Organic light emitting display panel

Abstract

Provided is an organic light emitting display panel including a first electrode, a second electrode on the first electrode, an organic layer between the first electrode and the second electrode, the organic layer including an emission layer, a first layer on the second electrode and contacting the second electrode, a second layer on the first layer and contacting the first layer, a third layer on the second layer and contacting the second layer, an organic capping layer on the third layer and contacting the third layer, and an upper layer on the organic capping layer, wherein each of the second layer and the third layer includes a silicon compound.

Description

[0001] This application is a divisional application of the invention patent application "Organic Light Emitting Display Panel" filed on November 3, 2017, with application number 201711070483.2. Technical Field

[0002] This disclosure relates to a display panel and a method of manufacturing the same, and more specifically, to a display panel and a method of manufacturing the same having a simplified manufacturing process. Background Technology

[0003] The display panel responds to electrical signals to display images and provides information to the user through the images. The display panel may include various embodiments, such as liquid crystal display panels, organic light-emitting display panels, electrophoretic display panels, electrowetting display panels, etc.

[0004] Organic light-emitting display panels (OLEDs) feature fast response times, low-voltage operation, and include organic light-emitting diodes (OLEDs) as self-emissive devices. Therefore, OLEDs offer numerous advantages, such as lightweight and thinness due to the elimination of a light source, excellent brightness, and independence from viewing angle.

[0005] Organic light-emitting display panels consist of multiple organic and inorganic layers. These panels can be formed using various manufacturing processes that create the multiple layers. Summary of the Invention

[0006] An embodiment provides an organic light-emitting display panel, the organic light-emitting display panel comprising: a first electrode; a second electrode disposed on the first electrode; an organic layer disposed between the first electrode and the second electrode, and including at least one light-emitting layer; an organic capping layer disposed on the second electrode; a lower layer disposed between the organic capping layer and the second electrode, and including a first layer, a second layer and a third layer that are different from each other and stacked sequentially; and an upper layer disposed on the organic capping layer, wherein the first layer is in contact with the second electrode, and the second layer and the third layer both comprise silicon compounds.

[0007] The optical path of the second layer is defined by the product of the refractive index and the thickness of the second layer, and can be obtained from approximately up to approximately The range.

[0008] In an embodiment, the second layer may have a lower refractive index than the first layer, and the difference between the refractive index of the second layer and the refractive index of the first layer may be equal to or greater than 0.2.

[0009] In an embodiment, the second layer may include silicon oxide.

[0010] In an embodiment, the thickness of the second layer can range from approximately up to approximately Within the range.

[0011] In an embodiment, the third layer may include silicon oxynitride or silicon nitride.

[0012] In an embodiment, when the third layer comprises silicon nitride, the thickness ratio of the third layer to the second layer may be relatively smaller than when the third layer comprises silicon oxynitride.

[0013] In an embodiment, the lower layer may further include a fourth layer disposed between the third layer and the organic capping layer and in contact with the third layer, wherein the fourth layer may include a silicon compound.

[0014] In an embodiment, the fourth layer may have a higher oxygen content than the third layer.

[0015] In an embodiment, the organic layer may further include a first charge control layer disposed between the light-emitting layer and the first electrode and a second charge control layer disposed between the light-emitting layer and the second electrode. The first layer may include the body material of the first charge control layer or the second charge control layer.

[0016] In an embodiment, a plurality of first electrodes may be provided; the light-emitting layer may include a first organic pattern disposed on one of the plurality of first electrodes and generating a first color light and a second organic pattern disposed on another of the plurality of first electrodes and generating a second color light different from the first color light; the first organic pattern and the second organic pattern may have different thicknesses from each other; the thickness of the portion of the second layer that overlaps with the first organic pattern may be substantially the same as the thickness of the portion of the second layer that overlaps with the second organic pattern.

[0017] In one embodiment, a method for manufacturing an organic light-emitting display panel includes: forming a first electrode, an organic layer disposed on the first electrode, and a second electrode disposed on the organic layer on a substrate; forming a first layer contacting the second electrode on the second electrode; sequentially stacking a second layer and a third layer, both comprising silicon compounds, on the first layer; forming an organic capping layer of organic material on the third layer; and forming an upper layer of inorganic material on the third layer, wherein the second and third layers are formed by the same process.

[0018] In an embodiment, the second layer may be formed of silicon oxide.

[0019] In an embodiment, the third layer may be formed of silicon nitride or silicon oxynitride.

[0020] In the embodiments, both the second and third layers can be formed by chemical vapor deposition.

[0021] In one embodiment, the second and third layers may be formed continuously in the same chamber. Attached Figure Description

[0022] Features will become apparent to those skilled in the art from the detailed description of exemplary embodiments with reference to the accompanying drawings, in which:

[0023] Figure 1A A simplified perspective view of the display panel according to an embodiment is shown;

[0024] Figure 1B Show Figure 1A A cross-sectional view of the display panel shown in the image;

[0025] Figure 1C Show Figure 1A The equivalent circuit diagram of a part of the construction;

[0026] Figure 2 A partial cross-sectional view of the display panel according to an embodiment is shown;

[0027] Figure 3 A cross-sectional view of a portion of the display panel according to an embodiment is shown;

[0028] Figure 4 A cross-sectional view showing a portion of the optical path of a display panel according to an embodiment;

[0029] Figure 5A A graph showing the brightness lifespan of the display panel according to an embodiment is provided.

