Display device and electronic device including the same

Abstract

A display device and an electronic device including the same are disclosed. The display device may include: a red pixel, a green pixel, and a blue pixel each including a transistor and an organic light emitting element, in which a capacitance change amount ([Delta] Cap 'max (c, T)) at a maximum value of Equation 10 has a value equal to or greater than 100% with respect to the organic light emitting element, Equation 10 variable c is color, T is temperature, T0 is 25 DEG C, Cap is capacitance, and [Delta] Cap' max (c, T) satisfies Equation 9 [Delta] Cap 'max (c, T) = [Delta] Capmax (c, T) / [Delta] Vmax (c, T), the capacitance change amount ([delta] Capmax (c, T)) expressed on the basis of the maximum value satisfies Equation 6, Equation 6 and the maximum voltage change amount ([delta] Vmax (c, T)) satisfies Equation 8, Equation 8 [delta] Vmax (c, T) = Vmax (c, T) / Vmax (c, T0).

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2024-0129779, filed on September 25, 2024, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] One or more embodiments of this disclosure relate to a display device including an organic light-emitting element and an electronic device including the display device. Background Technology

[0004] Display devices display images, and organic light-emitting diode (OLED) displays have received considerable attention.

[0005] Because organic light-emitting diode (OLED) displays include organic light-emitting elements and are self-emissive, they do not require an additional light source, which distinguishes them from liquid crystal displays, thus reducing thickness and weight. OLED displays exhibit high-quality characteristics such as low power consumption, high brightness, and high response speed.

[0006] An organic light-emitting diode (OLED) display includes a substrate, thin-film transistors (TFTs) on the substrate, an insulating (e.g., electrically insulating) layer between the wiring constituting the TFTs, and an organic light-emitting element for receiving current from the TFTs. Using at least two TFTs enables one organic light-emitting element to emit light. Summary of the Invention

[0007] One or more aspects of embodiments of this disclosure relate to display devices including organic light-emitting elements whose brightness does not change with temperature. One or more aspects of embodiments of this disclosure relate to determining whether brightness changes with temperature based on tests performed on the organic light-emitting element.

[0008] Further aspects of the embodiments 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 practicing the embodiments presented in this disclosure.

[0009] One or more embodiments of this disclosure provide a display device comprising: a red pixel, a green pixel, and a blue pixel, each comprising a transistor and an organic light-emitting element, wherein, relative to the organic light-emitting element, the capacitance change (ΔCap') at the maximum value of Equation 10... max (c,T)) has a value equal to or greater than 100%.

[0010] Equation 10

[0011]

[0012] Where c is color, T is temperature, T0 is 25℃, Cap is capacitance, and ΔCap' max (c,T) satisfies equation 9.

[0013] Equation 9

[0014] ΔCap' max (c,T)=ΔCap max (c,T) / ΔV max (c,T)

[0015] Capacitance change based on the maximum value (ΔCap) max (c,T) satisfies equation 6.

[0016] Equation 6

[0017]

[0018] Maximum voltage change (ΔV) max (c,T) satisfies equation 8.

[0019] Equation 8

[0020] ΔV max (c,T)=V max (c,T) / V max (c,T0)

[0021] For red and green, the change in capacitance at the maximum value (ΔCap') max (c,T) can have a value equal to or greater than 500%.

[0022] The entire voltage range of the operating voltage applied to the organic light-emitting element can have values ​​equal to or greater than -1V and equal to or less than 10V.

[0023] The difference between the electron mobility and hole mobility of the organic layer in an organic light-emitting element can be equal to or greater than 1 e. - 9 cm 2 / V·s and equal to or less than 1e -3 cm 2 / V·s.

[0024] The interfacial barrier value at the boundary between adjacent layers in an organic light-emitting element can have a value equal to or greater than -0.3 eV and equal to or less than 0.5 eV.

[0025] Organic light-emitting elements may include a p-doped hole injection layer, and the doping concentration of the p-doped hole injection layer may be equal to or greater than 0.1% and equal to or less than 5%.

[0026] An organic light-emitting element may include a hole transport layer and a light-emitting layer, and may further include at least one auxiliary layer between the hole transport layer and the light-emitting layer.

[0027] Organic light-emitting elements can have a series structure including a light-emitting layer and a charge-generating layer.

[0028] The charge generation layer (e.g., each of the charge generation layers) can be an n-charge generation layer or a p-charge generation layer, and the n-charge generation layer or the p-charge generation layer can have a value equal to or greater than 0.1 eV and equal to or less than 3.0 eV as the interface barrier value.

[0029] The doping of the n-charge generation layer and / or the p-charge generation layer is performed at a lower concentration at the boundary portions than at the middle portions of the corresponding layers. In one or more embodiments, the boundary portions of the n-charge generation layer and / or the p-charge generation layer are doped at a lower concentration than at the middle portions of the corresponding layers.

[0030] The energy disorder value of the organic layer in an organic light-emitting element can be equal to or greater than 0.1 eV.

[0031] Organic light-emitting elements can have a size equal to or greater than 0.15 × 10⁻⁶. -1 Cd·m 2 / V and equal to or less than 0.7×10 - 1 Cd·m 2 / V, the value of the temperature sensitivity factor (TSF) in Equation 3.

[0032] Equation 3

[0033]

[0034] In this paper, ΔJ is the change in current density, ΔL is the change in brightness, V is the voltage, c is the color, and T is the temperature.

[0035] Organic light-emitting elements can be doped with iridium or platinum dopants.

[0036] An organic light-emitting element may include at least two layers selected from a hole injection layer, a p-doped hole injection layer, a hole transport layer, a light-emitting layer, a dopant (e.g., a dopant layer), a buffer layer, an electron transport layer, and an auxiliary layer. Each layer of the organic light-emitting element (e.g., each of the at least two layers) may be doped with an iridium or platinum dopant, and the average value of the dipole moment of each layer of the organic light-emitting element (e.g., each of the at least two layers) excluding the dopant may be equal to or greater than 2 Debye.

[0037] Display devices can be included in electronic devices such as mobile phones, televisions, monitors, laptops, and / or vehicles.

[0038] One or more embodiments of this disclosure provide a display device comprising: a red pixel, a green pixel, and a blue pixel, each comprising a transistor and an organic light-emitting element, wherein, relative to the organic light-emitting element, as in Equation 3, the value of the temperature sensitivity factor (TSF) is equal to or greater than 0.15 × 10⁻⁶. -1 Cd·m 2 / V and equal to or less than 0.25×10 -1 Cd·m 2 / V or equal to or greater than 0.51×10 -1 Cd·m 2 / V and equal to or less than 0.7×10 -1 Cd·m 2 / V.

[0039] Equation 3

[0040]

[0041] In this paper, ΔJ is the change in current density, ΔL is the change in brightness, V is the voltage, c is the color, and T is the temperature.

[0042] The maximum current density change (maximum ΔJ) at low grayscale ranges from 380% to 60%, and the minimum current density change (minimum ΔJ) at high grayscale ranges from 170% to 30%.

[0043] The minimum value of the ratio (ΔL / ΔJ) of the change in current density (ΔJ) to the change in brightness (ΔL) at low grayscale can be in the range of 30% ± 10%, and the maximum value of the ratio (ΔL / ΔJ) of the change in current density (ΔJ) to the change in brightness (ΔL) at high grayscale can be in the range of 55% ± 10%.

[0044] Low gray levels can be equal to or less than the 23rd gray level, and high gray levels can be greater than the 23rd gray level.

[0045] The difference between the initial voltage value on one side of the voltage range applied to the organic light-emitting element and the saturation voltage at which it begins to saturate, and the ratio of the change in current density (ΔJ) or the ratio of the change in current density (ΔJ) to the change in luminance (ΔL) (ΔL / ΔJ), can be equal to or greater than 0.3V.

[0046] The initial voltage can be equal to or greater than -1V and equal to or less than 6V, and the saturation voltage can be equal to or greater than 1.3V and equal to or less than 10V.

[0047] The entire voltage range of the operating voltage applied to the organic light-emitting element can have values ​​equal to or greater than -1V and equal to or less than 10V.

[0048] The difference between the electron mobility and hole mobility of the organic layer in an organic light-emitting element can be equal to or greater than 1 e. - 9 cm 2 / V·s and equal to or less than 1e -3 cm 2 / V·s.

[0049] The interfacial barrier value at the boundary between adjacent layers in an organic light-emitting element can have a value equal to or greater than -0.3 eV and equal to or less than 0.5 eV.

[0050] Organic light-emitting elements may include a p-doped hole injection layer, and the doping concentration of the p-doped hole injection layer may be equal to or greater than 0.1% and equal to or less than 5%.

[0051] An organic light-emitting element may include a hole transport layer and a light-emitting layer, and may further include at least one auxiliary layer between the hole transport layer and the light-emitting layer.

[0052] Organic light-emitting elements can have a series structure including a light-emitting layer and a charge-generating layer.

[0053] The charge generation layer (e.g., each of the charge generation layers) can be an n-charge generation layer or a p-charge generation layer, and the n-charge generation layer or the p-charge generation layer can have a value equal to or greater than 0.1 eV and equal to or less than 3.0 eV as the interface barrier value.

[0054] Doping of the n-charge generation layer and / or the p-charge generation layer can be performed at a lower concentration at the boundary portions of the corresponding layers than at the middle portions of the corresponding layers. In one or more embodiments, the boundary portions of the n-charge generation layer and / or the p-charge generation layer can be doped at a lower concentration than at the middle portions of the corresponding layers.

[0055] The energy disorder value of the organic layer in an organic light-emitting element can be equal to or greater than 0.1 eV.

[0056] The capacitance change (ΔCap') at the maximum value of Equation 10 relative to the organic light-emitting element. max (c,T)) can have a value equal to or greater than 100%.

[0057] Equation 10

[0058]

[0059] In this paper, variable c is color, T is temperature, T0 is 25℃, and Cap is capacitance, and ΔCap' max (c,T) can satisfy equation 9.

[0060] Equation 9

[0061] ΔCap' max x(c,T)=ΔCap max (c,T) / △V max (c,T)

[0062] In this paper, the capacitance change (ΔCap) is represented by its maximum value. max (c,T) can satisfy equation 6.

[0063] Equation 6

[0064]

[0065] Maximum voltage change (ΔV) max (c,T) can satisfy equation 8.

[0066] Equation 8

[0067] ΔV max (c,T)=V max (c,T) / V max (c,T0)

[0068] For red and green, the change in capacitance at the maximum value (ΔCap') max (c,T) can have a value equal to or greater than 500%.

[0069] Organic light-emitting elements can be doped with iridium or platinum dopants.

[0070] An organic light-emitting element may include at least two layers selected from a hole injection layer, a p-doped hole injection layer, a hole transport layer, a light-emitting layer, a dopant (e.g., a dopant layer), a buffer layer, an electron transport layer, and an auxiliary layer. Each layer of the organic light-emitting element (e.g., each of the at least two layers) may be doped with an iridium or platinum dopant, and the average value of the dipole moment of each layer of the organic light-emitting element (e.g., each of the at least two layers) excluding the dopant may be equal to or greater than 2 Debye.

[0071] Display devices can be included in electronic devices such as mobile phones, televisions, monitors, laptops, and vehicles.

[0072] According to an embodiment, a display device including an organic light-emitting element (OLED) for preventing or reducing brightness changes sensitive to temperature variations can be formed by checking whether the brightness sensitivity changes relative to temperature based on testing the OLED. According to an embodiment, a display device with low temperature sensitivity can be provided by checking the temperature sensitivity of the OLED based on measurements taken by a test element group (TEG).

[0073] According to one or more embodiments, the electronic device includes a display device as described in one or more embodiments.

[0074] Electronic devices can be smartphones, televisions, monitors, tablets, electric vehicles, mobile phones, tablet PCs, mobile communication terminals, electronic notebooks, e-books, portable multimedia players (PMPs), navigation devices, ultra-mobile PCs (UMPCs), laptops, billboards, Internet of Things (IoT) devices, smartwatches, watch phones, and / or head-mounted displays (HMDs). Attached Figure Description

[0075] The accompanying drawings, together with the specification, illustrate embodiments of the subject matter of this disclosure, and together with the description, serve to illustrate the principles of embodiments of the subject matter of this disclosure.

[0076] Figure 1 This is a top plan view of a display device according to one or more embodiments.

[0077] Figure 2 It is an equivalent circuit diagram of a pixel included in a display device according to one or more embodiments.

[0078] Figure 3 This is a cross-sectional view of a test element of a display device according to one or more embodiments.

[0079] Figure 4 This is a table providing definitions of the abbreviations and acronyms used in this disclosure.

[0080] Figures 5 to 14 The illustration shows the meaning of the expression corresponding to the temperature sensitivity of the organic light-emitting element according to one or more embodiments.

[0081] Figure 15 This is a graph showing the results of measuring the temperature sensitivity factor (TSF) of organic light-emitting elements.

