Organic electroluminescent device

Abstract

The invention relates to an organic electroluminescent device. Embodiments of the disclosed subject matter provide an apparatus comprising at least two stacked emissive layers. A peak wavelength difference between the at least two stacked emission layers may be less than or equal to 30 nm, less than or equal to 20 nm, and / or less than or equal to 10 nm. The emission outputs of the two emissive layers have a difference in the 1976 CIE color space that may be at least 0.004, at least 0.006, at least 0.008, at least 0.010, at least 0.015, at least 0.020, at least 0.025, and / or at least 0.050 [Delta] u'v '.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. patent application serial number 63 / 523,432 filed on June 27, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to an emission device including an organic emission device having a plurality of stacked emission layers and a manufacturing technology thereof. Background Art

[0004] Optoelectronic devices utilizing organic materials are becoming increasingly popular for many reasons. Many materials used to make the devices are relatively inexpensive, so organic optoelectronic devices have the potential to have cost advantages over inorganic devices. In addition, the inherent properties of organic materials (e.g., their flexibility) can make them more suitable for specific applications, such as manufacturing on flexible substrates. Examples of organic optoelectronic devices include organic light emitting diodes / devices (OLEDs), organic phototransistors, organic photovoltaic cells, and organic photodetectors. For OLEDs, organic materials can have performance advantages over conventional materials. For example, the wavelength at which the organic emissive layer emits light can generally be easily adjusted with appropriate dopants.

[0005] OLEDs utilize organic thin films that emit light when voltage is applied to the device. OLEDs are becoming an increasingly popular technology for applications such as flat panel displays, lighting, and backlighting. Several OLED materials and configurations are described in U.S. Pat. Nos. 5,844,363, 6,303,238, and 5,707,745, which are incorporated herein by reference in their entirety.

[0006] One application of phosphorescent molecules capable of phosphorescent emission is full-color displays. Industry standards for such displays require pixels suitable for emitting specific colors (called "saturated" colors). Specifically, these standards require saturated red, green, and blue pixels. Alternatively, OLEDs can be designed to emit white light. In conventional liquid crystal displays, an absorption filter is used to filter the emission from a white backlight to produce red, green, and blue emissions. The same technology can also be used for OLEDs. White OLEDs can be single EML devices or stacked structures. Color can be measured using CIE coordinates well known in the art.

[0007] As used herein, the term "organic" includes polymeric materials and small molecule organic materials that can be used to make organic optoelectronic devices. "Small molecule" refers to any organic material that is not a polymer, and a "small molecule" may actually be quite large. In some cases, a small molecule may include repeating units. For example, the use of a long chain alkyl group as a substituent does not remove the molecule from the "small molecule" category. Small molecules can also be incorporated into polymers, for example as side groups on the polymer backbone or as part of the backbone. Small molecules can also serve as the core part of a dendritic polymer, which consists of a series of chemical shells built on the core part. The core part of a dendritic polymer can be a fluorescent or phosphorescent small molecule emitter. A dendritic polymer can be a "small molecule", and all dendritic polymers currently used in the field of OLEDs are considered to be small molecules.

[0008] As used herein, "top" means farthest from the substrate, while "bottom" means closest to the substrate. Where a first layer is described as being "disposed "above" a second layer, the first layer is disposed farther from the substrate. Unless it is specified that the first layer is "in contact with" the second layer, there may be other layers between the first and second layers. For example, a cathode may be described as being "disposed "above" an anode even though various organic layers are present between the cathode and the anode.

[0009] As used herein, "solution processable" means capable of being dissolved, dispersed or transported in and / or deposited from a liquid medium in the form of a solution or suspension.

[0010] When a ligand is believed to directly contribute to the photosensitive property of an emissive material, the ligand may be referred to as "photosensitive." When a ligand is believed not to contribute to the photosensitive property of an emissive material, the ligand may be referred to as "ancillary," but the ancillary ligand may alter the properties of the photosensitive ligand.

[0011] As used herein, and as will be generally understood by one skilled in the art, a first "Highest Occupied Molecular Orbital" (HOMO) or "Lowest Unoccupied Molecular Orbital" (LUMO) energy level is "greater than" or "higher than" a second HOMO or LUMO energy level if the first energy level is closer to the vacuum energy level. Since the ionization potential (IP) is measured as a negative energy relative to the vacuum energy level, a higher HOMO energy level corresponds to an IP with a smaller absolute value (a less negative IP). Similarly, a higher LUMO energy level corresponds to an electron affinity (EA) with a smaller absolute value (a less negative EA). On a conventional energy level diagram with the vacuum energy level at the top, the LUMO energy level of a material is higher than the HOMO energy level of the same material. A "higher" HOMO or LUMO energy level appears closer to the top of this diagram than a "lower" HOMO or LUMO energy level.

[0012] As used herein, and as one skilled in the art would generally understand, a first work function is "greater than" or "higher than" a second work function if the first work function has a higher absolute value. Because work functions are typically measured as negative numbers relative to the vacuum level, this means that a "higher" work function is more negative. On a conventional energy level diagram with the vacuum level at the top, a "higher" work function is illustrated as being farther away from the vacuum level in a downward direction. Thus, the definition of HOMO and LUMO energy levels follows different rules than work functions.

[0013] Layers, materials, regions, and devices may be described herein with reference to the color of light they emit. Generally, as used herein, an emitting region described as producing light of a particular color may include one or more emitting layers disposed on top of each other in a stacked manner.

[0014] As used herein, a "red" layer, material, region or device refers to a layer, material, region or device that emits light in the range of about 580-700nm or whose emission spectrum has the highest peak in the region. Similarly, a "green" layer, material, region or device refers to a layer, material, region or device that emits or has an emission spectrum with a peak wavelength in the range of about 500-600nm; a "blue" layer, material or device refers to a layer, material or device that emits or has an emission spectrum with a peak wavelength in the range of about 400-500nm; a "yellow" layer, material, region or device refers to a layer, material, region or device that has an emission spectrum with a peak wavelength in the range of about 540-600nm; a "cyan" layer, material or device refers to a layer, material or device that emits or has an emission spectrum with a peak wavelength in the range of about 490-520nm; and an "orange" layer, material or device refers to a layer, material or device that emits or has an emission spectrum with a peak wavelength in the range of about 570-620nm. In some arrangements, separate regions, layers, materials, regions, or devices may provide separate "dark blue" and "light blue" light. As used herein, in arrangements that provide separate "light blue" and "dark blue" components, the "dark blue" component refers to a component having a peak emission wavelength that is at least about 4 nm less than the peak emission wavelength of the "light blue" component. Typically, the peak emission wavelength of the "light blue" component is in the range of about 465 nm to 500 nm, and the peak emission wavelength of the "dark blue" component is in the range of about 400 nm to 470 nm, but these ranges may vary for some configurations. Similarly, a color-changing layer refers to a layer that converts or modifies light of another color into light having a wavelength designated for that color. For example, a "red" color filter refers to a color filter that forms light having a wavelength in the range of about 580-700 nm. In general, there are two types of color-changing layers: color filters that modify the spectrum by removing undesirable wavelengths of light, and color-changing layers that convert higher energy photons into lower energy photons. A "color" component refers to a component that, when activated or used, produces or otherwise emits light having a specific color as previously described. For example, a "first emission region of a first color" and a "second emission region of a second color different from the first color" describe two emission regions that emit two different colors as previously described when activated within the device.

[0015] As used herein, emissive materials, layers, and regions may be distinguished from each other and from other structures based on the spectrum of light initially produced by the material, layer, or region, rather than the light ultimately emitted by the same or different structure. Initial light generation is typically the result of a change in energy levels that results in photon emission. For example, an organic emissive material may initially produce blue light, which may be converted to red or green light by a color filter, quantum dots, or other structure, such that the complete emissive stack or sub-pixel emits red or green light. In this case, the initial emissive material or layer may be referred to as the "blue" component, even if the sub-pixel is the "red" or "green" component.

[0016] In some cases, it may be preferred to describe the color of a component, such as the color of an emitting region, a sub-pixel, a color changing layer, etc., in terms of 1931 CIE coordinates. For example, a yellow emitting material may have multiple peak emission wavelengths, one in or near the edge of a "green" region, and one in or near the edge of a "red" region, as previously described. Thus, as used herein, each color term also corresponds to a shape in the 1931 CIE coordinate color space. Shapes in the 1931 CIE color space are constructed by following the trajectory between two color points and any other interior points. For example, the interior shape parameters for red, green, blue, and yellow may be defined as follows:

[0017]

[0018] Further details regarding OLEDs and the definitions set forth above can be found in US Pat. No. 7,279,704, which is incorporated herein by reference in its entirety. Summary of the invention

[0019] According to one embodiment, an organic light emitting diode / device (OLED) is provided. The OLED may include an anode, a cathode, and an organic layer disposed between the anode and the cathode. According to one embodiment, the organic light emitting device is incorporated into one or more devices selected from consumer products, electronic component modules, and / or lighting panels.

