Display device

Abstract

According to an embodiment of the disclosure, a display device is provided. The display device includes: a substrate; and a light emitting element layer on the substrate and including an anode electrode portion, a cathode electrode portion, a light emitting structure electrically connected between the anode electrode portion and the cathode electrode portion, and a pixel defining layer. The light emitting structure includes a first light emitting structure included in a first sub-pixel and a second light emitting structure included in a second sub-pixel adjacent to the first sub-pixel. The pixel defining layer is between the first sub-pixel and the second sub-pixel, and includes a separation structure between the first light emitting structure and the second light emitting structure. The cathode electrode portion includes a first cathode electrode including an opaque conductive material and a second cathode electrode including a transparent conductive material.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0159450 filed in the Korean Intellectual Property Office on November 16, 2023, the disclosure of which is incorporated herein in its entirety by reference. Technical Field

[0002] The disclosed embodiments relate to a display device. Background Art

[0003] With the recent increase in interest in information display, research and development of display devices has been substantially continued.

[0004] The display device may include sub-pixels, each of which includes an organic light emitting diode (OLED). OLED is an active light emitting display element that not only has the characteristics of a wide viewing angle and excellent contrast, but also has the characteristics of being able to be driven at a low voltage, being lightweight, thin, and having a fast response speed.

[0005] The organic light emitting diode may include a hole transport portion, an electron transport portion, and a light emitting layer between the hole transport portion and the electron transport portion. Holes provided from the hole transport portion and electrons provided from the electron transport portion may be recombined in the light emitting layer to generate excitons. The generated excitons may change from an excited state to a ground state, and thus may generate light.

[0006] The OLED may include a cathode electrode configured to provide electrons to emit light. The cathode electrode may be configured as a common electrode for each of the different sub-pixels. In order for the cathode electrode to provide a suitable cathode signal to each OLED, the cathode electrode should be appropriately or properly patterned in the entire area where the sub-pixel is formed. Summary of the invention

[0007] An aspect of an embodiment of the present disclosure is to provide a display device having improved display quality by reducing a risk due to a leakage current or the like.

[0008] An aspect of an embodiment of the present disclosure is to provide a display device which reduces risks such as voltage drop by providing a detailed cathode electrode structure.

[0009] According to the disclosed embodiments, the display device may include: a substrate; and a light-emitting element layer, on the substrate and including an anode electrode portion, a cathode electrode portion, a light-emitting structure electrically connected between the anode electrode portion and the cathode electrode portion, and a pixel defining layer. The light-emitting structure may include a first light-emitting structure and a second light-emitting structure, the first light-emitting structure being included in a first sub-pixel, and the second light-emitting structure being included in a second sub-pixel adjacent to the first sub-pixel. The pixel defining layer may be located between the first sub-pixel and the second sub-pixel, and may include a separation structure located between the first light-emitting structure and the second light-emitting structure. The cathode electrode portion may include a first cathode electrode and a second cathode electrode, the first cathode electrode including an opaque conductive material, and the second cathode electrode including a transparent conductive material. At least a portion of the first cathode electrode may be cut by the separation structure. The second cathode electrode may be arranged across the first sub-pixel and the second sub-pixel. The second cathode electrode may have a thickness greater than that of the first cathode electrode.

[0010] According to an embodiment, the first cathode electrode and the second cathode electrode may contact each other (eg, physically contact each other).

[0011] According to the embodiment, the first cathode electrode may be directly adjacent to the uppermost surface of the light emitting structure.

[0012] According to an embodiment, the first cathode electrode may include one or more selected from the group consisting of gold (Au), silver (Ag), aluminum (Al), molybdenum (Mo), chromium (Cr), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and platinum (Pt).

[0013] According to an embodiment, the second cathode electrode may include a material selected from the group consisting of indium zinc oxide (IZO), silver nanowires (AgNW), indium tin oxide (ITO), indium gallium zinc oxide (IGZO), antimony zinc oxide (AZO), indium tin zinc oxide (ITZO), zinc oxide (ZnO), tin oxide (SnO 2 ), at least one of the group consisting of carbon nanotubes and graphene.

[0014] According to an embodiment, the first cathode electrode may have a thickness in the range of 100Å to 180Å.

[0015] According to an embodiment, the second cathode electrode may have a thickness in the range of 600Å to 800Å.

[0016] According to an embodiment, the cathode electrode portion may further include an intermediate structure between the first cathode electrode and the second cathode electrode. The intermediate structure may include an N-type intermediate layer, a P-type intermediate layer on the N-type intermediate layer, and an intermediate electron injection layer on the P-type intermediate layer.

[0017] According to an embodiment, the N-type intermediate layer may be adjacent to the anode electrode portion. The P-type intermediate layer may be adjacent to the second cathode electrode.

[0018] According to an embodiment, the N-type intermediate layer, the P-type intermediate layer, and the intermediate electron injection layer may be directly adjacent to each other.

[0019] According to an embodiment, the N-type intermediate layer may have a thickness in a range of 40Å to 100Å.

[0020] According to an embodiment, the intermediate structure may have a thickness in the range of 400Å to 700Å.

[0021] According to an embodiment, the separation structure may include a trench providing a gap between the first sub-pixel and the second sub-pixel. The trench may include a plurality of trenches.

[0022] According to an embodiment, the trench may have a height in the range of 450 nm to 750 nm.

[0023] According to an embodiment, the trench may have a width in the range of 60 nm to 170 nm.

[0024] According to an embodiment, the plurality of grooves may include a first groove and a second groove. The width of each of the first groove and the second groove may be equal to the distance the first groove and the second groove are spaced apart from each other (eg, the first groove and the second groove may each have a width equal to the distance the first groove and the second groove are spaced apart from each other).

[0025] According to an embodiment, at least a portion of the first cathode electrode may be cut by the groove.The second cathode electrode may be continuously disposed on the groove.

[0026] According to an embodiment, the pixel defining layer may include: a first groove forming layer covering at least a portion of the anode electrode portion; a second groove forming layer having a width smaller than that of the first groove forming layer and on the first groove forming layer; and a third groove forming layer having a width smaller than that of the second groove forming layer and on the second groove forming layer.

[0027] According to an embodiment, the first trench forming layer may include silicon nitride (Si x N y The second trench forming layer may include silicon oxide (Si x O y The third trench forming layer may include silicon nitride (Si x N y ).

[0028] According to an embodiment, the light emitting structure may further include an intermediate light emitting structure located on a portion of the pixel defining layer between the first groove and the second groove. The cathode electrode portion may further include an intermediate cathode electrode on the same layer as the first cathode electrode and on the intermediate light emitting structure. The intermediate cathode electrode and the first cathode electrode may be spaced apart from each other.

[0029] According to an embodiment, the pixel defining layer may include a protrusion base layer and a protrusion spacer on the protrusion base layer.

[0030] According to an embodiment, the protrusion base layer may include: a first protrusion base layer covering the anode electrode portion; and a second protrusion base layer on the first protrusion base layer and having a width smaller than the width of the first protrusion base layer. The protrusion spacer may include: a first protrusion spacer on the second protrusion base layer and having a width larger than the width of the second protrusion base layer; a second protrusion spacer on the first protrusion spacer and having a width smaller than the width of the first protrusion spacer; and a third protrusion spacer on the second protrusion spacer and having a width smaller than the width of the second protrusion spacer.

[0031] According to an embodiment, the light emitting structure may further include an intermediate light emitting structure on the protruding spacer. The cathode electrode portion may further include an intermediate cathode electrode on the intermediate light emitting structure and spaced apart from the first cathode electrode. The second cathode electrode may cover the intermediate cathode electrode and may be arranged across the first sub-pixel and the second sub-pixel.

[0032] According to an embodiment, the pixel defining layer may include a base pixel defining layer and a planarization pixel defining layer which planarizes a step formed by the base pixel defining layer at the base pixel defining layer.

[0033] According to an embodiment, the light emitting structure may include a series structure. The series structure may include: a first light emitting portion; a first charge generation layer on the first light emitting portion; a third light emitting portion on the first charge generation layer; a second charge generation layer on the third light emitting portion; and a second light emitting portion on the second charge generation layer. Each of the first light emitting portion, the second light emitting portion, and the third light emitting portion may include a hole transport portion, a light emitting layer, and an electron transport portion. The first charge generation layer and the second charge generation layer may be cut by a partition structure.

[0034] According to an embodiment, the light emitting structure may include a series structure. The series structure may include: a first light emitting portion; a charge generation layer on the first light emitting portion; and a second light emitting portion on the charge generation layer. Each of the first light emitting portion and the second light emitting portion may include a hole transport portion, a light emitting layer, and an electron transport portion. The charge generation layer may be cut by a partition structure.

[0035] According to an embodiment, the light emitting structure may include a hole transport portion, a light emitting layer, and an electron transport portion. The electron transport portion may include a first electron transport layer and a second electron transport layer including different materials.

[0036] According to an embodiment, the display device may further include: a pixel circuit layer between the substrate and the light emitting element layer and including a pixel circuit; a reflective electrode on the pixel circuit layer; and a step forming layer between the reflective electrode and the anode electrode portion.

[0037] According to an embodiment, the light emitting structure may further include a third light emitting structure included in the third sub-pixel. The step-forming layer may be provided in the first sub-pixel, but not in the second sub-pixel and the third sub-pixel.

[0038] According to an embodiment, the light emitting structure may further include a third light emitting structure, the third light emitting structure being included in the third sub-pixel. The step-forming layer may be disposed in each of the first sub-pixel, the second sub-pixel, and the third sub-pixel. The step-forming layer may have a thickness greater in the second sub-pixel and the third sub-pixel than in the first sub-pixel.

[0039] According to the disclosed embodiment, the display device may include: a substrate; and a light-emitting element layer, on the substrate and including an anode electrode portion, a cathode electrode portion, a light-emitting structure electrically connected between the anode electrode portion and the cathode electrode portion, and a pixel defining layer. The light-emitting structure may include a first light-emitting structure and a second light-emitting structure, the first light-emitting structure is included in a first sub-pixel, and the second light-emitting structure is included in a second sub-pixel adjacent to the first sub-pixel. The pixel defining layer may be located between the first sub-pixel and the second sub-pixel, and may include a groove between the first light-emitting structure and the second light-emitting structure. The groove may include a first groove and a second groove, and the first groove and the second groove are spaced apart from each other in a direction in which the first sub-pixel and the second sub-pixel are spaced apart. The width of each of the first groove and the second groove may be in the range of 80nm to 150nm. The height of each of the first groove and the second groove may be in the range of 500nm to 700nm. The cathode electrode portion may include a first cathode electrode and a second cathode electrode comprising different materials (for example, the first cathode electrode may include a material different from that of the second cathode electrode).

[0040] According to the disclosed embodiments, the display device may include: a substrate; and a light-emitting element layer, on the substrate and including an anode electrode portion, a cathode electrode portion, a light-emitting structure electrically connected between the anode electrode portion and the cathode electrode portion, and a pixel defining layer. The light-emitting structure may include a first light-emitting structure and a second light-emitting structure, the first light-emitting structure being included in a first sub-pixel, and the second light-emitting structure being included in a second sub-pixel adjacent to the first sub-pixel. The pixel defining layer may be located between the first sub-pixel and the second sub-pixel, and may include a separation structure located between the first light-emitting structure and the second light-emitting structure. The cathode electrode portion may include: a first cathode electrode; a second cathode electrode including a material different from that of the first cathode electrode; and an intermediate structure, between the first cathode electrode and the second cathode electrode. The intermediate structure may include an N-type intermediate layer, a P-type intermediate layer on the N-type intermediate layer, and an intermediate electron injection layer on the P-type intermediate layer.

[0041] According to the disclosed embodiments, a display device having improved display quality by reducing risks due to leakage current and the like can be provided.

[0042] According to the disclosed embodiments, a display device that reduces risks such as voltage drop and the like by providing a detailed cathode electrode structure can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The above and other features of the disclosure will become more apparent by describing the disclosed embodiments in more detail with reference to the accompanying drawings, in which: Figure 1 is a schematic plan view showing a display device according to an embodiment; Figure 2 It is shown Figure 1 An exploded perspective view of a portion of a display device; Figure 3 It is shown Figure 2 A plan view of an embodiment of a pixel in a plurality of pixels; Figure 4 It is shown Figure 2 A plan view of an embodiment of a pixel in a plurality of pixels; Figure 5 It is shown Figure 2 A plan view of an embodiment of a pixel in a plurality of pixels; Figures 6 to 8 is a schematic cross-sectional view showing a light emitting element according to an embodiment; Fig. 9 is a schematic cross-sectional view showing a cathode electrode portion according to an embodiment; Fig.10 is a schematic cross-sectional view showing a cathode electrode portion according to an embodiment; Figures 11 to 14is a schematic cross-sectional view showing a display device according to an embodiment; Figures 15 to 20 is a schematic cross-sectional view showing a portion of a display device including a partition structure and a cathode electrode portion disposed adjacent to the partition structure according to an embodiment; Fig.21 is a block diagram illustrating an embodiment of a display system; Fig. 22 It is shown Fig.21 A perspective view of an application example of an embodiment of a display system; and Fig.23 It is shown by Fig. 22 FIG. 1 is a diagram of a head mounted display device worn by a user. DETAILED DESCRIPTION

[0044] The disclosed subject matter can be modified in various suitable ways and have various suitable forms. Therefore, example embodiments will be shown in the drawings and will be described in more detail in the specification. However, it should be understood that the disclosure is not intended to be limited to the disclosed form, and the disclosure includes all modifications, equivalents and substitutes within the spirit and technical scope of the disclosure.