[0030] Figure 5B A graph showing the color lifespan of a display panel according to an embodiment is provided.

[0031] Figure 6 A cross-sectional view of a portion of the display panel according to an embodiment is shown;

[0032] Figure 7A A plan view of a portion of the display panel according to an embodiment is shown;

[0033] Figure 7B Show along Figure 7A The sectional view of I-I' in the middle; and

[0034] Figure 8 A cross-sectional view of a portion of the display panel according to an embodiment is shown. Detailed Implementation

[0035] In the following description, exemplary embodiments will be described more fully with reference to the accompanying drawings; however, exemplary embodiments may be embodied in different forms and should not be construed as being limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey exemplary implementation to those skilled in the art.

[0036] In the accompanying drawings, the dimensions of layers and regions are exaggerated for clarity. It will also be understood that when a layer or element is referred to as "on" another layer or substrate, the layer or element may be directly on the other layer or substrate, or intermediate layers may be present. Furthermore, it will be understood that when a layer is referred to as "below" another layer, the layer may be directly below, and one or more intermediate layers may be present. Additionally, it will be understood that when a layer is referred to as "between two layers," the layer may be the only layer between the two layers, or one or more intermediate layers may be present. The same reference numerals consistently indicate the same elements.

[0037] Figure 1A This is a simplified perspective view showing the display panel according to an embodiment. Figure 1B yes Figure 1A The image shows a cross-sectional view of the display panel. Figure 1C It is shown Figure 1A The equivalent circuit diagram of a portion of the construction. See below for reference. Figures 1A to 1C The display panel 100 according to the embodiment is explained.

[0038] The display panel 100 displays an image generated based on electrical signals. The display panel 100 may include various embodiments. For example, the display panel 100 may be at least one of an organic light-emitting display panel, a liquid crystal display panel, an electrophoretic display panel, and an electrowetting display panel.

[0039] However, this is an exemplary description. The display panel 100 according to the embodiment can include various embodiments and is not limited to any particular display panel, as long as it displays an image in response to an electrical signal. In this embodiment, an organic light-emitting display panel is used as an example to explain the display panel 100.

[0040] The display panel 100 may include a plurality of pixels PX. The plurality of pixels PX may be arranged in a matrix on a plane defined by a first direction D1 and a second direction D2. However, this is an exemplary description. The plurality of pixels PX may be arranged in various forms and is not limited to any particular arrangement.

[0041] Multiple pixels PX may include a first pixel PX1, a second pixel PX2, and a third pixel PX3. The first pixel PX1 through the third pixel PX3 can produce light of different colors. For example, the first pixel PX1 can produce light of a first color, the second pixel PX2 can produce light of a second color, and the third pixel PX3 can produce light of a third color.

[0042] The display panel 100 can be divided in a plane into a non-pixel area NPA and a plurality of pixel areas PA. Each of the plurality of pixels PX can be disposed in the plurality of pixel areas PA. Therefore, the display panel 100 can realize an image using a combination of light generated through the plurality of pixel areas PA.

[0043] Reference Figure 1B The display panel 100 may include a substrate BS, a pixel layer PL, a lower layer LL, an organic cover layer MN, an upper layer UL, and a window component WM. The substrate BS may be an insulating layer. For example, the substrate BS may be an insulating film, a plastic substrate, or a glass substrate.

[0044] The pixel layer PL is disposed on the substrate BS. The pixel layer PL may include multiple pixels PX. For ease of explanation, in Figure 1C Exemplary description Figure 1A The equivalent circuit diagram of the first pixel PX1 is shown. Furthermore, each of the plurality of pixels PX according to the embodiment may have a structure corresponding to the first pixel PX1, and is not limited to any one embodiment.

[0045] like Figure 1C As shown, the first pixel PX1 may include a first transistor TFT1, a capacitor Cap, a second transistor TFT2, and an organic light-emitting diode (OLED). The first transistor TFT1 may include: a control electrode connected to a first signal line SL; an input electrode connected to a second signal line DL; and an output electrode.

[0046] The first transistor TFT1 can be a switching device configured to control the on / off state of the first pixel PX1. The first transistor TFT1 can transmit or block data signals transmitted via the second signal line DL in response to a scan signal transmitted via the first signal line SL.

[0047] The capacitor Cap includes a first capacitor electrode connected to the first transistor TFT1 and a second capacitor electrode that receives a first power supply voltage ELVDD. The capacitor Cap is charged until it reaches a charge amount corresponding to the difference between two voltages, namely the voltage of the first power supply voltage ELVDD and the voltage corresponding to the data signal received from the first transistor TFT1.

