Organic light-emitting element, organic light-emitting display device, and electronic apparatus

Abstract

Provided are an organic light-emitting element, an organic light-emitting display device, and an electronic apparatus, the organic light-emitting element including: a first electrode and a second electrode facing each other; an organic emission layer between the first electrode and the second electrode; a hole transport layer between the first electrode and the organic emission layer; and metal nanoparticles over the first electrode, in which a first distance between the organic emission layer and a lower surface of the metal nanoparticles is less than a distance between the organic emission layer and the second electrode.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2024-0062733, filed on May 13, 2024, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] One or more embodiments relate to organic light-emitting elements, organic light-emitting display devices, and electronic devices with improved light extraction efficiency and lifetime. Background Technology

[0004] Generally, a display device includes a light-emitting element and pixel circuitry configured to control electrical signals applied to the light-emitting element. The pixel circuitry includes thin-film transistors (TFTs), capacitors, and multiple wirings. The light-emitting element is configured to emit light in response to electrical signals transmitted from the wirings.

[0005] An organic light-emitting display device includes an organic light-emitting element, which includes a hole injection electrode, an electron injection electrode, and an organic emitting layer located between the hole injection electrode and the electron injection electrode. An organic light-emitting display device is a self-emissive display device in which excitons emit light when they transition from an excited state to a ground state. Excitons are generated when holes injected from the hole injection electrode recombine with electrons injected from the electron injection electrode in the organic emitting layer.

[0006] Organic light-emitting displays (OLEDs) are self-emissive display devices that do not require a separate light source and can therefore be driven at relatively low voltages. Furthermore, these OLEDs can be configured to have a slim profile and high-quality characteristics such as wide viewing angles, high contrast, and fast response times, making them a promising next-generation display device. Summary of the Invention

[0007] One or more embodiments include organic light-emitting elements, organic light-emitting display devices, and electronic devices that incorporate improved light extraction efficiency and lifetime. However, such aspects are exemplary, and this disclosure is not limited thereto.

[0008] Other aspects will be set forth in part in the description which follows and will be apparent in part from the description, or may be learned by practice of the embodiments presented in this disclosure.

[0009] According to one or more embodiments, an organic light-emitting element includes: a first electrode and a second electrode facing each other; an organic emitting layer between the first electrode and the second electrode; a hole transport layer between the first electrode and the organic emitting layer; and metal nanoparticles above the first electrode, wherein a first distance between the organic emitting layer and the lower surface of the metal nanoparticles is smaller than the distance between the organic emitting layer and the second electrode.

[0010] The first distance can be a first resonant distance relating to the intensity of light generated in the organic emitting layer.

[0011] The first distance could be approximately up to approximately

[0012] The organic light-emitting element may further include: a metal reflective layer above the second electrode, wherein the second distance between the upper surface of the first electrode and the lower surface of the metal reflective layer is approximately up to approximately

[0013] The organic light-emitting element may further include: a low-refractive-index layer above the second electrode and having a refractive index smaller than that of the second electrode, wherein the second electrode comprises a transparent conductive oxide and together with the low-refractive-index layer provides an upper reflective layer.

[0014] The organic light-emitting element may further include an electron transport layer between the organic emitting layer and the second electrode, wherein the thickness of the hole transport layer is less than the thickness of the electron transport layer.

[0015] The organic light-emitting element may further include a lower reflective layer between the first electrode and the metal nanoparticles.

[0016] The distance between the organic emitting layer and the upper surface of the first electrode can be a second resonant distance with respect to the intensity of the light generated in the organic emitting layer.

[0017] The organic light-emitting element may further include: a metal reflective layer above the second electrode, wherein the distance between the upper surface of the first electrode and the lower surface of the metal reflective layer is approximately [missing information]. up to approximately

[0018] The organic light-emitting element may further include a lower reflective layer between the first electrode and the metal nanoparticles.

[0019] According to one or more embodiments, an organic light-emitting display device includes a plurality of pixels comprising an organic light-emitting element and at least one thin-film transistor, the organic light-emitting element comprising: a first electrode and a second electrode facing each other; an organic emitting layer between the first electrode and the second electrode; a hole transport layer between the first electrode and the organic emitting layer; and metal nanoparticles above the first electrode, wherein a first distance between the organic emitting layer and the lower surface of the metal nanoparticles is smaller than the distance between the organic emitting layer and the second electrode.

[0020] The first distance can be a first resonant distance relating to the intensity of light generated in the organic emitting layer.

[0021] The organic light-emitting element may further include: a low-refractive-index layer above the second electrode and having a refractive index smaller than that of the second electrode, wherein the second electrode comprises a transparent conductive oxide and together with the low-refractive-index layer provides an upper reflective layer.

[0022] The organic light-emitting element may further include an electron transport layer between the organic emitting layer and the second electrode, wherein the thickness of the hole transport layer is less than the thickness of the electron transport layer.

[0023] The organic light-emitting element may further include a lower reflective layer between the first electrode and the metal nanoparticles.

[0024] According to one or more embodiments, an electronic device includes a display device comprising an organic light-emitting element, the organic light-emitting element comprising: a first electrode and a second electrode facing each other; an organic emitting layer between the first electrode and the second electrode; a hole transport layer between the first electrode and the organic emitting layer; and metal nanoparticles above the first electrode, wherein a first distance between the organic emitting layer and the lower surface of the metal nanoparticles is less than the distance between the organic emitting layer and the second electrode.

[0025] The first distance can be a first resonant distance relating to the intensity of light generated in the organic emitting layer.

[0026] The organic light-emitting element may further include: a low-refractive-index layer above the second electrode and having a refractive index smaller than that of the second electrode, wherein the second electrode comprises a transparent conductive oxide and together with the low-refractive-index layer provides an upper reflective layer.

[0027] The organic light-emitting element may further include an electron transport layer between the organic emitting layer and the second electrode, wherein the thickness of the hole transport layer is less than the thickness of the electron transport layer.

[0028] The organic light-emitting element may further include a lower reflective layer between the first electrode and the metal nanoparticles. Attached Figure Description

[0029] The above and other aspects of certain embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0030] Figure 1 This is a schematic plan view of an organic light-emitting display device according to one or more embodiments;

[0031] Figure 2A It is an equivalent circuit diagram of a sub-pixel of a display device according to one or more embodiments;

[0032] Figure 2B It is an equivalent circuit diagram of a sub-pixel of a display device according to one or more embodiments;

[0033] Figure 3 This is a schematic cross-sectional view of a portion of an organic light-emitting display device according to one or more embodiments;

[0034] Figure 4 This is a schematic diagram of a stacked structure of organic light-emitting elements according to one or more embodiments;

[0035] Figure 5 This is a schematic diagram of a stacked structure of organic light-emitting elements according to one or more embodiments; and

[0036] Figure 6 This is a schematic diagram of a stacked structure of organic light-emitting elements according to one or more embodiments. Detailed Implementation

[0037] Various aspects of some embodiments of this disclosure and their implementation methods can be more readily understood by referring to the detailed description and accompanying drawings of the embodiments. The described embodiments are provided as examples so that this disclosure will be comprehensive and complete, and will fully convey aspects of this disclosure to those skilled in the art. Accordingly, redundant processes, elements, and techniques that are irrelevant or unrelated to the description of the embodiments or are not essential for a full understanding of aspects of this disclosure by those skilled in the art may be omitted. Unless otherwise stated, the same reference numerals, characters, or combinations thereof denote the same elements throughout the drawings and written description, and therefore repeated descriptions may be omitted.