[0020] According to an embodiment, the device may include at least two stacked emission layers. The peak wavelength difference between the at least two stacked emission layers may be less than or equal to 30 nm, less than or equal to 20 nm, and / or less than or equal to 10 nm. The emission outputs of the two emission layers may have a difference of at least 0.004, at least 0.006, at least 0.008, at least 0.010, at least 0.015, at least 0.020, at least 0.025, and / or at least 0.050 Δu'v' in the 1976 CIE color space.

[0021] At least one charge generation layer may be disposed between at least two stacked emission layers.

[0022] The device may be a microcavity device.

[0023] At least two stacked emission layers may include at least two red emission layers, at least two green emission layers, at least two blue emission layers and / or at least two yellow emission layers. Two or more emission layers in at least two stacked emission layers may include different materials and / or different hosts. Two or more emission layers in at least two stacked emission layers may include different emitters. Two or more emission layers in at least two stacked emission layers may include different emission layer materials. At least one of the two or more emission layers may include a fluorescent emitter and a phosphorescent emitter. At least one of the two or more emission layers may include a phosphorescent emitter. At least one of the two or more emission layers may include a delayed fluorescent emitter. At least one of the two or more emission layers may include a non-delayed fluorescent emitter. At least two of the two or more emission layers may include a fluorescent emitter and a phosphorescent emitter. At least two of the two or more emission layers may include a phosphorescent emitter. At least two of the two or more emission layers contain a delayed fluorescent emitter. At least two of the two or more emission layers may include a non-delayed fluorescent emitter.

[0024] Two or more of the at least two stacked emission layers may have different line shapes, and their full width at half maximum (FWHM) or quarter full width at maximum (FWQM) differs by at least 2nm, at least 4nm, at least 6nm and / or at least 8nm. At least one of the two or more emission layers may have a FWHM of less than 80nm, less than 70nm, less than 60nm, less than 50nm, less than 40nm and / or less than 30nm. The device may have a FWHM of less than 60nm, less than 50nm, 40nm, 30nm, 20nm and / or 10nm. At least one of the two or more emission layers may have a FWQM of less than 100nm, 90nm, 80nm, 70nm, 60nm and / or 50nm. The device may have a FWQM of less than 70nm, less than 60nm, less than 50nm, less than 40nm, less than 30nm and / or less than 20nm. Two or more of the at least two stacked emission layers may have different external quantum efficiencies (EQEs) of at least 1%, at least 3%, and / or at least 5%. At least one of the two or more emission layers may have an EQE greater than 10%, greater than 20%, greater than 30%, and / or greater than 40%. At least two of the two or more emission layers may each have an EQE greater than 10%, greater than 20%, greater than 30%, and / or greater than 40%. Two or more of the at least two stacked emission layers may have different external quantum efficiency roll-offs when the driving current density increases by at least 1%, at least 3%, and at least 5%. At least one of the two or more emission layers may have a roll-off of less than 75%, less than 80%, less than 85%, and / or less than 90%. At least two of the two or more emission layers may each have a roll-off of less than 75%, less than 80%, less than 85%, and / or less than 90%. Two or more of the at least two stacked emission layers may have lifetimes that differ by at least 10%, at least 25%, and / or at least 50%. Two or more of the at least two stacked emission layers may have different operating voltages at a selected current density. Two or more of the at least two stacked emission layers may have different doping concentrations. Two or more of the at least two stacked emission layers may have lifetimes that differ by at least 10%, at least 25%, and / or at least 50%. At least and / or at least Thickness.

[0025] One of the at least two stacked emission layers may be located at the first linear emitter and the second linear emitter. One of the at least two stacked emission layers may be the first linear emitter and may be positioned closer to the reflective electrode of the device than the other of the at least two stacked emission layers. One of the at least two stacked emission layers may be the second linear emitter and may be positioned closer to the reflective electrode of the device than the other of the at least two stacked emission layers.

[0026] One of the at least two stacked emission layers may be blue-shifted compared to another of the at least two stacked emission layers and positioned closer to a reflective electrode of the device. One of the at least two stacked emission layers may be red-shifted compared to another of the at least two stacked emission layers and positioned closer to a reflective electrode of the device.

[0027] Two or more of the at least two stacked emission layers have different cavity conditions.

[0028] At least one of the at least two stacked emission layers is detuned from an optical cavity maximum determined by a maximum luminous efficiency (LE) by at least one selected from the group consisting of: 3%, 5%, 8% or 10% LE. The closest optical maximum may be 1 / 4, 2 / 4, 1 / 4, 4 / 4 and / or 5 / 4 wavelength (λ). At least two of the stacked emission layers may have a different degree of aging.

[0029] Two or more of the at least two stacked emission layers may age differently under operating conditions, wherein LT95 may differ by 10%, 25% and / or 50% between two or more emission layers of the at least two stacked emission devices.

[0030] The at least two stacked emission layers may be a stack of at least three emission layers, a stack of at least four emission layers and / or a stack of at least five emission layers.

[0031] The angular dependence of one or more of the at least two emission layers may change as the one or more emission layers age. When the angular dependence of one or more of the at least two stacked emission layers changes, the brightness of the one or more emission layers may change. When the angular dependence of one or more of the at least two stacked emission layers changes, the CIE value of the one or more emission layers may change.

[0032] There may be different angular dependencies between different emission layers in at least two emission layers, wherein when light is emitted at 45° or 60° to the normal direction, the angular dependencies have brightness that may differ by at least 2%, at least 4%, at least 6% and at least 8% and / or at least 10%, and CIE that may differ by at least 0.002, at least 0.004, at least 0.006, 0.008 and 0.010.

[0033] The device may include at least one charge generation layer, the charge generation layer comprising a metal layer.The at least one charge generation layer may have a transparency greater than 10%, greater than 30%, greater than 50% and / or greater than 75%.

[0034] At least two stacked emitting layers of the device may have different transparencies.

[0035] Two or more of the at least two stacked emitting layers of the device may be individually addressable, and wherein the device having at least two stacked emitting layers has a transparent anode and a transparent cathode.

[0036] Two or more of the at least two stacked emitting layers are individually addressable, wherein the device having the at least two stacked emitting layers may have a transparent electrode and a reflective electrode.

[0037] According to an embodiment, the device may include at least two stacked emission layers. The peak wavelength difference between the at least two stacked emission layers may be less than or equal to 50nm, less than or equal to 40nm, less than or equal to 30nm, less than or equal to 20nm and / or less than or equal to 10nm. The peak wavelength difference between the at least two stacked emission layers may be greater than 1nm, greater than 2nm, greater than 3nm, greater than 4nm and / or greater than 5nm.

[0038] According to one embodiment, the device may include at least two stacked emission layers. The emission outputs of the two stacked emission layers may have a difference of at least 0.004, at least 0.006, at least 0.008, at least 0.010, at least 0.015, at least 0.020, at least 0.025 and / or at least 0.050 Δu'v' in the 1976 CIE color space. The emission outputs of the two stacked emission layers may have a difference of less than 0.35, less than 0.30, less than 0.25, less than 0.20 and / or less than 0.10 Δu'v' in the 1976 CIE color space.

[0039] According to an embodiment, a consumer electronic device may include at least two stacked emission layers. The peak wavelength difference between the at least two stacked emission layers may be less than or equal to 30 nm, less than or equal to 20 nm, and / or less than or equal to 10 nm. The emission outputs of the two emission layers may have a difference of at least 0.004, at least 0.006, at least 0.008, at least 0.010, at least 0.015, at least 0.020, at least 0.025, and / or at least 0.050 Δu'v' in the 1976 CIE color space.

[0040] The consumer electronic device may be a flat panel display, a curved display, a computer monitor, a medical monitor, a television, a sign, a light for interior or exterior lighting and / or signaling, a head-up display, a fully or partially transparent display, a flexible display, a rollable display, a foldable display, a stretchable display, a laser printer, a telephone, a cellular phone, a tablet computer, a phablet, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a microdisplay having a diagonal of less than 2 inches, a 3D display, a virtual reality or augmented reality display, a vehicle, an in-vehicle display, a video wall comprising multiple displays tiled together, a theater or stadium screen, and / or a sign.

[0041] According to one embodiment, a device may include an organic light emitting device (OLED) having at least one pixel, wherein each pixel has one or more sub-pixels, and wherein at least one of the one or more sub-pixels may have at least two stacked emission layers. The peak wavelength difference between the at least two stacked emission layers may be less than or equal to 30nm, less than or equal to 20nm, and / or less than or equal to 10nm. The emission outputs of the two emission layers may have a difference in the 1976 CIE color space selected from the group consisting of: at least 0.004, at least 0.006, at least 0.008, at least 0.010, at least 0.015, at least 0.020, at least 0.025, and at least 0.050Δu'v'.