[0048] The second transistor TFT2 includes: a control electrode, a first capacitor electrode connected to the output electrode of the first transistor TFT1 and the capacitor Cap; an input electrode receiving a first power supply voltage ELVDD; and an output electrode. The output electrode of the second transistor TFT2 is connected to an organic light-emitting diode (OLED).

[0049] The second transistor TFT2 controls the driving current flowing in the organic light-emitting diode (OLED), which corresponds to the amount of charge stored in the capacitor Cap. The on-time of the second transistor TFT2 is determined based on the amount of charge stored in the capacitor Cap. Essentially, the output electrode of the second transistor TFT2 supplies a voltage to the OLED that is lower than the first power supply voltage ELVDD.

[0050] An organic light-emitting diode (OLED) is connected to a second transistor (TFT2) and receives a second power supply voltage (ELVSS). The OLED emits light during the on-time period of the second transistor (TFT2).

[0051] Organic light-emitting diodes (OLEDs) consist of light-emitting materials. OLEDs can produce light of a color corresponding to the color of the light-emitting material. The color of light produced in an OLED can be one of red, green, blue, or white.

[0052] Return to reference Figure 1B The lower layer LL is located on and covers the pixel layer PL, for example, it is superimposed on at least the top surface of the pixel layer PL in the third direction D3. The lower layer LL may contact (e.g., directly contact) the pixel layer PL. At least a portion of the lower layer LL may cover the side surface of the pixel layer PL, for example, it may directly contact the side surface. The lower layer LL may extend along the entire side surface and may extend along the upper surface of the substrate BS in the first direction D1. The lower layer LL may include multiple thin film layers, as will be described in detail below.

[0053] An organic capping layer MN is located on the lower layer LL. The organic capping layer MN may include organic materials. Compared to adjacent layers, the organic capping layer MN may have a relatively large thickness. For example, the organic capping layer MN may have a thickness greater than both the lower layer LL and the upper layer UL.

[0054] An organic capping layer MN can cover the upper surface of the lower layer LL to provide a flat surface on the upper side of the organic capping layer MN. Therefore, the organic capping layer MN can have different thicknesses depending on its region. The thickness distribution of the organic capping layer MN can vary depending on the conditions of the upper surface of the lower layer LL.

[0055] The upper UL layer is located on the organic overlay MN. The upper UL layer may be electrically insulating. The upper UL layer may include inorganic materials. For example, the upper UL layer may include silicon compounds.

[0056] The upper UL layer covers the organic covering layer MN (e.g., the upper surface of the organic covering layer MN) and blocks contact between the outside and the organic covering layer MN. In addition, the upper UL layer can prevent moisture and other substances generated from the organic covering layer MN from escaping to the outside.

[0057] The window element WM is located on the upper UL layer. The window element WM can completely cover the pixel layer PL on a plane, for example, it can be superimposed on the pixel layer PL on a third direction D3. The window element WM can include a material with high transmittance. The window element WM allows light generated in the pixel layer PL to be easily seen from the outside and protects the pixel layer PL from external impacts.

[0058] Figure 2 This is a partial cross-sectional view of the display panel according to an embodiment. For ease of explanation, Figure 2 The arrangement is shown in Figure 1C The region shown is part of the construction of the first pixel PX1.

[0059] like Figure 2 As shown, pixel layer PL (see Figure 1B The second transistor TFT2 may also include a first insulating layer L1, a second insulating layer L2, a third insulating layer L3, and a fourth insulating layer PDL. The semiconductor pattern SM2 of the second transistor TFT2 may be located between the first insulating layer L1 and the substrate BS. The control electrode GE2 of the second transistor TFT2 may be located between the first insulating layer L1 and the second insulating layer L2.

[0060] Furthermore, the input electrode IE2 and output electrode OE2 of the second transistor TFT2 can be located between the second insulating layer L2 and the third insulating layer L3. The input electrode IE2 and the output electrode OE2 are separated from each other along the first direction D1. The input electrode IE2 and the output electrode OE2 can penetrate the first insulating layer L1 and the second insulating layer L2, respectively, to connect to the semiconductor pattern SM2.

[0061] This is an exemplary description. The second transistor TFT2 according to an embodiment may include an input electrode IE2, an output electrode OE2, a semiconductor pattern SM2, and a control electrode GE2 disposed in various locations, and is not limited to any one embodiment.

[0062] The organic light-emitting diode (OLED) is located on the third insulating layer L3. The OLED may include a first electrode ED1, an organic layer OL, and a second electrode ED2 that are stacked (e.g., layered) sequentially along the third direction D3.

[0063] The first electrode ED1 is located on the third insulating layer L3. The first electrode ED1 can penetrate the third insulating layer L3 and be connected to the second transistor TFT2. At the same time, multiple first electrodes ED1 can be set and set while being separated from each other, for example, they can be set for each individual pixel PX.

[0064] In an exemplary embodiment, the first electrode ED1 is connected to the output electrode OE2. The first electrode ED1 penetrates the third insulating layer L3 and is connected to the output electrode OE2 to electrically connect the organic light-emitting diode (OLED) to the second transistor (TFT2).