[0038] The described embodiments may have various modifications and may be embodied in different forms, and should not be construed as being limited to the embodiments shown herein. The terms "can," "may," or "may not" are used in the description of embodiments to correspond to one or more embodiments of this disclosure.

[0039] In view of the overall content of this disclosure, those skilled in the art will understand that each suitable feature of the various embodiments of this disclosure may be combined in whole or in part or with one another, and may be technically interlocked and operated in a variety of suitable ways, and each embodiment may be implemented independently of one another or in combination with one another in any suitable way, unless otherwise stated or implied.

[0040] In the accompanying drawings, the relative dimensions of elements, layers, and regions may be exaggerated for clarity and / or descriptive purposes. In other words, this disclosure is not limited to the dimensions and thicknesses of elements shown in the drawings arbitrarily for ease of description. Additionally, the use of crosshairs and / or shading in the drawings is generally provided to clarify boundaries between adjacent elements. Therefore, unless specified otherwise, the presence or absence of crosshairs or shading does not convey or indicate any preference or requirement for particular materials, material properties, dimensions, scales, commonalities between elements, and / or any other characteristics, properties, or characteristics of the elements.

[0041] This document describes various embodiments with reference to cross-sectional views illustrating schematic examples and / or intermediate structures. Therefore, variations in the shapes shown in the illustrations should be expected due to factors such as manufacturing techniques and / or tolerances. Furthermore, the specific structural or functional descriptions disclosed herein are merely illustrative and are intended to describe embodiments based on the concepts of this disclosure. Therefore, the embodiments disclosed herein should not be construed as limited to the shapes of the elements, layers, or regions shown, but rather include shape deviations caused, for example, by manufacturing processes.

[0042] For example, an injection region shown as rectangular will typically have circular or curved features and / or a gradient of injection concentration at its edges rather than a binary variation from the injection region to the non-injection region. Similarly, a buried region formed by injection can result in some injection in the region between the buried region and the surface through which the injection is carried out.

[0043] For ease of explanation, spatial relative terms such as “below,” “under,” “lower,” “lower side,” “below,” “above,” “above,” “higher,” “upper side,” and “side” (e.g., as in “sidewall”) are used herein to describe the relationship of one element or feature relative to another element(s) as shown in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of the device in use or operation, other than those depicted in the drawings. For example, if the device in the drawings is flipped, the element described as “below,” “under,” or “below” other elements or features will be oriented “above” the other elements or features. Thus, the example terms “below” and “below” can encompass both upper and lower orientations. The device may be oriented in other ways (e.g., rotated 90 degrees or oriented in other orientations), and the spatial relative descriptors used herein should be interpreted accordingly. Similarly, when a first component is described as being arranged “on” a second component, this means that the first component is arranged on the upper or lower side of the second component, and not limited to being on the upper side of the second component based on the direction of gravity.

[0044] Furthermore, the term "in a plan view" refers to the view of a portion of an object from above, and the term "in a schematic cross-sectional view" refers to the view of a schematic cross-section taken by vertically cutting the portion of the object from the side. The term "overlapping" or "overlapping" means that the first object may be above, below, or to the side of the second object, or vice versa. Additionally, the term "overlapping" may include layering, stacking, facing, variations thereof, extending over, covering, or partially covering, or any other suitable terminology known and understood by one of ordinary skill in the art. The expression "non-overlapping" may include meanings such as "separated from," "beside," or "offset from," and any other suitable equivalent meaning that one of ordinary skill in the art would understand and understand. The term "facing," variations thereof, may mean that the first object may be directly or indirectly opposite the second object. In the case where a third object is located between the first and second objects, the first and second objects may be understood as indirectly opposite each other, although still facing each other.

[0045] It will be understood that when an element, layer, region, or component is referred to as "formed on," "on," "connected to," or "(operably or communicatively) coupled to" another element, layer, region, or component," it can be directly formed on, directly connected to, or coupled to that other element, layer, region, or component, or indirectly formed on, indirectly connected to, or coupled to that other element, layer, region, or component, such that one or more intermediary elements, layers, regions, or components may be present. Additionally, this can collectively refer to direct or indirect coupling or connection, as well as integral or non-integral coupling or connection. For example, when a layer, region, or component is referred to as "electrically connected" or "electrically coupled" to another layer, region, or component, it can be directly electrically connected or coupled to that other layer, region, or component, or one or more intermediary layers, regions, or components may be present. One or more intermediary components may include switches, resistors, and / or capacitors, etc. In describing embodiments, unless explicitly described as a direct connection, the term "connection" refers to an electrical connection, and "direct connection / direct coupling" or "directly on" means that one component is directly connected to or coupled to another component or on another component without the need for an intermediary component.

[0046] Furthermore, in this specification, when a portion of a layer, film, region, or plate is formed on another portion, the forming direction is not limited to the upward direction, but includes forming the portion on a side surface or in a downward direction. Conversely, when a portion of a layer, film, region, or plate is formed "below" another portion, this includes not only the case where the portion is "directly below" the other portion, but also the case where there is another portion between the two portions. Similarly, other expressions describing the relationship between components, such as "between," "immediately between," "adjacent to," and "directly adjacent to," can be interpreted in a similar manner. It will be understood that when an element or layer is referred to as being "between" two elements or layers, it can be the only element or layer between those two elements or layers, or there may be one or more intervening elements or layers.

[0047] For the purposes of this disclosure, expressions such as “at least one of” or “any one of” or “one or more of” modify the entire list of elements when placed after a list of elements, without modifying any individual element in that list. For example, “at least one of X, Y, and Z” and “at least one selected from the group consisting of X, Y, and Z” can be interpreted as only X, only Y, only Z, any combination of two or more of X, Y, and Z such as XYZ, XYY, YZ, and ZZ, or any variation thereof. Similarly, the expression “at least one of A and B” can include A, B, or A and B. As used herein, “or” generally means “and / or”, and the term “and / or” includes any and all combinations of one or more items in the relevant list. For example, the expression “A and / or B” can include A, B, or A and B. Similarly, expressions such as “at least one of”, “multiple”, “one of”, and other prepositional phrases modify the entire list of elements when placed before or after a list of elements, without modifying any individual element in that list. Unless otherwise stated, when “C to D” is stated, it means above C and below D.

[0048] It will be understood that although the terms “first,” “second,” “third,” etc., may be used herein to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms do not correspond to a particular order, position, or advantage, and are used only to distinguish one element, component, part, area, region, layer, segment, or part from another element, component, part, area, region, layer, segment, or part. Therefore, the first element, component, area, layer, or segment described below may be referred to as the second element, component, area, layer, or segment without departing from the spirit and scope of this disclosure. Describing an element as a “first” element does not require or imply the existence of a second element or other elements. The terms “first,” “second,” etc., may also be used herein to distinguish elements of different categories or sets. For the sake of brevity, the terms “first,” “second,” etc., may respectively represent “first category (or first set),” “second category (or second set),” etc.

