Organic electroluminescent device

Abstract

The invention relates to an organic electroluminescent device. Embodiments of the disclosed subject matter provide an apparatus that may include a substrate, a first electrode disposed over the substrate, and a first organic emissive layer (EML) disposed over the first electrode, where the first EML includes a first emissive material. A second electrode may be disposed over the first EML. A first self-absorbing material (SAM) may be disposed with the substrate stack, wherein the SAM may include a material that transfers at least a portion of energy from the first EML to the first SAM.

Description

[0001] Cross-reference of related applications

[0002] This application claims priority to U.S. Patent Application Serial No. 63 / 723,149, filed November 21, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to apparatus and techniques for manufacturing organic emitting devices, such as organic light-emitting diodes, and to apparatus and techniques comprising organic emitting devices including a highly absorbing material to absorb light generated by a stack of organic devices. Background Technology

[0004] For many reasons, optoelectronic devices utilizing organic materials are becoming increasingly popular. Many of the materials used to manufacture these devices are relatively inexpensive, thus organic optoelectronic devices have the potential to offer a cost advantage over inorganic devices. Furthermore, the inherent properties of organic materials, such as their flexibility, make them more suitable for specific applications, such as fabrication 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 exhibit performance advantages over conventional materials. For instance, the wavelength of light emitted by an organic emitting layer can often be easily tuned using appropriate dopants.

[0005] OLEDs utilize organic thin films that emit light when a 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. Patent 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 emitting molecules is in devices for full-color displays. Industry standards for such displays require pixels suited to emitting specific colors (called "saturated" colors). Specifically, these standards require pixels saturated with red, green, and blue light. Alternatively, OLEDs can be designed to emit white light. In conventional liquid crystal displays, absorption filters are used to filter the emission from a white backlight to produce red, green, and blue emission. The same technology can 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 field.

[0007] As used herein, the term "organic" includes both polymeric materials and small-molecule organic materials that can be used to manufacture organic optoelectronic devices. "Small molecule" refers to any organic material that is not a polymer, and "small molecule" can actually be quite large. In some cases, small molecules may include repeating units. For example, using long-chain alkyl groups as substituents 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 portion of dendritic polymers, which consist of a series of chemical shells built upon the core portion. The core portion of a dendritic polymer can be a fluorescent or phosphorescent small-molecule emitter. Dendritic polymers can be "small molecules," and all dendritic polymers currently used in the OLED field are considered small molecules.

[0008] As used herein, "top" means furthest from the substrate, and "bottom" means closest to the substrate. When the first layer is described as being "placed" "above" the second layer, the first layer is placed further away from the substrate. Unless specified that the first layer "contacts" the second layer, other layers may exist between the first and second layers. For example, even if various organic layers exist between the cathode and anode, the cathode may still be described as being "placed" "above" the anode.

[0009] As used herein, “solution-handleable” means capable of dissolving, dispersing or transporting in and / or depositing from a liquid medium in the form of a solution or suspension.

[0010] When a ligand is considered to directly contribute to the photosensitivity of the emissive material, the ligand may be referred to as "photosensitive." When a ligand is considered not to contribute to the photosensitivity of the emissive material, the ligand may be referred to as "auxiliary," but auxiliary ligands can alter the properties of photosensitizing ligands.

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

[0012] As used herein, and as will generally be understood by those skilled in the art, if the first work function has a higher absolute value, then the first work function is “greater” or “higher” than the second work function. This is because the work function is typically measured as a negative number relative to the vacuum level, meaning that the “higher” work function is more negative. On a conventional energy level diagram with the vacuum level at the top, the “higher” work function is illustrated as being farther from the vacuum level in the downward direction. Therefore, the definitions of HOMO and LUMO levels follow different rules than those for the work function.

[0013] This document may describe layers, materials, regions, and devices by referring to the color of light emitted. Generally, as used herein, an emitting region that produces light of a particular color may include one or more emitting layers arranged in a stacked manner on top of each other.

[0014] As used herein, a "red" layer, material, region, or device refers to a layer, material, region, or device that emits light or whose emission spectrum has a peak in the range of about 580-700 nm. 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 500-600 nm; 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 400-500 nm; and a "yellow" layer, material, region, or device refers to a layer, material, region, or device with an emission spectrum with a peak wavelength in the range of about 540-600 nm. In some arrangements, individual regions, layers, materials, regions, or devices may provide separate "dark blue" and "light blue" light. As used herein, in an arrangement that provides separate "light blue" and "dark blue" components, the "dark blue" component refers to a component whose peak emission wavelength is at least about 4 nm smaller 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 approximately 465 nm to 500 nm, and the peak emission wavelength of the "dark blue" component is in the range of approximately 400 nm to 470 nm, although these ranges can vary for some configurations. Similarly, a color-changing layer refers to a layer that converts or modifies light of another color to have a wavelength specified for that color. For example, a "red" filter refers to a filter that forms light with wavelengths in the range of approximately 580-700 nm. Generally, there are two types of color-changing layers: filters that modify the spectrum by removing unwanted wavelengths of light, and color-changing layers that convert higher-energy photons into lower-energy ones. A "color" component refers to a component that, when activated or used, produces or otherwise emits light of a specific color as described above. 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 described above when activated within the device.

[0015] As used herein, emitting materials, layers, and regions can be distinguished from each other and from other structures based on the light initially generated by said material, layer, or region, rather than by the light ultimately emitted by the same or different structures. Initial light generation is typically a result of energy level changes that lead to photon emission. For example, an organic emitting material can initially generate blue light, which can be converted into red or green light by a color filter, quantum dot, or other structure, causing the entire emitting stack or sub-pixel to emit red or green light. In this case, the initial emitting material or layer can be referred to as the "blue" component, even if the sub-pixel is a "red" or "green" component.