[0065] A fourth insulating layer PDL is located on the third insulating layer L3. A plurality of openings may be defined on the fourth insulating layer PDL. Each of the plurality of openings exposes at least a portion of each of the plurality of first electrodes ED1.

[0066] The organic layer OL is located on the first electrode ED1. The organic layer OL can have a single-layer structure of a single material, a single-layer structure of multiple different materials, or a multi-layer structure of multiple different materials.

[0067] The organic layer OL may include a light-emitting material. For example, the organic layer OL may be composed of at least one of materials that emit red, green, and blue light, and may include a fluorescent material or a phosphor. The organic layer OL may emit light in response to the potential difference between the first electrode ED1 and the second electrode ED2.

[0068] Although not shown, the organic layer OL may include multiple luminescent patterns, each containing a different luminescent material. Each of the multiple luminescent patterns may be configured to correspond to each of the multiple first electrodes ED1.

[0069] The second electrode ED2 is located on the organic layer OL. The second electrode ED2 may face the first electrode ED1. The organic light-emitting diode (OLED) can be connected to the second power supply voltage ELVSS (see [reference needed]) through the second electrode ED2. Figure 1C ).

[0070] The lower layer LL may be located between the second electrode ED2 and the organic capping layer MN. The lower layer LL may include a first layer IL1, a second layer IL2, and a third layer IL3 stacked sequentially in an upward direction.

[0071] The first layer IL1 can be directly disposed on and in contact with the second electrode ED2. The first layer IL1 may include an insulating material. For example, the first layer IL1 may include an organic material or an inorganic material.

[0072] The second IL2 layer may be directly located on and in contact with the first IL1 layer (e.g., in direct contact with the first IL1 layer). The second IL2 layer may block the penetration of external moisture or oxygen. The second IL2 layer may comprise an inorganic insulating material. For example, the second IL2 layer may comprise a silicon compound.

[0073] The third IL3 layer can be located directly on top of and in contact with the second IL2 layer (e.g., in direct contact with the second IL2 layer). The third IL3 layer can block the penetration of external moisture or oxygen.

[0074] The third layer IL3 may comprise an inorganic insulating material. For example, the third layer IL3 may comprise a silicon compound. In this case, the silicon compound constituting the third layer IL3 and the silicon compound constituting the second layer IL2 may be different from each other.

[0075] The organic capping layer MN may be located directly on the underlying layer LL and may contact (e.g., directly contact) the underlying layer LL. The organic capping layer MN may contact the top layer of the underlying layer LL (e.g., the third layer IL3).

[0076] As described above, the organic capping layer MN provides a flat surface on its upper side. Therefore, any bends appearing on the upper surface of the lower layer LL, or particles present on the lower layer LL, can be covered by the organic capping layer MN, thus allowing the upper layer UL to be stably formed on a flat surface. Additionally, the organic capping layer MN can mitigate stress between layers in contact with each other.

[0077] The organic capping layer MN may include organic materials. For example, the organic capping layer MN may include resins or polymers.

[0078] The upper UL layer may be directly located on and in contact with the organic overlay MN. The upper UL layer blocks the penetration of external moisture or oxygen. The upper UL layer may include an inorganic insulating material. For example, the upper UL layer may include a silicon compound.

[0079] The window component WM can be disposed on the organic cover layer MN. The window component WM can cover the organic cover layer MN and protect the organic light-emitting diode (OLED) from external impacts.

[0080] Each of the second layer IL2 and the third layer IL3 of the lower layer LL of the display panel 100 according to the embodiment may include a silicon compound. Therefore, the second layer IL2 and the third layer IL3 can be formed by substantially the same process, thus reducing process costs and simplifying the process. A detailed explanation will be described later.

[0081] Figure 3 This is a cross-sectional view showing a portion of the display panel according to an embodiment. Figure 4 This is a cross-sectional view showing a portion of the optical path of a display panel according to an embodiment. For ease of explanation, a comparative example CM and an example EX according to an embodiment are shown simultaneously. In the following, reference is made to... Figure 3 and Figure 4 The following explains the display panel according to the embodiment.

[0082] like Figure 3 As shown, the first electrode ED1 and the second electrode ED2 of the organic light-emitting diode (OLED) can be separated by a predetermined interval. The separation distance between the first electrode ED1 and the second electrode ED2 can correspond to the thickness D-OL of the organic layer OL.

[0083] In this embodiment, the organic light-emitting diode (OLED) may have a resonant structure. Therefore, the thickness D-OL of the organic layer OL can be an integer multiple of half the wavelength of the light generated from the organic layer OL.

[0084] A portion of the light generated by the organic layer OL can be reflected at the interfaces between the first electrode ED1 and the organic layer OL, and at the interfaces between the second electrode ED2 and the organic layer OL, to resonate within the organic light-emitting diode (OLED). Therefore, the OLED can achieve improved light efficiency by controlling the thickness D-OL of the organic layer OL.

[0085] The first layer IL1 to the third layer IL3 may have different predetermined refractive indices n1 to n3. For example, the first layer IL1 may have a first refractive index n1, the second layer IL2 may have a second refractive index n2, and the third layer IL3 may have a third refractive index n3.