[0042] At least one charge generation layer may be disposed between at least two stacked emission layers.

[0043] The device may be a microcavity device.

[0044] At least two stacked emission layers may include at least two red emission layers, at least two green emission layers, at least two blue emission layers and / or at least two yellow emission layers. Two or more emission layers in at least two stacked emission layers may include different materials and / or different hosts. Two or more emission layers in at least two stacked emission layers may include different emitters. Two or more emission layers in at least two stacked emission layers may include different emission layer materials. At least one of the two or more emission layers may include a fluorescent emitter and a phosphorescent emitter. At least one of the two or more emission layers may include a phosphorescent emitter. At least one of the two or more emission layers may include a delayed fluorescent emitter. At least one of the two or more emission layers may include a non-delayed fluorescent emitter. At least two of the two or more emission layers may include a fluorescent emitter and a phosphorescent emitter. At least two of the two or more emission layers may include a phosphorescent emitter. At least two of the two or more emission layers contain a delayed fluorescent emitter. At least two of the two or more emission layers may include a non-delayed fluorescent emitter.

[0045] Two or more of the at least two stacked emission layers may have different line shapes, and their full width at half maximum (FWHM) or quarter full width at maximum (FWQM) differs by at least 2nm, at least 4nm, at least 6nm and / or at least 8nm. At least one of the two or more emission layers may have a FWHM of less than 80nm, less than 70nm, less than 60nm, less than 50nm, less than 40nm and / or less than 30nm. The device may have a FWHM of less than 60nm, less than 50nm, 40nm, 30nm, 20nm and / or 10nm. At least one of the two or more emission layers may have a FWQM of less than 100nm, 90nm, 80nm, 70nm, 60nm and / or 50nm. The device may have a FWQM of less than 70nm, less than 60nm, less than 50nm, less than 40nm, less than 30nm and / or less than 20nm. Two or more of the at least two stacked emission layers may have different external quantum efficiencies (EQEs) of at least 1%, at least 3%, and / or at least 5%. At least one of the two or more emission layers may have an EQE greater than 10%, greater than 20%, greater than 30%, and / or greater than 40%. At least two of the two or more emission layers may each have an EQE greater than 10%, greater than 20%, greater than 30%, and / or greater than 40%. Two or more of the at least two stacked emission layers may have different external quantum efficiency roll-offs when the driving current density increases by at least 1%, at least 3%, and at least 5%. At least one of the two or more emission layers may have a roll-off of less than 75%, less than 80%, less than 85%, and / or less than 90%. At least two of the two or more emission layers may each have a roll-off of less than 75%, less than 80%, less than 85%, and / or less than 90%. Two or more of the at least two stacked emission layers may have lifetimes that differ by at least 10%, at least 25%, and / or at least 50%. Two or more of the at least two stacked emission layers may have different operating voltages at a selected current density. Two or more of the at least two stacked emission layers may have different doping concentrations. Two or more of the at least two stacked emission layers may have lifetimes that differ by at least 10%, at least 25%, and / or at least 50%. At least and / or at least Thickness.

[0046] One of the at least two stacked emission layers may be located at the first linear emitter and the second linear emitter. One of the at least two stacked emission layers may be the first linear emitter and may be positioned closer to the reflective electrode of the device than the other of the at least two stacked emission layers. One of the at least two stacked emission layers may be the second linear emitter and may be positioned closer to the reflective electrode of the device than the other of the at least two stacked emission layers.

[0047] One of the at least two stacked emission layers may be blue-shifted compared to another of the at least two stacked emission layers and positioned closer to a reflective electrode of the device. One of the at least two stacked emission layers may be red-shifted compared to another of the at least two stacked emission layers and positioned closer to a reflective electrode of the device.

[0048] Two or more of the at least two stacked emission layers have different cavity conditions.

[0049] At least one of the at least two stacked emission layers is detuned from an optical cavity maximum determined by a maximum luminous efficiency (LE) by at least one selected from the group consisting of: 3%, 5%, 8% or 10% LE. The closest optical maximum may be 1 / 4, 2 / 4, 1 / 4, 4 / 4 and / or 5 / 4 wavelength (λ). At least two of the stacked emission layers may have a different degree of aging.

[0050] Two or more of the at least two stacked emission layers may age differently under operating conditions, wherein LT95 may differ by 10%, 25% and / or 50% between two or more emission layers of the at least two stacked emission devices.

[0051] The at least two stacked emission layers may be a stack of at least three emission layers, a stack of at least four emission layers and / or a stack of at least five emission layers.

[0052] The angular dependence of one or more of the at least two emission layers may change as the one or more emission layers age. When the angular dependence of one or more of the at least two stacked emission layers changes, the brightness of the one or more emission layers may change. When the angular dependence of one or more of the at least two stacked emission layers changes, the CIE value of the one or more emission layers may change.

[0053] There may be different angular dependencies between different emission layers in at least two emission layers, wherein when light is emitted at 45° or 60° to the normal direction, the angular dependencies have brightness that may differ by at least 2%, at least 4%, at least 6% and at least 8% and / or at least 10%, and CIE that may differ by at least 0.002, at least 0.004, at least 0.006, 0.008 and 0.010.

[0054] The device may include at least one charge generation layer, the charge generation layer comprising a metal layer.The at least one charge generation layer may have a transparency greater than 10%, greater than 30%, greater than 50% and / or greater than 75%.

[0055] At least two stacked emitting layers of the device may have different transparencies.

[0056] Two or more of the at least two stacked emitting layers of the device may be individually addressable, and wherein the device having at least two stacked emitting layers has a transparent anode and a transparent cathode.

[0057] Two or more of the at least two stacked emitting layers are individually addressable, wherein the device having the at least two stacked emitting layers may have a transparent electrode and a reflective electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 An organic light-emitting device is demonstrated.

[0059] Figure 2 An inverted organic light-emitting device without a separate electron transport layer is demonstrated.

[0060] Figure 3 Exemplary devices having at least two stacked emitting layers according to embodiments of the disclosed subject matter are shown. DETAILED DESCRIPTION

[0061] In general, an OLED comprises at least one organic layer disposed between and electrically connected to an anode and a cathode. When an electric current is applied, the anode injects holes and the cathode injects electrons into the organic layer. The injected holes and electrons each migrate toward the oppositely charged electrode. When electrons and holes are localized on the same molecule, an "exciton" is formed, which is a localized electron-hole pair with an excited energy state. When the exciton relaxes through a light emission mechanism, light is emitted. In some cases, the exciton can be localized on an excimer or an excited complex. Non-radiative mechanisms (such as thermal relaxation) may also occur, but are generally considered undesirable.

[0062] The first OLEDs used emissive molecules that emitted light from a singlet state ("fluorescence"), as disclosed, for example, in US Pat. No. 4,769,292, which is incorporated by reference in its entirety. Fluorescence emission typically occurs in a time frame of less than 10 nanoseconds.

[0063] Recently, OLEDs with emissive materials that emit light from triplet states ("phosphorescence") have been demonstrated. Baldo et al., "Highly Efficient Phosphorescent Emission from Organic Electroluminescent Devices", Nature, Vol. 395, 151-154, 1998 ("Baldo-I"); and Baldo et al., "Very high-efficiency green organic light-emitting devices based on electrophosphorescence", Appl. Phys. Lett., Vol. 75, Nos. 3, 4-6 (1999) ("Baldo-II"), which are incorporated by reference in their entirety. Phosphorescence is described in more detail in U.S. Pat. No. 7,279,704, Columns 5-6, which is incorporated by reference.

[0064] Figure 1 An organic light-emitting device 100 is shown. The figure is not necessarily drawn to scale. The device 100 may include a substrate 110, an anode 115, a hole injection layer 120, a hole transport layer 125, an electron blocking layer 130, an emission layer 135, a hole blocking layer 140, an electron transport layer 145, an electron injection layer 150, a protective layer 155, a cathode 160, and a blocking layer 170. The cathode 160 is a composite cathode having a first conductive layer 162 and a second conductive layer 164. The device 100 can be manufactured by depositing the layers in sequence. The properties and functions of these various layers and example materials are described in more detail in US 7,279,704, columns 6-10, which is incorporated by reference.