[0049] The terminology used herein is for the purpose of describing embodiments only and is not intended to limit this disclosure. As used herein, the singular form “a” is intended to include the plural form as well as the plural form, unless the context clearly indicates otherwise. It will be further understood that, when used in this specification, the terms “comprising,” “having,” and “including” specify the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof.

[0050] As used herein, the terms “substantially,” “approximately,” “approximately,” and similar terms are used as approximate terms rather than terms of degree and are intended to describe the inherent deviations of measured or calculated values ​​that will be recognized by those skilled in the art. For example, “substantially” can include a range of ±5% of the corresponding value. Taking into account the measurement in question and the error associated with a particular quantity of measurement (i.e., limitations of the measurement system), “approximately” or “approximately” as used herein includes stated values ​​and means within an acceptable range of deviation for that particular value as determined by those skilled in the art. For example, “approximately” may mean within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of the stated value. Furthermore, when describing embodiments of this disclosure, the use of “may” refers to “one or more embodiments of this disclosure.”

[0051] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will also be understood that, unless expressly defined herein, terms such as those defined in common dictionaries shall be interpreted as having the same meaning as they have in the relevant field and / or the context of this specification, and shall not be interpreted in an idealized or overly formal sense.

[0052] Figure 1 This is a schematic plan view of an organic light-emitting display device according to one or more embodiments.

[0053] Multiple pixels (PX) can be arranged in the display area DA of the substrate 100, wherein each pixel PX includes an organic light-emitting element (OLED) (see...). Figure 2A Each pixel PX can represent a subpixel, and a pixel PX can be configured to emit, for example, red, green, blue, or white light. A pixel PX can be implemented using an organic light-emitting element (OLED), and the OLED can be driven by a pixel circuit connected to it. The pixel circuit can include a storage capacitor and multiple thin-film transistors (TFTs). The number of TFTs included in a pixel circuit can be one to seven. However, various modifications are possible.

[0054] The edges of the display area DA can generally have a shape similar to a rectangle or a square. Correspondingly, the substrate 100 can also generally have a shape similar to a rectangle or a square. The edges of the display area DA can have shapes such as circular, elliptical, or other polygonal shapes.

[0055] Various wirings configured to transmit electrical signals to be applied to the display area DA can be arranged in the peripheral area PA of the substrate 100. Thin-film transistors may also be provided in the peripheral area PA. In this case, the thin-film transistors arranged in the peripheral area PA may be part of a circuit configured to control the electrical signals applied to the display area DA.

[0056] Figure 2A and Figure 2B It is an equivalent circuit diagram of a sub-pixel of a display device according to one or more embodiments.

[0057] refer to Figure 2A The organic light-emitting element (OLED) corresponding to the sub-pixel can be electrically connected to the pixel circuit PC, and the pixel circuit PC can include a first transistor T1, a second transistor T2, and a storage capacitor Cst. The pixel circuit PC can be electrically connected to signal lines and voltage lines. The signal lines can include gate lines (such as a first scan line SL1) and data lines DL, and the voltage lines can include a first voltage line VDDL.

[0058] The second transistor T2 can be electrically connected to the first scan line SL1 and the data line DL. The first scan line SL1 can be configured to provide a first scan signal GW to the gate electrode of the second transistor T2. The second transistor T2 can be configured to transmit a data signal Dm to the first transistor T1 according to the first scan signal GW input from the first scan line SL1, wherein the data signal Dm is input from the data line DL.

[0059] The storage capacitor Cst can be electrically connected to the second transistor T2 and the first voltage line VDDL, and can be configured to store a voltage corresponding to the difference between the voltage transmitted from the second transistor T2 and the first power supply voltage VDD supplied by the first voltage line VDDL.

[0060] The first transistor T1 is a driving transistor and is configured to control the driving current flowing through the organic light-emitting element (OLED). The first transistor T1 can be connected to a first voltage line VDDL and a storage capacitor Cst. The first transistor T1 can be configured to control the driving current flowing from the first voltage line VDDL to the OLED in response to the voltage stored in the storage capacitor Cst. The OLED can be configured to emit light with a corresponding brightness (e.g., a preset brightness) corresponding to the driving current. A first electrode of the OLED can be electrically connected to the first transistor T1, and a second electrode can be electrically connected to a second voltage line VSSL configured to supply a second power supply voltage VSS.

[0061] Despite Figure 2AThe image shows a pixel circuit PC comprising two transistors and a storage capacitor, but a pixel circuit PC may include three or more transistors.

[0062] refer to Figure 2B The pixel circuit PC may include a first transistor T1, a second transistor T2, a third transistor T3, a fourth transistor T4, a fifth transistor T5, a sixth transistor T6, a seventh transistor T7, and a storage capacitor Cst.

[0063] The pixel circuit PC can be electrically connected to signal lines and voltage lines. Signal lines may include gate lines (such as the first scan line SL1, the second scan line SL2, the third scan line SL3, and the transmit control line EL) and data lines DL. Voltage lines may include the first initialization voltage line VIL1, the second initialization voltage line VIL2, and the first voltage line VDDL.

[0064] The first voltage line VDDL can be configured to transmit a first power supply voltage VDD to a first transistor T1. The first initialization voltage line VIL1 can be configured to transmit a first initialization voltage Vint to the pixel circuit PC, wherein the first initialization voltage Vint initializes the first transistor T1. The second initialization voltage line VIL2 can be configured to transmit a second initialization voltage Vaint to the pixel circuit PC, wherein the second initialization voltage Vaint initializes the first electrode of the organic light-emitting element OLED.

[0065] The first transistor T1 is electrically connected to the first voltage line VDDL via the fifth transistor T5, and is electrically connected to the organic light-emitting element OLED via the sixth transistor T6. The first transistor T1 acts as a driving transistor, receiving the data signal Dm according to the switching operation of the second transistor T2 and supplying driving current to the organic light-emitting element OLED.

[0066] The second transistor T2 is a data write transistor and is electrically connected to the first scan line SL1 and the data line DL. The second transistor T2 can be electrically connected to the first voltage line VDDL via the fifth transistor T5. The second transistor T2 is turned on according to the first scan signal GW transmitted through the first scan line SL1 and performs a switching operation to transmit the data signal Dm to the first node N1, the data signal Dm being transmitted through the data line DL.

[0067] The third transistor T3 can be electrically connected to the first scan line SL1 and to the organic light-emitting element OLED via the sixth transistor T6. The third transistor T3 can be turned on according to the first scan signal GW to connect the first transistor T1 diode, wherein the first scan signal GW is transmitted through the first scan line SL1.

[0068] The fourth transistor T4 is the first initialization transistor and is electrically connected to the third scan line SL3 and the first initialization voltage line VIL1. The fourth transistor T4 can be turned on according to the third scan signal GI to initialize the voltage at the gate electrode of the first transistor T1 by transmitting the first initialization voltage Vint from the first initialization voltage line VIL1 to the gate electrode of the first transistor T1, wherein the third scan signal GI is transmitted through the third scan line SL3. The third scan signal GI can correspond to the first scan signal of another pixel circuit arranged in the row preceding the associated pixel circuit PC.