[0045] Although the terms "first", "second", etc. can be used to describe various suitable components, the components should not be limited by these terms. The terms are only used for the purpose of distinguishing one component from another component. For example, without departing from the scope of the disclosure, a first component can be referred to as a second component, and similarly, a second component can also be referred to as a first component. In the following description, unless the context clearly indicates otherwise, a singular expression includes a plural expression.

[0046] It will be understood that in the present disclosure, the terms "including", "having" and the like are used to illustrate the presence of features, quantities, steps, operations, components, parts or combinations thereof described in the specification, but do not exclude the pre-existence or addition of one or more other features, quantities, steps, operations, components, parts or combinations thereof. In addition, the case where a part of a layer, film, region, plate, etc. is referred to as "on" another part not only includes the case where the part is "directly on" the other part, but also includes the case where there is another part between the part and the other part. In addition, in the present specification, when a part of a layer, film, region, plate, etc. is formed on another part, the formation direction is not limited to the upper direction, but includes forming the part on the side surface or in the lower direction. On the contrary, when a part of a layer, film, region, plate, etc. is formed "under" another part, this includes not only the case where the part is "directly under" the other part, but also includes the case where there is another part between the part and the other part.

[0047] The disclosure relates to a display device. Hereinafter, a display device of an embodiment is described with reference to the accompanying drawings.

[0048] Figure 1 is a schematic plan view showing a display device according to an embodiment.

[0049] Reference Figure 1 , the display device 100 according to the embodiment is configured to emit light.

[0050] The display device 100 may include a display area DA and a non-display area NDA. The display device 100 displays an image through the display area DA. The non-display area NDA is disposed around the display area DA.

[0051] The display device 100 may include a substrate SUB, a sub-pixel SP, and a pad (or referred to as a “pad” or “pad pad”) PD.

[0052] When the display device 100 is used as a display screen for a head mounted display (HMD) device, a virtual reality (VR) device, a mixed reality (MR) device, an augmented reality (AR) device, etc., the display device 100 is positioned very close to the user's eyes. In this case, relatively high integration of sub-pixels SP is beneficial. In order to increase the integration of the sub-pixels SP, the substrate SUB can be set to a silicon substrate. The sub-pixels SP can be on a substrate SUB that is a silicon substrate. The display device 100 including an OLED formed directly on a substrate SUB that is a silicon substrate can be referred to as an OLED on silicon (OLEDoS) display device.

[0053] The sub-pixels SP are located in the display area DA on the substrate SUB. The sub-pixels SP may be arranged in a matrix shape along a first direction DR1 and a second direction DR2 intersecting the first direction DR1. However, the embodiment is not limited thereto. For example, the sub-pixels SP may be arranged in a zigzag pattern along the first direction DR1 and the second direction DR2. For example, the sub-pixels SP may be arranged in a PENTILE ® Arrangement structure (eg, RGBG matrix, RGBG structure, or RGBG matrix structure), but the present disclosure is not limited thereto. ® is an officially registered trademark of Samsung Display Co., Ltd. The first direction DR1 may be a row direction, and the second direction DR2 may be a column direction.

[0054] Each of the sub-pixels SP may include at least one light emitting element LD configured to generate light (refer to Figure 6 ). Therefore, each of the sub-pixels SP may generate light of a set or specific color (such as red, green, blue, cyan, magenta, or yellow). Two or more sub-pixels SP among the sub-pixels SP may provide a pixel PXL. For example, Figure 1 As shown in FIG. , three sub-pixels SP may provide a pixel PXL.

[0055] Hereinafter, based on the sub-pixel SP including a first sub-pixel SP1 (refer to Figure 2 ), providing a second sub-pixel SP2 of a second color (eg, green) (refer to Figure 2 ) and a third sub-pixel SP3 (refer to Figure 2 ) embodiments to describe the disclosed subject matter.

[0056] According to an embodiment, the first sub-pixel SP1 may be a red pixel and may provide light having a wavelength band of 600nm to 750nm. The second sub-pixel SP2 may be a green pixel and may provide light having a wavelength band of 480nm to 560nm. The third sub-pixel SP3 may be a blue pixel and may provide light having a wavelength band of 370nm to 460nm.

[0057] Components for controlling the sub-pixel SP may be located in the non-display area NDA on the substrate SUB. For example, lines connected to the sub-pixel SP (e.g., gate lines, data lines, etc. for driving the sub-pixel SP) may be in the non-display area NDA. In an embodiment, a gate driver, a data driver, a voltage generator, a controller, a temperature sensor, etc. that obtain a driving signal provided to the sub-pixel SP may be integrated into the non-display area NDA of the display device. However, the disclosure is not limited thereto.

[0058] The pad PD is located in the non-display area NDA on the substrate SUB. The pad PD may be electrically connected to the sub-pixel SP through a line. For example, the pad PD may be connected to the sub-pixel SP through a data line.

[0059] The pad PD may interface components in the display area DA and the non-display area NDA with other components of the display device 100. In an embodiment, voltages and signals useful for the operation of components included in the display device 100 may be provided from the driver integrated circuit through the pad PD. For example, a data line may be electrically connected to the driver integrated circuit through the pad PD. For example, a power voltage for driving the sub-pixel SP may be received from the driver integrated circuit through the pad PD. For example, a gate control signal for controlling a gate driver may be transmitted from the driver integrated circuit to the gate driver through the pad PD.

[0060] In an embodiment, the circuit board may be electrically connected to the pad PD using a conductive adhesive member (e.g., an electrically conductive adhesive member) such as an anisotropic conductive film. In an embodiment, the circuit board may be a flexible circuit board (FPCB) and / or a flexible film having a flexible material. A driver integrated circuit may be mounted on the circuit board to be electrically connected to the pad PD.

[0061] In an embodiment, the display area DA may have various suitable shapes. The display area DA may have a closed loop shape including straight edges and / or curved edges. For example, the display area DA may have a shape such as a polygon, a circle, a semicircle, and / or an ellipse.

[0062] In an embodiment, the display device 100 may have a flat display surface. In an embodiment, the display device 100 may have a display surface that is at least partially circular. In an embodiment, the display device 100 may be bendable, foldable and / or rollable. In an embodiment, the display device 100 and / or the substrate SUB may include a material having a flexible property.

[0063] Figure 2 It is shown Figure 1 An exploded perspective view of a portion of a display device. Figure 2 In the embodiment, for the sake of clarity and simplicity, the display device 100 is schematically shown. Figure 1 Portions corresponding to the two pixels PXL1 and PXL2 among the pixels PXL of the display device 100 may be similarly configured.

[0064] Reference Figure 1 to Figure 2 , each of the first pixel PXL1 and the second pixel PXL2 may include first to third sub-pixels SP1, SP2, and SP3. However, the embodiment is not limited thereto. For example, each of the first pixel PXL1 and the second pixel PXL2 may include four sub-pixels or two sub-pixels.

[0065] exist Figure 2 In the embodiment, when viewed from a third direction DR3 crossing the first direction DR1 and the second direction DR2, the first to third sub-pixels SP1, SP2, and SP3 have a quadrilateral shape and have sizes equal to each other. However, the embodiment is not limited thereto. The first to third sub-pixels SP1, SP2, and SP3 may be modified to have various suitable shapes.

[0066] The display device 100 may include a substrate SUB, a pixel circuit layer PCL, a light emitting element layer LDL, an encapsulation layer TFE, an optical function layer OFL, an overcoat layer OC, and a cover window CW.

[0067] In an embodiment, the substrate SUB may include a silicon wafer substrate formed using a semiconductor process. The substrate SUB may include a semiconductor material suitable for providing circuit elements. For example, the semiconductor material may include silicon, germanium and / or silicon germanium. The substrate SUB may be provided by a bulk wafer, an epitaxial layer, a silicon on insulator (SOI) layer, a semiconductor on insulator (SeOI) layer, etc. In an embodiment, the substrate SUB may include a glass substrate. In an embodiment, the substrate SUB may include a polyimide (PI) substrate.

[0068] The pixel circuit layer PCL is on the substrate SUB. The substrate SUB and / or the pixel circuit layer PCL may include an insulating layer (e.g., an electrical insulating layer) and a conductive pattern (e.g., an electrical conductive pattern) between the insulating layers. The conductive pattern of the pixel circuit layer PCL may be used as at least a part of a circuit element, a line, etc. The conductive pattern may include copper, but the embodiment is not limited thereto.

[0069] The circuit element may include a sub-pixel circuit for each of the first to third sub-pixels SP1, SP2, and SP3. The sub-pixel circuit may include a transistor and one or more capacitors. Each transistor may include a semiconductor portion and a gate electrode superimposed with the semiconductor portion, the semiconductor portion including a source region, a drain region, and a channel region. In an embodiment, when the substrate SUB is set to a silicon substrate, the semiconductor portion may be included in the substrate SUB, and the gate electrode may be included in the pixel circuit layer PCL as a conductive pattern (e.g., an electrical conductive pattern) of the pixel circuit layer PCL. In an embodiment, when the substrate SUB is set to a glass substrate and / or a PI substrate, the semiconductor portion and the gate electrode may be included in the pixel circuit layer PCL. Each capacitor may include electrodes spaced apart from each other. For example, each capacitor may include electrodes spaced apart from each other on a plane defined by the first direction DR1 and the second direction DR2. For example, each capacitor may include electrodes spaced apart from each other in the third direction DR3 and an insulating layer (e.g., an electrical insulating layer) is located between them.

[0070] The lines of the pixel circuit layer PCL may include signal lines connected to each of the first to third sub-pixels SP1 , SP2 , and SP3 , for example, gate lines, emission control lines, data lines, and the like.

[0071] The light emitting element layer LDL may include an anode electrode portion ANP, a pixel defining layer PDL, a light emitting structure EMS, and / or a cathode electrode portion CAP.

[0072] The anode electrode portion ANP may be on the pixel circuit layer PCL. The anode electrode portion ANP may include an anode electrode corresponding to each sub-pixel SP. The anode electrode portion ANP may contact a circuit element of the pixel circuit layer PCL.

[0073] The pixel defining layer PDL is on the anode electrode portion ANP. The pixel defining layer PDL may include an opening OP exposing a portion of each of the anode electrode portions ANP. The opening OP of the pixel defining layer PDL may be understood as emission regions corresponding to the first to third subpixels SP1 to SP3, respectively.

[0074] In an embodiment, the pixel defining layer PDL may include an inorganic material. In an embodiment, the pixel defining layer PDL may include a plurality of stacked inorganic layers. For example, the pixel defining layer PDL may include silicon oxide (Si x O y ) and / or silicon nitride (Si x N y ). In an embodiment, the pixel defining layer PDL may include an organic material. However, the material of the pixel defining layer PDL is not limited thereto.

[0075] The pixel defining layer PDL may have various suitable structures and may form a partition structure. Details about the partition structure are further described below.

[0076] The light emitting structure EMS may be on the anode electrode portion ANP exposed through the opening OP of the pixel defining layer PDL. The light emitting structure EMS may include a light emitting layer EML (refer to Figure 6 ), the electron transport unit ETU configured to transport electrons (refer to Figure 6 ), a hole transport unit HTU configured to transport holes (refer to Figure 6 )wait.

[0077] In an embodiment, the light emitting structure EMS may fill the opening OP of the pixel defining layer PDL and may be entirely on the pixel defining layer PDL. In an embodiment, the light emitting structure EMS may extend across the first sub-pixel SP1 to the third sub-pixel SP3. In an embodiment, at least a portion of a layer in the light emitting structure EMS may be disconnected or bent at a boundary between the first sub-pixel SP1 to the third sub-pixel SP3. However, the embodiment is not limited thereto. For example, portions of the light emitting structure EMS corresponding to the first sub-pixel SP1 to the third sub-pixel SP3 may be spaced apart from each other, and each of the portions may be located in the opening OP of the pixel defining layer PDL.