[0065] More examples of each of these layers can be obtained. For example, a flexible and transparent substrate-anode combination is disclosed in U.S. Patent No. 5,844,363, which is incorporated by reference in its entirety. An example of a p-doped hole transport layer is m-MTDATA doped with F4-TCNQ at a molar ratio of 50:1, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated by reference in its entirety. Examples of emissive and host materials are disclosed in U.S. Patent No. 6,303,238 to Thompson et al., which is incorporated by reference in its entirety. An example of an n-doped electron transport layer is BPhen doped with Li at a molar ratio of 1:1, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated by reference in its entirety. U.S. Patent Nos. 5,703,436 and 5,707,745, which are incorporated by reference in their entirety, disclose examples of cathodes including composite cathodes having a thin layer of a metal (e.g., Mg:Ag) with an overlying transparent, conductive, sputter-deposited ITO layer. The theory and use of barrier layers are described in more detail in U.S. Patent No. 6,097,147 and U.S. Patent Application Publication No. 2003 / 0230980, which are incorporated by reference in their entirety. Examples of injection layers are provided in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated by reference in its entirety. Barrier layer 170 can be a single or multilayer barrier layer and can cover or surround other layers of the device. Barrier layer 170 can also surround substrate 110, and / or it can be disposed between the substrate and other layers of the device. Barrier layers can also be referred to as encapsulants, encapsulation layers, protective layers, or permeation barriers, and generally provide protection against moisture, ambient air, and other similar materials from penetrating through other layers of the device. Examples of barrier layer materials and structures are provided in U.S. Patent Nos. 6,537,688, 6,597,111, 6,664,137, 6,835,950, 6,888,305, 6,888,307, 6,897,474, 7,187,119, and 7,683,534, each of which is incorporated by reference in its entirety.

[0066] Figure 2 An inverted OLED 200 is shown. The device includes a substrate 210, a cathode 215, an emissive layer 220, a hole transport layer 225, and an anode 230. Device 200 can be manufactured by depositing the layers in order. Because the most common OLED configuration has a cathode disposed above the anode, and device 200 has cathode 215 disposed below anode 230, device 200 can be referred to as an "inverted" OLED. Materials similar to those described with respect to device 100 can be used in the corresponding layers of device 200. Figure 2An example is provided of how some layers may be omitted from the structure of device 100 .

[0067] Figure 1 and 2 The simple layered structures described in are provided by way of non-limiting examples, and it should be understood that embodiments of the present invention may be used in conjunction with various other structures. The specific materials and structures described are exemplary in nature, and other materials and structures may be used. Functional OLEDs may be obtained by combining the various layers described in different ways, or the layers may be omitted entirely based on design, performance, and cost factors. Other layers not specifically described may also be included. Materials other than the specifically described materials may be used. Although many of the examples provided herein describe the various layers as comprising a single material, it should be understood that a combination of materials may be used, such as a mixture of a host and a dopant, or more generally, a mixture. In addition, the layers may have various sublayers. The names given to the various layers herein are not intended to be strictly limiting. For example, in device 200, hole transport layer 225 transports holes and injects holes into emissive layer 220, and may be described as a hole transport layer or a hole injection layer. In one embodiment, the OLED may be described as having an "organic layer" disposed between a cathode and an anode. This organic layer may include a single layer, or may further include, for example, Figure 1 and 2 Multiple layers of said different organic materials.

[0068] Structures and materials not specifically described may also be used, such as OLEDs containing polymeric materials (PLEDs), such as disclosed in U.S. Pat. No. 5,247,190 to Friend et al., which is incorporated by reference in its entirety. By way of another example, an OLED having a single organic layer may be used. OLEDs may be stacked, such as described in U.S. Pat. No. 5,707,745 to Forrest et al., which is incorporated by reference in its entirety. OLED structures may deviate from Figure 1 and 2 For example, the substrate may include angled reflective surfaces to improve out-coupling, such as a mesa structure as described in U.S. Pat. No. 6,091,195 to Forrest et al., and / or a pit structure as described in U.S. Pat. No. 5,834,893 to Bulovic et al., which are incorporated by reference in their entirety.

[0069] In some embodiments disclosed herein, an emissive layer or material, such as Figure 1-2The emission layer 135 and the emission layer 220 shown in the figure, respectively, may include quantum dots. The emission layer may use different emission display technologies. Such technologies may include inorganic and / or organic devices, such as LEDs, mini LEDs, micro LEDs, thin electroluminescent films, organic light-emitting devices, etc. Unless explicitly indicated to the contrary or in accordance with the understanding of a technician in the field, the "emission layer" or "emission material" disclosed herein may include organic emission materials and / or emission materials containing quantum dots or equivalent structures. In general, the emission layer includes an emission material within a host matrix. Such an emission layer may only include quantum dot materials that convert light emitted by a separate emission material or other emitter, or it may also include a separate emission material or other emitter, or it may directly emit light by applying an electric current. Similarly, a color change layer, a color filter, an up-conversion or down-conversion layer or structure may include a material containing quantum dots, but such a layer may not be considered an "emission layer" as disclosed herein. Typically, an "emissive layer" or material is one that emits initial light based on injected charge, where the initial light can be altered by another layer, such as a color filter or other color-changing layer, that does not itself emit the initial light within the device, but can re-emit altered light with different spectral content based on absorption and down-conversion of the initial light emitted by the emissive layer into lower energy light emission. In some embodiments disclosed herein, the color-changing layer, color filter, up-conversion and / or down-conversion layer can be disposed external to the OLED device, such as above or below an electrode of the OLED device.

[0070] Unless otherwise specified, any of the layers of the various embodiments may be placed, arranged or deposited by any suitable method. For organic layers, preferred methods include thermal evaporation, inkjet (as described in U.S. Pat. Nos. 6,013,982 and 6,087,196, incorporated by reference in their entirety), organic vapor phase deposition (OVPD) (as described in U.S. Pat. No. 6,337,102 to Forrest et al., incorporated by reference in their entirety) and deposition by organic vapor jet printing (OVJP) (as described in U.S. Pat. No. 7,431,968, incorporated by reference in their entirety). Other suitable deposition methods include spin coating and other solution-based processes. Solution-based processes are preferably carried out in nitrogen or an inert atmosphere. For other layers, preferred methods include thermal evaporation. Preferred patterning methods include deposition through a mask, cold welding (as described in U.S. Pat. Nos. 6,294,398 and 6,468,819, which are incorporated by reference in their entirety), and patterning associated with some of the deposition methods such as inkjet and OVJD. Other methods may also be used. The material to be deposited may be modified to make it compatible with a specific deposition method. For example, branched or unbranched substituents such as alkyl and aryl groups, preferably containing at least 3 carbons, may be used in small molecules to enhance their ability to withstand solution processing. Substituents having 20 or more carbons may be used, and 3 to 20 carbons are a preferred range. Materials having asymmetric structures may have better solution processability than materials having symmetric structures because asymmetric materials may have a lower tendency to recrystallize. Dendritic polymer substituents may be used to enhance the ability of small molecules to withstand solution processing.

[0071] The device manufactured according to the embodiment of the present invention may further optionally include a barrier layer. One purpose of the barrier layer is to protect the electrode and the organic layer from being exposed to harmful substances in the environment including moisture, steam and / or gas, etc. The barrier layer can be deposited on the substrate, the electrode, under the substrate, the electrode, or beside the substrate, the electrode, or on any other part (including the edge) of the device. The barrier layer may include a single layer or multiple layers. The barrier layer may be formed by various known chemical vapor deposition techniques, and may include a composition having a single phase and a composition having multiple phases. Any suitable material or material combination may be used for the barrier layer. The barrier layer may be combined with an inorganic compound or an organic compound or both. A preferred barrier layer includes a mixture of a polymeric material and a non-polymeric material, as described in U.S. Patent No. 7,968,146, PCT Patent Application No. PCT / US2007 / 023098, and No. PCT / US2009 / 042829, which are incorporated herein by reference in their entirety. In order to be considered a "mixture", the aforementioned polymeric material and non-polymeric material constituting the barrier layer should be deposited under the same reaction conditions and / or deposited simultaneously. The weight ratio of polymeric material to non-polymeric material can be in the range of 95:5 to 5:95. The polymeric material and non-polymeric material can be produced from the same precursor material. In one example, the mixture of polymeric material and non-polymeric material consists essentially of polymeric silicon and inorganic silicon.

[0072] In some embodiments, at least one of the anode, cathode, or a new layer disposed above the organic emission layer is used as an enhancement layer. The enhancement layer includes a plasmon material that exhibits a surface plasmon resonance, the plasmon material non-radiatively couples to the emitter material, and transfers excited state energy from the emitter material to a non-radiative mode of a surface plasmon polariton. The enhancement layer is provided at a threshold distance not exceeding the organic emission layer, wherein due to the presence of the enhancement layer, the emitter material has a total non-radiative decay rate constant and a total radiative decay rate constant, and the threshold distance is the distance at which the total non-radiative decay rate constant is equal to the total radiative decay rate constant. In some embodiments, the OLED further includes an outcoupling layer. In some embodiments, the outcoupling layer is disposed above the enhancement layer on the opposite side of the organic emission layer. In some embodiments, the outcoupling layer is disposed on the side of the emission layer opposite to the enhancement layer, but still outcouples energy from the surface plasmon mode of the enhancement layer. The outcoupling layer scatters energy from the surface plasmon polaritons. In some embodiments, this energy is scattered to free space in the form of photons. In other embodiments, energy is scattered from the surface plasmon modes of the device into other modes, such as, but not limited to, an organic waveguide mode, a substrate mode, or another waveguide mode. If the energy is scattered into a non-free space mode of the OLED, other outcoupling schemes may be incorporated to extract the energy into free space. In some embodiments, one or more intervening layers may be disposed between the enhancement layer and the outcoupling layer. Examples of intervening layers may be dielectric materials, including organics, inorganics, perovskites, oxides, and may include stacks and / or mixtures of these materials.