[0069] The fifth transistor T5 can be an operation control transistor, and the sixth transistor T6 can be an emission control transistor. The fifth transistor T5 and the sixth transistor T6 can be electrically connected to the emission control line EL, and can be turned on concurrently or substantially simultaneously according to the emission control signal EM transmitted through the emission control line EL, and can form a current path such that the drive current flows in the direction from the first voltage line VDDL to the organic light-emitting element OLED.

[0070] The seventh transistor T7 acts as the second initialization transistor and can be electrically connected to the second scan line SL2, the second initialization voltage line VIL2, and the sixth transistor T6. The seventh transistor T7 is turned on according to the second scan signal GB transmitted through the second scan line SL2 and is configured to transmit the second initialization voltage Vaint from the second initialization voltage line VIL2 to the first electrode of the organic light-emitting element OLED, thereby initializing the first electrode of the organic light-emitting element OLED.

[0071] The storage capacitor Cst may include a first storage electrode CE1 and a second storage electrode CE2. The first storage electrode CE1 is electrically connected to the gate electrode of the first transistor T1, and the second storage electrode CE2 is electrically connected to the first voltage line VDDL. The storage capacitor Cst can maintain the voltage applied to the gate electrode of the first transistor T1 by storing and holding a voltage corresponding to the difference between the voltages connected to the gate electrode of the first transistor T1 and the opposite ends of the first voltage line VDDL, respectively.

[0072] Despite Figure 2B The diagram shows multiple transistors T1, T2, T3, T4, T5, T6, and T7 as P-type transistors, but this disclosure is not limited thereto. At least one of the multiple transistors T1, T2, T3, T4, T5, T6, and T7 may be an N-type transistor. However, various modifications are possible.

[0073] In one or more embodiments, at least one of the plurality of transistors T1, T2, T3, T4, T5, T6, and T7 may include a semiconductor layer comprising oxide, and one or more of the other transistors may include a semiconductor layer comprising silicon. As an example, the third transistor T3 and the fourth transistor T4 may include oxide semiconductor layers, and the remaining transistors may include silicon semiconductor layers. However, this disclosure is not limited thereto. All of the plurality of transistors T1, T2, T3, T4, T5, T6, and T7 may include silicon semiconductor layers.

[0074] Figure 3 This is a schematic cross-sectional view of a portion of an organic light-emitting display device according to one or more embodiments.

[0075] refer to Figure 3 The organic light-emitting display device includes a substrate 100, thin-film transistors TFT1 and TFT2 located on the substrate 100, and organic light-emitting elements 300 electrically connected to the thin-film transistors TFT1 and TFT2 (as used herein, "located on" can mean "above"). Additionally, the organic light-emitting display device may further include various insulating layers 111, 112, 113, 115, 118, and 119, and a storage capacitor Cst.

[0076] The substrate 100 may comprise various materials such as glass, metal, or plastic. In one or more embodiments, where the substrate 100 is flexible, the substrate 100 may comprise a polymer resin, including polyethersulfone (PES), polyacrylate (PAE), polyetherimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyarylate (PAR), polyimide (PI), polycarbonate (PC), or cellulose acetate propionate (CAP).

[0077] A buffer layer 111 may be disposed on the substrate 100 to reduce or block the infiltration of foreign matter, moisture, or external air from beneath the substrate 100, and may provide a flat surface on the substrate 100. The buffer layer 111 may comprise inorganic materials, organic materials, or organic / inorganic composite materials, and may comprise a single layer or multiple layers containing both inorganic and organic materials, wherein the inorganic materials include oxides or nitrides. In one or more embodiments, a barrier layer may be further disposed between the substrate 100 and the buffer layer 111, the barrier layer being used to reduce or block the infiltration of external air. In one or more embodiments, the buffer layer 111 may comprise silicon oxide (SiO2) or silicon nitride (SiN). x ).

[0078] The first thin-film transistor TFT1 and / or the second thin-film transistor TFT2 may be located on the buffer layer 111. The first thin-film transistor TFT1 includes a semiconductor layer A1, a gate electrode G1, a source electrode S1, and a drain electrode D1. The second thin-film transistor TFT2 includes a semiconductor layer A2, a gate electrode G2, a source electrode S2, and a drain electrode D2.

[0079] The first thin-film transistor TFT1 can be connected to the organic light-emitting element 300 to act as a driving thin-film transistor configured to drive the organic light-emitting element 300. The second thin-film transistor TFT2 can be connected to the data line DL to act as a switching thin-film transistor. Although two thin-film transistors are shown in the figure, this disclosure is not limited thereto. The number of thin-film transistors can be modified in various ways.

[0080] Semiconductor layers A1 and A2 may comprise amorphous silicon or polycrystalline silicon. In one or more other embodiments, semiconductor layers A1 and A2 may comprise an oxide of at least one of indium (In), gallium (Ga), tin (Sn), zirconium (Zr), vanadium (V), hafnium (Hf), cadmium (Cd), germanium (Ge), hafnium (Cr), titanium (Ti), and zinc (Zn). Semiconductor layers A1 and A2 may comprise a channel region, a source region, and a drain region, wherein the source and drain regions are doped with impurities.

[0081] Gate electrodes G1 and G2 are located above semiconductor layers A1 and A2, wherein a first gate insulating layer 112 is located between gate electrodes G1 and G2 and semiconductor layers A1 and A2. Gate electrodes G1 and G2 may include at least one of molybdenum (Mo), aluminum (Al), copper (Cu), and titanium (Ti), and may comprise a single layer or multiple layers. As an example, gate electrodes G1 and G2 may comprise a single Mo layer.

[0082] The first gate insulating layer 112 may include silicon oxide (SiO2) or silicon nitride (SiN). x ), silicon oxynitride (SiO) x N y Aluminum oxide (Al2O3), titanium oxide (TiO2), tantalum oxide (Ta2O5), hafnium oxide (HfO2), or zinc oxide (ZnO) x ZnO x It can be ZnO2 and / or ZnO.

[0083] A second gate insulating layer 113 may be provided to cover the gate electrodes G1 and G2. The second gate insulating layer 113 may include silicon oxide (SiO2) or silicon nitride (SiN). x ), silicon oxynitride (SiO) x N y Aluminum oxide (Al2O3), titanium oxide (TiO2), tantalum oxide (Ta2O5), hafnium oxide (HfO2), or zinc oxide (ZnO)x ).

[0084] The first storage electrode CE1 of the storage capacitor Cst may overlap with the first thin-film transistor TFT1. As an example, the gate electrode G1 of the first thin-film transistor TFT1 may serve as the first storage electrode CE1 of the storage capacitor Cst. However, this disclosure is not limited thereto. The storage capacitor Cst may not overlap with the first thin-film transistor TFT1, but may be separate from the first thin-film transistor TFT1 and the second thin-film transistor TFT2.

[0085] The second storage electrode CE2 of the storage capacitor Cst overlaps with the first storage electrode CE1, with a second gate insulating layer 113 between them. In this case, the second gate insulating layer 113 can act as the dielectric layer of the storage capacitor Cst. The second storage electrode CE2 may include a conductive material comprising molybdenum (Mo), aluminum (Al), copper (Cu), and / or titanium (Ti), and may have a single-layer structure or a multilayer structure comprising the above materials. As an example, the second storage electrode CE2 may be a single Mo layer or a multilayer of Mo / Al / Mo.