[0082] Figures 16 to 20 It is a graph showing the change in capacitance.

[0083] Figure 21 This is a cross-sectional view of an organic light-emitting element with a series structure.

[0084] Figures 22 to 26 This is a graph showing the characteristics of an organic light-emitting element with a series structure.

[0085] Figures 27 to 30 The illustration shows a portion of the energy levels of an organic light-emitting element in a series structure according to one or more embodiments.

[0086] Figure 31A , Figure 31B , Figure 32A and Figure 32B It is a graph showing the changes based on the additional doping of iridium.

[0087] Figure 33 It is the number of elements corresponding to the actual measured value (TLS) of the brightness change of one or more organic light-emitting elements.

[0088] Figure 34 It is a table of energy levels of the various layers of an organic light-emitting element according to one or more embodiments.

[0089] Figure 35 It is a table of conditions based on the characteristics of organic light-emitting elements according to one or more embodiments.

[0090] Description of reference numerals in the attached figures

[0091] 1000: Display device; DA: Display area

[0092] PA: Non-display area; P: Pixel

[0093] LED: Organic Light Emitting Device; PC: Pixel Driver

[0094] T1, T2: Transistors; C1: First capacitor

[0095] Pad-A, Pad-C: Pad 380: Pixel confinement layer

[0096] OP: Opening; EML: Emissive Layer

[0097] FL, FL1, FL2: Functional layer 161: First scan line

[0098] 171: Data line; 172: First drive voltage line

[0099] 179: Second driving voltage line

[0100] TEGΔL: Expected value of the change in brightness

[0101] TLS: Actual measurement of brightness change

[0102] TSF: Temperature Sensitivity Factor

[0103] LL: Lateral leakage factor; J: Current density

[0104] L: Brightness Op.V: Operating Voltage Detailed Implementation

[0105] In the following description, the subject matter of this disclosure will be described more fully with reference to the accompanying drawings, in which embodiments of this disclosure are illustrated. As those skilled in the art will recognize, the described embodiments may be modified in one or more suitable different ways without departing from the spirit or scope of this disclosure. The drawings and description are to be considered illustrative rather than restrictive in nature. Throughout the drawings and written description, the same reference numerals denote the same elements, and their repeated description may not be provided in the specification.

[0106] As used herein, unless the context explicitly indicates otherwise, the singular forms “a” and “the (said)” are intended to include the plural forms as well.

[0107] Unless the context explicitly indicates otherwise, the singular form as used herein is intended to include the plural form as well.

[0108] The term “and / or” should include a combination of multiple listed items or any one of multiple listed items.

[0109] When describing embodiments of this disclosure (e.g., when describing embodiments of this disclosure), the use of "may" refers to "one or more embodiments of this disclosure".

[0110] As used in this article, the term “use” and its variants can be considered synonymous with the term “utilize” and its variants, respectively.

[0111] Parts unrelated to the description may be omitted to clearly describe this disclosure, and substantially the same elements will be identified by the same reference numerals throughout the specification.

[0112] For better understanding and ease of description, the dimensions and thicknesses of each construction or arrangement shown in the accompanying drawings may be arbitrarily illustrated, but the embodiments of this disclosure are not limited thereto. For clarity, the thicknesses of layers, films, panels, and / or regions, etc., may be exaggerated. The thicknesses of one or more layers and regions may be exaggerated to effectively or appropriately illustrate the technical content of this disclosure.

[0113] It should be understood that if an element such as a layer, film, region, or substrate is referred to as being "on" another element (e.g., when an element such as a layer, film, region, or substrate is referred to as being "on" another element), then it can be directly on that other element, or an intervening element may also be present therein. Conversely, if an element is referred to as being "directly on" another element (e.g., when an element is referred to as being "directly on" another element), then there is no intervening element present therein.

[0114] The phrase "on" or "above" refers to a part of an object being on or below it, and does not necessarily mean that it is on the upper side of the object based on the direction of gravity.

[0115] It will be understood that although the terms “first,” “second,” and / or “third,” etc., may be used herein to describe one or more elements, components, regions, layers, and / or portions, such elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, a first element, first component, first region, first layer, or first portion as described herein may be referred to as a second element, second component, second region, second layer, or second portion without departing from the spirit and scope of this disclosure.

[0116] It will be further understood that the terms “having,” “comprising,” and / or variations thereof, as used herein, indicate the presence of a feature or component of a statement, but do not exclude the presence or addition of one or more other features or components. For example, it should be understood that the terms “comprising,” “including,” or “having,” and variations thereof, indicate the presence of a feature, integral, step, operation, element, and / or component of a statement, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Additionally, the terms “comprising,” “including,” “having,” or similar terms and variations thereof include or support the terms “consisting of…” and “essentially composed of…”, which indicate the presence of a feature, integral, step, operation, element, and / or component of a statement, without or essentially without the presence of other features, integrals, steps, operations, elements, components, and / or groups thereof.

[0117] Any numerical range described herein is intended to include all subranges with the same numerical precision contained within the described range. For example, the range “1.0 to 10.0” is intended to include all subranges between the described minimum value of 1.0 and the described maximum value of 10.0 (inclusive) (e.g., having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0), such as 2.4 to 7.6. Any maximum numerical limit described herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit described in this disclosure is intended to include all higher numerical limits contained therein. Accordingly, the applicant reserves the right to amend this specification (including the claims) to expressly describe any subranges contained within the range expressly described herein.

[0118] As used herein, the terms “basic,” “approximately,” and similar terms are used as terms of approximation rather than terms of degree and are intended to describe the inherent biases of measurements or calculations that will be recognized by one of ordinary skill in the art.

[0119] As used herein, the term "approximately" or similar terms are used as terms of approximation rather than terms of degree, and are intended to describe the inherent bias of a measured or calculated value that will be recognized by one of ordinary skill in the art. Taking into account the measurements discussed and the errors associated with the measurement of a particular quantity (i.e., limitations of the measurement system), the terms "approximately" or "approximately" as used herein also include stated values ​​and refer to a range of acceptable deviations from that particular value as determined by one of ordinary skill in the art. For example, "approximately" may refer to within one or more standard deviations, or within ±30%, ±20%, ±10%, or ±5% of the stated value.

[0120] The phrase “in a plan view” refers to a portion of an object viewed from above, while the phrase “in a cross-sectional view” refers to a section of an object viewed from the side that is vertically cut.

[0121] Throughout the specification, if it is stated that a part is “connected” to another part (e.g., when it is stated that a part is “connected” to another part), then that part may be directly connected to that other part, may be connected to that other part through a third part, or may be physically or electrically connected to that other part, and they may be referred to by different names depending on location or function, but parts that are substantially integrated into one unit may be connected to each other.

[0122] If a portion of a wiring, layer, film, area, plate, or component is referred to as extending in a “first direction or second direction” (e.g., when a portion of a wiring, layer, film, area, plate, or component is referred to as extending in a “first direction or second direction”), this refers not only to a straight line shape extending in the corresponding direction, but also to a structure that generally extends in the first or second direction, a structure that bends at a set or predetermined portion, a zigzag structure, or a structure that includes a curved structure.

[0123] Electronic devices including display devices and display panels as described in one or more embodiments of this disclosure (e.g., mobile phones, TVs, monitors, and / or laptops, etc.) or electronic devices including display devices and display panels manufactured by the manufacturing methods described in one or more embodiments of this disclosure are not excluded from the scope of protection claimed in this disclosure.

[0124] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have substantially the same meaning as that commonly understood by one of ordinary skill in the art to which this disclosure pertains. Any term defined in a general dictionary shall be interpreted as having substantially the same meaning in the context of the relevant field and shall not be construed as having an ideal or overly formalistic meaning unless otherwise expressly specified.

[0125] This article will refer to Figure 1 A schematic structure of a display device according to one or more embodiments is described in more detail.

[0126] Figure 1 This is a top plan view of a display device according to one or more embodiments.

[0127] Reference Figure 1 The display device 1000 may include a display area DA in which pixels P are arranged or provided and an image is displayed, and a non-display area PA provided near the display area DA. The non-display area PA may not display an image.

[0128] Depending on one or more embodiments, the display area DA may, for example, have a quadrilateral shape (e.g., a basic quadrilateral shape), and as... Figure 1 As shown, each corner DA-C of the display area DA can have an arc shape (e.g., a basic arc shape). The non-display area PA can have a shape around the display area DA (e.g., surrounding the display area DA). However, it is not limited thereto; the display area DA and the non-display area PA can have one or more suitable shapes.

[0129] The display area DA may include pixels P and display images. Pixel P may include transistors, capacitors, and organic light-emitting elements.

[0130] A non-display area PA may surround (e.g., around) the display area DA. The non-display area PA may not display an image and may be located in an external portion of the display device 1000. The display device 1000 may be a flexible display device including at least a bent portion. For example, the display device 1000 may have a flat (e.g., substantially flat) central portion and a bent edge portion. At least a portion of the display area DA may be in the bent portion, such that at least a portion of the display area DA may have a bent shape (e.g., substantially bent shape). Test elements formed or provided by substantially the same process as the organic light-emitting element of the pixel P may be formed or provided in the non-display area PA.

[0131] Relative to the display device 1000, the surface used for displaying an image may be parallel (e.g., substantially parallel) to the surface defined by the first direction DR1 and the second direction DR2. The normal direction of the surface used for displaying the image (e.g., the thickness direction of the display device 1000) may be indicated by a third direction DR3. The front (or upper) and rear (or lower) surfaces of various components may be divided by the third direction DR3. The directions indicated by the first direction DR1, the second direction DR2, and the third direction DR3 may be relative concepts and may be converted into other directions.

[0132] The display device 1000 may further include a touch unit on the upper side and / or a cover window.

[0133] The display device 1000 may be a flat (e.g., substantially flat) rigid display device, or it may be a flexible display device, not limited thereto. The display device 1000 may include a color conversion layer comprising quantum dots and / or color filters.

[0134] This article will refer to Figure 2 The basic circuit structure of pixel P in the display area DA is described in more detail.

[0135] Figure 2 It is an equivalent circuit diagram of pixels included in a display device according to one or more embodiments.

[0136] like Figure 2 The pixel P shown includes two transistors T1 and T2, a first capacitor C1, and an organic light-emitting element LED.

[0137] Compared to Figure 2 The structure of a pixel P can include an organic light-emitting element (LED) and a pixel driver PC for driving the LED. The pixel driver PC can include, except for... Figure 2 All components other than the organic light-emitting element (LED) in the system, and according to Figure 2 The pixel driver PC of pixel P may include a first transistor T1, a second transistor T2, and a first capacitor C1.

[0138] The pixel driver PC can be connected to a first scan line 161 for applying a first scan signal GW and a data line 171 for applying a data voltage VDATA. The pixel P can be connected to a first drive voltage line 172 for applying a drive voltage ELVDD (or a first drive voltage) and a second drive voltage line 179 for applying a drive low voltage ELVSS (or a second drive voltage).

[0139] This paper will focus on describing the circuit structure of a pixel in more detail, focusing on the individual components included in the pixel (e.g., transistors, capacitors, and organic light-emitting elements).

[0140] The first transistor T1 (or driving transistor) may include a gate electrode connected to the first electrode of the first capacitor C1 and the second electrode of the second transistor T2, a first electrode connected to the first driving voltage line 172 (e.g., input side electrode), and a second electrode connected to the anode of the organic light-emitting element LED (e.g., output side electrode).

[0141] The conduction level of the first transistor T1 can be determined by the voltage at its gate electrode, and the magnitude of the current flowing from the first electrode to the second electrode of the first transistor T1 can be determined by the conduction level. This current flowing from the first electrode to the second electrode of the first transistor T1 can be transmitted to the anode of the organic light-emitting element (LED), and can be referred to as the luminous current. The first transistor T1 can be a negative-type or negative-class transistor (e.g., an n-type transistor), and the higher the voltage at its gate electrode, the greater the luminous current that can flow. If the luminous current is large (e.g., when the luminous current is large), the organic light-emitting element (LED) can display high brightness.

[0142] The second transistor T2 (or data input transistor) may include a gate electrode connected to a first scan line 161 for applying the first scan signal GW, a first electrode (e.g., an input-side electrode) connected to a data line 171 for applying the data voltage VDATA, and a second electrode (e.g., an output-side electrode) connected to the first electrode of the first capacitor C1 and the gate electrode of the first transistor T1. The second transistor T2 can input the data voltage VDATA to pixel P according to the first scan signal GW, transfer the data voltage VDATA to the gate electrode of the first transistor T1, and store the data voltage VDATA in the first electrode of the first capacitor C1.

[0143] All transistors can be n-type transistors, which can be turned on if the voltage at the gate electrode is high (e.g., when the voltage at the gate electrode is high), and can be turned off if the voltage at the gate electrode is low (e.g., when the voltage at the gate electrode is low). The semiconductor layers included in the individual transistors can be polycrystalline silicon semiconductors and / or oxide semiconductors, and can additionally use amorphous (e.g., non-crystalline) semiconductors and / or single-crystal semiconductors.