[0073] The enhancement layer modifies the effective properties of the medium in which the emitter material resides, resulting in any or all of the following: reduced emissivity, modification of the emission line shape, changes in emission intensity versus angle, changes in robustness of the emitter material, changes in the efficiency of the OLED, and reduced efficiency decay of the OLED device. Placing the enhancement layer on the cathode side, the anode side, or both produces an OLED device that exploits any of the above effects. In addition to the specific functional layers described in the various OLED examples mentioned herein and shown in the figures, the OLED according to the present invention may also include any of the other functional layers typically found in OLEDs.

[0074] The enhancement layer may be composed of a plasmonic material, an optically active metamaterial, or a hyperbolic metamaterial. As used herein, a plasmonic material is a material whose real part of the dielectric constant crosses zero in the visible or ultraviolet region of the electromagnetic spectrum. In some embodiments, the plasmonic material includes at least one metal. In such embodiments, the metal may include at least one of the following: Ag, Al, Au, Ir, Pt, Ni, Cu, W, Ta, Fe, Cr, Mg, Ga, Rh, Ti, Ru, Pd, In, Bi, Ca, alloys or mixtures of these materials, and stacks of these materials. In general, a metamaterial is a medium composed of different materials, where the function of the medium as a whole is different from the sum of its material parts. Specifically, we define an optically active metamaterial as a material having both a negative dielectric constant and a negative magnetic permeability. On the other hand, a hyperbolic metamaterial is an anisotropic medium in which the permittivity or magnetic permeability has different signs for different spatial directions. Optically active metamaterials and hyperbolic metamaterials are strictly distinguished from many other photonic structures, such as distributed Bragg reflectors ("DBRs"), because the medium should be uniform in the direction of propagation for the length scale of the wavelength of light. Using terms that are understood by those skilled in the art: the dielectric constant of the metamaterial in the direction of propagation can be described approximately by the effective medium. Plasmonic materials and metamaterials provide a way to control light propagation that can enhance OLED performance in many ways.

[0075] In some embodiments, the enhancement layer is provided as a planar layer. In other embodiments, the enhancement layer has wavelength-sized features arranged periodically, quasi-periodically, or randomly, or has sub-wavelength-sized features arranged periodically, quasi-periodically, or randomly. In some embodiments, the wavelength-sized features and sub-wavelength-sized features have sharp edges.

[0076] In some embodiments, the outcoupling layer has wavelength-sized features that are periodically, quasi-periodically, or randomly arranged, or has sub-wavelength-sized features that are periodically, quasi-periodically, or randomly arranged. In some embodiments, the outcoupling layer may be composed of a plurality of nanoparticles, and in other embodiments, the outcoupling layer is composed of a plurality of nanoparticles disposed on a material. In these embodiments, the outcoupling can be tuned by at least one of: changing the size of the plurality of nanoparticles, changing the shape of the plurality of nanoparticles, changing the material of the plurality of nanoparticles, adjusting the thickness of the material, changing the refractive index of the material or an additional layer disposed on the plurality of nanoparticles, changing the thickness of the enhancement layer, and / or changing the material of the enhancement layer. The plurality of nanoparticles of the device may be formed of at least one of: a metal, a dielectric material, a semiconductor material, a metal alloy, a mixture of dielectric materials, a stack or layering of one or more materials, and / or a core of one type of material coated with a shell of a different type of material. In some embodiments, the outcoupling layer is composed of at least metal nanoparticles, wherein the metal is selected from the group consisting of: Ag, Al, Au, Ir, Pt, Ni, Cu, W, Ta, Fe, Cr, Mg, Ga, Rh, Ti, Ru, Pd, In, Bi, Ca, alloys or mixtures of these materials, and stacks of these materials. Multiple nanoparticles can have additional layers disposed above them. In some embodiments, the polarization of the emission can be tuned using the outcoupling layer. Changing the dimensionality and periodicity of the outcoupling layer can select a class of polarizations that preferentially outcouple to air. In some embodiments, the outcoupling layer also acts as an electrode of the device.

[0077] In an embodiment of the disclosed subject matter, a device may include an enhancement layer disposed over an emission region of at least one subpixel configured to have Lambertian emission and / or at least one subpixel having a microcavity configured for direct emission, as described in detail below. In at least some of such embodiments, the enhancement layer may include a plasmonic structure disposed at a predetermined threshold distance from the emission region. The predetermined threshold distance may be a distance at which the total non-radiative decay rate constant is equal to the total radiative decay rate constant. In some such embodiments, a device may include an outcoupling layer disposed over the enhancement layer on opposite sides of the emission region.

[0078] It is believed that the internal quantum efficiency (IQE) of fluorescent OLEDs can exceed the 25% spin statistics limit through delayed fluorescence. As used herein, there are two types of delayed fluorescence, namely P-type delayed fluorescence and E-type delayed fluorescence. P-type delayed fluorescence is produced by triplet-triplet annihilation (TTA).

[0079] In some embodiments, the emitting material and / or compound in the layer in the OLED can be used as a phosphorescent sensitizer, wherein one or more layers in the OLED can include one or more fluorescent and / or delayed fluorescent emitter forms of acceptors. In some embodiments, the compound can be used as a component of an excited complex to be used as a sensitizer. As a phosphorescent sensitizer, the compound can be able to transfer energy to the acceptor, and the acceptor can emit energy or further transfer energy to the final emitter. The acceptor concentration can be in the range of 0.001% to 100%. The acceptor can be in the same layer as the phosphorescent sensitizer or in one or more different layers. In some embodiments, the acceptor can be a TADF emitter. In some embodiments, the acceptor can be a fluorescent emitter. In some embodiments, the emission can be generated by any one or all of the sensitizer, the acceptor and / or the final emitter.

[0080] On the other hand, the E-type delayed fluorescence described above does not rely on the collision of two triplets, but on the thermal population between triplet and singlet excited states. It is necessary to produce a compound capable of producing E-type delayed fluorescence so as to have a very small singlet-triplet gap. Thermal energy can activate the transition from triplet to singlet. This type of delayed fluorescence is also referred to as thermally activated delayed fluorescence (TADF). A notable feature of TADF is that, due to the increase in thermal energy, the delayed component increases with increasing temperature. If the reverse intersystem crossing rate is fast enough to minimize the non-radiative decay from the triplet, the fraction of backfilling the singlet excited state may reach 75%. The total singlet fraction can be 100%, which is far more than the spin statistical limit of the electrically generated exciton.

[0081] E-type delayed fluorescence characteristics can be seen in exciplex systems or single compounds. Without being bound by theory, it is believed that E-type delayed fluorescence requires the luminescent material to have a small singlet-triplet energy gap (ΔES-T). Organic, metal-free donor-acceptor luminescent materials may be able to achieve this. The emission of these materials is usually characterized by donor-acceptor charge transfer (CT) type emission. The spatial separation of HOMO and LUMO in these donor-acceptor type compounds usually leads to a small ΔES-T. These states may involve CT states. Typically, donor-acceptor luminescent materials are constructed by connecting an electron donor moiety (e.g., an amino or carbazole derivative) to an electron acceptor moiety (e.g., a six-membered aromatic ring containing N).

[0082] Devices manufactured according to embodiments of the present invention may be incorporated into a wide variety of electronic component modules (or units), which may be incorporated into a variety of electronic products or intermediate components. Examples of electronic products or intermediate components include display screens, lighting devices (such as discrete light source devices or lighting panels), etc. that can be utilized by end-user product manufacturers. The electronic component module may optionally include drive electronics and / or a power supply. Devices manufactured according to embodiments of the present invention may be incorporated into a wide variety of consumer products, which have one or more electronic component modules (or units) incorporated therein. A consumer product comprising an OLED is disclosed, wherein the OLED comprises a compound of the present disclosure in an organic layer in the OLED. The consumer product should include any kind of product containing one or more of one or more light sources and / or a certain type of visual display. Some examples of such consumer products include flat panel displays, curved displays, computer monitors, medical monitors, televisions, billboards, lights for interior or exterior lighting and / or signaling, heads-up displays, fully or partially transparent displays, flexible displays, rollable displays, foldable displays, stretchable displays, laser printers, telephones, cellular phones, tablet computers, tablet phones, personal digital assistants (PDAs), wearable devices, laptop computers, digital cameras, video cameras, viewfinders, microdisplays with a diagonal of less than 2 inches, 3D displays, virtual reality or augmented reality displays, vehicles, in-vehicle displays, video walls comprising multiple displays tiled together, theater or stadium screens and signage. Various control mechanisms can be used to control devices made according to the present invention, including passive matrices and active matrices. Many of the devices are intended to be used in a temperature range that is comfortable for humans (e.g., 18° C. to 30° C., and more preferably at room temperature (20-25° C.)), but can be used outside this temperature range (e.g., -40° C. to 80° C.).