[0078] The cathode electrode portion CAP may be on the light emitting structure EMS. The cathode electrode portion CAP may extend across the first to third subpixels SP1 to SP3. As described above, the cathode electrode portion CAP may be provided as a common electrode for the first to third subpixels SP1 to SP3.

[0079] The cathode electrode portion CAP may be configured to transmit light emitted from the light emitting structure EMS. For example, the cathode electrode portion CAP may include a thin metal layer.

[0080] According to an embodiment, the cathode electrode portion CAP may include a multi-metal structure. For example, the cathode electrode portion CAP may include a first cathode electrode CE1 (refer to Fig. 9 ) and the second cathode electrode CE2 (reference Fig. 9 ). Refer to the following Figure 6 The following figures provide a more detailed description of this.

[0081] It can be understood that any one selected from the anode electrode portion ANP, the portion of the light emitting structure EMS overlapping the anode electrode portion ANP, and the portion of the cathode electrode portion CAP overlapping the anode electrode portion ANP may be included in the light emitting element LD. In an embodiment, each of the light emitting elements LD of the first to third subpixels SP1 to SP3 may include one anode electrode, the portion of the light emitting structure EMS overlapping the one anode electrode, and the portion of the cathode electrode portion CAP overlapping the one anode electrode.

[0082] In each of the first to third sub-pixels SP1 to SP3, holes injected from the anode electrode portion ANP and electrons injected from the cathode electrode portion CAP may be transferred to the light-emitting layer EML of the light-emitting structure EMS to form excitons, and when the excitons transition from an excited state to a ground state, light may be generated. The brightness of the light may be determined according to the amount of current flowing through the light-emitting layer EML. According to the configuration of the light-emitting layer EML, the wavelength range of the generated light may be determined or controlled.

[0083] The encapsulation layer TFE is on the cathode electrode portion CAP. The encapsulation layer TFE may cover the light emitting element layer LDL and / or the pixel circuit layer PCL. The encapsulation layer TFE may be configured to prevent or reduce the penetration of oxygen, moisture, etc. into the light emitting element layer LDL. In an embodiment, the encapsulation layer TFE may include a structure in which one or more inorganic layers and one or more organic layers are alternately stacked. For example, the inorganic layer may include silicon nitride, silicon oxide, silicon oxynitride (Si x O y N z ) and the like. For example, the organic layer may include an organic insulating material (e.g., an organic electrical insulating material) such as acrylic resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene ether resin, polyphenylene sulfide resin and / or benzocyclobutene (BCB). However, the materials of the organic layer and the inorganic layer of the encapsulation layer TFE are not limited thereto.

[0084] In order to improve the encapsulation efficiency of the encapsulation layer TFE, the encapsulation layer TFE may further include aluminum oxide (AlOx The thin film including aluminum oxide may be on an upper surface of the encapsulation layer TFE facing the optical function layer OFL and / or a lower surface of the encapsulation layer TFE facing the light emitting element layer LDL.

[0085] The thin film including aluminum oxide may be formed by an atomic layer deposition (ALD) method. However, the embodiment is not limited thereto. The encapsulation layer TFE may further include a thin film including at least one selected from various materials suitable for improving encapsulation efficiency.

[0086] The optical function layer OFL is on the encapsulation layer TFE. The optical function layer OFL may include a color filter layer CFL and a lens array LA.

[0087] The color filter layer CFL is located between the encapsulation layer TFE and the lens array LA. The color filter layer CFL is configured to filter the light emitted from the light emitting structure EMS, and selectively output light having a wavelength range and / or color corresponding to each sub-pixel. The color filter layer CFL may include color filters CF corresponding to the first to third sub-pixels SP1 to SP3, respectively, and each of the color filters CF may allow light having a wavelength range corresponding to the corresponding sub-pixel to pass through. For example, the color filter corresponding to the first sub-pixel SP1 may allow red light to pass through, the color filter corresponding to the second sub-pixel SP2 may allow green light to pass through, and the color filter corresponding to the third sub-pixel SP3 may allow blue light to pass through. Depending on the light emitted from the light emitting structure EMS of each sub-pixel, at least a portion of the color filter CF may be omitted.

[0088] The lens array LA is on the color filter layer CFL. The lens array LA may include lenses LS corresponding to the first to third sub-pixels SP1 to SP3, respectively. Each of the lenses LS may improve light output efficiency by outputting light emitted from the light emitting structure EMS to a set or intended path. The lens array LA may have a relatively high refractive index. For example, the lens array LA may have a refractive index higher than that of the overcoat layer OC. In an embodiment, the lens LS may include an organic material. In an embodiment, the lens LS may include an acrylic material. However, the material of the lens LS is not limited thereto.

[0089] In an embodiment, at least a portion of the color filter CF of the color filter layer CFL and at least a portion of the lens LS of the lens array LA may be offset in a direction parallel to the plane defined by the first direction DR1 and the second direction DR2, compared to the opening OP of the pixel defining layer PDL. In an embodiment, in the central area of ​​the display area DA, when viewed in the third direction DR3, the center of the color filter CF and the center of the lens LS may be aligned and / or overlapped with the center of the opening OP of the corresponding pixel defining layer PDL. For example, in the central area of ​​the display area DA, the opening OP of the pixel defining layer PDL may be completely overlapped with the corresponding color filter CF of the color filter layer CFL and the corresponding lens LS of the lens array LA. In an area adjacent to the non-display area NDA in the display area DA, when viewed in the third direction DR3, the center of the color filter CF and the center of the lens LS may be offset from the center of the opening OP of the corresponding pixel defining layer PDL in the plane direction. For example, in an area adjacent to the non-display area NDA in the display area DA, the opening OP of the pixel defining layer PDL may partially overlap with the corresponding color filter CF of the color filter layer CFL and the corresponding lens LS of the lens array LA. Therefore, at the center of the display area DA, the light emitted from the light emitting structure EMS may be effectively output in the normal direction of the display surface. At the periphery or edge of the display area DA, the light emitted from the light emitting structure EMS may be effectively output in a direction inclined at a set or predetermined angle relative to the normal direction of the display surface.

[0090] The outer coating OC may be on the lens array LA. The outer coating OC may cover the optical function layer OFL, the encapsulation layer TFE, the light emitting structure EMS and / or the pixel circuit layer PCL. The outer coating OC may include various materials suitable for protecting the layers thereunder from foreign substances such as dust and / or moisture. For example, the outer coating OC may include at least one selected from an inorganic insulating layer (e.g., an inorganic electrical insulating layer) and an organic insulating layer (e.g., an organic electrical insulating layer). For example, the outer coating OC may include an epoxy resin, but the embodiment is not limited thereto. The outer coating OC may have a refractive index lower than that of the lens array LA.

[0091] The cover window CW may be on the outer coating layer OC. The cover window CW is configured to protect the layers thereunder. The cover window CW may have a refractive index higher than that of the outer coating layer OC. The cover window CW may include glass, but the embodiment is not limited thereto. For example, the cover window CW may be an encapsulation glass configured to protect the components thereunder. In an embodiment, the cover window CW may be omitted.

[0092] Figure 3 It is shown Figure 2 A plan view of an embodiment of a pixel in a plurality of pixels. Figure 3In order to make the description clear and concise, the schematic diagram is shown. Figure 2 The remaining pixels may be configured similarly to the first pixel PXL1.

[0093] Reference Figures 2 to 3 , the first pixel PXL1 may include a first sub-pixel SP1 , a second sub-pixel SP2 , and a third sub-pixel SP3 arranged in the first direction DR1 .

[0094] The first subpixel SP1 may include a first emission area EMA1 and a non-emission area NEA around the first emission area EMA1. The second subpixel SP2 may include a second emission area EMA2 and a non-emission area NEA around the second emission area EMA2. The third subpixel SP3 may include a third emission area EMA3 and a non-emission area NEA around the third emission area EMA3.

[0095] The first emission area EMA1 may be a portion of the light emitting structure EMS corresponding to the first sub-pixel SP1 (eg, the first light emitting structure EMS1 ( Fig.11 The second emission area EMA2 may be a portion of the light emitting structure EMS corresponding to the second sub-pixel SP2 (eg, the second light emitting structure EMS2 ( Fig.11 The third emission area EMA3 may be a portion of the light emitting structure EMS corresponding to the third sub-pixel SP3 (eg, the third light emitting structure EMS3 ( Fig.11 )) The area where light is emitted. Figure 2 As described, each emission region may be understood as an opening OP of the pixel defining layer PDL corresponding to each of the first sub-pixel SP1 , the second sub-pixel SP2 , and the third sub-pixel SP3 .

[0096] Figure 4 It is shown Figure 2 A plan view of an embodiment of a pixel among a plurality of pixels.

[0097] Reference Figure 4 , the first pixel PXL1 ′ may include first to third sub-pixels SP1 ′ to SP3 ′.

[0098] The first subpixel SP1' may include a first emission area EMA1' and a non-emission area NEA' around the first emission area EMA1'. The second subpixel SP2' may include a second emission area EMA2' and a non-emission area NEA' around the second emission area EMA2'. The third subpixel SP3' may include a third emission area EMA3' and a non-emission area NEA' around the third emission area EMA3'.

[0099] The first subpixel SP1' and the second subpixel SP2' may be arranged in the second direction DR2. The third subpixel SP3' may be arranged in the first direction DR1 with respect to each of the first subpixel SP1' and the second subpixel SP2'.

[0100] The second sub-pixel SP2' may have an area larger than that of the first sub-pixel SP1', and the third sub-pixel SP3' may have an area larger than that of the second sub-pixel SP2'. Therefore, the second emission area EMA2' may have an area larger than that of the first emission area EMA1', and the third emission area EMA3' may have an area larger than that of the second emission area EMA2'. However, the embodiment is not limited thereto. For example, the first sub-pixel SP1' and the second sub-pixel SP2' may have substantially the same area, and the third sub-pixel SP3' may have an area larger than that of each of the first sub-pixel SP1' and the second sub-pixel SP2'. As described above, the areas of the first to third sub-pixels SP1' to SP3' may be appropriately varied according to the embodiment.

[0101] Figure 5 It is shown Figure 2 A plan view of an embodiment of a pixel among a plurality of pixels.

[0102] Reference Figure 5 , the first subpixel SP1'' may include a first emission area EMA1'' and a non-emission area NEA'' around the first emission area EMA1''. The second subpixel SP2'' may include a second emission area EMA2'' and a non-emission area NEA'' around the second emission area EMA2''. The third subpixel SP3'' may include a third emission area EMA3'' and a non-emission area NEA'' around the third emission area EMA3''.

[0103] When viewed in the third direction DR3, the first to third sub-pixels SP1'' to SP3'' may have a polygonal shape. For example, the shapes of the first to third sub-pixels SP1'' to SP3'' may be as follows: Figure 5 The hexagonal shape shown in .

[0104] When viewed in the third direction DR3, the first to third emission areas EMA1″ to EMA3″ may have a circular shape. However, the embodiment is not limited thereto. For example, each of the first to third emission areas EMA1″ to EMA3″ may have a polygonal shape.

[0105] The first subpixel SP1 ″ and the third subpixel SP3 ″ may be arranged in the first direction DR1 . The second subpixel SP2 ″ may be in a direction (or a diagonal direction) inclined at an acute angle based on the second direction DR2 with respect to the first subpixel SP1 ″.

[0106] Figures 3 to 5 The arrangement of the sub-pixels shown in is an example, and the embodiment is not limited thereto. Each pixel PXL may include two or more sub-pixels SP, the sub-pixels SP may be arranged in various ways, each sub-pixel SP may have various suitable shapes, and each emission area EMA1, EMA2, and EMA3 of each sub-pixel SP may have various suitable shapes.

[0107] In the following, reference is made to Figures 6 to 18 A display device 100 including a cathode electrode portion CAP according to an embodiment is described. Contents that may overlap with the above contents are briefly described or not repeated.

[0108] Figures 6 to 8 is a schematic cross-sectional view showing a light emitting element according to the embodiment. Figure 6 The cross-sectional structure of the light emitting element LD according to the embodiment can be shown, and Figures 7 and 8 The cross-sectional structure of the light emitting element LD including the series structure according to the embodiment can be shown. For example, Figure 7 It can be schematically shown that the light emitting element LD includes a series structure including three light emitting portions EU, and Figure 8 The light emitting element LD including a series structure including two light emitting portions EU may be schematically illustrated.

[0109] Reference Figures 6 to 8 , the light emitting element LD may include an anode electrode portion ANP, a light emitting structure EMS, and a cathode electrode portion CAP.

[0110] The anode electrode portion ANP may be electrically connected to the light emitting structure EMS, and may supply holes to the light emitting structure EMS.