[0144] According to one or more embodiments, the semiconductor layer included in each of the transistors may further include an overlapping layer (or an additional gate electrode) that overlaps with the semiconductor layer, and a voltage may be applied to the overlapping layer (or the additional gate electrode) to change the characteristics of the transistor and further improve or enhance the display quality of the pixel.

[0145] The first capacitor C1 may include a first electrode connected to the gate electrode of the first transistor T1 and the second electrode of the second transistor T2, and a second electrode for receiving the first drive voltage ELVDD. The first electrode of the first capacitor C1 can receive and store the data voltage VDATA from the second transistor T2.

[0146] The organic light-emitting element (LED) may include a cathode connected to a second driving voltage line 179 to receive a second driving voltage ELVSS, and an anode connected to a second electrode of a first transistor T1. The LED may be supplied with a current substantially the same as the current flowing to the first transistor T1 of the pixel driver PC between the pixel driver PC and the second driving voltage line 179, and the luminous intensity may be determined according to the magnitude of the corresponding current. The LED may include an anode, a cathode, and a light-emitting layer comprising an organic light-emitting material between the anode and the cathode. A hole injection layer and / or a hole transport layer may be further provided between the anode and the light-emitting layer, and an electron transport layer and / or an electron injection layer may be further provided between the cathode and the light-emitting layer.

[0147] Figure 2 The illustration shows that a single pixel P may include two transistors T1 and T2 and a capacitor (i.e., a first capacitor C1), but this is not a limitation, and depending on one or more embodiments, pixel P may further include a capacitor or transistors. Depending on one or more embodiments, the transistors may be positive or positive-type transistors (e.g., p-type transistors). Furthermore, a pixel according to one or more embodiments may include two transistors, a capacitor, and an organic light-emitting element, and their interconnections may differ from those of other pixels. Figure 2 The connection relationship.

[0148] This article will refer to Figure 3 The cross-sectional structure of the test element is described in more detail. The test element is formed or provided with the organic light-emitting element (LED) of the pixel P in the display area DA through substantially the same process, and is formed or provided in the non-display area PA for testing purposes.

[0149] Figure 3 This is a cross-sectional view of a test element of a display device according to one or more embodiments.

[0150] like Figure 3 The test element shown and the stacked structure of the organic light-emitting element LED of the pixel P in the display area DA can be generated by essentially the same materials and essentially the same process, and can have essentially the same stacked structure.

[0151] This article will refer to Figure 3 Describe the stacking structure of the test components in more detail.

[0152] The anode can be on an organic membrane.

[0153] The anode can be made of a single layer comprising a transparent (e.g., substantially transparent) conductive (e.g., electrically conductive) oxide layer or a metallic material, or of a multilayer comprising a transparent conductive oxide layer and / or a metallic material. The transparent (e.g., substantially transparent) conductive (e.g., electrically conductive) oxide layer can include indium tin oxide (ITO), polycrystalline ITO, indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), and / or indium tin zinc oxide (ITZO). The metallic material can include silver (Ag), molybdenum (Mo), copper (Cu), gold (Au), and / or aluminum (Al).

[0154] The pixel-limiting layer 380, including the opening OP, can be on the anode.

[0155] The opening OP (or light-emitting element opening) of the pixel limiting layer 380 can correspond to the organic light-emitting element LED in the plan view, and the light-emitting layer EML can be formed or provided inside.

[0156] A first functional layer FL1 may be located between the anode and the light-emitting layer EML, and a second functional layer FL2 may be located between the cathode and the light-emitting layer EML. The first functional layer FL1 may include a hole injection layer and / or a hole transport layer, and the second functional layer FL2 may include an electron transport layer and / or an electron injection layer. The functional layers FL and the light-emitting layer EML may be constructed or provided as an intermediate layer. Depending on one or more embodiments, the first functional layer FL1 and the second functional layer FL2 may be located on the pixel defining layer 380.

[0157] The cathode can be on the second functional layer FL2, or it can be on the pixel limiting layer 380 and the opening OP.

[0158] The cathode may be a transparent (e.g., substantially transparent) conductive (e.g., electrically conductive) layer comprising indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), and / or indium tin zinc oxide (ITZO). The cathode may also have semi-transparent properties.

[0159] Multiple test elements can be located in the non-display area PA, and the cross-sectional structure of the test elements can have a stacked structure that is essentially the same as that of the organic light-emitting elements (LEDs) in the display area DA.

[0160] The organic light-emitting element (LED) in the display area DA may include an anode, a light-emitting layer (EML), and a cathode, and may further include a first functional layer (FL1) and a second functional layer (FL2).

[0161] A transistor and a capacitor can be located beneath the organic film in the display area DA, and the transistor can be electrically connected to the anode in the display area DA. As a result, the anode can receive current from the transistor located beneath the organic film in the display area DA, and the current flowing to the anode can pass through the first functional layer FL1, the light-emitting layer EML, and the second functional layer FL2 and can be transmitted to the cathode. Due to the current flowing to the light-emitting layer EML, the light-emitting layer EML can emit light, and the organic light-emitting element (LED) can provide brightness.

[0162] Due to the organic light-emitting elements (LEDs) in the display area DA and such Figure 3 The test elements in the non-display area PA shown are formed or supplied using substantially the same materials and substantially the same processes, and therefore they can have substantially the same characteristics. As a result, the test results obtained by applying the current voltage to the test elements in the non-display area PA can correspond to the characteristics of the organic light-emitting elements (LEDs) in the display area DA.

[0163] Therefore, it can be checked by testing the test element in the non-display area PA to determine whether the organic light-emitting elements (LEDs) in the display area DA generate less variation in brightness, gamma, and color relative to temperature. For example, if the display brightness, gamma, and color change according to the temperature used by the display device 1000 (e.g., when the display brightness, gamma, and color change according to the temperature used by the display device 1000), the display quality may not be constant (e.g., not substantially constant). Therefore, the resulting values ​​measured from the test element can be used below to form or provide a display device 1000 with low temperature sensitivity, and if certain (e.g., set or predetermined) conditions are met (e.g., when certain (e.g., set or predetermined) conditions are met), the display quality may not be degraded.

[0164] Depending on one or more embodiments, in order to examine the characteristics of the light-emitting layer (EML), it can be stacked separately from the display device and formed or provided as a test element, and tests can be performed.

[0165] Reference Figure 3 Pad A can be connected to the anode of the test element, and Pad C can be connected to the cathode of the test element.

[0166] For example, voltage and current can be supplied to pads Pad-A and Pad-C to test test elements in the non-display area PA, and corresponding values ​​such as current, voltage, and / or capacitance can be measured. The brightness of light emitted by the emissive layer EML can be measured, and the measured current, voltage, capacitance, and / or brightness can be used to determine whether they are within set or predetermined conditions, thereby determining whether the sensitivity to temperature has decreased. The values ​​to be measured by the test elements can be divided into two groups, and these groups can be measured by separate tests. The first measurement group may include brightness, current (or current density), and voltage corresponding to JVL characteristic tests, and the second measurement group may include capacitance and voltage corresponding to CV characteristic tests.

[0167] According to one or more embodiments, the expected value of the amount of brightness change represented in Equation 1 (TEGΔL(c,T,G)) can be found using each of the values ​​calculated by the test element.

[0168] Equation 1

[0169]

[0170] exist Figure 4 The abbreviations and acronyms used in Equation 1 are described in more detail below.

[0171] Figure 4 This is a table providing definitions of the abbreviations and acronyms used in this disclosure.

[0172] Reference Figure 4 Gray level (G), temperature (T) (or Temp.), color (c) (e.g., red, green, or blue), brightness (L) (or luminance), current density (J), voltage (V), operating voltage (Op.V), a factor corresponding to lateral leakage (LL) (or lateral leakage factor; see Equation 5), capacitance (Cap), and constants (α and β) are written as abbreviations and acronyms. In the abbreviations and acronyms, gray level (G), temperature (T), and color (c) can be used as variables, and brightness (L), current density (J), voltage (V), and operating voltage (Op.V) can be functions using at least one variable selected from gray level (G), temperature (T), and color (c). The reference gray level (G0) can be 23 gray levels selected from 64 gray levels from 0 to 63, and the reference temperature (T0) can be 25°C, which is room temperature. The color can be selected from red, green, and blue, and the current density (J) can correspond to the operating voltage (Op.V). The temperature (T) in this article can be 40°C. However, the temperature value is given for the sake of detailed description and is not limited to this.

[0173] This article will refer to Figure 4Equation 1 will be described in more detail.

[0174] The expected value of the brightness change in Equation 1 (TEGΔL(c,T,G)) can be a function of color, temperature and grayscale, and Equation 1 can be expressed as Equation 2.

[0175] Equation 2

[0176] TEGΔL(c,T,G)=(1+ΔLF)×100(%)

[0177] Comparing Equations 1 and 2, ΔLF represents the luminance variation factor, and the luminance variation factor (ΔLF) can include five factors. The expected value of the amount of luminance change (TEGΔL(c,T,G)) can be a value that indicates the degree of luminance change as a percentage relative to 100% (or a reference luminance).

[0178] If temperature sensitivity is determined (for example, when temperature sensitivity is determined), the most important factor selected from the five brightness variation factors (ΔLF) can be the temperature sensitivity factor (TSF) included in Equation 3.

[0179] Equation 3

[0180]

[0181] The temperature sensitivity factor (TSF) in Equation 3 represents a value that takes into account voltage (V), current density (J), and brightness (L), and it can be calculated without measuring capacitance by means of separate tests, including measurements corresponding to the first set of measurements. For example, the temperature sensitivity factor (TSF) represents a graph of ΔL / ΔJ versus voltage (see...). Figure 8 The slope of the tangent in the image is determined by the region of highest temperature sensitivity, which is the low-grayscale region, and thus corresponds to the slope of the tangent at the low-grayscale area. A smaller Temperature Sensitivity Factor (TSF) value indicates lower temperature sensitivity. This will be discussed in this paper. Figures 5 to 15 The method for determining the temperature sensitivity of an organic light-emitting element (LED) based on the temperature sensitivity factor (TSF) of Equation 3 is described in more detail.

[0182] The second and third factors, selected from the five luminance variation factors (ΔLF), are described in more detail in this paper.

[0183] Of the five luminance variation factors (ΔLF), the second factor corresponds to the reciprocal of the current density of a specific (e.g., set or predetermined) grayscale (G) with respect to the current density of a reference grayscale G0, and additionally includes a constant (α) as the reciprocal. Of the five luminance variation factors (ΔLF), the third factor indicates the operating voltage value at the grayscale and / or temperature corresponding to each color.

[0184] The second and third factors can have values ​​independent of temperature, or they can have values ​​that vary with temperature, but the range of variation can be small. As a result, since the temperature sensitivity of the organic light-emitting element (LED) can be considered (e.g., when the temperature sensitivity of the organic light-emitting element (LED) is taken into account), the factors described in one or more embodiments can have relatively small temperature sensitivity compared to the temperature sensitivity factor (TSF) in Equation 3, so the second and third factors can be disregarded.

[0185] Among the five brightness variation factors (ΔLF), as shown in Equation 4, the fourth factor represents the change in current density value.

[0186] Equation 4

[0187]

[0188] According to Equation 4, the fourth factor represents the ratio of the current density corresponding to a specific (e.g., set or predetermined) temperature (T) to the current density corresponding to a reference temperature (T0) relative to substantially the same color and substantially the same gray level.

[0189] The fourth factor can have a value that varies with temperature and can be indirectly included in Equation 3 in correspondence with the change in current density included in Equation 3. Therefore, if the temperature sensitivity of the organic light-emitting element LED is taken into account (e.g., when considering the temperature sensitivity of the organic light-emitting element LED), and the temperature sensitivity factor (TSF) of Equation 3 is taken into account, it can be disregarded separately.

[0190] Among the five brightness variation factors (ΔLF), the fifth factor is the lateral leakage factor (LL) expressed in Equation 5.

[0191] Equation 5

[0192]

[0193] The lateral leakage factor (LL) is a value that takes into account both capacitance (Cap) and operating voltage (Op.V), and it can be calculated without measuring luminance (L) or current density (J) based on the performance of another test, while including measurements corresponding to a second set of measurements. For example, the lateral leakage factor (LL) can correspond to the leakage current generated by an organic light-emitting element (LED), and to the amount of electrons or holes that are leaked instead of moving between the cathode and anode (see...). Figure 17This corresponds to the lateral leakage factor (LL). Because the lateral leakage factor (LL) can have a large value, indicating greater lateral leakage and less current flowing between the cathode and anode, the amount of brightness change with temperature (hereinafter referred to as temperature sensitivity based on lateral leakage) can be relatively small. Reference will be made in this paper. Figures 16 to 20 The lateral leakage factor (LL) of Equation 5 is described in more detail, and the method for determining the temperature sensitivity of an organic light-emitting element (LED) based on the lateral leakage factor (LL) value will be described in more detail in this paper.