[0083] The materials and structures described herein can be applied to devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors can employ the materials and structures. More generally, organic devices such as organic transistors can employ the materials and structures.

[0084] In some embodiments, the OLED has one or more features selected from the group consisting of: flexible, rollable, foldable, stretchable, and bendable. In some embodiments, the OLED is transparent or translucent. In some embodiments, the OLED further comprises a layer having carbon nanotubes.

[0085] In some embodiments, the OLED further comprises a layer having a delayed fluorescent emitter. In some embodiments, the OLED comprises an RGB pixel arrangement or a white plus color filter pixel arrangement. In some embodiments, the OLED is a mobile device, a handheld device, or a wearable device. In some embodiments, the OLED is a display panel having a diagonal of less than 10 inches or an area of ​​less than 50 square inches. In some embodiments, the OLED is a display panel having a diagonal of at least 10 inches or an area of ​​at least 50 square inches. In some embodiments, the OLED is a lighting panel.

[0086] In some embodiments of the emission region, the emission region further comprises a body.

[0087] In some embodiments, the compound causing light generation can be an emissive dopant. In some embodiments, the compound can generate emission via phosphorescence, fluorescence, thermally activated delayed fluorescence (i.e., TADF, also known as E-type delayed fluorescence), triplet-triplet annihilation, or a combination of these processes (including phosphor-sensitized fluorescence).

[0088] The OLEDs disclosed herein may be incorporated into one or more of consumer products, electronic component modules, and lighting panels.The organic layer may be an emissive layer, and the compound may be an emissive dopant in some embodiments, while the compound may be a non-emissive dopant in other embodiments.

[0089] The organic layer may also include a host. In some embodiments, two or more hosts are preferred. In some embodiments, the host used may be a) bipolar, b) electron transport, c) hole transport, or d) wide bandgap material that plays a small role in charge transport. In some embodiments, the host may include a metal complex. The host may be an inorganic compound.

[0090] Combination with other materials

[0091] The materials described herein as being suitable for use in a particular layer in an organic light-emitting device can be used in combination with a variety of other materials present in the device. For example, the emissive dopants disclosed herein can be used in combination with a wide variety of hosts, transport layers, barrier layers, injection layers, electrodes, and other layers that may be present. The materials described or mentioned below are non-limiting examples of materials that can be used in combination with the compounds disclosed herein, and those skilled in the art can readily consult the literature to identify other materials that can be used in combination.

[0092] The various emissive and non-emissive layers and arrangements disclosed herein may use different materials. Examples of suitable materials are disclosed in U.S. Patent Application Publication No. 2017 / 0229663, which is incorporated by reference in its entirety.

[0093] Conductive dopants:

[0094] The charge transport layer can be doped with a conductivity dopant to substantially change its charge carrier density, which in turn will change its conductivity. The conductivity is increased by generating charge carriers in the matrix material, and depending on the type of dopant, a change in the Fermi level of the semiconductor can also be achieved. The hole transport layer can be doped with a p-type conductivity dopant, and an n-type conductivity dopant is used in the electron transport layer.

[0095] HIL / HTL:

[0096] The hole injection / transport material used in the present invention is not particularly limited, and any compound may be used as long as the compound is generally used as a hole injection / transport material.

[0097] EBL:

[0098] An electron blocking layer (EBL) can be used to reduce the number of electrons and / or excitons that leave the emissive layer. The presence of such a blocking layer in a device can produce substantially higher efficiency and / or longer lifetime than a similar device lacking a blocking layer. In addition, a blocking layer can be used to confine emission to desired areas of the OLED. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and / or a higher triplet energy than the emitter closest to the EBL interface. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and / or a higher triplet energy than one or more of the hosts closest to the EBL interface. In one aspect, the compound used in the EBL contains the same molecule or the same functional group as used in one of the hosts described below.

[0099] main body:

[0100] The light-emitting layer of the organic EL device of the present invention preferably contains at least a metal complex as a light-emitting material, and may contain a host material using the metal complex as a dopant material. Examples of the host material are not particularly limited, and any metal complex or organic compound may be used as long as the triplet energy of the host is greater than the triplet energy of the dopant. Any host material may be used with any dopant as long as the triplet criterion is satisfied.

[0101] HBL:

[0102] A hole blocking layer (HBL) can be used to reduce the number of holes and / or excitons that leave the emissive layer. The presence of such a blocking layer in a device can result in substantially higher efficiency and / or longer lifetime than a similar device lacking a blocking layer. In addition, a blocking layer can be used to confine emission to a desired area of ​​the OLED. In some embodiments, the HBL material has a lower HOMO (further from the vacuum level) and / or a higher triplet energy than the emitter closest to the HBL interface. In some embodiments, the HBL material has a lower HOMO (further from the vacuum level) and / or a higher triplet energy than one or more of the hosts closest to the HBL interface.

[0103] ETL:

[0104] The electron transport layer (ETL) may include a material capable of transporting electrons. The electron transport layer may be intrinsic (undoped) or doped. Doping may be used to enhance conductivity. Examples of ETL materials are not particularly limited, and any metal complex or organic compound may be used as long as it is generally used to transport electrons.

[0105] Charge Generation Layer (CGL)

[0106] In a tandem or stacked OLED, the CGL plays a fundamental role in the performance and consists of an n-doped layer and a p-doped layer for injecting electrons and holes, respectively. Electrons and holes are supplied by the CGL and electrodes. The electrons and holes consumed in the CGL are refilled by electrons and holes injected from the cathode and anode, respectively; then, the bipolar current gradually reaches a steady state. Typical CGL materials include n- and p-conductivity dopants used in the transport layer.

[0107] Two or more stacked pixels using the same primary color can provide higher brightness at the same current density, and longer device lifetime at a given brightness, for display applications where these are important factors. These stacked devices can have additional design variables that can be optimized for advantages unique to these devices. Embodiments of the disclosed subject matter can optimize these types of single-color stacked OLEDs.

[0108] Optimizing each OLED within a stacked device independently can provide performance and / or manufacturability advantages for stacked monochrome OLEDs. Some benefits of independently optimizing these two or more EMLs / cavities can include increased manufacturing tolerances, reduced color shifts for monochrome and white (e.g., where white can come from the combined emission of different color sub-pixels) with viewing angle, reduced brightness shifts with viewing angle, increased color pixel color saturation, increased pixel efficiency, reduced color shifts with aging, reduced brightness loss with aging, increased and / or reduced angular dependence with aging, and / or improved coupling with quantum dots and / or other down-conversion layers and / or color filters. In some embodiments, the reflectivity from the bottom electrode can be reduced, which can increase contrast, particularly for devices without polarizers. When the stack is configured to be individually addressable, the device transparency can be changed by selecting different devices.

[0109] Embodiments of the disclosed subject matter optimize multiple emitters. The optimization can be different for different emissive layers within a stack (e.g., a single color stack). The cavity observed by the emitter can change relative to the position of the emitter within the OLED and / or the position of the emitter relative to the electrode interface (e.g., cavity node position). The emission spectrum of the emitter can be optimized relative to the positioning of the cavity and / or the stacked OLEDs can be different depending on the position.

[0110] By emitting monochromatic light from OLEDs using different emitters in different stacks, angular dependence can be minimized. Color saturation can be balanced with efficiency and / or efficacy. The arrangement can balance color with aging, maximize efficiency for a given desired output color, and / or minimize drive voltage.

[0111] The emitters used within the stack may include different types of OLED emitters, such as phosphorescent, fluorescent, thermally activated delayed fluorescence (TADF), sensitized OLEDs, and the like.

[0112] The position of each emission layer within the optical cavity can be optimized. For example, forward efficiency can be maximized. The cavity can be tuned separately for different emitters. For example, a first emission layer can have a cavity tuned to maximize forward luminous efficacy, and a second emission layer can deviate from the maximum to optimize another parameter. One or more cavities can be tuned for angular dependence. In some embodiments, there can be different detunings of one or more emission layer positions. In some embodiments, the angular dependence of brightness and / or CIE shift (i.e., shift in CIE 1931 color space) can be minimized. One or more emission layers can be set at different cavity resonances, for example between 1 / 4 wavelength (λ), 1 / 2λ, 3 / 4λ, and / or 5 / 4λ. In some embodiments, reflections from the bottom electrode can be reduced. Embodiments can provide improved coupling with down-conversion films, down-conversion layers, and / or color filters.

[0113] In some embodiments, emitter doping can be optimized. For example, for one or more emission layers and / or each emission layer, there can be emitters of different colors. In some embodiments, there can be a different balance of emission from one or more emission layers and / or each emission layer. Differential aging can be optimized to compensate for aging color shift.