[0086] An interlayer insulating layer 115 is formed over the entire surface of the substrate 100 to cover the second storage electrode CE2. The interlayer insulating layer 115 may include silicon oxide (SiO2) or silicon nitride (SiN). x ), silicon oxynitride (SiO) x N y Aluminum oxide (Al2O3), titanium oxide (TiO2), tantalum oxide (Ta2O5), hafnium oxide (HfO2), or zinc oxide (ZnO) x ).

[0087] Source electrodes S1 and S2, and drain electrodes D1 and D2 are located on the interlayer insulating layer 115. Source electrodes S1 and S2, and drain electrodes D1 and D2 may each comprise a conductive material containing molybdenum (Mo), aluminum (Al), copper (Cu), and / or titanium (Ti), and may comprise a single layer or multiple layers containing the aforementioned materials. As an example, source electrodes S1 and S2, and drain electrodes D1 and D2 may have a Ti / Al / Ti multilayer structure.

[0088] The planarization layer 118 may be located on the source electrodes S1 and S2 and the drain electrodes D1 and D2, and the organic light-emitting element 300 may be located on the planarization layer 118. The organic light-emitting element 300 includes a first electrode 310, an intermediate layer 320 and a second electrode 330, wherein the intermediate layer 320 includes an organic emitting layer.

[0089] The planarization layer 118 may have a flat upper surface, such that the first electrode 310 is formed substantially flat. The planarization layer 118 may comprise a single layer or multiple layers containing organic or inorganic materials. The planarization layer 118 may comprise general polymers such as benzocyclobutene (BCB), polyimide, hexamethyldisiloxane (HMDSO), polymethyl methacrylate (PMMA), or polystyrene (PS), polymer derivatives having phenolic groups, acryloyl polymers, imide polymers, aryl ether polymers, amide polymers, fluorinated polymers, p-xylene polymers, vinyl alcohol polymers, and / or mixtures thereof. The planarization layer 118 may comprise silicon oxide (SiO2), silicon nitride (SiN2), etc. x ), silicon oxynitride (SiO) x N y Aluminum oxide (Al2O3), titanium oxide (TiO2), tantalum oxide (Ta2O5), hafnium oxide (HfO2), or zinc oxide (ZnO) x After the planarization layer 118 is formed, chemical mechanical polishing can be performed to provide a flat upper surface.

[0090] An opening exists in the planarization layer 118 that exposes one of the source electrode S1 and the drain electrode D1 of the first thin-film transistor TFT1. The first electrode 310 is electrically connected to the first thin-film transistor TFT1 by contacting the source electrode S1 or the drain electrode D1 through the opening.

[0091] A pixel defining layer 119 may be located on the first electrode 310. The pixel defining layer 119 defines pixels by including openings 119OP corresponding to each sub-pixel, i.e., openings 119OP expose at least the central portion of the first electrode 310. Additionally, the pixel defining layer 119 can reduce or prevent the possibility of arcing or similar phenomena between the edge of the first electrode 310 and the second electrode 330 by increasing the distance between them. The pixel defining layer 119 may comprise organic materials such as polyimide or hexamethyldisiloxane (HMDSO).

[0092] In one or more embodiments, spacers may be located on the pixel defining layer 119. The spacers can be used to reduce or prevent the possibility of mask imprinting that may occur during the masking process required to form the intermediate layer 320 of the organic light-emitting element 300. The spacers may comprise organic materials such as polyimide or hexamethyldisiloxane (HMDSO). The spacers may comprise the same material as the pixel defining layer 119 and may be formed concurrently with or substantially simultaneously with the pixel defining layer 119. In this case, a halftone mask may be used.

[0093] The intermediate layer 320 of the organic light-emitting element 300 may include an organic emitting layer (EML) (see...). Figure 4 The organic emitting layer (EML) may include an organic material comprising a fluorescent or phosphorescent material configured to emit red, green, blue, or white light. The organic emitting layer (EML) may include a polymeric organic material or a low molecular weight organic material. Functional layers may optionally be further disposed below and above the organic emitting layer (EML), including a hole transport layer (HTL), a hole injection layer (HIL), an electron transport layer (ETL), and / or an electron injection layer (EIL). The intermediate layer 320 may be configured to correspond to each of the plurality of first electrodes 310. However, this disclosure is not limited thereto. The intermediate layer 320 may include a layer integrally distributed across the plurality of first electrodes 310. However, various modifications may be made.

[0094] The second electrode 330 can be a transparent electrode or a reflective electrode. In one or more embodiments, the second electrode 330 can be a transparent or translucent electrode and can include a metal thin film containing Li, Ca, Al, Ag, Mg or compounds thereof (e.g., LiF) or a material having a multilayer structure such as LiF / Ca or LiF / Al and having a small work function. Additionally, a transparent conductive oxide (TCO) layer such as indium tin oxide (ITO), indium zinc oxide (IZO), ZnO, or In2O3 can be further disposed on the metal thin film. The second electrode 330 can be arranged throughout the display area DA and the peripheral area PA, and is located on the intermediate layer 320 and the pixel defining layer 119. The second electrode 330 can be integrally formed throughout a plurality of organic light-emitting elements 300 to correspond to a plurality of first electrodes 310. A more specific construction of the organic light-emitting element 300 according to one or more embodiments is described below.

[0095] A thin-film encapsulation layer 400 may be further disposed on the organic light-emitting element 300, wherein the thin-film encapsulation layer 400 is configured to encapsulate the display area DA. The thin-film encapsulation layer 400 may be configured to protect the organic light-emitting element 300 from external moisture or oxygen by covering the display area DA. The thin-film encapsulation layer 400 may include a first inorganic encapsulation layer 410, an organic encapsulation layer 420, and a second inorganic encapsulation layer 430.

[0096] The first inorganic encapsulation layer 410 may cover the second electrode 330 and may include ceramics, metal oxides, metal nitrides, metal carbides, metal oxide nitrides, indium oxide (In₂O₃), tin oxide (SnO₂), indium tin oxide (ITO), silicon oxide, silicon nitride, and / or silicon oxynitride, etc. When needed, other layers, including the capping layer, may be disposed between the first inorganic encapsulation layer 410 and the second electrode 330. Because the first inorganic encapsulation layer 410 is formed along the underlying structure, its upper surface is not flat, such as... Figure 3 As shown in the image.

[0097] The organic encapsulation layer 420 may cover the first inorganic encapsulation layer 410, and unlike the first inorganic encapsulation layer 410, the upper surface of the organic encapsulation layer 420 may be approximately flat. For example, the upper surface of the portion of the organic encapsulation layer 420 corresponding to the display area DA may be approximately flat. The organic encapsulation layer 420 may include at least one material selected from acrylic acid, methacrylic acid, polyester, polyethylene, polypropylene, polyethylene terephthalate (PET), polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, and hexamethyldisiloxane.

[0098] The second inorganic encapsulation layer 430 may cover the organic encapsulation layer 420 and may include ceramics, metal oxides, metal nitrides, metal carbides, metal oxide nitrides, indium oxide (In2O3), tin oxide (SnO2), indium tin oxide (ITO), silicon oxide, silicon nitride, and / or silicon oxynitride, etc. Because the second inorganic encapsulation layer 430 contacts the first inorganic encapsulation layer 410 at the edge outside the display area DA, the organic encapsulation layer 420 is not exposed to the outside.