[0194] This article will refer to Figures 5 to 14 The temperature sensitivity factor (TSF) of Equation 3 is described in more detail.

[0195] Referring to Equation 3, the temperature sensitivity factor (TSF) can be determined by the changes in current density (J) and luminance (L) based on the temperature (T) change, and it can be obtained by differentiating the value obtained by dividing the luminance change (ΔL) by the current density change (ΔJ) with respect to voltage (V). Furthermore, the temperature sensitivity factor (TSF) can be represented by a graph (see...). Figure 8 The slope of the tangent line on (and the following, etc.), where the x-axis is the voltage (V) and the y-axis is ΔL / ΔJ.

[0196] Referring to Equation 3, the change in current density (ΔJ) and the change in brightness (ΔL) can be functions of color (c) and temperature (T), respectively, and voltage (V) can be a function of color (c). Current density (J) can correspond to the operating voltage (Op.V).

[0197] Furthermore, the values ​​ΔJ, ΔL, and V in Equation 3 can vary depending on the grayscale, and refer to... Figures 5 to 14 Because the brightness of an organic light-emitting element (LED) can vary significantly or drastically in the low grayscale region depending on temperature, the values ​​of ΔJ, ΔL, and V in Equation 3 can be used in the low grayscale range. The temperature sensitivity of the LED can be determined by the temperature sensitivity factor (TSF) in the low grayscale range. The low grayscale range can be a set or predetermined grayscale range selected from the 23rd grayscale level, which is less than the reference grayscale G0.

[0198] Because if the temperature sensitivity factor (TSF) of Equation 3 increases (for example, when the temperature sensitivity factor (TSF) of Equation 3 increases), it can represent a change that is sensitive to temperature changes. Therefore, if the temperature sensitivity factor (TSF) is low (for example, when the temperature sensitivity factor (TSF) is low), the brightness and / or color of the display device 1000 can change regardless of temperature, and the display quality can be improved or enhanced.

[0199] This article will refer to Figures 5 to 14 The meaning of the temperature sensitivity factor (TSF) corresponding to Equation 3 will be described in more detail.

[0200] Figures 5 to 14 The illustration shows the meaning of the expression corresponding to the temperature sensitivity of the organic light-emitting element according to one or more embodiments.

[0201] Figures 5 to 14 The temperature sensitivity factor (TSF) of Equation 3 and its constituent terms are illustrated as a graph.

[0202] This will be described in more detail in this article. Figure 5 .

[0203] Figure 5 This is a graph showing the change in current density with respect to voltage (ΔJ) and the ratio (ΔL / ΔJ) of the change in current density with respect to voltage (ΔJ) to the change in brightness (ΔL). Tests can be performed at temperatures of 25°C and 40°C to check... Figure 5 And the variation relative to temperature in the figure below; for example, the change in current density (ΔJ) at a specific (e.g., set or predetermined) voltage can represent the difference in current density at 25°C and 40°C at a specific (e.g., set or predetermined) voltage.

[0204] Because the change in current density (ΔJ) corresponds to the change in the amount of electrons or holes, it can correspond to the change in current flowing to the organic light-emitting element (LED). (Refer to...) Figure 6 and Figure 7 Since the amount of change in electrons or holes increases with temperature, the change in current density (ΔJ) can be used to increase the temperature sensitivity factor (TSF).

[0205] If viewed relative to the change in current density (ΔJ) Figure 5 The two curves (for example, when viewed relative to the change in current density (ΔJ)) Figure 5 When two curves are plotted (e.g., when two curves are plotted), they can have an inverse relationship with each other. For example, if Figure 5 The left curve is set to Y=X (for example, when Figure 5 When the left curve is set to Y=X, then Figure 5 The right curve can be indicated as Y = 1 / X.

[0206] This article will refer to Figures 5 to 14 A more detailed description Figure 5 The two curves, and will be referred to in this article Figure 6 and Figure 7 A more detailed description Figure 5 The left curve graph.

[0207] Figure 6 yes Figure 5 The enlarged left curve graph, and Figure 7 It is about Figure 6 The curve graph.

[0208] Figure 6 This is the change in current density (ΔJ) with respect to voltage for each color (e.g., red, green, and blue). (Refer to...) Figure 6 Because if the voltage is very low (e.g., when the voltage is very low), it may deviate from the trend line, so the corresponding voltage range may not be used. The change in current density (ΔJ) at the low voltage value (corresponding to low grayscale) can be relatively high, and the change in current density (ΔJ) can decrease as it approaches a high voltage value (or high grayscale). Low grayscale can use a set or predetermined grayscale range selected from grayscale values ​​less than the 23rd grayscale value, which is the reference grayscale G0.

[0209] exist Figure 7 The middle shows Figure 6 Its characteristics. (Refer to...) Figure 7 The maximum current density change (or maximum ΔJ) can be the current density change (ΔJ) value at the initial voltage (Vini) within the range of voltages applied to the organic light-emitting element (LED). The minimum current density change (or minimum ΔJ) can be the current density change (ΔJ) value at the highest voltage within the range of voltages applied to the organic light-emitting element (LED), and because it can have substantially the same current density change (ΔJ) if the voltage is equal to or greater than the set or predetermined voltage (hereinafter, the saturation voltage (Vsat)) (e.g., when the voltage is equal to or greater than the set or predetermined voltage (hereinafter, the saturation voltage (Vsat))), it can have the minimum current density change (minimum ΔJ) at the saturation voltage (Vsat).

[0210] Reference Figure 6 The maximum current density change (maximum ΔJ) at low grayscale can range from 380% ± 60%, and the minimum current density change (minimum ΔJ) at high grayscale can range from 170% ± 30%. Low grayscale can be equal to or less than the 23rd grayscale, and high grayscale can be greater than the 23rd grayscale. The grayscale values ​​used as references for low and high grayscale can vary depending on one or more embodiments.

[0211] The difference (|Vsat-Vini|) between the initial voltage (Vini) corresponding to the maximum current density change (maximum ΔJ) and the saturation voltage (Vsat) at the point where it converges to the minimum current density change (minimum ΔJ) can have a value equal to or greater than 0.3V. The initial voltage (Vini) can have a value equal to or greater than -1V and equal to or less than 6V, and the saturation voltage (Vsat) can have a value equal to or greater than 1.3V and equal to or less than 10V. In one or more embodiments, the entire voltage range of the operating voltage applied to the organic light-emitting element LED can have a value equal to or greater than -1V and equal to or less than 10V.

[0212] The initial voltage (Vini) can be the value of one side of the range of voltages applied to the organic light-emitting element (LED), and is related to... Figure 7 Refer to together Figure 10 and Figure 11 The saturation voltage (Vsat) can represent the voltage at which the change in current density (ΔJ) or the ratio of the change in current density (ΔJ) to the change in brightness (ΔL) (ΔL / ΔJ) begins to saturate. (See reference...) Figure 7 The initial voltage (Vini) can have the lowest voltage value, but depending on one or more embodiments, since the initial voltage (Vini) can have the highest voltage value, an absolute value sign is added to the difference between the initial voltage (Vini) and the saturation voltage (Vsat).

[0213] This article will refer to Figures 8 to 14 A more detailed description Figure 5 The right curve graph.

[0214] Figure 8 yes Figure 5 The enlarged right curve graph, and Figures 9 to 14 The illustration shows one or more embodiments for reducing the temperature sensitivity factor (TSF).

[0215] Figure 8 The graph shows the ratio (ΔL / ΔJ) of the change in current density (ΔJ) and the change in brightness (ΔL) for each color (e.g., red, green, and blue) relative to voltage. (See reference...) Figure 8 The ratio (ΔL / ΔJ) of the change in current density (ΔJ) to the change in brightness (ΔL) at low voltage values ​​(corresponding to low grayscale) can be relatively small, and the ratio (ΔL / ΔJ) can increase as the voltage (or grayscale) approaches (e.g., when approaching high voltage (or high grayscale)). Low grayscale can use a set or predetermined grayscale range selected from grayscale values ​​less than the 23rd grayscale value, which is the reference grayscale G0.

[0216] exist Figures 9 to 14 The text shows how to improve or enhance something. Figure 8 One or more embodiments of the characteristics.

[0217] Since the ratio (ΔL / ΔJ) of the change in current density (ΔJ) to the change in brightness (ΔL) is the numerator of the temperature sensitivity factor (TSF) in Equation 3, it is desirable or necessary to reduce the change in the ratio (ΔL / ΔJ) of the change in current density (ΔJ) to the change in brightness (ΔL) to reduce the temperature sensitivity factor (TSF). Reducing the change in the ratio (ΔL / ΔJ) of the change in current density (ΔJ) to the change in brightness (ΔL) can be compared with... Figure 8 The decrease in the slope of the curve corresponds to...

[0218] For example, Figure 8 This is a graph obtained by dividing the change in brightness (ΔL) by the change in current density (ΔJ) for each voltage. The temperature sensitivity factor (TSF) in Equation 3 is... Figure 8 The differential value of the curve, and with Figure 8 The slope of the tangent line in the graph corresponds to the temperature sensitivity factor (TSF). Because the slope of the tangent line changes with voltage / grayscale, and the temperature-sensitive part is the low grayscale, the slope of the tangent line on the low grayscale part of each component is shown as a line. The slope marked by the line corresponds to the magnitude of the temperature sensitivity factor (TSF), and the lower the slope, the lower the temperature sensitivity of the corresponding component.

[0219] Figure 9 The diagram illustrates how increasing the ratio (ΔL / ΔJ) of the change in current density (ΔJ) to the change in brightness (ΔL) in the low grayscale region can reduce the slope. However, as... Figure 9 The improvement directions shown may require altering the material properties of the layers included in an organic light-emitting element (LED). For example, the conductivity (e.g., electrical conductivity) of the material must be improved by increasing or enhancing mobility or reducing impedance (e.g., resistance), or the energy disorder (or energy dispersion) of the material or the interfacial barrier at the boundary must be reduced. Therefore, concurrent (e.g., accompanying) applications such as... Figure 9 The changing characteristics in the light-emitting element (e.g., an organic light-emitting element LED) are different in direction from those predicted based on the values ​​measured in this disclosure according to the temperature of the light-emitting element.

[0220] Figures 10 to 14 The diagram illustrates how to reduce [the voltage] by changing the initial voltage (Vini) and the saturation voltage (Vsat). Figure 8 One or more embodiments of the slope of the curve in the graph.

[0221] Figure 10 The illustration shows one or more embodiments of reducing the slope while changing the saturation voltage (Vsat). For example, Figure 10 The illustration shows one or more embodiments of reducing the slope of the curve by increasing the voltage value from the previous saturation voltage (Vsat') to the improved saturation voltage (Vsat) and reducing the change in the ratio (ΔL / ΔJ) of the change in current density (ΔJ) and the change in brightness (ΔL).

[0222] For example, Figure 10 The conductivity (e.g., electrical conductivity) of a material can be reduced by decreasing its mobility or increasing its impedance (e.g., resistance), or by increasing the material's energy disorder.

[0223] Figure 11 The illustration shows one or more embodiments of reducing the slope by changing the initial voltage (Vini). For example, Figure 11 The illustration shows one or more embodiments in which the slope of the curve is reduced and the change in the ratio (ΔL / ΔJ) of the change in current density (ΔJ) and brightness (ΔL) is reduced by decreasing the voltage value from the previous initial voltage (Vini') to the improved initial voltage (Vini).

[0224] Figure 11 This can be achieved, for example, by increasing conductivity (e.g., electrical conductivity) (e.g., lowering the dopant injection barrier or lowering the energy level, reducing the difference in the work function of electrons, lowering the interface barrier of the charge generation layer (CGL), electron generation layer (NCGL), or hole generation layer (PCGL), lowering the p-doped hole injection layer PHIL (p-doped HIL), or further lowering the energy level of the highest occupied molecular orbital (HOMO) of the p-doped hole injection layer PHIL). The doping concentration of the p-doped hole injection layer PHIL can be equal to or greater than 0.1% and equal to or less than 5%.

[0225] Figures 12 to 14 The illustration is by Figure 10 and Figure 11 One or more embodiments of the basic transformation application are illustrated, and one or more embodiments of adjusting the operating voltage (Op.V) are shown. Figure 12 Diagram and Figure 11 Correspondingly, the operating voltage (Op.V) is reduced. Figure 13 Diagram and Figure 10 Correspondingly, the saturation voltage is increased from the operating voltage (Op.V), and Figure 14 Diagram Application Figure 10 and Figure 11 .