[0086] The second refractive index n2 can be less than the first refractive index n1. Therefore, a portion of the light generated from the organic layer OL can reach the interface between the first layer IL1 and the second layer IL2, be easily reflected from this interface, and re-enter the organic light-emitting diode (OLED).

[0087] The re-entering light can resonate through the first electrode ED1 and the second electrode ED2, and be emitted to the outside with improved intensity. Therefore, by controlling the refractive index of the second layer IL2, the display panel according to the embodiment can have improved light extraction efficiency.

[0088] The optical path of the second IL2 layer can be from approximately up to approximately Within the range. The optical path length of the second IL2 is the distance that incident light on the second IL2 travels through the vacuum per unit time, and can be defined by the product of the second refractive index n2 and the thickness D2 of the second IL2.

[0089] When the second IL2 layer comprises silicon oxide, the thickness D2 of the second IL2 layer can be equal to or greater than approximately And may be equal to or less than approximately When the second layer IL2 comprises silicon oxide, the second refractive index n2 can be from approximately 1.4 to 1.5. In this case, a portion of the light incident on the interface between the first layer IL1 and the second layer IL2 is reflected again. Therefore, light efficiency can be improved. However, this is an exemplary description. The thickness D2 of the second layer IL2 can vary depending on the second refractive index n2.

[0090] For more details, please refer to Figure 4The layers constituting comparative example CM and example EX may have the same refractive index, but may have different thicknesses. More specifically, the first layer IL1 of comparative example CM may be formed of the same material as the first layer IL1 of example EX, and have the same thickness TH1 as the first layer IL1 of example EX. That is, the first layer IL1 of comparative example CM may be substantially the same layer as the first layer IL1 of example EX.

[0091] The second layer IL2-C of the comparative example CM can be formed from the same material as the second layer IL2 of example EX, but has a different thickness. The thickness TH2 of the second layer IL2 in example EX can be greater than the thickness TH-C of the second layer IL2-C in the comparative example CM. The thickness TH2 of the second layer IL2 in example EX can be a value that satisfies the optical path condition of the second layer IL2.

[0092] In this case, the incident light L-CM of the contrast example CM passes through the first layer IL1 and is incident at a first angle θ1 relative to the interface between the second layer IL2-C and the first layer IL1. At least a portion of the incident light can pass through the second layer IL2-C at a second angle θ2 and can be emitted to the outside.

[0093] That is, although there is a change in optical path in the comparative example CM, most of the incident light in L-CM passes through the second IL2-C and exits. Therefore, the intensity of the light visible from the outside of the second IL2-C can be the same as or less than the intensity of the light passing through the second IL2-C.

[0094] Meanwhile, the incident light L-EX in Example EX passes through the first layer IL1 and is incident at a first angle θ1 relative to the interface between the second layer IL2 and the first layer IL1. The incident light L-EX can correspond to the incident light L-CM incident on the contrast example CM.

[0095] However, in the following example, the incident light L-EX in Example EX does not pass through the second layer IL2, but is reflected from the interface between the second layer IL2 and the first layer IL1. In this case, the difference between the second refractive index n2 and the first refractive index n1 can be equal to or greater than 0.2. The difference between the second refractive index n2 and the first refractive index n1 can be substantially proportional to the reflection efficiency of the interface between the second layer IL2 and the first layer IL1.

[0096] Light reflected from the interface between the second layer IL2 and the first layer IL1 can pass through the first layer IL1 and re-enter the organic light-emitting diode (OLED) located below the first layer IL1. The re-entering light can resonate inside the OLED and be emitted from the OLED with improved intensity, making it visible from the outside.

[0097] The display panel 100 according to the embodiment can improve light efficiency by controlling the optical path length of the second layer IL2. Furthermore, by controlling the optical path length of the second layer IL2, the display panel 100 can achieve improved light extraction efficiency by controlling the thickness when applying layers with the same refractive index.

[0098] Return to reference Figure 3 The third layer IL3 can have a higher refractive index than the second layer IL2. That is, the second refractive index n2 can be less than the third refractive index n3. Therefore, light incident on the interface between the second layer IL2 and the third layer IL3 can pass through the third layer IL3 and be emitted to the outside without being reflected.

[0099] As described above, the third IL3 comprises a silicon compound. The silicon compound constituting the third IL3 may be different from the silicon compound constituting the second IL2. For example, the third IL3 may comprise silicon oxynitride (SiON) or silicon nitride (SiN). x ).

[0100] The second IL2 layer and the third IL3 layer can be formed using the same process. Specifically, each of the second IL2 layer and the third IL3 layer can be formed by chemical vapor deposition.

[0101] Simultaneously, a second IL2 layer and a third IL3 layer can be continuously formed in the same chamber. Each of the second IL2 layer and the third IL3 layer comprises a silicon compound, therefore, each of the second IL2 layer and the third IL3 layer can be formed by controlling the injected plasma.