[0099] Because the thin-film encapsulation layer 400 includes a first inorganic encapsulation layer 410, an organic encapsulation layer 420, and a second inorganic encapsulation layer 430, even if cracks appear inside the thin-film encapsulation layer 400, the multilayer structure prevents the cracks from connecting between the first inorganic encapsulation layer 410 and the organic encapsulation layer 420, or between the organic encapsulation layer 420 and the second inorganic encapsulation layer 430. This structure prevents or reduces the formation of external moisture or oxygen through the display area DA.

[0100] Various functional layers, such as a touch screen layer and a polarizing film, can be further disposed on the upper part of the thin film encapsulation layer 400, and a capping layer configured to improve light efficiency can be further disposed between the second electrode 330 and the thin film encapsulation layer 400.

[0101] In the following, a more specific construction of the organic light-emitting element 300 according to one or more embodiments is described.

[0102] Figure 4 This is a schematic diagram of a stacked structure of organic light-emitting elements 300 according to one or more embodiments. (Reference) Figure 4 The organic light-emitting element 300 may include a first electrode 310, an intermediate layer 320 and a second electrode 330 stacked in sequence, and the intermediate layer 320 may include a hole transport layer HTL, an organic emission layer EML and an electron transport layer ETL in which metal nanoparticles NP are located in the lower portion.

[0103] That is, the organic light-emitting element 300 according to one or more embodiments includes a first electrode 310 and a second electrode 330 facing each other, an organic emission layer EML located between the first electrode 310 and the second electrode 330, a hole transport layer HTL located between the first electrode 310 and the organic emission layer EML, and metal nanoparticles NP located on the first electrode 310. In one or more embodiments, the first distance d1 between the organic emission layer EML (e.g., a point at or near the center of the organic emission layer EML) and the lower surface of the metal nanoparticles NP may be smaller than the distance between the organic emission layer EML and the second electrode 330.

[0104] The first electrode 310 can serve as an anode electrode and may include a material with a large work function for rapidly injecting holes into the organic emitter layer (EML). The first electrode 310 may have a work function of approximately 4.0 eV to approximately 5.1 eV. The first electrode 310 may be a reflective electrode, a semi-transparent electrode, or a transmissive electrode. When the first electrode 310 includes a transmissive electrode, it may include ITO, IZO, tin oxide (SnO2), ZnO, and / or In2O3, etc. When the first electrode 310 includes a reflective electrode, it may include a reflective layer comprising Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or compounds thereof, and a transparent layer comprising ITO, IZO, ZnO, or In2O3 on the reflective layer. In one or more embodiments, the first electrode 310 may have a single-layer or multilayer structure with two or more layers. As an example, the first electrode 310 may have a two-layer structure of ITO / Ag or a three-layer structure of ITO / Ag / ITO. The topmost layer of the first electrode 310 includes ITO, and the work function of the ITO can be from approximately 4.9 eV to approximately 5.1 eV. In this case, the work function of the ITO can be adjusted by plasma processing.

[0105] The intermediate layer 320 includes a hole transport layer HTL containing metal nanoparticles NP in the lower portion, an organic emission layer EML, and an electron transport layer ETL.

[0106] Metal nanoparticles (NPs) can be used to extract light in a direction toward the second electrode 330, wherein the light is generated by surface plasmons appearing on the surface of the first electrode 310. The metal nanoparticles (NPs) can be located in the lower portion of the hole transport layer (HTL). Alternatively, it can be understood that the metal nanoparticles (NPs) are located on the first electrode 310, and the hole transport layer (HTL) covers the metal nanoparticles (NPs).

[0107] Metal nanoparticles (NPs) may include one of Ag, Au, Co, Cu, their alloys, and their compounds. Metal nanoparticles (NPs) may have a height and / or width ranging from approximately 5 nm to approximately 500 nm. Metal nanoparticles (NPs) may be separated from each other. Metal nanoparticles (NPs) may be arranged periodically or non-periodically.

[0108] Metal nanoparticles (NPs) can be formed by depositing metal and then etching it, or by depositing metal and then performing a heat treatment process. Deposition can be performed by, for example, plasma-enhanced CVD (PECVD) or chemical vapor deposition (CVD). The conditions for deposition (e.g., CVD or PECVD) are not particularly limited. The etching process can be either dry etching or wet etching.

[0109] Even when the metal nanoparticles NP are located on the second electrode 330, light generated by surface plasmons can still be extracted. However, when the metal nanoparticles NP are located on the second electrode 330, the organic light-emitting element 300 may be damaged during the formation of the metal nanoparticles NP because the metal nanoparticles NP should be formed after the organic layer included in the organic light-emitting element 300 is formed. Accordingly, in one or more embodiments, the metal nanoparticles NP may be located below the organic emitting layer EML.

[0110] A hole transport layer (HTL) can be configured to cover metal nanoparticles (NPs). It is understood that the metal nanoparticles (NPs) are located in the lower portion of the hole transport layer (HTL). The hole transport layer (HTL) can include known hole transport materials. As examples, the hole transport layer (HTL) can include carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, fluorinated derivatives, and triphenylamine derivatives such as TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine), TCTA (4,4',4”-tris(N-carbazolyl)triphenylamine), NPB (N,N'-bis(1-naphthyl)-N,N'-diphenylbenzidine), or TAPC (4,4'-cyclohexene bis[N,N-bis(4-methylphenyl)aniline]).

[0111] In one or more embodiments, the hole injection layer may be further included between the first electrode 310 and the organic emitter layer EML. The hole injection layer may be located between the hole transport layer HTL and the organic emitter layer EML or between the first electrode 310 and the hole transport layer HTL.

[0112] The hole injection layer may include at least one of the following: copper phthalocyanine compounds, DNTPD (N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4'-diamine), m-MTDATA (4,4',4"-tris(3-methylphenylamino)triphenylamine), TDATA (4,4',4"-tris(N,N-diphenylamino)triphenylamine), 2-TNATA (4,4',4"-tri{N,-(2-naphthyl)-N-phenylamino}-triphenylamine), PEDOT / PSS (poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate)), PANI / DBSA (polyaniline / dodecylbenzenesulfonic acid), PANI / CSA (polyaniline / camphorsulfonic acid), and PANI / PSS ((polyaniline) / poly(4-styrenesulfonate)).

[0113] Hole transport layer (HTL) and hole injection layer can be formed using various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodget, inkjet printing, laser printing, and laser-induced thermal imaging (LITI).

[0114] Organic emission layers (EMLs) can include low- or high-molecular-weight materials that emit fluorescence or phosphorescence. In an organic emission layer EML, holes and electrons injected from the first electrode 310 and the second electrode 330 recombine to form excitons, and light is emitted when the excitons transition to the ground state. In this case, emission wavelengths such as green, red, and blue can be determined based on the materials used in the organic emission layer EML.

[0115] In one or more embodiments, the organic emission layer (EML) may include copper phthalocyanine (CuPc), N,N'-di(naphthyl-1-yl)-N,N'-diphenyl-benzidine (NPB), tris-(8-hydroxyquinoline)aluminum (Alq3), PPV (polyphenylenevinyl chloride) materials, or polyfluorene materials. The organic emission layer EML can be formed by vacuum deposition, screen printing, inkjet printing, or laser-induced thermal imaging (LITI).