[0226] Reference Figures 12 to 14 , The ratio (ΔL / ΔJ) of the change in current density (ΔJ) and the change in brightness (ΔL) at the initial voltage (Vini) is given. The ratio (ΔL / ΔJ) of the change in current density (ΔJ) and the change in brightness (ΔL) at the saturation voltage (Vsat) is indicated. This indicates the ratio (ΔL / ΔJ) of the change in current density (ΔJ) and the change in luminance (ΔL) at the voltage opposite to the initial voltage (Vini) (or the final voltage) within a range of voltages applied to the organic light-emitting element (LED). In this embodiment, the initial voltage (Vini) may have the lowest voltage value and the final voltage may have the highest voltage value, and depending on one or more embodiments, they may have opposite voltage values.

[0227] If as in Figures 12 to 14 Reduce the slope of the curve (e.g., when as in...) Figures 12 to 14 When the slope of the curve is reduced, the change in the ratio (ΔL / ΔJ) of the change in current density (ΔJ) and brightness (ΔL) can be reduced.

[0228] Reference Figure 8 The minimum value of ΔL / ΔJ at low gray levels can be in the range of 30% ± 10%, and the maximum value of ΔL / ΔJ at high gray levels can be in the range of 55% ± 10%. Low gray levels can be equal to or less than the 23rd gray level, and high gray levels can be greater than the 23rd gray level. The standard gray level values ​​for low and high gray levels can vary depending on the embodiment.

[0229] Reference Figure 8 , as reference Figure 6 As described, the difference (|Vsat-Vini|) between the initial voltage (Vini) corresponding to the maximum current density change (maximum ΔJ) and the saturation voltage (Vsat) at the point converging to the minimum current density change (minimum ΔJ) can have a value equal to or greater than 0.3V. The initial voltage (Vini) can have a value equal to or greater than -1V and equal to or less than 6V, and the saturation voltage (Vsat) can have a value equal to or greater than 1.3V and equal to or less than 10V. In one or more embodiments, the entire voltage range of the operating voltage applied to the organic light-emitting element LED can have a value equal to or greater than -1V and equal to or less than 10V.

[0230] Figure 15 This is a graph showing the results of measuring the temperature sensitivity factor (TSF) of organic light-emitting elements.

[0231] Figure 15 This is a graph measuring the temperature sensitivity factor (TSF) of an organic light-emitting element (LED). The brightness of an organic light-emitting element (LED) is essentially unaffected by temperature changes and is usable.

[0232] Figure 15The components used can have a value equal to or greater than 0.15 × 10⁻⁶. -1 Cd·m 2 / V and equal to or less than 0.7×10 -1 Cd·m 2 The temperature sensitivity factor (TSF) value can range from 0.15 × 10⁻⁶ V. For example, an organic light-emitting element (LED) can have a TSF value equal to or greater than 0.15 × 10⁻⁶ V. -1 Cd·m 2 / V and equal to or less than 0.25×10 -1 Cd·m 2 / V or equal to or greater than 0.51×10 -1 Cd·m 2 / V and equal to or less than 0.7×10 -1 Cd·m 2 Temperature sensitivity factor (TSF) value per V.

[0233] The difference between the electron mobility and hole mobility in the organic layer of an organic light-emitting element (LED) can be equal to or greater than 1 e -9 cm 2 / V·s and equal to or less than 1e -3 cm 2 / V·s.

[0234] according to Figures 5 to 15 One or more embodiments of the organic light-emitting element (LED) can be as follows: Figures 21 to 26 The organic light-emitting element (LED) shown has a series structure and can meet the reference requirements. Figure 34 The range of values ​​described.

[0235] Since the value corresponding to the temperature sensitivity factor (TSF) in Equation 3 can be calculated using luminance, current density, and voltage, and can be predicted through JVL characteristic testing, it is not necessary to calculate the capacitance by performing additional tests. Furthermore, it is beneficial or advantageous to understand the temperature-dependent changes in the luminance / color of an organic light-emitting element (LED) through simple testing.

[0236] This article will refer to Figures 16 to 20 The lateral leakage factor (LL) of Equation 5 is described in more detail.

[0237] Referring to Equation 5, the transverse leakage factor (LL) can be calculated based on the operating voltage (Op.V) and capacitance (Cap), and the factors constituting the transverse leakage factor (LL) can include three factors other than the constant (β). The first of the three factors constituting the transverse leakage factor (LL) can be the capacitance change (ΔCap(c,T)), and the second and third factors can be related to the operating voltage and represent the operating voltage change (ΔOp.V(c,T,G)) and the operating voltage (Op.V(c,G)) value.

[0238] If described based on the maximum value (e.g., when described based on the maximum value), then the first factor (the change in capacitance (ΔCap)) max (c,T) can be represented in Equation 6.

[0239] Equation 6

[0240]

[0241] In this article, Cap max express Figure 16 The maximum value of the capacitance curve shown in the figure, and Cap' max It is represented in Equation 7.

[0242] Equation 7

[0243] Cap' max (c,T)=Cap max (c,T) / ΔV max (c,T)

[0244] In this paper, the maximum voltage change (ΔV) max ) is represented in Equation 8.

[0245] Equation 8

[0246] ΔV max (c,T)=V max (c,T) / V max (c,T0)

[0247] In this article, V max Indicates in Figure 16 The maximum value of the capacitance in the curve (Cap) max The voltage value, and the maximum voltage change (ΔV) max Instruction V max The change in the value of relative to temperature.

[0248] ΔCap' maxThe value of Δ (in the following text, the change in capacitance at the maximum value) can be derived by combining Equations 6 and 7. For example, adding Δ to Equation 7 yields Equation 9, and applying the maximum value of Equation 6 to ΔCap in Equation 9. max The value generates equation 10.

[0249] Equation 9

[0250] ΔCap' max (c,T)=ΔCap max (c,T) / △V max (c,T)

[0251] Equation 10

[0252]

[0253] The change in capacitance at the maximum value of Equation 10 (ΔCap') max It can correspond to the first factor of the transverse leakage factor (LL) and can be calculated based on capacitance (Cap) and voltage (V).

[0254] This article will refer to Figures 16 to 20 A more detailed description of the capacitance change (ΔCap') at the maximum value according to Equation 10. max ).

[0255] Figures 16 to 20 It is a graph showing the change in capacitance.

[0256] This will be described in more detail in this article. Figure 16 .

[0257] Figure 16 The diagram illustrates the change in capacitance based on the injection of holes and / or electrons; Figure 16 The left curve plot only considers the change in capacitance of holes or electrons, and Figure 16 The right-hand curve diagram illustrates the changes in capacitance of holes and electrons. Figure 16 The right curve graph shows two lines: the thick line indicates the change in capacitance at a high temperature of 40°C, and the thin line indicates the change in capacitance at a low temperature of 25°C.

[0258] Reference Figure 16 The left curve shows that if holes or electrons are injected as charge carriers (e.g., when holes or electrons are injected as charge carriers), the capacitance in the element can increase and reach its maximum capacitance (C) before the electrodes are connected to each other. max The capacitance can decrease if electrodes are connected (e.g., when electrodes are connected), and can increase according to the Mott transition phenomenon.

[0259] However, if as Figure 16 The right-hand curve diagram shows consideration of holes and electrons (e.g., when...). Figure 16 As shown in the right-hand curve (considering holes and electrons), the Mott transition phenomenon can be avoided, and at the maximum capacitance (C)... max The value has a maximum value (Max C). max Before that, the capacitance value can be reduced. For example, Figure 16 The right-hand curve illustrates the change in capacitance when holes and electrons are injected as first carriers (Carrier-1) and second carriers (Carrier-2) with opposite charges to the first carriers (Carrier-1) (e.g., when holes and electrons are injected as first carriers (Carrier-1) and second carriers (Carrier-2) with opposite charges to the first carriers (Carrier-1)). If the first carrier (Carrier-1) is injected (e.g., when the first carrier (Carrier-1) is injected), the capacitance can increase, and if the second carrier (Carrier-2) is injected (e.g., when the second carrier (Carrier-2) is injected), the first carrier (Carrier-1) and the second carrier (Carrier-2) can recombine and disappear, and the capacitance can decrease accordingly.

[0260] Reference Figure 16 The right curve shows that the capacitance value is at the maximum capacitance (C). max The value has a maximum value (Max C). max The number of second carriers (Carrier-2) injected earlier decreases, which corresponds to a decrease in capacitance when leakage current is generated by the light-emitting element. This will be referred to in this paper. Figure 17 This will be described in more detail.

[0261] Figure 17 The illustration includes portions of two light-emitting layers (blue light emitting layer B-EML and green light emitting layer G-EML) selected from two emitting elements, including a blue light emitting element and a green light emitting element.

[0262] Reference Figure 17 If current is applied (see...) Figure 17 The drift) to the emissive EML (blue emitting layer B-EML and green emitting layer G-EML) (for example, when current is applied (see...) Figure 17 When the current (drifts) to the emissive layer EML (blue emitting layer B-EML and green emitting layer G-EML), it can emit light, and as described in one or more embodiments, applying current to the emissive layer EML (blue emitting layer B-EML and green emitting layer G-EML) can interact with... Figure 5The current density corresponds to this. The injected charge can be greater than the charge applied to the emissive EML layers (blue emitting layer B-EML and green emitting layer G-EML), and one or more of the injected charges can be transferred to the lateral surfaces and can be leaked (also known as lateral leakage; see horizontal arrows). Figure 17 In the case of 25°C, the amount formed or provided at 40°C is wider in the horizontal direction and leaks to the lateral surface, which can be increased. Therefore, the maximum capacitance (C) max The value of ) can decrease due to lateral leakage because if the temperature increases (e.g., when the temperature rises), lateral leakage can increase, the current transmitted to the light-emitting layer EML can increase relatively less, and the brightness of the light emitted by the light-emitting element can decrease, so the maximum capacitance (C) will decrease. max The value can be used to reduce the temperature sensitivity factor (TSF) to determine whether the brightness increases with temperature.

[0263] Therefore, in addition to considering the increase in current density change (ΔJ) with increasing temperature, it is expected or necessary to consider the maximum capacitance (C) associated with lateral leakage. max The change of ) and Equation 10 can be combined with the maximum capacitance (C) max Consider the value.

[0264] Equation 10 suggests that as temperature increases, the current or current density can increase, and if the temperature increases (e.g., when the temperature increases), the brightness can increase, but the increased current or current density can be offset by lateral leakage. For example, since energy disorder and mobility may be inherent characteristics of light-emitting elements that are difficult to change, the brightness can be controlled to have a smaller change relative to temperature by using the values ​​of Equation 3 or Equation 10.

[0265] Figure 18 and Figure 19 The diagram illustrates the inclusion of a hole transport layer (HTL) in an organic light-emitting element (LED). Figure 34 ) and / or auxiliary layers between the hole transport layer HTL and the light-emitting layer EML (e.g., the first auxiliary layer G' and the second auxiliary layer GIL in a green organic light-emitting element (see Figure 34 The energy disorder is altered (e.g., when the hole transport layer HTL and / or the auxiliary layer between the hole transport layer HTL and the light-emitting layer EML in an organic light-emitting element LED (e.g., the first auxiliary layer G' and the second auxiliary layer GIL in a green organic light-emitting element (see...)). Figure 34 When the energy disorder of a variable is altered, the maximum capacitance (C) will increase. max How to change it.

[0266] Figure 18The illustration shows the capacitance changes in the comparative example. In this example, the highest occupied molecular orbital (HOMO) energy disorder of the hole transport layer (HTL) and auxiliary layer has a value of less than 0.15 eV, and... Figure 19 The diagram illustrates how HOMO energy disorder in the hole transport layer (HTL) and auxiliary layers is achieved through... Figure 18 The change in capacitance after the HOMO energy of each layer is disordered by a factor of 1.25, resulting in a value greater than 0.15 eV.

[0267] Figure 18 The diagram shows that compared to the 25°C case, the maximum capacitance increases by 14.2% at 40°C, and references... Figure 19 It was found that the maximum capacitance increased by 40.2% at 40°C compared to 25°C. Therefore, it is expected or necessary to increase the maximum capacitance by ensuring that the highest occupied molecular orbital (HOMO) energy disorder of the hole transport layer (HTL) and auxiliary layers has a value equal to or greater than 0.15 eV. Consequently, the increase in brightness can be reduced if lateral leakage increases and temperature rises (e.g., when lateral leakage increases and temperature rises).

[0268] For reference only. Figure 34 The first auxiliary layer G' and the second auxiliary layer GIL of the green organic light-emitting element can be auxiliary layers with the following characteristics. The first auxiliary layer G' can put electrons received on the light-emitting layer EML into the light-emitting layer EML and can effectively or appropriately inject holes transmitted from the hole transport layer HTL into the light-emitting layer EML, and the second auxiliary layer GIL can adjust the hole charge balance of the light-emitting layer EML to increase or enhance the efficiency of the light-emitting layer EML.

[0269] Figure 20 The maximum capacitance shown in the figure (C) max How to change this by adding an auxiliary layer between the hole transport layer (HTL) and the light emission layer (EML).