[0102] For example, a second layer IL2 comprising silicon oxide can be formed in the same chamber using a plasma with a high oxygen content, and a third layer IL3 comprising silicon nitride or silicon oxynitride can be continuously formed in the same chamber using a plasma with a relatively high nitrogen content. Therefore, compared to discontinuous deposition, the interface between the second layer IL2 and the third layer IL3 according to the embodiment can be formed relatively indistinctly by continuous deposition.

[0103] The method for manufacturing a display panel according to an embodiment may include forming a second IL2 layer and a third IL3 layer using the same process, thereby simplifying the process. Additionally, according to an embodiment, the second IL2 layer and the third IL3 layer can be formed continuously in the same chamber. Therefore, processing time and costs can be reduced.

[0104] The thickness D3 of the third IL3 layer can be thicker than the thickness D2 of the second IL2 layer. For example, the thickness D3 of the third IL3 layer can be equal to or greater than... and equal to or less than Therefore, for optical control, the thickness portion defined by the second layer IL2 is compensated by the thickness of the third layer IL3, thus ensuring that the lower layer LL has sufficient thickness to function as a stop.

[0105] In the display panel according to the embodiment, the thickness D3 of the third layer IL3 can be set differently depending on the material constituting the third layer IL3. For example, for the same second layer IL2, the thickness D3 of the third layer IL3 composed of silicon nitride can be less than the thickness D3 of the third layer IL3 composed of silicon oxynitride. According to the embodiment, by controlling the material of the third layer IL3, the thickness D3 of the third layer IL3 can be changed, and the processing time can be easily reduced.

[0106] Figure 5A This is a graph showing the brightness lifespan of the display panel according to an embodiment. Figure 5B This is a graph showing the color lifespan of the display panel according to an embodiment. Figure 5A and Figure 5B For ease of explanation, a comparative example, a first example, and a second example are shown.

[0107] Apart from the different constructions of the lower IL layer, the comparative example, the first example, and the second example can be embodiments with the same structure. In the comparative example, the first example, and the second example, the first layer IL1 can be the same, but its second layer IL2 and third layer IL3 can be different from each other.

[0108] For the comparative example, the second IL2 layer comprises lithium fluoride (LiF), and its third IL3 layer comprises silicon oxynitride. For the first example, the second IL2 layer comprises silicon oxide, and its third IL3 layer comprises silicon oxynitride. That is, the first example has a different composition of the second IL2 layer compared to the comparative example. For the second example, the second IL2 layer comprises silicon oxide, and its third IL3 layer may comprise silicon oxynitride. That is, the second example has a different composition of the third IL3 layer compared to the first example. In the following, reference will be made to... Figure 5A and Figure 5B The following explains the display panel according to the embodiment.

[0109] exist Figure 5A In the diagram, curve PL1 shows the brightness lifetime of the comparative example, curve PL2 shows the brightness lifetime of the first example, and curve PL3 shows the brightness lifetime of the second example. As shown in curves PL1 to PL3, the brightness ratio relative to the initial brightness gradually decreases over time.

[0110] In this case, curves PL1 through PL3 show substantially similar patterns. Specifically, curves PL2 and PL3 show substantially improved brightness ratios over the same elapsed time. That is, even if the LiF in the second IL2 layer is replaced by a silicon compound, at least equivalent brightness lifetime properties are achieved.

[0111] Referring to the second curve PL2 and the third curve PL3, the third curve PL3 has a gentler slope than the second curve PL2. Therefore, over the same elapsed time, the third curve PL3 has a larger luminance ratio than the second curve PL2. That is, the second example including silicon nitride can have an improved luminance lifetime than the first example including silicon oxynitride.

[0112] exist Figure 5B In the diagram, curve PL4 (fourth curve) shows the color lifetime of the comparative example, curve PL5 (fifth curve) shows the color lifetime of the first example, and curve PL6 (sixth curve) shows the color lifetime of the second example. Color lifetime is related to the phenomenon of residual light afterimages due to continuous heat damage during operation; therefore, color lifetime is also related to the lifespan of the device. Thus, as shown in curves PL4 to PL6, the initial color afterimage generally increases over time.

[0113] In this case, among curves PL4 to PL6, curves PL5 and PL6 are shown to have a relatively lower color retention ratio than curve PL4 over the same elapsed time. That is, the first example and the second example have a relatively improved color lifetime compared to the comparative example.

[0114] Referring to curves PL5 (fifth) and PL6 (sixth), the second example shown by curve PL6 has an improved color lifetime than the first example shown by curve PL5. That is, the example including a third layer of IL3 composed of silicon nitride has an improved color lifetime than the example including a third layer of IL3 composed of silicon oxynitride.

[0115] The advantage of the display panel according to the embodiment is that the second IL2 and the third IL3 are each composed of silicon compound, therefore, they can be formed using the same process. Additionally, as... Figure 5A and Figure 5BAs shown, because the color lifespan and brightness lifespan are at least equivalent to those of the case where the second layer IL2 is composed of lithium fluoride (LiF), the display panel according to the embodiment also has excellent properties in terms of device lifespan. Therefore, in this embodiment, a display panel with excellent properties can be formed without adding a step of forming a lithium fluoride layer. Thus, the manufacturing of the display panel can be simplified. Furthermore, the display panel according to the embodiment allows for appropriate control of the device lifespan or image retention properties by selecting various materials from the silicon compound.