[0116] An electron transport layer (ETL) may be located between the organic emitter layer (EML) and the second electrode 330. The ETL may comprise a material capable of readily receiving electrons from the second electrode 330. The ETL may include PBP (4-phenylbenzophenone), t-Bu-PBD (2-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), 3TPYMB (tris-[3-(3-pyridyl)trimethylyl]borane), and / or B3PYMPM (bis-4,6-(3,5-di-3-pyridylphenyl)-2-methylpyrimidine). In one or more embodiments, an electron injection layer may be further disposed between the ETL and the second electrode 330.

[0117] The second electrode 330 is located on the electron transport layer (ETL). To obtain a front-facing emission device, the second electrode 330 may comprise a transparent conductive oxide such as ITO, IZO, ZnO, or In2O3. In one or more embodiments, the second electrode 330 may have a high refractive index. As an example, the second electrode 330 may have a refractive index of approximately 2 to approximately 3.

[0118] A low-refractive-index layer 331 may be located on the second electrode 330. The low-refractive-index layer 331 may have a refractive index of approximately 1.2 to approximately 1.6. In one or more embodiments, the low-refractive-index layer 331 may comprise LiF. The second electrode 330 and the low-refractive-index layer 331 may have a stacked structure of high-refractive-index layers / low-refractive-index layers to act as an upper reflective layer DBRa. The upper reflective layer DBRa may be a dispersive Bragg reflector layer. The upper reflective layer DBRa may further comprise a high-refractive-index layer and / or a low-refractive-index layer.

[0119] The metallic reflective layer 333 may be located on the low refractive index layer 331. The metallic reflective layer 333 may include aluminum (Al) or silver (Ag). The metallic reflective layer 333 may be provided as relatively very thin and may act as a semi-transparent reflective layer.

[0120] In one or more embodiments, the organic emitting layer EML may be located above the metal nanoparticle NP, and the vertical distance between the organic emitting layer EML (e.g., a point at or near the center of the organic emitting layer EML) and the lower surface of the metal nanoparticle NP may be set as a first distance d1. The first distance d1 may be a first resonant distance based on the intensity of the light emitted in the organic emitting layer EML. The first distance d1 may be approximately... up to approximately

[0121] When the first distance d1 is When the distance is within a certain range, a hole transport layer (HTL) cannot be sufficiently formed, and the light extraction efficiency may decrease due to the difference from the first resonant distance. When the first distance d1 is approximately... In the above cases, the surface plasmons formed on the surface of the first electrode 310 will not affect the organic emission layer EML.

[0122] Typically, when surface plasmons are formed, the light efficiency may be significantly reduced because the light generated in the organic emission layer EML due to surface plasmons propagates along the surface, and therefore the first electrode 310 on which plasmons are generated is positioned away from the organic emission layer EML.

[0123] Conversely, in one or more embodiments, the organic emission layer EML is disposed close to the first electrode 310, such that surface plasmons instead affect the organic emission layer EML.

[0124] During the extinction process following luminescence, excitons formed in the organic emitter layer (EML) may damage the EML. In one or more embodiments, the lifetime of the organic emitter layer (EML) can be improved because surface plasmons quench the excitons before they damage the EML.

[0125] In other words, because light generated by surface plasmons is extracted in the direction toward the second electrode 330 by arranging metal nanoparticles NP, the light efficiency is improved. Furthermore, the surface plasmons and the organic emission layer EML are arranged close to each other. Accordingly, the lifetime of the organic emission layer EML is improved.

[0126] The distance between the upper surface of the first electrode 310 and the lower surface of the metal reflective layer 333 can be a second distance d2. The second distance d2 can be a second resonant distance based on the intensity of the light emitted in the organic emitting layer EML.

[0127] The organic emitting layer EML can be configured to emit blue light, and the second distance d2 can be approximately up to approximately By adjusting the first distance d1 and / or the second distance d2, color purity and light efficiency can be improved. Accordingly, the thickness t1 of the hole transport layer HTL can be less than the thickness t2 of the electron transport layer ETL. As an example, the thickness t1 of the hole transport layer HTL can be approximately... up to approximately Furthermore, the thickness t2 of the electron transport layer (ETL) can be approximately up to approximately

[0128] Figure 5 This is a schematic diagram of a stacked structure of organic light-emitting elements 300' according to one or more embodiments. Figure 5 In, with Figure 4 The same reference numerals in the accompanying drawings indicate the same components.

[0129] That is, the organic light-emitting element 300' according to one or more embodiments includes a first electrode 310 and a second electrode 330 facing each other, an organic emission layer EML located between the first electrode 310 and the second electrode 330, a hole transport layer HTL located between the first electrode 310 and the organic emission layer EML, and metal nanoparticles NP located on the first electrode 310. The first distance d1 between the organic emission layer EML (e.g., a point in the middle or near the middle of the organic emission layer EML) and the lower surface of the metal nanoparticles NP may be smaller than the distance between the organic emission layer EML and the second electrode 330.

[0130] The first distance d1 can be a first resonant distance based on the intensity of the light emitted in the organic emission layer EML. The first distance d1 can be approximately... up to approximately

[0131] The second electrode 330 may include a reflective metal. As an example, the second electrode 330 may include a thin film comprising lithium (Li), magnesium (Mg), aluminum (Al), silver (Ag), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), LiF / Al, or LiO2 / Al, and may include a reflective semi-transparent electrode. The second electrode 330 may further include a transparent conductive oxide using ITO, IZO, ZnO, or In2O3.

[0132] The distance between the upper surface of the first electrode 310 and the lower surface of the second electrode 330 can be a second distance d2. The second distance d2 can be a second resonant distance based on the intensity of the wavelength of light emitted in the organic emission layer EML. Specifically, the second distance d2 refers to a second resonant distance with respect to the optical length (d2 = 2OL).

[0133] The organic emitting layer EML can be configured to emit blue light, and the second distance d2 can be approximately up to approximately

[0134] A low-refractive-index layer 311 and a high-refractive-index layer 313 may be sequentially located between the first electrode 310 and the metal nanoparticles NP. The low-refractive-index layer 311 may have a refractive index of about 1.2 to about 1.6. In one or more embodiments, the low-refractive-index layer 311 may include LiF. The high-refractive-index layer 313 may have a refractive index of about 2 to about 3. The high-refractive-index layer 313 may include a transparent conductive oxide comprising ITO, IZO, ZnO, or In2O3.

[0135] The low-refractive-index layer 311 and the high-refractive-index layer 313 can serve as the lower reflective layer DBRb. The lower reflective layer DBRb can be a dispersive Bragg reflective layer. The lower reflective layer DBRb can further include a high-refractive-index layer and / or a low-refractive-index layer.

[0136] The thickness of the lower reflective layer DBRb can be set by considering a third distance d3. The third distance d3 is the vertical distance between the organic emitting layer EML (e.g., a point at or near the center of the organic emitting layer EML) and the upper surface of the first electrode 310, and can be a second resonant distance based on the intensity of light emitted in the organic emitting layer EML. The range of the third distance d3 can be from approximately... up to approximately The third distance d3 corresponds to the second resonant distance (d3 = 2CD) of the intensity of the amplitude with respect to wavelength.