[0270] Figure 20 The left curve diagram illustrates the hole transport layer (HTL) (see...). Figure 34 One or more embodiments where there is no auxiliary layer between the light-emitting layer (EML) and the light-emitting layer (EML), and Figure 20 The right curve diagram illustrates the addition of a second auxiliary layer, GIL, between the hole transport layer (HTL) and the emissive layer (EML) (see...). Figure 34 One or more embodiments of ).

[0271] Reference Figure 20 The left-hand curve without the auxiliary layer shows that the maximum capacitance at 40°C increased by 14.2% compared to 25°C, but reference... Figure 20The right-hand plot of the second auxiliary layer GIL between the hole transport layer HTL and the emissive layer EML shows that the maximum capacitance increases by 21.1% at 40°C compared to 25°C. Therefore, it was found that the maximum capacitance increases when at least one auxiliary layer is between the hole transport layer HTL and the emissive layer EML.

[0272] Figure 20 The difference between the electron mobility and hole mobility in the organic layer of the organic light-emitting element (LED) used can be equal to or greater than 1e -9 cm 2 / V·s and equal to or less than 1e -3 cm 2 / V·s.

[0273] like Figure 19 and Figure 20 As shown, increasing the maximum capacitance value can increase the capacitance change (ΔCap') at the maximum value of Equation 10. max The corresponding lateral leakage, the change (ΔCap') max It is related to the first of the three factors selected from those that constitute the transverse leakage factor (LL).

[0274] The second factor of the transverse leakage factor (LL) (the change in operating voltage (ΔOp.V(c,T,G))) is expressed in more detail in Equation 11.

[0275] Equation 11

[0276] The maximum value among Δ0p.V(c,T,G) = (red-blue) & (green-blue)

[0277] In this paper, the change in operating voltage (ΔOp.V(c,T,G)) represents the larger of the difference between the operating voltages between red and blue and the difference between the operating voltages between green and blue, and Equation 5, used to find the transverse leakage factor (LL), can use the absolute value of the value of Equation 11.

[0278] The operating voltage (Op.V(c,G)) is the third factor of the transverse leakage factor (LL), representing the operating voltage based on color and grayscale.

[0279] The lateral leakage factor (LL) can correspond to the magnitude of the current leaking from the organic light-emitting element (LED), and with reference to Equation 5, the value of the lateral leakage factor (LL) can be changed based on the values ​​calculated from the first factor, the second factor, and the third factor of the lateral leakage factor (LL).

[0280] Because if the value of the lateral leakage factor (LL) is high (for example, when the value of the lateral leakage factor (LL) is high), the change in the current flowing between the two electrodes (cathode and anode) of the organic light-emitting element LED can be relatively reduced, and the change in the brightness of the organic light-emitting element LED can be reduced, so the change in brightness relative to temperature (in the following text, according to the temperature sensitivity of lateral leakage) can be relatively small.

[0281] If the value of the transverse leakage factor (LL) varies within 10% of 1 (e.g., when the value of the transverse leakage factor (LL) varies within 10% of 1), it corresponds to the transverse leakage current being high and the temperature sensitivity of the transverse leakage being low.

[0282] The change in operating voltage (ΔOp.V) represents the difference between the operating voltage of an organic light-emitting element (OLED) displaying blue and the operating voltage of an organic light-emitting element (OLED) displaying green and / or red. The operating voltages for green and red can be substantially the same, and the change in operating voltage (ΔOp.V) can have a value equal to or greater than 0.34V and equal to or less than 0.54V.

[0283] The capacitance change (ΔCap') at the maximum value of Equation 10 corresponding to the first factor of the transverse leakage factor (LL). max The numerical range of ) can have values ​​equal to or greater than 100%.

[0284] For an organic light-emitting diode (OLED) displaying blue, the capacitance change (ΔCap') at the maximum value of an OLED displaying green and / or red is... max The value can be equal to or greater than 5 times (or 500%). Compared to the blue organic light-emitting element with the highest operating voltage, this can increase the capacitance change of another color organic light-emitting element LED, which can be achieved or provided by increasing the operating voltage, decreasing the mobility, increasing the impedance (e.g., resistance), increasing the energy disorder of the organic material, or increasing or removing the interface barrier.

[0285] Because, according to the numerical range shown in Equation 10, the change in capacitance at the maximum value relative to the temperature change (ΔCap') max The lateral leakage can be equal to or greater than a set or predetermined level, and the lateral leakage can increase, so if the temperature increases by that amount (e.g., when the temperature increases by that amount), the brightness emitted by the organic light-emitting element LED can increase relatively little.

[0286] The change in capacitance (ΔCap) in Equation 6 can be calculated as shown in Equation 12.

[0287] Equation 12

[0288] ΔCap(c,T)=ΔCap(T)×ΔCap(c)

[0289] In this paper, ΔCap(T) is the capacitance change at each temperature, and ΔCap(c) is the capacitance change for each color and can have Cap max - The value of Cgeo. Cgeo represents the capacitance value that exists when there is no voltage (e.g., when there is no voltage), and the temperature can be calculated with reference to one or more temperatures, for example, it can be calculated with reference to 40°C and 25°C.

[0290] Equations 12 and 6 represent the capacitance change (ΔCap) of the first factor of the transverse leakage factor (LL), with Equation 12 simplifying the complex Equation 6. The first factor expressed as capacitance change (ΔCap) in Equation 6 corresponds to the first factor expressed as capacitance change (ΔCap) in Equation 12.

[0291] If the value range is met (e.g., when the value range is met), then as an organic light-emitting element LED in which the value of the lateral leakage factor (LL) varies with 1 within 10%, the lateral leakage value can be high and the temperature sensitivity can be low.

[0292] The transverse leakage factor (LL) in Equation 5 takes into account capacitance (Cap) and voltage (V), and it can include measurements corresponding to the second measurement group and can be calculated without measuring brightness (L) or current density (J) based on additional tests.

[0293] according to Figures 16 to 20 One or more embodiments of the organic light-emitting element LED can satisfy the reference Figures 5 to 15 The described characteristics can be as follows: Figures 21 to 26 The organic light-emitting element (LED) shown has a series structure, and it can satisfy the following requirements: Figure 34 The numerical range described in the document.

[0294] The difference between the electron mobility and hole mobility of the organic layer in an organic light-emitting diode (LED) can be equal to or greater than 1 e. -9 cm 2 / V·s and equal to or less than 1e -3 cm 2 / V·s, and if the mobility difference is high (e.g., when the mobility difference is high), the capacitance change can be increased.

[0295] One or more embodiments in which an organic light-emitting element (LED) has a single light-emitting layer (EML) have been described herein.

[0296] This paper will describe in more detail the organic light-emitting element (LED) with a series structure including an emissive layer (EML).

[0297] Figure 21 It is a cross-sectional structure of an organic light-emitting element (LED) with a series structure according to one or more embodiments.

[0298] Figure 21 This is a cross-sectional view of an organic light-emitting element with a series structure.

[0299] Figure 21 The illustration includes a first electrode (or anode) and a second electrode (or cathode) in an organic light-emitting element (LED), and also illustrates three enlarged light-emitting layers EMLb1, EMLb2 and EMLb3 in the LED, as well as a functional layer between the first and second electrodes.

[0300] exist Figure 21 In this light-emitting element, three light-emitting layers EMLb1, EMLb2, and EMLb3 may be included; a hole injection layer HIL, a first hole transport layer HTL1, and a second hole transport layer HTL2 may be located between a first electrode (or anode) and the first light-emitting layer EMLb1; a first electron transport layer ETL1, a first n-charge generation layer CGLn1, a first p-charge generation layer CGLp1, and a third hole transport layer HTL3 may be located between the first light-emitting layer EMLb1 and the second light-emitting layer EMLb2; a second electron transport layer ETL2, a second n-charge generation layer CGLn2, a second p-charge generation layer CGLp2, and a fourth hole transport layer HTL4 may be located between the second light-emitting layer EMLb2 and the third light-emitting layer EMLb3; and the third electron transport layer ETL3 and the electron injection layer EIL may be located between the third light-emitting layer EMLb3 and the second electrode (or cathode).

[0301] Reference Figure 21 For each organic light-emitting element (LED), the three light-emitting layers EMLb1, EMLb2, and EMLb3, as well as the functional layer, can be disconnected, and depending on one or more embodiments, they can extend to adjacent organic light-emitting elements and can be connected to the light-emitting layers EMLb1, EMLb2, and EMLb3 and / or the functional layer of adjacent organic light-emitting elements.

[0302] Figure 21 At least one of the functional layers can be connected to the functional layer of an adjacent organic light-emitting element, and the light-emitting layers EMLb1, EMLb2 and EMLb3 can be not connected to the light-emitting layers EMLb1, EMLb2 and EMLb3 of the adjacent organic light-emitting element.

[0303] Reference Figure 21The light-emitting element may further include at least one additional light-emitting layer. A charge-generating layer may be further included as a functional layer between the light-emitting layer and the additional light-emitting layer, and the charge-generating layer may be between the hole transport layer and the electron transport layer.

[0304] This article will refer to Figures 22 to 26 A more detailed description of having Figure 21 The characteristics of an organic light-emitting element (LED) with a series cross-sectional structure are shown in the figure.

[0305] Figures 22 to 26 It is a graph showing the characteristics of organic light-emitting elements with a series structure.

[0306] Figures 22 to 24 The diagram illustrates one or more variations in the characteristics of an organic light-emitting element (LED) based on temperature changes in a series configuration. Figure 22 It is a graph about current density (J). Figure 23 It is a graph about luminous efficiency, and Figure 24 It is a graph about capacitance. Figures 22 to 24 It is a graph of temperatures at 25°C and 40°C, including direct measurements (ex) and simulation results (sim).

[0307] Reference Figure 22 The current density (J) of an organic light-emitting element (LED) with a series structure increases with increasing temperature, and therefore it can function in a similar manner to that of an organic light-emitting element (LED) comprising a single light-emitting layer (EML).

[0308] Reference Figure 23 The luminous efficiency characteristics of a tandem organic light-emitting element (LED) are illustrated, showing that the luminous efficiency decreases rapidly with increasing temperature, indicating that it operates in a manner similar to an organic light-emitting element (LED) comprising a single light-emitting layer (EML).

[0309] Reference Figure 24 The capacitance characteristics of an organic light-emitting element (LED) with a series structure and Figures 18 to 20 The characteristics shown are similar to those of an organic light-emitting element (LED) that includes a single light-emitting layer (EML).

[0310] This article will refer to Figure 25 The temperature sensitivity characteristics of tandem organic light-emitting elements (LEDs) are described in more detail.

[0311] and Figure 8 resemblance, Figure 25 The figure shows the ratio (ΔL / ΔJ) of the change in current density (ΔJ) to the change in brightness (ΔL) for series connections 1, 2, and 3. Series connection 1 is... Figure 21From the hole injection layer HIL to the first electron transport layer ETL1, including the first light-emitting layer EMLb1, tandem 2 is Figure 21 From the third hole transport layer HTL3 to the second electron transport layer ETL2, including the second light-emitting layer EMLb2, and 3 in series are Figure 21 From the fourth hole transport layer HTL4 to the electron injection layer EIL, including the third luminescent layer EMLb3. Comparison Figure 25 and Figure 8 They found that their general properties were similar to each other, but their slopes were different.

[0312] Figure 26 The diagram shows the maximum capacitance (C) of an organic light-emitting element (LED) with a series connection structure. max How to change it. Figure 20 resemblance, Figure 26 The maximum capacitance shown in the figure (C) max How to distinguish between hole transport layer (HTL) (see) Figure 34 The auxiliary layer between the light-emitting layer (EML) and the light-emitting layer is changed.

[0313] Figure 26 The left curve diagram illustrates that there is no reference layer (REF) between the hole transport layer (HTL) and the emissive layer (EML), and Figure 26 The right curve diagram illustrates the separation between the hole transport layer (HTL) and the emissive layer (EML), providing a second auxiliary layer (GIL) (see...). Figure 34 ) Implementation example (Split).

[0314] Reference Figure 26 The left curve without the auxiliary layer shows that, compared to 25°C, the maximum capacitance is slightly increased at 40°C, and references... Figure 26 The right-hand plot of the hole transport layer (HTL) and the light-emitting layer (EML) with a second auxiliary layer (GIL) separated shows that the maximum capacitance increases significantly at 40°C compared to 25°C. Therefore, it was found that if at least one auxiliary layer is provided between the hole transport layer (HTL) and the light-emitting layer (EML) (e.g., when at least one auxiliary layer is provided between the hole transport layer (HTL) and the light-emitting layer (EML), the maximum capacitance of the tandem organic light-emitting element (LED) can be increased.

[0315] An organic light-emitting element (LED) with a series structure of multiple light-emitting layers (EMLs) can further include a charge-generating layer (CGL), and refer to Figures 22 to 26 It can be found that the tandem structure of the organic light-emitting element (LED) operates in accordance with the equations and numerical ranges corresponding to the organic light-emitting element (LED) having a light-emitting layer (EML) as described in one or more embodiments.