[0114] In some embodiments, host selection can be optimized. For example, different hosts and / or host compositions can be used for different emission layers and / or each emission layer in an OLED stack. In some embodiments, different emission layer thicknesses can be used for emission layers and / or each emission layer in an OLED stack. Hosts can be selected to optimize effects on aging, such as color shift, etc.

[0115] In some embodiments, the barrier layer may be selected to optimize the stack arrangement. Different barrier layers may be used for different emitting layers and / or each emitting layer in the OLED stack. Different barrier layer thicknesses may be used for different emitting layers and / or each emitting layer in the OLED stack.

[0116] Figure 3 An exemplary device 300 having at least two stacked emissive layers according to an embodiment of the disclosed subject matter is shown. Device 300 can include substrate 310, anode 315, first emissive layer 320, charge generation layer 325, second emissive layer 330, and cathode 335.

[0117] The device 300 may be an organic light emitting device (OLED) having at least two stacked emission layers (eg, a first emission layer 320 and a second emission layer 330). Figure 3Two stacked layers are shown in FIG. 3 , but there may be more than two stackable emission layers. For example, the at least two stacked emission layers may be a stack of at least three emission layers, a stack of at least four emission layers, and / or a stack of at least five emission layers. In some embodiments, the OLED of device 300 may be a microcavity device.

[0118] The peak wavelength difference between at least two stacked emission layers can be less than or equal to 50 nm, less than or equal to 40 nm, less than or equal to 30 nm, less than or equal to 20 nm, and / or less than or equal to 10 nm. The emission outputs of the two emission layers can have a difference of at least 0.004, at least 0.006, at least 0.008, at least 0.010, at least 0.015, at least 0.020, at least 0.025, and at least 0.050 Δu'v' in the 1976 CIE color space.

[0119] At least one charge generation layer (eg, charge generation layer 325) may be disposed between at least two stacked emission layers. Figure 3 As shown in FIG. 3 , the charge generation layer 325 may be disposed between the first emission layer 320 and the second emission layer 330. In some embodiments, the charge generation layer 325 may be an electrode.

[0120] At least two stacked emission layers (e.g. Figure 3 The first emission layer 320 and the second emission layer 330 shown in FIG. 3 may include at least two red emission layers, at least two green emission layers, at least two blue emission layers and / or at least two yellow emission layers.

[0121] Two or more of the at least two stacked emitting layers may include different materials and / or different hosts. In some embodiments, the different emitters may be chemically different from each other.

[0122] Two or more of the at least two stacked emission layers may include different emitters. Two or more of the at least two stacked emission layers may include different emission layer materials. Different emission materials may be fluorescent materials, phosphorescent materials, quantum dots, etc. For example, at least one of the two or more emission layers may include a fluorescent emitter and a phosphorescent emitter. In another example, at least one of the two or more emission layers may include a phosphorescent emitter. In another example, at least one of the two or more emission layers may include a delayed fluorescent emitter. In yet another example, at least one of the two or more emission layers may include a non-delayed fluorescent emitter. In another example, at least two of the two or more emission layers may include a fluorescent emitter and a phosphorescent emitter. In another example, at least two of the two or more emission layers may include a phosphorescent emitter. In another example, at least two of the two or more emission layers contain a delayed fluorescent emitter. In yet another example, at least two of the two or more emission layers may include a non-delayed fluorescent emitter.

[0123] In some embodiments, at least two stacked emitter layers (e.g., Figure 3 Two or more emission layers in the first emission layer 320 and the second emission layer 330 shown in the figure may have different line shapes. That is, any type of different line shapes may be provided between the two or more emission layers. For example, the two or more emission layers may have different line shapes, and their full width at half maximum (FWHM) or quarter full width at peak (FWQM) differ by at least 2nm, at least 4nm, at least 6nm and / or at least 8nm. For example, at least one of the two or more emission layers may have a FWHM of less than 80nm, less than 70nm, less than 60nm, less than 50nm, less than 40nm and / or less than 30nm. In another example, the device may have a FWHM of less than 60nm, less than 50nm, 40nm, 30nm, 20nm and / or 10nm. In another example, at least one of the two or more emission layers may have a FWQM of less than 100nm, 90nm, 80nm, 70nm, 60nm and / or 50nm. In yet another example, the device can have a FWQM of less than 70 nm, less than 60 nm, less than 50 nm, less than 40 nm, less than 30 nm, and / or less than 20 nm.

[0124] One of the at least two stacked emission layers may be located at the first linear emitter and / or the second linear emitter. For example, the first emission layer 320 may have a first linear shape, which is a wider linear shape, and the second emission layer 330 may have a second linear shape, which may be a narrower linear shape. Any difference in linear shape may exist between the first linear emitter and the second linear emitter. The wider linear shape may be based on M / T, with a wider quarter-peak full width (FWQM) and / or half-peak full width (FWHM). Similarly, the narrower in the M / T-based specification has a narrower quarter-peak full width (FWQM) and / or half-peak full width (FWHM). In some embodiments, the linear shape may be defined primarily by M / T, secondarily by FWQM, and then by FWHM. M / T may be defined as the integral of the main (M) peak (e.g., + / -15nm, or 10nm, or 70meV, etc.) divided by the integral of the total spectrum.

[0125] In some embodiments, at least two stacked emitter layers (e.g., Figure 3 One of the first emission layer 320 and the second emission layer 330 shown in the figure may be a first linear emitter (e.g., emitting a wider linear shape), and may be positioned closer to the reflective electrode (e.g., anode 315 and / or cathode 335) of the OLED than the other of the at least two stacked emission layers. One of the at least two stacked emission layers may be a second linear emitter (e.g., emitting a narrower linear shape), and may be positioned closer to the reflective electrode of the OLED than the other of the at least two stacked emission layers.

[0126] In some embodiments, two or more of the at least two stacked emission layers may have different external quantum efficiencies (EQEs) of at least 1%, at least 3%, and / or at least 5%. In one example, at least one of the two or more emission layers may have an EQE greater than 10%, greater than 20%, greater than 30%, and / or greater than 40%. In another example, at least two of the two or more emission layers may each have an EQE greater than 10%, greater than 20%, greater than 30%, and / or greater than 40%. Two or more of the at least two stacked emission layers may have different EQE roll-offs when the current density increases by at least 1%, at least 3%, and / or at least 5%. The EQE roll-off may be defined as 10 mA / cm 2 The device EQE is divided by 1mA / cm 2Device EQE under. In one example, two or more of the at least two stacked emission layers may have different external quantum efficiency roll-offs when the driving current density increases by at least 1%, at least 3%, and at least 5%. In another example, at least one of the two or more emission layers may have a roll-off of less than 75%, less than 80%, less than 85%, and / or less than 90%. In another example, at least two of the two or more emission layers may each have a roll-off of less than 75%, less than 80%, less than 85%, and / or less than 90%. Two or more of the at least two stacked emission layers may have lifetimes that differ by at least 10%, at least 25%, and / or at least 50%. Two or more of the at least two stacked emission layers may have different operating voltages at a selected current density or a selected brightness. For example, the selected current density may be 10 mA / cm2, 40 mA / cm 2 、80mA / cm 2 wait.

[0127] Two or more of the at least two stacked emission layers (e.g., the first emission layer 320 and the second emission layer 330) may have different doping concentrations. Two or more of the at least two stacked emission layers may have different thicknesses from each other. For example, the thickness may differ by at least At least and / or at least

[0128] In some embodiments, one of the at least two stacked emission layers may be coupled to another of the at least two stacked emission layers (eg, Figure 3 The first emission layer 320 and / or the second emission layer 330 shown in FIG. 3 are blue-shifted compared to the first emission layer 320 and / or the second emission layer 330 shown in FIG. 3 and are arranged closer to the reflective electrode of the OLED (eg, Figure 3 ). One of the at least two stacked emitting layers may be red-shifted compared to another of the at least two stacked emitting layers and positioned closer to a reflective electrode of the OLED.

[0129] Two or more of the at least two stacked emission layers have different cavity conditions. That is, the two or more emission layers may not be at the same position in the luminous efficiency (LE) relative to the CIE x curve (of the CIE 1931 color space). LE is a measure of the extent to which a light source produces visible light, and is the ratio of luminous flux to power (measured in lumens / watt). At least one of the at least two stacked emission layers is detuned from the optical cavity maximum determined by the maximum LE by at least one selected from the group consisting of: 3%, 5%, 8% or 10% LE. The closest optical maximum may be 1 / 4, 2 / 4, 1 / 4, 4 / 4 and / or 5 / 4 wavelength (λ).