[0111] The anode electrode portion ANP may include various suitable conductive materials (e.g., electrically conductive materials). For example, the anode electrode portion ANP may include a transparent conductive material (e.g., a transparent electrically conductive material). For example, the anode electrode portion ANP may include at least one selected from transparent conductive materials such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium gallium zinc oxide (IGZO), and indium tin zinc oxide (ITZO). However, the disclosure is not limited thereto. The anode electrode portion ANP may include an opaque conductive material (e.g., an opaque electrically conductive material) that can reflect light. For example, the anode electrode portion ANP may include one or more selected from titanium nitride (TiN), silver (Ag), and aluminum (Al).

[0112] For example, the anode electrode portion ANP may include a structure of ITO / Ag on TiN / Ag. According to an embodiment, the anode electrode portion ANP may include a conductive layer structure (eg, an electrical conductive structure) including Al / TiN and not including ITO / Ag. However, the disclosure is not limited thereto.

[0113] The light emitting structure EMS may be between the anode electrode portion ANP and the cathode electrode portion CAP. The light emitting structure EMS may include a multilayer structure. For example, the light emitting structure EMS may include a light emitting portion EU including a hole transport portion HTU, a light emitting layer EML (or light generating layer), and an electron transport portion ETU.

[0114] In the embodiment, the light emitting structure EMS may be formed by a method such as vacuum deposition, spin coating, inkjet printing, etc., but the embodiment is not limited thereto.

[0115] The light emitting structure EMS may include various suitable organic materials, and according to an embodiment, the light emitting structure EMS may further include a metal-containing compound, an inorganic material such as a quantum dot, or the like.

[0116] The hole transport part HTU may include a multilayer structure having a plurality of layers including different materials, for example, the hole transport part HTU may include at least one selected from a hole injection layer and a hole transport layer, and according to an embodiment, the hole transport part HTU may also include a light emitting auxiliary layer, an electron blocking layer, etc.

[0117] The hole injection layer may be a layer that performs and / or improves the hole injection function from the anode electrode portion ANP to another adjacent organic layer. The hole transport layer may be a layer that provides the provided holes to the light emitting layer EML. The light emitting auxiliary layer may be a layer that compensates for the resonance distance based on the wavelength of the light provided by the light emitting layer EML. The electron blocking layer may be a layer that prevents or reduces the injection of electrons from the electron transport portion ETU and thus reduces the number of carriers (e.g., holes or electrons) leaving the light emitting layer EML.

[0118] For example, the hole transport portion HTU may have a multilayer structure such as hole injection layer / hole transport layer, hole injection layer / hole transport layer / luminescence auxiliary layer, hole injection layer / luminescence auxiliary layer, hole transport layer / luminescence auxiliary layer, electron blocking layer / hole injection layer / hole transport layer, hole transport layers sequentially arranged and including different materials, or hole injection layer / hole transport layer / electron blocking layer. However, the disclosure is not limited thereto.

[0119] According to an embodiment, the hole transport part HTU may include various suitable organic hole transport materials. For example, the hole transport part HTU may include one or more selected from HAT-CN (Formula 1), HTL1 (Formula 2), HTL2 (Formula 3), HTL3 (Formula 4), HTL4 (Formula 5) and TAPC (Formula 6). According to an embodiment, the hole transport part HTU may include a stacked structure including HAT-CN as a hole injection layer, one selected from HTL1 to HTL4 as a hole transport layer, and TAPC as a light-emitting auxiliary layer.

[0120] Formula 1

[0121] Formula 2

[0122] Formula 3

[0123] Formula 4

[0124] Formula 5

[0125] Formula 6

[0126] However, the disclosure is not limited thereto. According to an embodiment, the hole transport portion HTU may include any suitable spin-on polymer, etc., and may further include a p-type dopant.

[0127] The light emitting layer EML may include a material that can emit light of one color. The light emitting layer EML may include a host and a dopant. The host of the light emitting layer EML may be a light emitting material that can capture carriers (electrons and holes) to generate light, and may induce excitons to be efficiently generated. The dopant may include a phosphorescent dopant or a fluorescent dopant. According to an embodiment, the dopant may include an organic material, and may include a metal complex, etc. For example, the dopant may include TBP (Formula 7). However, examples of the dopant are not particularly limited.

[0128] Formula 7

[0129] The electron transport portion ETU may include a multilayer structure having a plurality of layers including different materials, respectively. The electron transport portion ETU may include at least one selected from an electron injection layer and an electron transport layer, and according to an embodiment, the electron transport portion ETU may also include an electron buffer layer, a hole blocking layer, etc.

[0130] The electron injection layer may be a layer that performs and / or improves the electron injection function from the cathode electrode portion CAP to another adjacent organic layer. The electron transport layer may be a layer that provides the provided electrons to the light emitting layer EML. The hole blocking layer may be a layer that prevents or reduces the injection of holes from the hole transport portion HTU and thus reduces the number of carriers leaving the light emitting layer EML.

[0131] For example, the electron transport unit ETU may have a multi-layer structure such as electron transport layer / electron injection layer, hole blocking layer / electron transport layer / electron injection layer, electron control layer / electron transport layer / electron injection layer, or buffer layer / electron transport layer / electron injection layer. However, the disclosure is not limited thereto.

[0132] According to an embodiment, the electron transport layer among the layers forming the electron transport part ETU may include two or more electron transport layers. According to an embodiment, the electron transport layer may include a first electron transport layer and a second electron transport layer on the first electron transport layer. Compared with the second electron transport layer, the first electron transport layer may be adjacent to the anode electrode part ANP, and compared with the first electron transport layer, the second electron transport layer may be adjacent to the cathode electrode part CAP. The first electron transport layer and the second electron transport layer may contact each other. According to an embodiment, the first electron transport layer and the second electron transport layer may include different materials. For example, the first electron transport layer may include a material such that the lowest unoccupied molecular orbital (LUMO) energy level is 2.0 eV or greater, so the electron injection characteristics of the electron transport part ETU can be further improved. The second electron transport layer may include a material such that the LUMO energy level is 2.0 eV or less. For example, the second electron transport layer may have a molar mass of 550 g / mol or greater, for example, the second electron transport layer may include a triazine material. In an embodiment, the second electron transport layer may further reduce the disconnection risk of the cathode electrode part CAP. For example, due to the molecular structure of the second electron transport layer, the cathode electrode portion CAP is located in a discontinuous region (eg, trenches TR1 and TR2 (refer to Fig.15 , Fig.16 , Fig.19 and Fig. 20 )) The lower layer in can be formed to be substantially flat, and disconnection of the cathode electrode portion CAP can be further prevented or reduced.

[0133] According to an embodiment, the electron transport unit ETU may have a multilayer structure such as a first electron transport layer / a second electron transport layer / an electron injection layer, a hole blocking layer / a first electron transport layer / a second electron transport layer / an electron injection layer, an electron control layer / a first electron transport layer / a second electron transport layer / an electron injection layer, or a buffer layer / a first electron transport layer / a second electron transport layer / an electron injection layer. However, the disclosure is not limited thereto.

[0134] According to embodiments, the electron transport portion ETU may include various suitable electron transport compounds. For example, the electron transport portion ETU may include a metal-free organic material and / or may include a metal-containing organic material and / or various suitable metal materials (eg, alkaline earth metals, rare earth metals, etc.).

[0135] For example, the electron transport unit ETU may include one or more selected from T2T (Formula 8), TPBi (Formula 9), lithium quinolate LiQ (Formula 10), lithium fluoride LiF, and Yb. According to an embodiment, the electron transport unit ETU may include a stacked structure including T2T as a hole blocking layer, TPBi and LiQ as an electron transport layer, and LiF as an electron injection layer.

[0136] Formula 8

[0137] Formula 9

[0138] Formula 10

[0139] According to the embodiment, referring to Figure 7 , the light emitting structure EMS may include a series structure. For example, the light emitting structure EMS may be configured to emit white light. According to an embodiment, the light emitting part EU may include a first light emitting part EU1 configured to emit light of a first color, a second light emitting part EU2 configured to emit light of a second color, and a third light emitting part EU3 configured to emit light of a third color. The first light emitting part EU1 includes a first hole transport part HTU1, a first light emitting layer EML1, and a first electron transport part ETU1. The second light emitting part EU2 includes a second hole transport part HTU2, a second light emitting layer EML2, and a second electron transport part ETU2. The third light emitting part EU3 includes a third hole transport part HTU3, a third light emitting layer EML3, and a third electron transport part ETU3.

[0140] According to an embodiment, the first light emitting part EU1, the third light emitting part EU3, and the second light emitting part EU2 may be sequentially located on the anode electrode part ANP, and the charge generation layers CGL1 and CGL2 may be between adjacent light emitting parts EU. For example, the first charge generation layer CGL1 may be between the first light emitting part EU1 and the third light emitting part EU3, and the second charge generation layer CGL2 may be between the third light emitting part EU3 and the second light emitting part EU2.

[0141] Each of the first charge generation layer CGL1 and the second charge generation layer CGL2 may have a stacked structure of a p-dopant layer and an n-dopant layer. The p-dopant layer may include a p-type dopant such as HAT-CN, and the n-dopant layer may include an alkali metal, an alkaline earth metal, a lanthanide metal, or a combination thereof. However, the embodiment is not limited thereto.

[0142] According to the embodiment, referring to Figure 8 , the light emitting structure EMS may include a series structure including two light emitting parts EU. For example, the light emitting part EU may include a first light emitting part EU1 and a second light emitting part EU2, or the light emitting part EU may include a first light emitting part EU1 and a third light emitting part EU3. In an embodiment, the light emitting part EU may include a second light emitting part EU2 and a third light emitting part EU3. For ease of description, Figure 8 An embodiment in which the light emitting part EU includes a first light emitting part EU1 and a second light emitting part EU2 is shown. The first light emitting part EU1 includes a first hole transport part HTU1, a first light emitting layer EML1 and a first electron transport part ETU1. The second light emitting part EU2 includes a second hole transport part HTU2, a second light emitting layer EML2 and a second electron transport part ETU2.

[0143] According to an embodiment, the light emitting structure EMS may include a single charge generation layer CGL between the first light emitting portion EU1 and the second light emitting portion EU2. Similar to the first charge generation layer CGL1 and the second charge generation layer CGL2, the charge generation layer CGL may have a stacked structure of a p-dopant layer and an n-dopant layer. The p-dopant layer may include a p-type dopant such as HAT-CN, and the n-dopant layer may include an alkali metal, an alkaline earth metal, a lanthanide metal, or a combination thereof.

[0144] Reference Figures 9 and 10 The cathode electrode portion CAP is described.

[0145] Fig. 9 is a schematic cross-sectional view showing a cathode electrode portion according to the embodiment. Fig.10 is a schematic cross-sectional view showing a cathode electrode portion according to the embodiment.

[0146] Reference Figures 9 and 10 According to an embodiment, the cathode electrode portion CAP includes a multi-metal structure. For example, the cathode electrode portion CAP may include a first cathode electrode CE1 and a second cathode electrode CE2. For ease of description, the disclosure is described based on an embodiment in which the cathode electrode portion CAP includes a bimetal structure, but the disclosure is not limited thereto.

[0147] Experimentally, the electric signals supplied to the sub-pixels SP adjacent to each other should be distinguished from each other. For example, there is a risk that the electric signals may be confused due to a leakage current (lateral leakage) generated between the sub-pixels SP.

[0148] For example, the separation structure (eg, the trenches TR1 and TR2 (see Fig.15 , Fig.16 and Figures 19 to 20 ) and / or protruding separator PTP (refer to Figure 17 to Figure 18 ) may be included in the display device 100 so that at least a portion of the light emitting structure EMS (eg, the charge generation layers CGL1 and CGL2 , etc.) may be distinguished from each other between sub-pixels SP adjacent to each other.

[0149] The separation structure may physically separate at least a portion of the light emitting structure EMS of each of the adjacent sub-pixels SP, but there may be a concern that the separation structure may physically separate the cathode providing the common electrode in addition to physically separating the light emitting layer EML, the charge generating layers CGL1 and CGL2, etc. In this case, there is a concern such as a risk of voltage drop being generated in the entire region where the sub-pixels SP are provided.

[0150] However, the cathode electrode portion CAP according to the embodiment may include at least the first cathode electrode CE1 and the second cathode electrode CE2, so the electrical path formed by the cathode electrode portion CAP may not be cut off between adjacent sub-pixels SP (eg, in a partition structure).

[0151] First, refer to Fig. 9 , describing the cathode electrode portion CAP according to the first embodiment.

[0152] The first cathode electrode CE1 may form a lower electrode portion of the cathode electrode portion CAP. The first cathode electrode CE1 may be adjacent to the light emitting structure EMS.

