the first thickness is to within the range.

14. The display device according to claim 1, characterized in that The optical auxiliary layer further includes a third optical auxiliary body having a third thickness and arranged side by side with the first optical auxiliary body and the second optical auxiliary body, wherein: In the plan view, the third optical auxiliary body overlaps with the second color filter, The third thickness is smaller than the first thickness and the second thickness, The difference between the third thickness and the second thickness is to , and the difference between the second thickness and the third thickness is six times the difference between the first thickness and the second thickness.

15. The display device according to claim 1, characterized in that The thickness of the intermediate layer is to within the range.

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