[0130] The degree of aging of at least two of the stacked emission layers may be different. In some embodiments, the degree of aging of two or more of the at least two stacked emission layers under operating conditions may be different, wherein LT95 may differ by 10%, 25% and / or 50% between two or more emission layers of the at least two stacked emission devices. LT95 may be a 5% reduction in brightness from an initial brightness (100%). The angular dependence of one or more of the at least two emission layers may change as one or more emission layers age. When the angular dependence of one or more of the at least two stacked emission layers changes, the brightness of the one or more emission layers may change. When the angular dependence of one or more of the at least two stacked emission layers changes, the CIE value of the one or more emission layers may change.

[0131] There may be different angular dependencies between different emission layers of at least two emission layers. For example, when emitting light at 45° or 60° from the normal direction, the angular dependencies may have brightness that may differ by at least 2%, at least 4%, at least 6%, at least 8%, and / or at least 10%, and CIE that may differ by at least 0.002, at least 0.004, at least 0.006, 0.008, and 0.010.

[0132] The device may include at least one charge generation layer (e.g., Figure 3 The charge generation layer 325 shown in FIG. 3 ) includes a metal layer. At least one charge generation layer may have a transparency greater than 10%, greater than 30%, greater than 50%, and / or greater than 75%. In some embodiments, at least two stacked emission layers (e.g., Figure 3 The first emission layer 320 and / or the second emission layer 330 shown in FIG. 3 may have different transparencies. The at least two stacked emission layers of the device (e.g., Figure 3Two or more of the first emitting layer 320 and / or the second emitting layer 330 shown in FIG. 3 may be individually addressable and have a transparent anode (eg, Figure 3 ) and a transparent cathode (e.g., Figure 3 In some embodiments, two or more of the at least two stacked emissive layers are individually addressable, wherein a device having at least two stacked emissive layers can have a transparent electrode (e.g., anode 315 and / or cathode 335) and a reflective electrode (e.g., anode 315 and / or cathode 335).

[0133] According to one embodiment, a device (e.g., Figure 3 The device 300 shown in FIG. 3 may include an organic light-emitting device (OLED) having at least two stacked emission layers (e.g., a first emission layer 320 and a second emission layer 330). The peak wavelength difference between the at least two stacked emission layers may be, for example, less than or equal to 50 nm, less than or equal to 40 nm, less than or equal to 30 nm, less than or equal to 20 nm, and / or less than or equal to 10 nm. The peak wavelength difference between the at least two stacked emission layers may be, for example, greater than 1 nm, greater than 2 nm, greater than 3 nm, greater than 4 nm, and / or greater than 5 nm.

[0134] According to one embodiment, a device (e.g., Figure 3 The device 300 shown in FIG. 3 may include at least two stacked emission layers (eg, Figure 3 The organic light emitting device (OLED) of the first emission layer 320 and the second emission layer 330 shown in FIG. 1 can have an emission output of the two stacked emission layers having a difference of, for example, at least 0.004, at least 0.006, at least 0.008, at least 0.010, at least 0.015, at least 0.020, at least 0.025, and / or at least 0.050 Δu'v' in the 1976 CIE color space. The emission output of the two stacked emission layers can have a difference of, for example, less than 0.35, less than 0.30, less than 0.25, less than 0.20, and / or less than 0.10 Δu'v' in the 1976 CIE color space.

[0135] According to one embodiment, a consumer electronic device (e.g., Figure 3 The device 300 shown in FIG. 3 may include at least two stacked emission layers (eg, Figure 3The organic light emitting device (OLED) of the first emission layer 320 and the second emission layer 330 shown in FIG. The peak wavelength difference between the at least two stacked emission layers can be less than or equal to 30 nm, less than or equal to 20 nm, and / or less than or equal to 10 nm. The emission outputs of the two emission layers can have a difference of at least 0.004, at least 0.006, at least 0.008, at least 0.010, at least 0.015, at least 0.020, at least 0.025, and / or at least 0.050 Δu'v' in the 1976 CIE color space.

[0136] In one embodiment, the device may include an organic light emitting device (OLED) having at least one pixel, wherein each pixel has one or more sub-pixels, and wherein at least one of the one or more sub-pixels may have at least two stacked emission layers. The peak wavelength difference between the at least two stacked emission layers may be less than or equal to 30nm, less than or equal to 20nm, and / or less than or equal to 10nm. The emission outputs of the two emission layers may have a difference in the 1976 CIE color space selected from the group consisting of: at least 0.004, at least 0.006, at least 0.008, at least 0.010, at least 0.015, at least 0.020, at least 0.025, and at least 0.050Δu'v'.

[0137] The device of one or more disclosed embodiments may be a flat panel display, a curved display, a computer monitor, a medical monitor, a television, a sign, a light for interior or exterior lighting and / or signaling, a head-up display, a fully or partially transparent display, a flexible display, a rollable display, a foldable display, a stretchable display, a laser printer, a telephone, a cellular phone, a tablet computer, a phablet, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a microdisplay having a diagonal of less than 2 inches, a 3D display, a virtual reality or augmented reality display, a vehicle, an in-vehicle display, a video wall comprising multiple displays tiled together, a theater or stadium screen, and / or a sign.

[0138] It should be understood that the various embodiments described herein are by way of example only, and are not intended to limit the scope of the present invention. For example, other materials and structures may be used to replace many materials and structures described herein without departing from the spirit of the present invention. The present invention as required may therefore include variations of specific examples and preferred embodiments described herein, as will be apparent to those skilled in the art. It should be understood that the various theories about why the present invention works are not intended to be restrictive.

Claims

1. A device comprising: At least two stacked emitter layers, wherein the peak wavelength difference between the at least two stacked emission layers is at least one selected from the group consisting of: less than or equal to 30 nm, less than or equal to 20 nm, and less than or equal to 10 nm, and wherein the emission outputs of the two emission layers have a difference in the 1976 CIE color space selected from the group consisting of: at least 0.004, at least 0.006, at least 0.008, at least 0.010, at least 0.015, at least 0.020, at least 0.025, and at least 0.050Δu'v'. 2 . The device of claim 1 , further comprising at least one charge generation layer disposed between the at least two stacked emissive layers. 3 . The device of claim 1 , wherein the at least two stacked emission layers comprise a selection selected from the group consisting of: at least two red emission layers, at least two green emission layers, at least two blue emission layers, and at least two yellow emission layers. 4 . The device of claim 1 , wherein two or more of the at least two stacked emitting layers are composed of at least one selected from the group consisting of: different materials and different hosts. 5 . The device of claim 1 , wherein the two or more emitting layers of the at least two stacked emitting layers are composed of different emitters. 6 . The device of claim 1 , wherein the two or more emitting layers of the at least two stacked emitting layers are composed of different emitting layer materials.

7. A device according to claim 1, wherein two or more of the at least two stacked emission layers have different line shapes selected from the group consisting of: a full width at half maximum (FWHM) or a quarter maximum full width (FWQM) that differs by at least 2 nm, at least 4 nm, at least 6 nm and at least 8 nm. 8 . The device of claim 1 , wherein one emitting layer of the at least two stacked emitting layers is at least one selected from the group consisting of: a first linear emitter and a second linear emitter.

9. The device of claim 8, wherein one of the at least two stacked emitting layers is the first linear emitter and is positioned closer to a reflective electrode of the device than another of the at least two stacked emitting layers.

10. The device of claim 8, wherein one of the at least two stacked emitting layers is the second linear emitter and is positioned closer to a reflective electrode of the device than another of the at least two stacked emitting layers.

11. The device of claim 1, wherein one of the at least two stacked emitting layers is blue-shifted compared to another of the at least two stacked emitting layers and is positioned closer to a reflective electrode of the device.

12. The device of claim 1, wherein one of the at least two stacked emitting layers is red-shifted compared to another of the at least two stacked emitting layers and is positioned closer to a reflective electrode of the device.

13. The device of claim 1, wherein the at least two stacked emissive layers comprise at least one selected from the group consisting of: a stack of at least three emissive layers, a stack of at least four emissive layers, and a stack of at least five emissive layers.

14. A device according to claim 1, wherein there are different angular dependencies between different emission layers in the at least two emission layers, wherein when light is emitted at 45° or 60° to the normal direction, the angular dependency has a brightness of at least one selected from the group consisting of: a difference of at least 2%, at least 4%, at least 6%, at least 8% and at least 10%; and a CIE of at least one selected from the group consisting of: a difference of at least 0.002, at least 0.004, at least 0.006, 0.008 and 0.

010.

15. The device of claim 1, wherein the device is of at least one type selected from the group consisting of: a flat panel display, a curved display, a computer monitor, a medical monitor, a television, a billboard, a light for interior or exterior lighting and / or signaling, a head-up display, a fully or partially transparent display, a flexible display, a rollable display, a foldable display, a stretchable display, a laser printer, a telephone, a cellular phone, a tablet computer, a tablet phone, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a microdisplay having a diagonal of less than 2 inches, a 3D display, a virtual reality or augmented reality display, a vehicle, an in-vehicle display, a video wall comprising multiple displays tiled together, a theater or stadium screen, and a sign.

Images