[0116] Figure 6 This is a cross-sectional view showing a portion of the display panel according to an embodiment. Figures 1A to 5B The same constructions explained in the figure are given the same reference numerals, and repeated explanations are omitted.

[0117] like Figure 6 As shown, the organic layer OL-1 may include multiple layers. For example, the organic layer OL-1 may include a first charge control layer CML1, a light-emitting layer EML, and a second charge control layer CML2.

[0118] The emissive layer (EML) produces light of the first color. The EML may include at least one of organic and inorganic light-emitting materials. Alternatively, the EML may include a phosphor or a fluorescent material.

[0119] The first charge control layer CML1 may consist of a single layer or multiple layers. In this embodiment, the first charge control layer CML1 may include a first charge injection layer CML11 and a first charge transport layer CML12.

[0120] Each of the first charge injection layer CML11 and the first charge transport layer CML12 facilitates charge transport from the first electrode ED1 to the light-emitting layer EML. The charge can be a hole or an electron, and can be determined according to the driving method of the organic light-emitting diode.

[0121] The second charge control layer CML2 may consist of a single layer or multiple layers. In this embodiment, the second charge control layer CML2 may include a second charge injection layer CML21 and a second charge transport layer CML22.

[0122] Each of the second charge injection layer CML21 and the second charge transport layer CML22 facilitates charge transport from the second electrode ED2 to the light-emitting layer EML. The charge can be a hole or an electron and can have the opposite polarity to the charge transported from the first electrode ED1.

[0123] Each of the first charge control layer CML1 and the second charge control layer CML2 may include a host and a dopant. The host material and the dopant material may be varied according to the charge transferred in each of the first charge control layer CML1 and the second charge control layer CML2.

[0124] The first layer IL1 of the lower layer LL may include at least one of the first charge control layer CML1 and the second charge control layer CML2 as the host material. Therefore, the first layer IL1 can use the material used to form the organic layer OL-1, thus reducing processing costs. However, this is an exemplary description. The first layer IL1 may be formed of an inorganic insulating material and is not limited to any particular material.

[0125] The distance from the interface between the first electrode ED1 and the organic layer OL-1 to the interface between the second electrode ED2 and the organic layer OL-1 can be defined by the light-emitting layer EML, the first charge control layer CML1, and the second charge control layer CML2. The distance from the interface between the first electrode ED1 and the organic layer OL-1 to the interface between the second electrode ED2 and the organic layer OL-1 can be the resonant distance of the first color light generated by the light-emitting layer EML. Therefore, the display panel according to the embodiment can improve the luminous efficiency of the organic light-emitting diode by controlling the thickness and number of layers constituting the organic layer OL-1.

[0126] Figure 7A This is a plan view showing a portion of the display panel according to an embodiment. Figure 7B It is along Figure 7A The cross-sectional view of I-I' shown in the figure. Figure 7B For ease of explanation, some details have been omitted.

[0127] In the following text, refer to Figure 7A and Figure 7B This explains the display panel 100 according to an embodiment. Meanwhile, with... Figures 1A to 6 The same constructions explained in the figure are given the same reference numerals, and repeated explanations are omitted.

[0128] like Figure 7A As shown, pixel region PA may include a first pixel region PA1, a second pixel region PA2, and a third pixel region PA3. The first pixel region PA1, the second pixel region PA2, and the third pixel region PA3 may be regions arranged sequentially in one direction.

[0129] Each of the first pixel area PA1, the second pixel area PA2, and the third pixel area PA3 can produce light of a different color. For example, the first pixel area PA1 produces light of a first color, the second pixel area PA2 produces light of a second color, and the third pixel area PA3 produces light of a third color.

[0130] Specifically, such as Figure 7BAs shown, the organic layer OL may include a first light-emitting pattern EL1 to a third light-emitting pattern EL3, each disposed in a first pixel region PA1, a second pixel region PA2, and a third pixel region PA3. A first color light may be generated from the first light-emitting pattern EL1. A second color light may be generated from the second light-emitting pattern EL2, and a third color light may be generated from the third light-emitting pattern EL3.

[0131] Each of the first luminescent pattern EL1 to the third luminescent pattern EL3 can be designed to have a different thickness from each other. For example, the first luminescent pattern EL1 can be designed to have a first thickness D-EL1, the second luminescent pattern EL2 can be designed to have a second thickness D-EL2, and the third luminescent pattern EL3 can be designed to have a third thickness D-EL3.

[0132] Each of the first thickness D-EL1 to the third thickness D-EL3 can be a resonant distance of light generated from the corresponding luminescent pattern. In this embodiment, among the first color light to the third color light, the case where the wavelength of the first color light is the longest and the wavelength of the third color light is the shortest is exemplarily described. Therefore, it is possible to design that, among the first thickness D-EL1 to the third thickness D-EL3, the first thickness D-EL1 is the largest and the third thickness D-EL3 is the smallest.