[0316] Included Figures 22 to 26In the tandem structure, the charge generation layer (CGL) can be divided into an n-charge generation layer (CGLn) or a p-charge generation layer (CGLp), and the two charge generation layers (CGLs) can have a value equal to or greater than 0.1 eV and equal to or less than 3.0 eV as the interface barrier value. In one or more embodiments, n-charges (or electrons) or p-charges (or holes) can be doped into the n-charge generation layer (CGLn) or the p-charge generation layer (CGLp), and they can be doped at a lower concentration at the boundary portions compared to the middle portions of the corresponding layers.

[0317] This article will refer to Figures 27 to 30 A more detailed description of the energy level changes between one or more layers in a series-connected organic light-emitting element (LED).

[0318] Figures 27 to 30 The illustration shows a portion of the energy levels of an organic light-emitting element in a series structure according to one or more embodiments.

[0319] Figure 27 Illustration Figures 28 to 30 The reference for the energy levels in the middle, and Figures 28 to 30 The diagram illustrates the use of... Figure 27 The energy level is changed due to modifications.

[0320] For example, refer to Figure 27 The lower part of the diagram illustrates the hole injection layer (HIL), the light-emitting layer (EML), and the electron transport layer (ETL) in a series-connected organic light-emitting element (LED) (see...). Figure 34 The layers within ) Figure 27 The upper part of the diagram Figure 27 The lower part of the diagram illustrates the highest occupied molecular orbital (HOMO) energy level where holes can move. (See reference...) Figure 27 The voltages that can be varied before and after an luminescent layer EML at the highest occupied molecular orbital (HOMO) level are labeled V1bi and V2bi.

[0321] Reference Figure 28 Compared to the tandem structure of organic light-emitting elements (LEDs), the hole injection layer HIL can be changed to a p-doped hole injection layer PHIL, and the highest occupied molecular orbital (HOMO) energy level of the hole injection layer HIL can be reduced, which is shown as "deeper HOMO low doping".

[0322] As a result, V1bi-1 and V2bi-1 ( Figure 28 The voltage changes before and after the emission layer EML at the highest occupied molecular orbital (HOMO) level can respectively have lower than Figure 27The voltage values ​​of V1bi and V2bi. The interface barrier between the electron transport layer ETL and the adjacent p-doped hole injection layer PHIL can have a value equal to or greater than 0.13 eV and equal to or less than 3.0 eV. The doping concentration of the p-doped hole injection layer PHIL can be equal to or greater than 0.1% and equal to or less than 5%. The charge generation layer can be p-doped.

[0323] Figure 29 and Figure 30 The illustration shows additional iridium (Ir) doping, as in Figure 27 Central Figure 29 and Figure 30 A hole-injection layer (HIL) is applied. Depending on one or more embodiments, other atoms, such as platinum (Pt), may be doped. Figure 29 The diagram illustrates an energy level where no external voltage is applied (e.g., when no external voltage is applied), and Figure 30 The diagram illustrates what happens if an external voltage is applied to... Figure 29 Organic light-emitting elements (LEDs) with a series structure (e.g., when an external voltage is applied to) Figure 29 The change in energy level of an organic light-emitting element (LED) with a series structure.

[0324] Figure 29 The diagram illustrates that the energy levels of the emissive layer (EML) can be increased to the right through doping, which is consistent with... Figure 27 different. Figure 29 The holes and electrons injected through doping are illustrated as follows: and

[0325] Figure 30 The illustration shows the application of an external voltage and the doped electrons. and holes It can move and can be concentrated to one side by an electric field. Furthermore, the Fermi level can be controlled by an external voltage (V) through the electric field. ext This change alters and increases the voltage between the hole injection layer (HIL) and the emissive layer (EML). Through this change, the voltage variation between the hole injection layer (HIL) and the emissive layer (EML) can be reduced by a reverse field, and if the direction is to the right (e.g., when the direction is to the right), the energy level of the emissive layer (EML) can be reduced.

[0326] Figure 29 and Figure 30 The illustration shows that iridium (Ir) and / or platinum (Pt) can be additionally doped, and references will be made herein. Figure 31A , Figure 31B , Figure 32A and Figure 32B A more detailed description of how energy levels change based on doping and temperature sensitivity.

[0327] Figure 31A , Figure 31B, Figure 32A and Figure 32B The figure shows a graph showing the variation based on the additional doping of iridium.

[0328] The addition of iridium (Ir) and / or platinum (Pt) can result in large molecular sizes and large dipole properties. This will be discussed in reference to... Figure 31A and Figure 31B A more detailed description of the changes in energy levels generated if dopants with large dipole characteristics are used (e.g., the changes in energy levels generated when dopants with large dipole characteristics are used) will be provided herein, and references will be made to... Figure 32A and Figure 32B A more detailed description is given of the current density relative to the voltage, or the ratio of the change in current density to the change in brightness (ΔL / ΔJ).

[0329] This article will refer to Figure 31A and Figure 31B Describe the energy levels in more detail.

[0330] Figure 31A The diagram illustrates the energy levels of a light-emitting element to which iridium (Ir) or platinum (Pt) is not additionally doped. Figure 31B The diagram illustrates the energy levels of a light-emitting element to which iridium (Ir) or platinum (Pt) is additionally doped.

[0331] and Figure 31A The difference lies in Figure 31B In this process, because materials with large dipoles can be additionally doped, additional energy level changes (or shielding effects) can be generated around the emissive layer EML through the induced electrode effect, and the energy levels can be lowered relatively little. As a result, such as Figure 31B The diagram illustrates the energy level difference (V) of a light-emitting element doped with additional iridium (Ir) or platinum (Pt). bi ') can be seen from, for example Figure 31A The energy level difference (V) of the light-emitting element undoped with iridium (Ir) or platinum (Pt) is illustrated in the figure. bi () decrease.

[0332] This article will refer to Figure 32A and Figure 32B A more detailed description is given of the current density relative to the voltage, or the ratio of the change in current density to the change in brightness (ΔL / ΔJ).

[0333] Figure 32A The figure shows the current density relative to voltage, and Figure 32B The graph shows the ratio (ΔL / ΔJ) of the change in current density to the change in brightness relative to voltage. In each graph, light-emitting elements without additional iridium (Ir) or platinum (Pt) doping are labeled "reference", and light-emitting elements with additional iridium (Ir) doping are labeled "Ir-doped".

[0334] Reference Figure 32A It was found that if iridium (Ir) is additionally doped (e.g., when iridium (Ir) is additionally doped), the current density (J) can be relatively increased in the low voltage range. For example, if iridium (Ir) is additionally doped (e.g., when iridium (Ir) is additionally doped), as an effect, the voltage value applied with substantially the same current density can be reduced.

[0335] Reference Figure 32B It was found that if iridium (Ir) is additionally doped (e.g., when iridium (Ir) is additionally doped), the ratio (ΔL / ΔJ) of the change in current density to the change in brightness can be relatively increased in the low voltage range.

[0336] As described in one or more embodiments, the temperature sensitivity factor (TSF) can be plotted as a function of ΔL / ΔJ relative to voltage (see...). Figure 8 The slope of the tangent line corresponds to this. (Refer to...) Figure 32B It was found that when additionally doped with iridium (Ir), the slope value decreased from 0.505 to 0.279. Therefore, it was found that if additionally doped with iridium (Ir) (e.g., when additionally doped with iridium (Ir)), the temperature sensitivity factor (TSF) can be reduced, and the variability of the light-emitting element relative to temperature can be reduced.

[0337] like Figure 31A , Figure 31B , Figure 32A and Figure 32B The changes illustrated in the figure are also generated in the series structure.

[0338] Because the added iridium (Ir) or platinum (Pt) has a large molecular size, it may be relatively difficult to measure using methods that are usually available or commonly used, and therefore, the dipole moment value can be used to determine the degree of doping.

[0339] The dipole moment values ​​for each color of the light-emitting element, to which iridium (Ir) or platinum (Pt) is not additionally doped, are given in Tables 1 to 3, and the dipole moment is in Debye units.

[0340] Table 1

[0341] Red component dipole moment ETL 0.300 Buffer layer 2.260 REML 0.866 and 1.589 R-dopant 5.724 RIL 2.219 HTL 2.112 HIL 0.269

[0342] Table 2

[0343] Green components dipole moment ETL 0.300 Buffer layer 2.260 GEML 2.483 and 2.875 G-dopant 1.599 GIL 0.630 G' 0.964 HTL 2.112 PHIL 0.269

[0344] Table 3

[0345]

[0346]

[0347] The dipole moment values ​​in Tables 1 to 3 are values ​​under neutral conditions. The average dipole moment value for each color dopant (R dopant, G dopant, and B dopant) is approximately 3.7 Debye, and the average dipole moment value for the entire layer excluding the dopants (R dopant, G dopant, and B dopant) is approximately 1.5 Debye.

[0348] When iridium (Ir) or platinum (Pt) is additionally doped into each color of the light-emitting element in the neutral state, the average value of the dipole moment increases the value of the dipole moment of iridium (Ir) or platinum (Pt). As a result, the average value of the dipole moment of the entire layer, excluding the dopant (R dopant, G dopant, and B dopant), has a value equal to or greater than 2 Debye.

[0349] The red elements shown in Table 1, the green elements shown in Table 2, and the blue elements shown in Table 3 include one or more of the same layers and one or more different layers.

[0350] The red elements in Table 1 include a hole injection layer (HIL), a hole transport layer (HTL), an emissive layer (REML), a dopant (R-dopant), a buffer layer, an electron transport layer (ETL), and an auxiliary layer (RIL). The emissive layer (REML) of the red elements in Table 1 is described using two main components and two values.

[0351] The green element in Table 2 includes a p-doped hole injection layer (PHIL), a hole transport layer (HTL), an emissive layer (GEML), a dopant (G-dopant), a buffer layer, an electron transport layer (ETL), and auxiliary layers (GIL and G'). The emissive layer (GEML) of the green element in Table 2 is described using two main components and two values.

[0352] The blue components in Table 3 include the p-doped hole injection layer PHIL, the hole transport layer HTL, the auxiliary layer BIL, the dopant B-dopant, the light-emitting layer BEML, the buffer layer, and the electron transport layer ETL.

[0353] If iridium (Ir) or platinum (Pt) is additionally doped in each color of the organic light-emitting element LED (e.g., when iridium (Ir) or platinum (Pt) is additionally doped in each color of the organic light-emitting element LED), then iridium (Ir) or platinum (Pt) may be additionally included in each layer included in each organic light-emitting element LED, and the dipole moment of each layer may be increased.

[0354] The organic light-emitting elements (LEDs) summarized in Tables 1 to 3 may include at least two selected from hole injection layer HIL, p-doped hole injection layer PHIL, hole transport layer HTL, light-emitting layers REML, GEML and BEML, dopants R-dopant, G-dopant and B-dopant, buffer layer, electron transport layer ETL, and auxiliary layers RIL, GIL, BIL and G', and each layer of the organic light-emitting element LED may be further doped with additional dopants such as iridium (Ir) and / or platinum (Pt).

[0355] The average value of the dipole moment of each layer selected from the organic light-emitting element LED, excluding the dopants R-dopant, G-dopant and B-dopant, can be equal to or greater than 2 Debye.

[0356] Because the average dipole moment value of the entire layer, excluding the dopants R-dopant, G-dopant, and B-dopant, can have improved or enhanced temperature sensitivity characteristics when the average value increases (e.g., when the average value increases), it can be without an upper limit. Furthermore, since the values ​​in Tables 1 to 3 represent the neutral state, it is feasible to have a large dipole moment value when it is not neutral (e.g., when it is not neutral), so there can be no upper limit. However, the dipole moment value of the entire layer, excluding the dopants R-dopant, G-dopant, and B-dopant, can have 20 Debyes as an upper limit for the neutral state, and can have a range equal to or greater than 2 Debyes and equal to or less than 20 Debyes.

[0357] This article has already referred to Figures 27 to 30 The energy levels altered by doping and applying voltage in an organic light-emitting element (LED) with a tandem structure are described in more detail. Because the energy level alteration can be applied to both OLEDs with an emissive layer (EML), it is contemplated that OLEDs with tandem structures and OLEDs with a single emissive layer (EML) can operate in accordance with the equations and corresponding numerical ranges described in one or more embodiments.

[0358] This article will refer to Figure 33 A more detailed description of the actual measured value (TLS) of the brightness variation of one or more organic light-emitting elements (LEDs).

[0359] Figure 33 The diagram shows the number of elements corresponding to the actual measured value (TLS) of the brightness change of one or more organic light-emitting elements.

[0360] For example, Figure 33This is a graph that measures the actual luminance change (TLS) of one or more organic light-emitting elements (LEDs) and counts the number of elements falling within a set or predetermined range of luminance change. The luminance change between 25°C and 40°C is measured at the 23rd gray level of a green organic light-emitting element. Figure 33 Since there is no change in brightness relative to temperature, it corresponds 100% to the target value.