[0153] The second cathode electrode CE2 may form an upper electrode portion of the cathode electrode portion CAP. The second cathode electrode CE2 may be farther from the light emitting structure EMS than the first cathode electrode CE1.

[0154] The first cathode electrode CE1 and the second cathode electrode CE2 may include different conductive materials (eg, electrically conductive materials different from each other), respectively. For example, the first cathode electrode CE1 may include an opaque conductive material (eg, an opaque electrically conductive material), and the second cathode electrode CE2 may include a transparent conductive material (eg, a transparent electrically conductive material).

[0155] According to an embodiment, the opaque conductive material may include one or more selected from the group consisting of gold (Au), silver (Ag), aluminum (Al), molybdenum (Mo), chromium (Cr), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and platinum (Pt). The transparent conductive material may include one or more selected from the group consisting of indium zinc oxide (IZO), silver nanowires (AgNW), indium tin oxide (ITO), indium gallium zinc oxide (IGZO), antimony zinc oxide (AZO), indium tin zinc oxide (ITZO), zinc oxide (ZnO), tin oxide (SnO 2 ), one or more of carbon nanotubes and graphene. For example, the first cathode electrode CE1 may include silver (Ag), and the second cathode electrode CE2 may include IZO. However, the disclosure is not necessarily limited thereto.

[0156] The first cathode electrode CE1 and the second cathode electrode CE2 may have different thicknesses. For example, the first cathode electrode CE1 may have a first thickness T1. The second cathode electrode CE2 may have a second thickness T2. The second thickness T2 may be greater than the first thickness T1.

[0157] Experimentally, when the other cathode electrode has a single-layer structure of a material including silver (Ag) or the like, it is difficult to have a thickness equal to or greater than a set or specific thickness to prevent or reduce damage to transmittance (eg, light transmittance). Due to this, there is a risk that the other cathode electrode is cut off due to a partition structure or the like.

[0158] However, according to an embodiment, the second cathode electrode CE2 including a transparent conductive material may be thicker than the first cathode electrode CE1 including an opaque conductive material. In some embodiments, by providing a relatively thick second cathode electrode CE2 having excellent transmittance (e.g., excellent light transmittance), the light emitting efficiency of the light emitting structure EMS may be properly or sufficiently ensured, and since the cathode electrode portion CAP has an appropriate or sufficient thickness, the risk of the cathode electrode portion CAP being cut off in the separation structure may be prevented or reduced.

[0159] According to an embodiment, the first thickness T1 may be in the range of 100Å to 180Å. In an embodiment, the first thickness T1 may be in the range of 120Å to 160Å. For example, the first thickness T1 may be about 140Å. According to an embodiment, the second thickness T2 may be in the range of 600Å to 800Å. In an embodiment, the second thickness T2 may be in the range of 650Å to 750Å. For example, the second thickness T2 may be about 700Å.

[0160] When the thicknesses T1 and T2 of the first cathode electrode CE1 and the second cathode electrode CE2 satisfy the above numerical range, the light emitting efficiency of the light emitting element LD can be ensured and the risk of the cathode electrode portion CAP being cut off between adjacent sub-pixels SP can be reduced.

[0161] According to an embodiment, the lower surface of the first cathode electrode CE1 may be directly adjacent to the uppermost surface of the light emitting structure EMS. According to an embodiment, the first cathode electrode CE1 and the second cathode electrode CE2 may be directly adjacent to each other. For example, the first cathode electrode CE1 and the second cathode electrode CE2 may contact each other. The first surface (e.g., the lower surface) of the first cathode electrode CE1 may contact one surface of the light emitting structure EMS, and the second surface (e.g., the upper surface) of the first cathode electrode CE1 may contact the second cathode electrode CE2.

[0162] Next, refer to Fig.10 , a cathode electrode portion CAP according to a second embodiment is described based on points different from those of the above-described first embodiment.

[0163] The cathode electrode portion CAP according to the second embodiment is different from the cathode electrode portion CAP according to the first embodiment in that the cathode electrode portion CAP according to the second embodiment further includes an intermediate structure DS between the first cathode electrode CE1 and the second cathode electrode CE2 .

[0164] According to an embodiment, the intermediate structure DS may be between the first cathode electrode CE1 and the second cathode electrode CE2. For example, the intermediate structure DS may include a material different from that of the first cathode electrode CE1 and the second cathode electrode CE2, and may include various suitable organic materials.

[0165] The intermediate structure DS may include two or more layers. For example, the intermediate structure DS may include an N-type intermediate layer DSN, a P-type intermediate layer DSP, and an intermediate electron injection layer DEIL.

[0166] The N type intermediate layer DSN may be between the first cathode electrode CE1 and the P type intermediate layer DSP. For example, one surface of the N type intermediate layer DSN may contact the first cathode electrode CE1, and the other surface of the N type intermediate layer DSN may contact the P type intermediate layer DSP.

[0167] The N-type intermediate layer DSN may include an N-type body and a dopant. According to embodiments, the N-type intermediate layer DSN may include various suitable materials providing an N-type semiconductor layer, and is not limited to a specific example.

[0168] The P type intermediate layer DSP may include a P type body and a dopant. According to embodiments, the P type intermediate layer DSP may include various suitable materials providing a P type semiconductor layer, and is not limited to a specific example.

[0169] According to an embodiment, the intermediate structure DS may include a diode array in which an N-type intermediate layer DSN and a P-type intermediate layer DSP are adjacent to each other. In an embodiment, the N-type intermediate layer DSN may be adjacent to the light emitting structure EMS, and the P-type intermediate layer DSP may be adjacent to the intermediate electron injection layer DEIL. In an embodiment, even if the thickness of the intermediate structure DS increases, the flow of electrons may be controlled, the stability of the light emitting element LD may be ensured, and the life characteristics may be improved.

[0170] The intermediate electron injection layer DEIL may be between the P type intermediate layer DSP and the second cathode electrode CE2. For example, one surface of the intermediate electron injection layer DEIL may contact the P type intermediate layer DSP, and the other surface of the intermediate electron injection layer DEIL may contact the second cathode electrode CE2.

[0171] The intermediate electron injection layer DEIL may include various suitable materials (eg, organic materials) having electron injection properties. For example, the intermediate electron injection layer DEIL may include one or more of the materials described above with reference to the above electron transport unit ETU.

[0172] Since the intermediate electron injection layer DEIL is in the intermediate structure DS, the intermediate structure DS according to the embodiment may further prevent or reduce disconnection of the cathode electrode portion CAP and may improve electron injection characteristics.

[0173] According to an embodiment, the N-type intermediate layer DSN may have an N-type intermediate thickness T_DSN. The N-type intermediate thickness T_DSN may have a thickness of 100Å or less. For example, the N-type intermediate thickness T_DSN may be in the range of 40Å to 100Å. The N-type intermediate thickness T_DSN may be in the range of 60Å to 95Å. When the N-type intermediate thickness T_DSN exceeds 100Å, there is a risk of excessive increase in driving voltage. Therefore, when the N-type intermediate thickness T_DSN satisfies the above-mentioned numerical range, the characteristics of the driving voltage of the light-emitting element LD may be excellent.

[0174] According to an embodiment, the intermediate structure DS may have an intermediate thickness T_DS. The intermediate thickness T_DS may have a thickness of 400Å or more. For example, the intermediate thickness T_DS may be in the range of 400Å to 700Å. In an embodiment, the intermediate thickness T_DS may be in the range of 400Å to 600Å. In an embodiment, the intermediate thickness T_DS may be in the range of 400Å to 500Å. According to an embodiment, the thickness of each of the P-type intermediate layer DSP and the intermediate electron injection layer DEIL may be set or determined so that the intermediate thickness T_DS has a thickness of 400Å or more within a range in which the N-type intermediate layer DSN satisfies the above-mentioned numerical range. When the intermediate thickness T_DS has a thickness of 400Å or more, the disconnection improvement characteristics of the cathode electrode portion CAP may be improved.

[0175] In the embodiment, since the intermediate structure DS is included in the cathode electrode portion CAP, both excellent driving voltage characteristics and turn-off improvement characteristics may be provided.

[0176] In the following, reference will be made to Figures 11 to 14 A cross-sectional structure of a display device 100 according to an embodiment is described. Contents that may overlap with the above contents are briefly described or not repeated.

[0177] Figures 11 to 14 is a schematic cross-sectional view showing a display device according to an embodiment. Figures 11 to 14 It is along Figure 3 For ease of description, Figures 11 to 14 Illustration of the layers on the cathode electrode portion CAP is omitted.

[0178] Reference Figures 11 to 14 , the display device 100 may include a substrate SUB and a pixel circuit layer PCL on the substrate SUB.

[0179] The pixel circuit layer PCL may include a circuit element for each of the first to third subpixels SP1 to SP3. For example, the substrate SUB and the pixel circuit layer PCL may include a transistor T_SP1 of the first subpixel SP1, a transistor T_SP2 of the second subpixel SP2, and a transistor T_SP3 of the third subpixel SP3.

[0180] According to an embodiment, the display device 100 may further include a reflective electrode RE. The reflective electrode RE may include a first reflective electrode RE1 of the first sub-pixel SP1, a second reflective electrode RE2 of the second sub-pixel SP2, and a third reflective electrode RE3 of the third sub-pixel SP3.

[0181] The reflective electrode RE may reflect light emitted from the light emitting structure EMS to form a light recycling structure, and thus, the light emitting efficiency of the light emitting element LD may be improved.

[0182] According to an embodiment, the display device 100 may further include a step-forming layer SFL. The step-forming layer SFL may be located on the reflective electrode RE to change the distance between the light emitting structure EMS and the reflective electrode RE.

[0183] The step-forming layer SFL may include an inorganic material. For example, the step-forming layer SFL may include silicon oxide (Si x O y In an embodiment, the step-forming layer SFL may include tetraethyl orthosilicate (TEOS). However, the disclosure is not limited thereto.

[0184] According to the embodiment (refer to Fig.11 ), the step-forming layer SFL may be disposed throughout the sub-pixels SP1, SP2, and SP3, and may have a similar thickness throughout the sub-pixels SP1, SP2, and SP3.

[0185] In the embodiment, according to the embodiment (refer to Fig.12 ), the step-forming layer SFL may have different thicknesses in at least a portion of the sub-pixels SP1, SP2, and SP3. For example, the step-forming layer SFL in the first sub-pixel SP1 may have a thickness smaller than that of the step-forming layer SFL in the second and third sub-pixels SP2 and SP3.

[0186] In the examples (see Fig.13 ), the step-forming layer SFL may be in the first sub-pixel SP1, and may not be in the second and third sub-pixels SP2 and SP3. Therefore, the light emitting structure EMS of the first sub-pixel SP1 may be formed at a relatively higher position than the light emitting structures EMS of the second and third sub-pixels SP2 and SP3.

[0187] According to the embodiment, when the position, thickness, etc. of the step-forming layer SFL are adjusted, a display device 100 with improved brightness can be provided. For example, light emitted from the light emitting structure EMS can be amplified by the relationship between the spatial distance at which the light is reflected and the wavelength of the reflected light reflected by the reflective electrode RE, and the distance between the light emitting structure EMS and the reflective electrode RE can be adjusted, so a display device 100 including a light emitting element LD having a high brightness characteristic can be provided.

[0188] In the examples (see Fig.14 ), the step-forming layer SFL may not be separately provided. In an embodiment, the anode electrode parts ANP may be relatively adjacent on the reflective electrode RE.

[0189] According to an embodiment, the anode electrode portion ANP may be on the step-forming layer SFL. In an embodiment, when the step-forming layer SFL is not provided, the anode electrode portion ANP may be on the reflective electrode RE. According to an embodiment, when the display device 100 further includes a separate planarization layer, the anode electrode portion ANP may be on the planarization layer.

[0190] The anode electrode portion ANP may include a first anode electrode portion ANP1 of the first sub-pixel SP1, a second anode electrode portion ANP2 of the second sub-pixel SP2, and a third anode electrode portion ANP3 of the third sub-pixel SP3.

[0191] The first anode electrode portion ANP1 may be electrically connected to the first reflective electrode RE1. The second anode electrode portion ANP2 may be electrically connected to the second reflective electrode RE2. The third anode electrode portion ANP3 may be electrically connected to the third reflective electrode RE3.

[0192] The pixel defining layer PDL may be adjacent to the anode electrode portion ANP. The pixel defining layer PDL may be disposed to overlap a middle region between adjacent sub-pixels SP. The pixel defining layer PDL may overlap the anode electrode portion ANP.