[0133] like Figure 7B As shown, the second electrode ED2, the first layer IL1, the second layer IL2 and the third layer IL3 located on the organic layer OL can have substantially the same thickness in the first pixel region PA1 to the third pixel region PA3.

[0134] Since each of the second layer IL2 and the third layer IL3 comprises a silicon compound, each of the second layer IL2 and the third layer IL3 may have an upper surface that reflects the surface shape of the layer disposed thereunder. Therefore, the upper surface of the third layer IL3 may define an uneven surface in the first pixel region PA1, the second pixel region PA2, and the third pixel region PA3.

[0135] According to an embodiment, the organic capping layer MN can cover the upper surface of the third layer IL3 and provide a flat surface on the upper side of the organic capping layer MN. The organic capping layer MN can substantially compensate for the thickness differences of each of the first luminescent patterns EL1 to the third luminescent patterns EL3. Therefore, the upper layer UL disposed on the organic capping layer MN can be stably formed on the flat surface.

[0136] In the display panel 100 according to the embodiment, a first layer IL1, a second layer IL2, and a third layer IL3 can be jointly disposed on multiple pixel areas PA1 to PA3 that emit light of different colors, thereby improving the light efficiency of each of the multiple pixel areas PA1 to PA3. Therefore, the same lower layer can be applied to multiple pixel areas PA1 to PA3, thus simplifying the process.

[0137] Figure 8 This is a cross-sectional view showing a portion of the display panel according to an embodiment. Meanwhile, with Figures 1A to 7B The same constructions explained in the figure are given the same reference numerals, and repeated explanations are omitted.

[0138] like Figure 8 As shown, the lower layer LL-1 may include a fourth layer IL4. The fourth layer IL4 may be located on the third layer IL3 and may be the uppermost layer. Therefore, the organic capping layer MN may directly contact the fourth layer IL4 and form a predetermined interface.

[0139] The fourth layer IL4 may include silicon oxynitride. When the third layer IL3 includes silicon oxynitride, the silicon oxynitride in the fourth layer IL4 may have a higher oxygen content than the silicon oxynitride included in the third layer IL3. Therefore, even if the third layer IL3 and the fourth layer IL4 include the same material, the third layer IL3 and the fourth layer IL4 may be substantially distinguishable layers.

[0140] The fourth IL4 layer protects the third IL3 layer. The fourth IL4 layer prevents the third IL3 layer from being damaged during the process of setting the organic capping layer MN. The display panel according to an embodiment can improve process reliability by including a lower layer LL-1 that also contains the fourth IL4 layer.

[0141] According to this embodiment, since multiple layers that can be formed in the same process can be included, the manufacturing process of the display panel can be simplified, and the processing cost of the display panel can be reduced. Additionally, the light efficiency and lifespan of the display panel can be improved.

[0142] Example embodiments have been disclosed herein, and although specific terminology has been used, it is used and interpreted in a general and descriptive sense only, and not for limiting purposes. In some instances, as will be apparent to those skilled in the art up to the time of filing of this application, features, characteristics, and / or elements described in connection with specific embodiments may be used alone or in combination with features, characteristics, and / or elements described in connection with other embodiments, unless expressly stated otherwise. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of the invention as set forth in the claims.

Claims

1. An organic light-emitting display panel, the organic light-emitting display panel comprising: First electrode; The second electrode is located on the first electrode; An organic layer is located between the first electrode and the second electrode, and the organic layer includes a light-emitting layer; The first layer is located on and in contact with the second electrode; The second layer is located on top of and in contact with the first layer; The third layer is located on top of and in contact with the second layer; The fourth layer is located on top of and in contact with the third layer; An organic capping layer is located on and in contact with the fourth layer; as well as The upper layer, located on the organic coating layer, Each of the second, third, and fourth layers comprises a silicon compound, and the fourth layer has a higher oxygen content than the third layer.

2. The organic light-emitting display panel according to claim 1, wherein, The first layer comprises the same silicon compound as the second and third layers, and wherein the first, second, and third layers are essentially single, unbounded layers.

3. The organic light-emitting display panel according to claim 1, wherein, The third layer comprises silicon nitride.

4. The organic light-emitting display panel according to claim 1, wherein, The upper layer comprises the same silicon compound as the silicon compound in the second layer.

5. The organic light-emitting display panel according to claim 1, wherein, The combined thickness of the second and third layers is between 5200 Å and 10600 Å.

6. The organic light-emitting display panel according to claim 1, wherein, The refractive index of the second layer is different from that of the third layer.

7. The organic light-emitting display panel according to claim 1, wherein, The second layer has a lower refractive index than the first layer, and the difference between the refractive index of the second layer and the refractive index of the first layer is greater than or equal to 0.

2.

8. The organic light-emitting display panel according to claim 1, wherein, The organic layer further includes: Hole control layer, located on the first electrode; and The electronic control layer is located on top of the hole control layer. The light-emitting layer is located between the hole control layer and the electron control layer. Furthermore, the first layer includes the main material of the hole control layer or the electronic control layer.

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