[0361] exist Figure 33 The study found that brightness changes little with temperature, confirming that it is possible to expect or need to reduce brightness variation with temperature.

[0362] As shown in Equation 3, the change in brightness is further reduced by the improvement or enhancement of the change in current density (ΔJ), which gives the TLS prediction range when ΔJ is improved or enhanced.

[0363] Examples are shown where the actual measured value of the change in brightness (TLS) is close to 100% and the highest occupied molecular orbital (HOMO) energy disorder (σHOMO) value is greater than 0.13 eV. Therefore, it was found that if the actual measured value of the change in brightness (TLS) is 100% (e.g., when the actual measured value of the change in brightness (TLS) is 100%), the highest occupied molecular orbital (HOMO) energy disorder (σHOMO) value can be equal to or greater than 0.13 eV.

[0364] This article will refer to Figure 34 The characteristics of each layer of an organic light-emitting element (LED) according to one or more embodiments are described in more detail.

[0365] Figure 34 It is a table of energy levels for the various layers of an organic light-emitting element according to one or more embodiments.

[0366] like Figure 34 The organic light-emitting element (LED) illustrated herein is a green organic light-emitting element comprising an anode, a cathode, and a light-emitting layer (EML), and may further comprise therebetween a p-doped hole injection layer (PHIL), a hole transport layer (HTL), a first auxiliary layer (G'), a second auxiliary layer (GIL), a buffer layer (BUF), and an electron transport layer (ETL). Depending on one or more embodiments, the buffer layer (BUF) may be omitted, and the electron injection layer (EIL) may be further included. In this document, the first auxiliary layer (G') may be an auxiliary layer that traps electrons already in the light-emitting layer (EML) and can effectively or appropriately inject holes transported from the hole transport layer (HTL) into the light-emitting layer (EML), and the second auxiliary layer (GIL) may adjust the hole charge balance of the light-emitting layer (EML) to increase or enhance the efficiency of the light-emitting layer (EML).

[0367] Reference Figure 34 An IB (intermediate band), which shows the energy values ​​at the boundary between two adjacent layers and is additionally described to confirm the energy difference between layers, can be included between each layer.

[0368] like Figure 34 The units of the numbers described in the text are eV and, as shown... Figure 34 Each column illustrated in the diagram can typically be divided into two parts: the upper part depicts the lowest unoccupied molecular orbital (LUMO) energy levels, and the lower part depicts the highest occupied molecular orbital (HOMO) energy levels. For example, LUMO energy levels further describe the LUMO energy difference (ΔLUMO) between adjacent layers, the LUMO energy disorder, and the minimum LUMO energy difference (Min.ΔLUMO). Similarly, HOMO energy levels further describe the HOMO energy difference (ΔHOMO) between adjacent layers, the HOMO energy disorder, and the minimum HOMO energy difference (Min.ΔHOMO).

[0369] Reference Figure 34 Only HOMO energy can exist between the emissive layer EML and the anode, and only LUMO energy can exist between the emissive layer EML and the cathode.

[0370] Reference Figure 34 The average value of the interface barrier at the boundary of the hole transport path is 0.152 eV, and the average value calculated with reference to the minimum value is 0.123 eV. The average value of the interface barrier at the boundary of the electron transport path is 0.201 eV, and the average value calculated with reference to the minimum value is 0.152 eV.

[0371] In addition to the organic light-emitting element (LED) as described in one or more embodiments, the organic light-emitting element (LED) suitable for one or more embodiments of this disclosure may have the following characteristics.

[0372] The interfacial barrier value at the boundary between adjacent layers can have a value between -0.3 eV and 0.5 eV.

[0373] The doping concentration of the p-doped hole injection layer (PHIL) can be equal to or greater than 0.1% and equal to or less than 5%.

[0374] exist Figure 34 In this embodiment, there may be two auxiliary layers (e.g., a first auxiliary layer G' and a second auxiliary layer GIL) between the hole transport layer HTL and the light emission layer EML, but in one or more embodiments, there may be only one auxiliary layer.

[0375] The difference between the electron mobility and hole mobility in the organic layer of an organic light-emitting element (LED) can be equal to or greater than 1 e -9 cm2 / V·s and equal to or less than 1e -3 cm 2 / V·s.

[0376] This article will refer to Figure 35 The properties of the materials used in organic light-emitting elements (LEDs) are described in more detail to have mobility and / or bandgap below a set or predetermined level as described in one or more embodiments.

[0377] Figure 35 This is a table of conditions relating to the properties of an organic light-emitting element according to one or more embodiments.

[0378] Figure 35 The properties of matter are described by factors including the recombination energy, transfer integral (or transfer matrix), and energy disorder (or energy dispersion) in the Marcus equations based on Marcus theory.

[0379] Reference Figure 35 The use of recombination energy allows materials used in organic light-emitting elements (LEDs) to move electrons or holes, and organic light-emitting elements (LEDs) can be constructed or arranged using materials with a recombination energy of equal to or less than 0.19 eV.

[0380] The transfer integral represents the energy value that an electron belonging to one atom in an organic material can move to an orbital of another atom, and according to... Figure 35 Organic light-emitting elements (LEDs) can be produced by utilizing LEDs with an energy density equal to or greater than 2.8 e. -7 The material is used to construct or arrange the eV transfer integral value.

[0381] Energy disorder is a value used to indicate the varying degrees of energy distribution relative to locations within a material, and according to... Figure 35 Organic light-emitting elements (LEDs) can be constructed or arranged by using materials with a value equal to or greater than 0.1 eV as the energy disorder value of the organic layer in the organic light-emitting element LED.

[0382] Organic light-emitting elements (LEDs) can be used to meet requirements such as Figure 35 Materials with recombined energy, transfer integral, and energy disorder values ​​described herein can be constructed or arranged to have high mobility. Depending on one or more embodiments, organic light-emitting elements (LEDs) can be constructed or arranged using materials that satisfy one or more of the conditions.

[0383] Furthermore, if an organic light-emitting element (LED) is manufactured (e.g., when manufacturing an organic light-emitting element LED), an organic light-emitting element LED with low temperature sensitivity can be formed or provided by applying the above-mentioned items.

[0384] One or more embodiments of this disclosure provide an electronic device including a display device 1000 as described in one or more embodiments.

[0385] In one or more embodiments, the electronic device may be a smartphone, television, monitor, tablet computer, electric vehicle, mobile phone, tablet PC, mobile communication terminal, electronic notebook, e-book, portable multimedia player (PMP), navigation device, ultra-mobile PC (UMPC), laptop computer, billboard, Internet of Things (IoT) device, smartwatch, watch phone, and / or head-mounted display (HMD).

[0386] Because a numerical range can be perfectly valid or appropriate without an upper or lower limit, and also because even without an upper or lower limit (e.g., when there is no upper or lower limit), considering the size of the component, there exists an actual upper limit because it may not be infinitely large, or an actual lower limit because it must be greater than zero, one or more numerical ranges can be described without including an upper or lower limit. Therefore, even without an upper or lower limit (e.g., when there is no upper or lower limit), it can still be ambiguous.

[0387] Although the subject matter of this disclosure has been described in conjunction with embodiments now considered to be practice, it should be understood that this disclosure is not limited to the disclosed embodiments, but rather is intended to cover one or more suitable modifications and equivalent arrangements included within the spirit and scope of the claims and their equivalents. Therefore, it will be understood that the one or more embodiments described herein are merely illustrative and not restrictive in all respects.

Claims

1. A display device, comprising: The red, green, and blue pixels each consist of a transistor and an organic light-emitting element. Among them, the capacitance change ΔCap' at the maximum value of Equation 10 relative to the organic light-emitting element max (c,T) has a value equal to or greater than 100%. Equation 10 Variable c is color, T is temperature, T0 is 25℃, and Cap is capacitance. ΔCap' max (c,T) satisfies equation 9. Equation 9 ΔCap′ max (c,T)=ΔCap max (c,T) / ΔV max (c,T), The capacitance change ΔCap is represented by its maximum value. max (c,T) satisfies equation 6. Equation 6 Maximum voltage change ΔV max (c,T) satisfies equation 8. Equation 8 ΔV max (c,T)=V max (c,T) / V max (c,T0)。 2. The display device as claimed in claim 1, wherein: For red and green, the capacitance change ΔCap' at the maximum value max (c,T) has a value equal to or greater than 500%.

3. The display device as claimed in claim 2, wherein: The entire voltage range of the operating voltage applied to the organic light-emitting element has a value equal to or greater than -1V and equal to or less than 10V.

4. The display device as claimed in claim 2, wherein: The difference between the electron mobility and hole mobility of the organic layer of the organic light-emitting element is equal to or greater than 1e -9 cm 2 / V·s and equal to or less than 1e -3 cm 2 / V·s.

5. The display device as claimed in claim 2, wherein: The interface barrier value at the boundary between adjacent layers in the organic light-emitting element has a value equal to or greater than -0.3 eV and equal to or less than 0.5 eV.

6. The display device as claimed in claim 2, wherein: The organic light-emitting element includes a p-doped hole injection layer, and The doping concentration of the p-doped hole injection layer is equal to or greater than 0.1% and equal to or less than 5%.

7. The display device as claimed in claim 2, wherein: The organic light-emitting element includes a hole transport layer, a light-emitting layer, and at least one auxiliary layer between the hole transport layer and the light-emitting layer.

8. The display device as claimed in claim 2, wherein: The organic light-emitting element has a series structure comprising a light-emitting layer and a charge-generating layer.

9. The display device as claimed in claim 8, wherein: Each of the charge generation layers is an n-charge generation layer or a p-charge generation layer, and The n-charge generation layer or the p-charge generation layer has a value equal to or greater than 0.1 eV and equal to or less than 3.0 eV as the interface barrier value.

10. The display device as claimed in claim 9, wherein: The boundary portion of the n-charge generation layer or the p-charge generation layer is doped at a lower concentration than the middle portion of the n-charge generation layer or the p-charge generation layer.

11. The display device as claimed in claim 2, wherein: The organic layer in the organic light-emitting element has an energy disorder value equal to or greater than 0.1 eV.

12. The display device as claimed in claim 1, wherein: The organic light-emitting element has a density equal to or greater than 0.15 × 10⁻⁶. -1 Cd·m 2 / V and equal to or less than 0.7×10 -1 Cd·m 2 The value of the temperature sensitivity factor TSF in Equation 3, / V; Equation 3 ΔJ is the change in current density, ΔL is the change in brightness, V is the voltage, c is the color, and T is the temperature.

13. The display device as claimed in claim 1, wherein: The organic light-emitting element is doped with iridium or platinum dopants.

14. The display device as claimed in claim 13, wherein: The organic light-emitting element includes at least two layers selected from the following: a hole injection layer, a p-doped hole injection layer, a hole transport layer, a light-emitting layer, a dopant layer, a buffer layer, an electron transport layer, and an auxiliary layer. Each of the at least two layers of the organic light-emitting element is doped with the iridium or platinum dopant, and The average value of the dipole moment of each of the at least two layers selected from the organic light-emitting element, excluding the dopant, is equal to or greater than 2 Debye.

15. A display device, comprising: The red, green, and blue pixels each consist of a transistor and an organic light-emitting element. Wherein, relative to the organic light-emitting element, as expressed by Equation 3, the temperature sensitivity factor TSF is equal to or greater than 0.15 × 10⁻⁶. -1 Cd·m 2 / V and equal to or less than 0.25×10 -1 Cd·m 2 / V or equal to or greater than 0.51×10 -1 Cd·m 2 / V and equal to or less than 0.7×10 -1 Cd·m 2 / V; Equation 3 ΔJ is the change in current density, ΔL is the change in brightness, V is the voltage, c is the color, and T is the temperature.

16. The display device as claimed in claim 15, wherein: The maximum current density variation at low grayscale ranges from 380% to 60%, and The minimum current density variation at high grayscale ranges from 170% to 30%.

17. The display device as claimed in claim 16, wherein: The minimum value of the ratio ΔL / ΔJ of the current density change ΔJ and the brightness change ΔL at the low grayscale level has a range of 30% ± 10%, and The maximum value of the ratio ΔL / ΔJ of the current density change ΔJ and the brightness change ΔL at the high grayscale level has a range of 55% ± 10%.

18. The display device as claimed in claim 17, wherein: The low grayscale is equal to or less than the 23rd grayscale, and the high grayscale is greater than the 23rd grayscale.

19. The display device as claimed in claim 18, wherein: The difference between the initial voltage value on one side of the voltage range applied to the organic light-emitting element and the saturation voltage at which the current density change ΔJ or the ratio ΔL / ΔJ of the current density change ΔJ to the brightness change ΔL begins to saturate is equal to or greater than 0.3V.

20. An electronic device comprising a display device according to any one of claims 1 to 19.

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