[0193] The pixel defining layer PDL may include a partition structure. For example, the pixel defining layer PDL may cut at least a portion of the light emitting structure EMS between adjacent sub-pixels SP. Figures 15 to 18 The separation structure of the pixel defining layer PDL is further described.

[0194] The light emitting structure EMS may form the light emitting element LD of each of the sub-pixels SP. For example, the light emitting structure EMS may include a first light emitting structure EMS1 of the first sub-pixel SP1, a second light emitting structure EMS2 of the second sub-pixel SP2, and a third light emitting structure EMS3 of the third sub-pixel SP3.

[0195] The first light emitting structure EMS1 may be electrically connected to the first anode electrode portion ANP1. The second light emitting structure EMS2 may be electrically connected to the second anode electrode portion ANP2. The third light emitting structure EMS3 may be electrically connected to the third anode electrode portion ANP3.

[0196] Among the first to third light emitting structures EMS1 to EMS3, at least a portion of adjacent structures may be cut by a partition structure formed by the pixel defining layer PDL. Figure 7 When the cross-sectional structure shown in FIG. 1 is shown in FIG. 2 , the first light emitting part EU1, the first charge generation layer CGL1, the second light emitting part EU2, and the second charge generation layer CGL2 may be cut. In an embodiment, when the light emitting structure EMS has a cross-sectional structure as shown in FIG. Figure 8When the cross-sectional structure is shown in FIG. 1 , the first light emitting part EU1 and the charge generation layer CGL may be cut. Therefore, the risk of leakage current between adjacent sub-pixels SP may be reduced.

[0197] The cathode electrode portion CAP may be on the light emitting structure EMS of the first to third sub-pixels SP1 to SP3. According to an embodiment, the cathode electrode portion CAP may be disposed across the first to third sub-pixels SP1 to SP3, and may define an electrical path formed across the first to third sub-pixels SP1 to SP3. Therefore, the cathode electrode portion CAP may form a common electrode for the first to third sub-pixels SP1 to SP3, and may each supply a cathode signal.

[0198] In the embodiment, as described above, the cathode electrode portion CAP may include a multi-cathode electrode structure, and thus the common electrode may be more stably defined.

[0199] In the following, reference is made to Figures 15 to 20 A partition structure and a cathode electrode portion CAP disposed adjacent to the partition structure according to an embodiment are described below. Contents that may overlap with the above contents are briefly described or not repeated.

[0200] Figures 15 to 20 1 is a schematic cross-sectional view showing a portion of a display device including a partition structure and a cathode electrode portion disposed adjacent to the partition structure according to an embodiment. Figures 15 to 18 Schematically shows the Fig.11 EA1 area is a schematic cross-section of the display device 100 showing an enlarged structure. For ease of description, Fig.19 and Fig. 20 Schematically shows the Fig.14 FIG. 1 is a cross section of the display device 100 showing a schematically enlarged structure of the EA2 region.

[0201] For example, despite Figures 15 to 20 A region where the first subpixel SP1 and the second subpixel SP2 are adjacent to each other is shown, but similar technical features may be equally applied to a region where the first subpixel SP1 and the third subpixel SP3 are adjacent to each other and a region where the second subpixel SP2 and the third subpixel SP3 are adjacent to each other. Figures 15 to 20 Each of the drawings shows a separation structure for cutting at least a portion of the light emitting structure EMS according to the embodiment.

[0202] Reference Figure 15 to Figure 16 , the pixel defining layer PDL according to an embodiment may include (or form) a trench TR.

[0203] The trench TR may form a separation structure. The trench TR may include a plurality of trenches TR. For example, the trench TR may include a first trench TR1 and a second trench TR2. However, the number of trenches TR is not particularly limited, and according to an embodiment, one trench TR may be formed between sub-pixels SP, and three or more trenches TR may be formed between sub-pixels SP.

[0204] According to an embodiment, the pixel defining layer PDL may include a first trench forming layer PTR1 , a second trench forming layer PTR2 , and a third trench forming layer PTR3 .

[0205] The first to third groove forming layers PTR1 to PTR3 may be sequentially disposed and may have different widths. Therefore, the first to third groove forming layers PTR1 to PTR3 may form steps. The first groove forming layer PTR1 may have a width greater than that of the second groove forming layer PTR2, and the second groove forming layer PTR2 may have a width greater than that of the third groove forming layer PTR3.

[0206] Each of the first to third trench forming layers PTR1 to PTR3 may include an inorganic material. For example, the first trench forming layer PTR1 may include silicon nitride (Si x N y ), the second trench forming layer PTR2 may include silicon oxide (Si x O y ), and the third trench formation layer PTR3 may include silicon nitride (Si x N y ).

[0207] The first to third trench forming layers PTR1 to PTR3 may form a trench TR. For example, the first and second trenches TR1 and TR2 may pass through the first to third trench forming layers PTR1 to PTR3 and may partially pass through the step forming layer SFL. According to an embodiment, when the step forming layer SFL is not included and a planarization layer is provided, the first and second trenches TR1 and TR2 may partially pass through the planarization layer.

[0208] Therefore, the trench TR may form a gap in a region between adjacent sub-pixels SP, thereby forming a discontinuous portion in a boundary region between adjacent sub-pixels SP.

[0209] Therefore, at least a portion of the light emitting structure EMS may be cut between adjacent sub-pixels SP, and at least a portion of the light emitting structure EMS may be bent. As described above, among the layers included in the light emitting structure EMS, the first charge generation layer CGL1 and the second charge generation layer CGL2 may be cut by the groove TR. In an embodiment, when the light emitting structure EMS includes a single charge generation layer CGL, the charge generation layer CGL among the layers included in the light emitting structure EMS may be cut by at least the groove TR.

[0210] In an embodiment, each of the first trench TR1 and the second trench TR2 may have a width W. The width W may be defined based on a direction in which the first sub-pixel SP1 and the second sub-pixel SP2 are spaced apart from each other. The width W may be in a range of 60 nm to 170 nm. In an embodiment, the width W may be in a range of 80 nm to 150 nm. In an embodiment, the width W may be in a range of 100 nm to 130 nm. According to an embodiment, the width W may be about 115 nm.

[0211] When the width W satisfies the above numerical range, the display device 100 may have high resolution, and at least a portion of the light emitting structure EMS may be closely cut.

[0212] The first trench TR1 and the second trench TR2 may have a height H. The height H may be defined based on a thickness direction (e.g., a third direction DR3) of the substrate SUB. The height H may be in a range of 450 nm to 750 nm. In an embodiment, the height H may be in a range of 500 nm to 700 nm. In an embodiment, the height H may be in a range of 550 nm to 650 nm. According to an embodiment, the height H may be about 600 nm.

[0213] When the height H satisfies the above numerical range, a suitable or sufficient space into which at least a portion of the light emitting structure EMS is to be inserted may be ensured, and thus at least a portion of the light emitting structure EMS may be closely cut.

[0214] The first trench TR1 and the second trench TR2 may be spaced apart from each other by a length L. The length L may be defined based on a direction in which the first subpixel SP1 and the second subpixel SP2 are spaced apart from each other. The length L may be equal to the width W. In an embodiment, the length L may be greater than the width W.

[0215] The light emitting structure EMS may include an intermediate light emitting structure EMS_M formed between the first trench TR1 and the second trench TR2. At least a portion of the first light emitting structure EMS1 (e.g., the first and second charge generation layers CGL1 and CGL2 or the charge generation layer CGL) and at least a portion of the intermediate light emitting structure EMS_M (e.g., the first and second charge generation layers CGL1 and CGL2 or the charge generation layer CGL) may be separated.

[0216] The first light emitting structure EMS1 may be on the first anode electrode portion ANP1. The first light emitting structure EMS1 may be on a portion of the pixel defining layer PDL between the first anode electrode portion ANP1 and the first trench TR1. At least a portion of the first light emitting structure EMS1 may cover an inner surface of the pixel defining layer PDL formed by the first trench TR1 and adjacent to the first anode electrode portion ANP1.

[0217] The second light emitting structure EMS2 may be on the second anode electrode portion ANP2. The second light emitting structure EMS2 may be disposed on a portion of the pixel defining layer PDL between the second anode electrode portion ANP2 and the second trench TR2. At least a portion of the second light emitting structure EMS2 may cover an inner surface of the pixel defining layer PDL formed by the second trench TR2 and adjacent to the second anode electrode portion ANP2.

[0218] The middle light emitting structure EMS_M may be between the first trench TR1 and the second trench TR2. The middle light emitting structure EMS_M may be disposed on an inner surface or a portion of the pixel defining layer PDL between the first trench TR1 and the second trench TR2.

[0219] although Fig.15 and Fig.16 The middle light emitting structure EMS_M is shown to be completely separated from the first light emitting structure EMS1 and the second light emitting structure EMS2, but at least a portion of the middle light emitting structure EMS_M and the first light emitting structure EMS1 and the second light emitting structure EMS2 may be connected to each other. Figure 7 , the layers above the second charge generation layer CGL2 in each of the middle light emitting structure EMS_M and the first and second light emitting structures EMS1 and EMS2 may be connected to each other. Figure 8 , layers above the charge generation layer CGL in each of the middle light emitting structure EMS_M and the first and second light emitting structures EMS1 and EMS2 may be connected to each other.

[0220] According to an embodiment, the cathode electrode portion CAP may be disposed across the sub-pixel SP to form a cathode signal path.

[0221] For example, the cathode electrode portion CAP may include a first cathode electrode CE1 and a second cathode electrode CE2, and may include an intermediate cathode electrode CE_M. In an embodiment, the first cathode electrode CE1 may include a 1-1th cathode electrode CE1_1 and a 1-2th cathode electrode CE1_2.

[0222] According to an embodiment, a portion of the cathode electrode portion CAP may be disconnected between adjacent sub-pixels SP, and at least a portion of the cathode electrode portion CAP may be continuous between adjacent sub-pixels SP.

[0223] For example, at least a portion of the first cathode electrode CE1 may be cut by the trench TR. The 1-1 cathode electrode CE1_1, the 1-2 cathode electrode CE1_2, and the middle cathode electrode CE_M may have a structure based on an electrode structure deposited in the same process, may include the same material, may be in the same layer, and may have an electrode structure separated by the first trench TR1 and the second trench TR2. The second cathode electrode CE2 may be disposed across the first subpixel SP1 and the second subpixel SP2.

[0224] The 1-1st cathode electrode CE1_1 may be on the first light emitting structure EMS1. The 1-2nd cathode electrode CE1_2 may be on the second light emitting structure EMS2. The middle cathode electrode CE_M may be on the middle light emitting structure EMS_M.

[0225] According to the embodiment (refer to Fig.15 ), the second cathode electrode CE2 may be continuously located on the 1-1 cathode electrode CE1_1, the 1-2 cathode electrode CE1_2, and the intermediate cathode electrode CE_M. As described above, the second cathode electrode CE2 may have a thickness greater than that of the first cathode electrode CE1, and may include a transparent conductive material (e.g., a transparent electrically conductive material). According to an embodiment, at least a portion of the second cathode electrode CE2 may be between the 1-1 cathode electrode CE1_1 and the intermediate cathode electrode CE_M. At least another portion of the second cathode electrode CE2 may be between the 1-2 cathode electrode CE1_2 and the intermediate cathode electrode CE_M. Therefore, the cathode connection structure may be tightly formed, and the transmittance characteristics (e.g., light transmittance characteristics) for light emitted by the light emitting structure EMS may be excellently provided.

[0226] In an embodiment, the first cathode electrode CE1 formed below the second cathode electrode CE2 may be continuous in the trench TR. For example, similar to the second cathode electrode CE2, the first cathode electrode CE1 may not be cut in the first trench TR1 and the second trench TR2, and a continuous cathode connection structure defined between the first sub-pixel SP1 and the second sub-pixel SP2 may be formed. In an embodiment, the cathode connection path may be formed by the first cathode electrode CE1, and the second cathode electrode CE2 may also form an additional cathode connection structure, so the risk of disconnection of the cathode connection structure in the display device 100 may be significantly reduced.

[0227] According to the embodiment (refer to Fig.16 ), the intermediate structure DS may be continuously located on the 1-1 cathode electrode CE1_1, the 1-2 cathode electrode CE1_2, and the intermediate cathode electrode CE_M, and the second cathode electrode CE2 may be on the intermediate structure DS. According to an embodiment, at least a portion of the intermediate structure DS may be between the 1-1 cathode electrode CE1_1 and the intermediate cathode electrode CE_M. At least another portion of the intermediate structure DS may be between the 1-2 cathode electrode CE1_2 and the intermediate cathode electrode CE_M. According to an embodiment, among the layers forming the intermediate structure DS, the P-type intermediate layer DSP and the intermediate electron injection layer DEIL may be continuous in the region where the trench TR is provided, and at least a portion of the N-type intermediate layer DSN among the layers forming the intermediate structure DS may be cut in the region where the trench TR is provided. In an embodiment, at least a portion of the intermediate structure DS and the second cathode electrode CE2 may be continuous between adjacent sub-pixels SP, and thus the cathode connection structure may be closely formed. In addition, as described above, because the relatively thick second cathode electrode CE2 includes a transparent conductive material, a transmittance characteristic (e.g., a light transmittance characteristic) for light emitted from the light emitting structure EMS may be excellently provided.