[0137] Because the organic light-emitting element 300' introduces metal nanoparticles NP, used to extract light generated by surface plasmon resonance (SPR), onto its front surface, light efficiency can be improved. Since the metal nanoparticles NP are located beneath the organic emission layer (EML), the organic emission layer EML is not damaged during this process. Furthermore, because the organic emission layer EML is positioned close to the SPR, its lifetime can be increased.

[0138] Furthermore, since the organic light-emitting element 300' introduces a lower reflective layer DBRb by taking into account a second resonant distance based on the intensity of light emitted in the organic emitting layer EML, the light efficiency can be improved.

[0139] Figure 6 This is a schematic diagram of a stacked structure of organic light-emitting elements 300” according to one or more embodiments. Figure 6 In, with Figure 4 The same reference numerals in the accompanying drawings indicate the same components.

[0140] That is, the organic light-emitting element 300 according to one or more embodiments includes a first electrode 310 and a second electrode 330 facing each other, an organic emission layer EML located between the first electrode 310 and the second electrode 330, a hole transport layer HTL located between the first electrode 310 and the organic emission layer EML, and metal nanoparticles NP located on the first electrode 310. In one or more embodiments, a first distance d1 between the organic emission layer EML (e.g., a point at or near the center of the organic emission layer EML) and the lower surface of the metal nanoparticles NP may be smaller than the distance between the organic emission layer EML and the second electrode 330.

[0141] The first distance d1 can be a first resonant distance based on the intensity of the light emitted in the organic emission layer EML. The first distance d1 can be approximately... up to approximately

[0142] The organic light-emitting element 300 incorporates both a lower reflective layer DBRb and an upper reflective layer DBRa.

[0143] That is, the low-refractive-index layer 311 and the high-refractive-index layer 313 may be sequentially located between the first electrode 310 and the metal nanoparticles NP. The low-refractive-index layer 311 may have a refractive index of about 1.2 to about 1.6. In one or more embodiments, the low-refractive-index layer 311 may include LiF. The high-refractive-index layer 313 may have a refractive index of about 2 to about 3. The high-refractive-index layer 313 may include a transparent conductive oxide comprising ITO, IZO, ZnO, or In2O3.

[0144] The low-refractive-index layer 311 and the high-refractive-index layer 313 can serve as the lower reflective layer DBRb. The lower reflective layer DBRb can be a dispersive Bragg reflective layer. The lower reflective layer DBRb can further include a high-refractive-index layer and / or a low-refractive-index layer.

[0145] The thickness of the lower reflective layer DBRb can be set by considering a third distance d3. The third distance d3 is the vertical distance between the organic emitting layer EML (e.g., a point at or near the center of the organic emitting layer EML) and the upper surface of the first electrode 310, and can be a second resonant distance based on the intensity of light emitted in the organic emitting layer EML. The third distance d3 can be approximately... up to approximately

[0146] The distance between the upper surface of the first electrode 310 and the lower surface of the metal reflective layer 333 can be a fourth distance d4. The fourth distance d4 can be a third resonant distance based on the intensity of the light emitted in the organic emitting layer EML.

[0147] The organic emitting layer EML can be configured to emit blue light, and the fourth distance d4 can be approximately up to approximately

[0148] Because the organic light-emitting element 300" introduces metal nanoparticles NP for extracting light generated by surface plasmon resonance (SPR) onto its front surface, light efficiency can be improved. Since the metal nanoparticles NP are located below the organic emission layer (EML), the organic emission layer EML is not damaged during this process. Furthermore, because the organic emission layer EML is positioned close to the SPR, its lifetime can be increased.

[0149] In addition, because the organic light-emitting element 300” incorporates an upper reflective layer DBRa and a lower reflective layer DBRb, its light efficiency can be improved.

[0150] As described above, because the organic light-emitting element according to the embodiment includes metal nanoparticles disposed adjacent to the lower portion of the emitting layer, light efficiency and lifetime can be improved.

[0151] The display device according to the embodiments can be included in an electronic device. The electronic device according to the embodiments can display moving or still images, and can be used not only as a display screen for portable electronic devices such as mobile phones, smartphones, tablet PCs, mobile communication terminals, e-notebooks, e-readers, portable multimedia players (PMPs), navigation devices, and ultra-mobile PCs (UMPCs), but also as a display screen for various products such as televisions (TVs), laptops, monitors, billboards, and Internet of Things (IoT) devices. The electronic device according to the embodiments can be used in wearable devices such as smartwatches, watch phones, glasses displays, and head-mounted displays (HMDs). The electronic device according to the embodiments can be used as: a central information display (CID) on a vehicle's instrument panel or a vehicle's central dashboard or instrument cluster; an interior mirror display replacing a vehicle's side mirrors; or a display mounted on the back of the front seat as a rear-seat entertainment system for the vehicle.

[0152] It should be understood that the embodiments described herein should be considered for descriptive purposes only and not for limiting purposes. The description of aspects in each embodiment should typically be considered as applicable to other similar aspects in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, those skilled in the art will understand that various modifications in form and detail may be made thereto without departing from the spirit and scope as defined by the claims (the functional equivalents of which will be included therein).

Claims

1. An organic light-emitting element, comprising: The first and second electrodes face each other. An organic emission layer is located between the first electrode and the second electrode; A hole transport layer is located between the first electrode and the organic emission layer; as well as Metal nanoparticles are positioned above the first electrode. The first distance between the organic emission layer and the lower surface of the metal nanoparticle is smaller than the distance between the organic emission layer and the second electrode.

2. The organic light-emitting element according to claim 1, wherein, The first distance is a first resonant distance relating to the intensity of light generated in the organic emitting layer.

3. The organic light-emitting element according to claim 1, wherein, The first distance is to 4. The organic light-emitting element according to claim 1, further comprising: A metallic reflective layer is placed above the second electrode. Wherein, the second distance between the upper surface of the first electrode and the lower surface of the metal reflective layer is to 5. The organic light-emitting element according to claim 1, further comprising: A low-refractive-index layer is placed above the second electrode and has a refractive index lower than that of the second electrode. The second electrode comprises a transparent conductive oxide and, together with the low refractive index layer, provides an upper reflective layer.

6. The organic light-emitting element according to claim 1, further comprising: An electron transport layer is located between the organic emission layer and the second electrode. The thickness of the hole transport layer is less than the thickness of the electron transport layer.

7. The organic light-emitting element according to claim 1, further comprising: A lower reflective layer is located between the first electrode and the metal nanoparticles.

8. The organic light-emitting element according to claim 1, wherein, The distance between the organic emitting layer and the upper surface of the first electrode is a second resonant distance relating to the intensity of light generated in the organic emitting layer.

9. The organic light-emitting element according to claim 1, further comprising: A metallic reflective layer is placed above the second electrode. Wherein, the distance between the upper surface of the first electrode and the lower surface of the metal reflective layer is to 10. The organic light-emitting element according to claim 9, further comprising: A lower reflective layer is located between the first electrode and the metal nanoparticles.

11. An organic light-emitting display device comprising a plurality of pixels including an organic light-emitting element and at least one thin-film transistor according to any one of claims 1 to 10.

12. An electronic device comprising a display device including an organic light-emitting element according to any one of claims 1 to 10.

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