[0228] Reference Fig.17 and Fig.18 , the pixel defining layer PDL according to the embodiment may include (or form) a protrusion base layer PTB and a protrusion spacer PTP.

[0229] The protrusion spacer PTP may form a separation structure. The protrusion spacer PTP may include a structure that protrudes in a direction in which the sub-pixels SP are spaced apart from each other.

[0230] The protrusion base layer PTB may form a base on which the protrusion spacer PTP is disposed. According to an embodiment, the protrusion base layer PTB may include a single-layer structure. In an embodiment, the protrusion base layer PTB may include a multi-layer structure. For example, the protrusion base layer PTB may include a first protrusion base layer PTB1 and a second protrusion base layer PTB2. However, the disclosure is not limited thereto.

[0231] The protrusion spacer PTP may include a multilayer structure. For example, the protrusion spacer PTP may include three layers. For example, the protrusion spacer PTP may include a first protrusion spacer PTP1, a second protrusion spacer PTP2, and a third protrusion spacer PTP3. However, the disclosure is not limited thereto. According to an embodiment, the protrusion spacer PTP may include six layers. For example, the protrusion spacer PTP may also include a fourth protrusion spacer to a sixth protrusion spacer on the first protrusion spacer PTP1 to the third protrusion spacer PTP3. In an embodiment, the protrusion spacer PTP may include four layers. For example, the protrusion spacer PTP may also include a fourth protrusion spacer on the first protrusion spacer PTP1 to the third protrusion spacer PTP3. In this specification, for ease of description, the disclosure is described based on an embodiment in which the protrusion spacer PTP includes the first protrusion spacer PTP1 to the third protrusion spacer PTP3, but the disclosure is not limited thereto.

[0232] According to an embodiment, the layers forming the protrusion spacer PTP may have different widths, respectively. For example, the first protrusion spacer PTP1, the second protrusion spacer PTP2, and the third protrusion spacer PTP3 may have different widths. The first protrusion spacer PTP1 may have a width greater than the width of the second protrusion spacer PTP2 and the width of the third protrusion spacer PTP3. The second protrusion spacer PTP2 may have a width greater than the width of the third protrusion spacer PTP3. The first protrusion spacer PTP1, the second protrusion spacer PTP2, and the third protrusion spacer PTP3 may have a width greater than the width of the second protrusion base layer PTB2.

[0233] Since the first, second, and third protrusion spacers PTP1, PTP2, and PTP3 are formed, an uneven portion may be formed in a boundary region between adjacent sub-pixels SP.

[0234] Therefore, at least a portion of the light emitting structure EMS may be cut between adjacent sub-pixels SP, and at least a portion of the light emitting structure EMS may be bent. As described above, among the layers included in the light emitting structure EMS, the first charge generation layer CGL1 and the second charge generation layer CGL2 (or the charge generation layer CGL) may be cut by the trench TR.

[0235] The first protrusion base layer PTB1 may be on the step-forming layer SFL and may form a substrate on which the second protrusion base layer PTB2 and the protrusion spacers PTP1, PTP2, and PTP3 are disposed. The first protrusion base layer PTB1 may cover at least a portion of each of the first and second anode electrode parts ANP1 and ANP2.

[0236] The second protrusion base layer PTB2 may be on the first protrusion base layer PTB1 and may form a base on which the protrusion spacers PTP are disposed. The second protrusion base layer PTB2 may have a width smaller than that of the first protrusion base layer PTB1 and the first to third protrusion spacers PTP1 to PTP3.

[0237] The light emitting structure EMS may include an intermediate light emitting structure EMS_M on the protrusion spacer PTP. At least a portion of the first light emitting structure EMS1 (e.g., the first and second charge generation layers CGL1 and CGL2 or the charge generation layer CGL) and at least a portion of the intermediate light emitting structure EMS_M (e.g., the first and second charge generation layers CGL1 and CGL2 or the charge generation layer CGL) may be separated.

[0238] According to an embodiment, the protrusion base layer PTB and the protrusion spacer PTP may include an inorganic material. For example, a layer forming each of the protrusion base layer PTB and the protrusion spacer PTP may independently include a silicon oxide (SiO2). x O y )、Silicon Nitride(Si x N y ) and silicon oxynitride (Si x O y N z For example, the first protrusion base layer PTB1, the second protrusion base layer PTB2, the first protrusion spacer PTP1, the second protrusion spacer PTP2, and the third protrusion spacer PTP3 may independently include a silicon oxide (Si x O y )、Silicon Nitride(Si x N y ) and silicon oxynitride (Si x O y N z )

[0239] According to an embodiment, a layer forming the protrusion base layer PTB and the protrusion spacer PTP may include a material different from another layer adjacent to the layer forming the protrusion base layer PTB and the protrusion spacer PTP. For example, the protrusion base layer PTB and the protrusion spacer PTP may be formed by alternately disposing layers including different materials.

[0240] For example, the first protrusion spacer PTP1 may include silicon nitride (Si x N y ), the second protrusion spacer PTP2 may include silicon oxide (Si x O y ), the third protrusion spacer PTP3 may include silicon nitride (Six N y ), and when the protrusion spacer PTP further includes a fourth protrusion spacer on the third protrusion spacer PTP3, the fourth protrusion spacer may include silicon oxide (Si x O y In an embodiment, the first protrusion spacer PTP1 may include silicon oxide (Si x O y ), the second protrusion spacer PTP2 may include silicon nitride (Si x N y ), and the third protrusion spacer PTP3 may include silicon oxide (Si x O y ), and when the protrusion spacer PTP further includes a fourth protrusion spacer on the third protrusion spacer PTP3, the fourth protrusion spacer may include silicon nitride (Si x N y ). However, the disclosure is not limited thereto.

[0241] The first light emitting structure EMS1 may cover the first anode electrode portion ANP1 and the first protrusion base layer PTB1, and may cover a side surface of the second protrusion base layer PTB2.

[0242] The second light emitting structure EMS2 may cover the second anode electrode portion ANP2 and the first protrusion base layer PTB1, and may cover a side surface of the second protrusion base layer PTB2.

[0243] The middle light emitting structure EMS_M may be disposed on the first to third bump spacers PTP1 to PTP3 , and may expose a side surface of the second bump base layer PTB2 .

[0244] According to an embodiment, the cathode electrode portion CAP may be disposed across the sub-pixel SP to form a cathode signal path.

[0245] For example, the cathode electrode portion CAP may include first and second cathode electrodes CE1 and CE2, and may include an intermediate cathode electrode CE_M. The first cathode electrode CE1 may include 1-1 cathode electrode CE1_1 and 1-2 cathode electrode CE1_2. In an embodiment, the second cathode electrode CE2 may be electrically connected to the 1-1 cathode electrode CE1_1 and the 1-2 cathode electrode CE1_2.

[0246] The 1-1st cathode electrode CE1_1 may be on the first light emitting structure EMS1. The 1-2nd cathode electrode CE1_2 may be on the second light emitting structure EMS2. The middle cathode electrode CE_M may be on the middle light emitting structure EMS_M.

[0247] According to the embodiment (refer to Fig.17 ), the second cathode electrode CE2 may be continuously located on the 1-1th cathode electrode CE1_1, the 1-2nd cathode electrode CE1_2, and the middle cathode electrode CE_M. Therefore, the cathode electrode portion CAP may appropriately or suitably form a common electrode for adjacent sub-pixels SP.

[0248] According to the embodiment (refer to Fig.18 ), the intermediate structure DS may be continuously located on the 1-1 cathode electrode CE1_1, the 1-2 cathode electrode CE1_2, and the intermediate cathode electrode CE_M, and the second cathode electrode CE2 may be on the intermediate structure DS. Therefore, the cathode electrode portion CAP may appropriately or suitably form a common electrode for adjacent sub-pixels SP.

[0249] In an embodiment, the cathode electrode portion CAP may include the first cathode electrode CE1 and the second cathode electrode CE2 , and the risk of being cut throughout the cathode electrode portion CAP may be reduced by steps formed by the first to third protrusion spacers PTP1 to PTP3 .

[0250] Reference Figures 19 to 20 , an embodiment of a pixel defining layer PDL including (or forming) a trench TR is described. Figures 19 to 20 The embodiment shown in FIG. 1 is an embodiment in which the pixel defining layer PDL includes (or forms) the trench TR, and may similarly include the embodiment described above with reference to FIG. Figure 15 to Figure 16 Therefore, based on the above reference Figure 15 to Figure 16 The different points of the display device 100 according to the embodiment are described with reference to Figures 19 to 20 A display device 100 according to an embodiment is described.

[0251] Reference Figures 19 to 20 , the pixel defining layer PDL may include a base pixel defining layer BPDL and a planarization pixel defining layer PPDL.

[0252] The trench TR may be formed (or defined) by passing through the interlayer insulating layer ILD of the base pixel defining layer BPDL, the planarized pixel defining layer PPDL, and the pixel circuit layer PCL. The interlayer insulating layer ILD may be a layer forming a base on which the anode electrode portion ANP and the pixel defining layer PDL are disposed, and the interlayer insulating layer ILD may be a layer of an upper portion (e.g., the uppermost portion) of the pixel circuit layer PCL. The interlayer insulating layer ILD may include an inorganic material and / or an organic material, and the disclosure is not limited to a specific example. The interlayer insulating layer ILD may be a via layer.

[0253] The base pixel defining layer BPDL may cover the reflective electrodes RE1 and RE2 and the first and second anode electrode portions ANP1 and ANP2. A portion of the base pixel defining layer BPDL may be between the first and second trenches TR1 and TR2. The base pixel defining layer BPDL may partially overlap the reflective electrodes RE1 and RE2 and the first and second anode electrode portions ANP1 and ANP2 in a plan view, and at least a portion of the base pixel defining layer BPDL may not overlap the reflective electrodes RE1 and RE2 and the first and second anode electrode portions ANP1 and ANP2 in a plan view.

[0254] The planarization pixel defining layer PPDL may eliminate the step formed by the base pixel defining layer BPDL. For example, the planarization pixel defining layer PPDL may form a planarization structure. At least a portion of the planarization pixel defining layer PPDL may be on a portion of the base pixel defining layer BPDL covering the first anode electrode portion ANP1 and the second anode electrode portion ANP2, and another portion of the planarization pixel defining layer PPDL may be on a portion of the base pixel defining layer BPDL between the first trench TR1 and the second trench TR2.

[0255] Each of the base pixel defining layer BPDL and the planarization pixel defining layer PPDL may include an inorganic material. The base pixel defining layer BPDL and the planarization pixel defining layer PPDL may include different inorganic materials, respectively. The base pixel defining layer BPDL and the planarization pixel defining layer PPDL may independently include a selected from silicon oxide (SiO2). x O y )、Silicon Nitride(Si x N y ) and silicon oxynitride (Si x O y N z ) at least one of. However, the disclosure is not limited thereto.

[0256] Embodiments may also provide a display device 100 that reduces the risk of disconnection of the cathode electrode portion CAP. Fig.19 Since the cathode electrode portion CAP according to the embodiment includes the first cathode electrode CE1 and the second cathode electrode CE2, the cathode connection structure can be tightly defined. Fig. 20 , the cathode electrode portion CAP according to the embodiment may include the first cathode electrode CE1 and the second cathode electrode CE2, and may further include an intermediate structure DS, which may closely define a cathode connection structure.

[0257] Fig.21 is a diagram showing an embodiment of a display system.

[0258] Reference Fig.21 , the display system 1000 may include a processor 1100 and one or more display devices 1210 and 1220 .

[0259] The processor 1100 may perform various suitable tasks and calculations. In an embodiment, the processor 1100 may include an application processor, a graphics processor, a microprocessor, a central processing unit (CPU), etc. The processor 1100 may be connected to other components of the display system 1000 through a bus system and may control the other components.

[0260] exist Fig.21 , the display system 1000 includes a first display device 1210 and a second display device 1220. The processor 1100 may be connected to the first display device 1210 through a first channel CH1, and may be connected to the second display device 1220 through a second channel CH2.

[0261] Through the first channel CH1, the processor 1100 may transmit the first image data IMG1 and the first control signal CTRL1 to the first display device 1210. The first display device 1210 may display an image based on the first image data IMG1 and the first control signal CTRL1. Figure 1 A display device 100 is described.

[0262] Through the second channel CH2, the processor 1100 may transmit the second image data IMG2 and the second control signal CTRL2 to the second display device 1220. The second display device 1220 may display an image based on the second image data IMG2 and the second control signal CTRL2. Figure 1 A display device 100 is described.

[0263] The display system 1000 may include a computing system that provides an image display function, such as a portable computer, a mobile phone, a smart phone, a tablet personal computer (PC), a smart watch, a watch phone, a portable multimedia player (PMP), a navigation device, and / or an ultra mobile personal computer (UMPC). In an embodiment, the display system 1000 may include at least one selected from a head mounted display (HMD) device, a virtual reality (VR) device, a mixed reality (MR) device, and an augmented reality (AR) device.

[0264] Fig. 22 It is shown Fig.21 A perspective view of an example application of the display system.

[0265] Reference Fig. 22 , Fig.21The display system 1000 may be applied to a head-mounted display device 2000. The head-mounted display device 2000 may be a wearable electronic device that may be worn on a user's head.

[0266] The head-mounted display device 2000 may include a head-mounted band 2100 and a display device accommodating housing 2200. The head-mounted band 2100 may be connected to the display device accommodating housing 2200. The head-mounted band 2100 may include a horizontal band and / or a vertical band for fixing the head-mounted display device 2000 to the user's head. The horizontal band may be configured to surround the side of the user's head, and the vertical band may be configured to surround the upper part of the user's head. However, the embodiment is not limited thereto. For example, the head-mounted band 2100 may be implemented in the form of a glasses frame, a helmet, etc.

[0267] The display device receiving housing 2200 can receive Fig.21 The first display device 1210 and the second display device 1220. The display device receiving housing 2200 may also receive Fig.21 Processor 1100.

[0268] Fig.23 It is shown by Fig. 22 FIG. 1 is a diagram of a head mounted display device worn by a user.

[0269] Reference Fig.23 , the first display panel DP1 of the first display device 1210 and the second display panel DP2 of the second display device 1220 are located in the head mounted display device 2000. The head mounted display device 2000 may further include one or more lenses LLNS and RLNS.

[0270] In the display device accommodating housing 2200, the right-eye lens RLNS may be between the first display device 1210 and the right eye of the user. In the display device accommodating housing 2200, the left-eye lens LLNS may be between the second display device 1220 and the left eye of the user.

[0271] The image output from the first display device 1210 may be displayed to the right eye of the user through the right eye lens RLNS. The right eye lens RLNS may refract light from the first display device 1210 to be directed toward the right eye of the user. The right eye lens RLNS may perform an optical function for adjusting the viewing distance between the first display device 1210 and the right eye of the user.

[0272] The image output from the second display device 1220 may be displayed to the left eye of the user through the left eye lens LLNS. The left eye lens LLNS may refract light from the second display device 1220 to be directed toward the left eye of the user. The left eye lens LLNS may perform an optical function for adjusting the viewing distance between the second display device 1220 and the left eye of the user.

[0273] In an embodiment, each of the right-eye lens RLNS and the left-eye lens LLNS may include an optical lens having a pancake-shaped cross-section. In an embodiment, each of the right-eye lens RLNS and the left-eye lens LLNS may include a multi-channel lens including sub-regions having different optical characteristics. In an embodiment, each display panel may output images respectively corresponding to the sub-regions of the multi-channel lens, and the output images may pass through the respective corresponding sub-regions and may be viewed by a user.

[0274] As described above, while the disclosure has been described with reference to example embodiments, those skilled in the art or ordinary skill in the art will appreciate that various modifications and changes may be made to the subject matter of the disclosure without departing from the spirit and technical field of the disclosure described in the appended claims and their equivalents.

[0275] Therefore, the disclosed technical scope should not be limited to the contents described in the detailed description of the specification but should be defined by the appended claims and their equivalents.

Claims

1. A display device, comprising: substrate; as well as a light emitting element layer on the substrate, comprising an anode electrode portion, a cathode electrode portion, a light emitting structure electrically connected between the anode electrode portion and the cathode electrode portion, and a pixel defining layer, The light emitting structure includes a first light emitting structure and a second light emitting structure, the first light emitting structure is included in a first sub-pixel, and the second light emitting structure is included in a second sub-pixel adjacent to the first sub-pixel. The pixel defining layer is located between the first sub-pixel and the second sub-pixel, and includes a partition structure located between the first light emitting structure and the second light emitting structure. The cathode electrode portion includes a first cathode electrode and a second cathode electrode, the first cathode electrode includes an opaque conductive material, and the second cathode electrode includes a transparent conductive material, At least a portion of the first cathode electrode is cut by the partition structure, The second cathode electrode is disposed across the first sub-pixel and the second sub-pixel, and The second cathode electrode has a thickness greater than that of the first cathode electrode.

2. The display device according to claim 1, wherein: The first cathode electrode and the second cathode electrode are in contact with each other, and The first cathode electrode is directly adjacent to an uppermost surface of the light emitting structure.

3. The display device according to claim 1, wherein: The first cathode electrode includes one or more selected from the group consisting of gold, silver, aluminum, molybdenum, chromium, titanium, nickel, neodymium, copper and platinum, and The second cathode electrode includes one or more selected from the group consisting of indium zinc oxide, silver nanowires, indium tin oxide, indium gallium zinc oxide, antimony zinc oxide, indium tin zinc oxide, zinc oxide, tin oxide, carbon nanotubes, and graphene.

4. The display device according to claim 1, wherein: The first cathode electrode has a thickness in a range of 100 Å to 180 Å, and The second cathode electrode has a thickness in a range of 600Å to 800Å.

5. The display device according to claim 1, wherein: The cathode electrode portion further includes an intermediate structure between the first cathode electrode and the second cathode electrode, The intermediate structure includes an N-type intermediate layer, a P-type intermediate layer on the N-type intermediate layer, and an intermediate electron injection layer on the P-type intermediate layer. The N-type intermediate layer is adjacent to the anode electrode portion, The P-type intermediate layer is adjacent to the second cathode electrode, and The N-type intermediate layer, the P-type intermediate layer, and the intermediate electron injection layer are directly adjacent to each other.

6. The display device according to claim 5, wherein: The N-type intermediate layer has a thickness in a range of 40Å to 100Å, and The intermediate structure has a thickness in the range of 400Å to 700Å.

7. The display device according to claim 1, wherein: The separation structure has a groove, and the groove provides a gap between the first sub-pixel and the second sub-pixel, The groove comprises a plurality of grooves, The trench has a height in the range of 450 nm to 750 nm, and The trench has a width in the range of 60 nm to 170 nm.

8. The display device according to claim 7, wherein: The plurality of grooves include a first groove and a second groove, and Each of the first trench and the second trench has a width equal to a distance at which the first trench and the second trench are spaced apart from each other.

9. The display device according to claim 7, wherein: At least a portion of the first cathode electrode is cut on the groove, and The second cathode electrode is continuously disposed on the groove.

10. The display device according to claim 7, wherein: The pixel defining layer includes: a first groove forming layer covering at least a portion of the anode electrode portion; a second groove forming layer having a width smaller than that of the first groove forming layer and on the first groove forming layer; and a third groove forming layer having a width smaller than that of the second groove forming layer and on the second groove forming layer. The first trench forming layer includes silicon nitride, The second trench forming layer includes silicon oxide, The third trench forming layer includes silicon nitride, The light emitting structure further includes an intermediate light emitting structure located on a portion of the pixel defining layer between the first groove and the second groove, The cathode electrode portion further includes an intermediate cathode electrode on the same layer as the first cathode electrode and on the intermediate light emitting structure, and The intermediate cathode electrode and the first cathode electrode are spaced apart from each other.

11. The display device according to claim 1, wherein: The pixel defining layer includes a protrusion base layer and a protrusion spacer on the protrusion base layer, The protrusion base layer includes: a first protrusion base layer covering the anode electrode portion; and a second protrusion base layer on the first protrusion base layer and having a width smaller than that of the first protrusion base layer, and The protrusion spacer includes: a first protrusion spacer, which is on the second protrusion base layer and has a width greater than a width of the second protrusion base layer; a second protrusion spacer, which is on the first protrusion spacer and has a width smaller than the width of the first protrusion spacer; and a third protrusion spacer, which is on the second protrusion spacer and has a width smaller than the width of the second protrusion spacer.

12. The display device according to claim 11, wherein: The light emitting structure further includes an intermediate light emitting structure on the protruding spacer, The cathode electrode portion further includes an intermediate cathode electrode on the intermediate light emitting structure and spaced apart from the first cathode electrode, and The second cathode electrode covers the intermediate cathode electrode and is disposed across the first sub-pixel and the second sub-pixel.

13. The display device according to claim 1, wherein: The pixel defining layer includes a base pixel defining layer and a planarization pixel defining layer, wherein the planarization pixel defining layer is on the base pixel defining layer and eliminates a step formed by the base pixel defining layer. The light emitting structure includes a series structure, The tandem structure includes: a first light emitting portion; a first charge generation layer on the first light emitting portion; a third light emitting portion on the first charge generation layer; a second charge generation layer on the third light emitting portion; and a second light emitting portion on the second charge generation layer. Each of the first light emitting portion, the second light emitting portion, and the third light emitting portion includes a hole transport portion, a light emitting layer, and an electron transport portion, The first charge generation layer and the second charge generation layer are cut by the partition structure.

14. The display device according to claim 1, wherein: The light emitting structure comprises a series structure, The tandem structure includes: a first light emitting portion; a charge generation layer on the first light emitting portion; and a second light emitting portion on the charge generation layer. Each of the first light emitting portion and the second light emitting portion includes a hole transport portion, a light emitting layer, and an electron transport portion, The charge generating layer is cut by the partition structure.

15. The display device according to claim 1, wherein: The light emitting structure includes a hole transporting portion, a light emitting layer and an electron transporting portion, and The electron transport portion includes a first electron transport layer and a second electron transport layer including different materials.

16. The display device according to claim 1, further comprising: A pixel circuit layer, between the substrate and the light emitting element layer, and comprising a pixel circuit; A reflective electrode, on the pixel circuit layer; as well as A step-forming layer is provided between the reflective electrode and the anode electrode portion.

17. The display device according to claim 16, wherein: The light emitting structure further includes a third light emitting structure, the third light emitting structure is included in a third sub-pixel, and The step-forming layer is located in the first sub-pixel, but is not located in the second sub-pixel and the third sub-pixel.

18. The display device according to claim 16, wherein: The light emitting structure further includes a third light emitting structure, and the third light emitting structure is included in a third sub-pixel. The step-forming layer is located in each of the first sub-pixel, the second sub-pixel, and the third sub-pixel, and The step-forming layer has a thickness greater in the second sub-pixel and the third sub-pixel than in the first sub-pixel.

19. A display device, comprising: substrate; as well as a light emitting element layer on the substrate, comprising an anode electrode portion, a cathode electrode portion, a light emitting structure electrically connected between the anode electrode portion and the cathode electrode portion, and a pixel defining layer, The light emitting structure includes a first light emitting structure and a second light emitting structure, the first light emitting structure is included in a first sub-pixel, and the second light emitting structure is included in a second sub-pixel adjacent to the first sub-pixel. The pixel defining layer is located between the first sub-pixel and the second sub-pixel and has a groove between the first light emitting structure and the second light emitting structure. The grooves include a first groove and a second groove, the first groove and the second groove are spaced apart from each other in a direction along which the first sub-pixel and the second sub-pixel are spaced apart, A width of each of the first trench and the second trench is in a range of 80 nm to 150 nm, The height of each of the first trench and the second trench is in the range of 500 nm to 700 nm, and The cathode electrode portion includes a first cathode electrode and a second cathode electrode including different materials.

20. A display device, comprising: substrate; as well as a light emitting element layer on the substrate, comprising an anode electrode portion, a cathode electrode portion, a light emitting structure electrically connected between the anode electrode portion and the cathode electrode portion, and a pixel defining layer, The light emitting structure includes a first light emitting structure and a second light emitting structure, the first light emitting structure is included in a first sub-pixel, and the second light emitting structure is included in a second sub-pixel adjacent to the first sub-pixel. The pixel defining layer is located between the first sub-pixel and the second sub-pixel, and includes a partition structure formed between the first light emitting structure and the second light emitting structure. The cathode electrode portion includes: a first cathode electrode; a second cathode electrode including a material different from that of the first cathode electrode; and an intermediate structure between the first cathode electrode and the second cathode electrode, and The intermediate structure includes an N-type intermediate layer, a P-type intermediate layer on the N-type intermediate layer, and an intermediate electron injection layer on the P-type intermediate layer.

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