[0016] In some cases, the color of components, such as the color of emitting regions, subpixels, color-changing layers, etc., can preferably be described according to 1931 CIE coordinates. For example, a yellow emitting material may have multiple peak emission wavelengths, one in or near the edge of the "green" region and one in or near the edge of the "red" region, as previously described. Therefore, as used herein, each color item also corresponds to a shape in the 1931 CIE coordinate color space. The shape in the 1931 CIE color space is 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 can be defined as follows:

[0017]

[0018] Further details about OLEDs and the definitions described above can be found in U.S. Patent 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 also 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 one embodiment, the device may include a substrate, a first electrode disposed above the substrate, and a first organic emission layer (EML) disposed above the first electrode, wherein the first EML includes a first emitting material. A second electrode may be disposed above the first EML. A first self-absorbing material (SAM) may be stacked with the substrate, and the first SAM may include a material that transfers at least a portion of the energy from the first EML to the first SAM. The first SAM may be disposed below, within, and / or above the substrate.

[0021] The second electrode of the device may include a reinforcement layer, wherein the reinforcement layer comprises plasmonic material exhibiting surface plasmon resonance coupled to the first emitting material.

[0022] The device may include a reinforcement layer comprising a plasmonic material exhibiting surface plasmon resonance coupled to a first emitting material. The plasmonic material may be capable of nonradiative or radiative transfer of excited-state energy.

[0023] SAMs may be able to perform at least one of the following operations: emit light, couple energy to plasmonic modes of the enhancement layer, and / or transfer energy to another material.

[0024] The first EML of the device may include a first SAM.

[0025] The first emission material of the device may be a first SAM.

[0026] The first electrode of the device can be a reflective electrode, and the first SAM can be disposed above or within the first EML. The first and second electrodes can form a microcavity structure tuned to the emission spectrum of the emitting material. Alternatively, the first and second electrodes can form a microcavity structure detuned to the wavelength emission of the emitter within the microcavity.

[0027] The first electrode of the device may be a transparent electrode, and the first SAM may be disposed above or within the first EML. The first electrode may be transparent and disposed above the first SAM. The device may further include a reflector disposed on the side of the substrate opposite to the first electrode. The reflector may be disposed at a distance of at least 10 µm from the first EML. The first SAM may be disposed between the reflector and the substrate.

[0028] The device may include an excoupling layer disposed above the first SAM. The excoupling layer may include a plasmon-to-photon excoupling layer.

[0029] The photoluminescence quantum yield (PLQY) of the first SAM of the device can be at least 80%. The relationship between the radiative rate (kR) and the non-radiative rate (kNR) of the first SAM or the first EML of the device can be kR ≥ 4 * kNR.

[0030] The device may include a second SAM disposed above a second electrode. The first and second electrodes may form a microcavity structure tuned to the emission spectrum of the emitting material. The first emitting layer of the device may be part of a first organic light-emitting diode (OLED) stack and may include a second emitting layer, which may be part of a second OLED stack, wherein the first emitting layer is closer to the enhancement layer than the second emitting layer, and wherein the first emitting layer is within a threshold distance. The first emitting material may have a total nonradiative decay rate constant. Total radiation attenuation rate constant The total nonradiative attenuation rate constant attributed to the enhancement layer and the total radiation attenuation rate constant attributed to the enhancement layer The reinforcing layer can be positioned at a distance from the first emissive material not exceeding a threshold distance, and the threshold distance is... The distance.

[0031] The device may include a charge generation layer disposed above a first EML and a second EML disposed above the charge generation layer, the second EML including a second emission material. The first EML of the device may include a first SAM. The second EML of the device may include a second SAM. At least two of the first electrode, the second electrode, and the charge generation layer may form a microcavity structure tuned or detuned for the emission spectrum of the first emission material and / or the second emission material.

[0032] The device may include a second SAM positioned above the first SAM and between the first electrode and the second electrode. The first and second electrodes may form a microcavity structure that is tuned or detuned for the emission spectrum of the emitting material.

[0033] The material of the first SAM of the device can absorb at least 1%, 5%, 10%, 25%, 50%, or 100% of the light emitted by the EML. The material of the first SAM of the device can absorb greater than 0.3%, greater than 1%, greater than 3%, greater than 5%, greater than 10%, greater than 20%, greater than 50%, and / or greater than 90% of the light emitted by the EML.

[0034] The SAM of the device may have at least one of the following characteristics: the Stokes shift between the absorption and emission spectra of the SAM is less than or equal to 100 nm; the extinction coefficient of the highest absorption band of the SAM is greater than or equal to 10. 3 M -1 ˑ cm -1 The following are descriptions of SAMs: a multi-carbon ring or heterocyclic system containing at least two fused rings; SAMs doped at a concentration greater than or equal to 0.5 vol%; SAMs uniformly doped into a first EML and capable of accepting energy transferred from one or more components of the first EML; SAMs doped at the interface between the first EML and the barrier layer (BL) and capable of accepting energy transferred from one or more components of the first EML or BL; and SAMs doped into a transport layer (e.g., an electron transport layer (ETL) or a hole transport layer (HTL)) and capable of accepting energy transferred from one or more components of the transport layer or one or more components of the EML.

[0035] The first SAM may include a self-absorbing emitter (SAE) layer having a vertical dipole ratio (VDR) selected from at least one of the following groups: less than 0.33, less than 0.25, and less than 0.2.

[0036] In one embodiment, the first electrode of the device may include a reinforcing layer, the second electrode may include a reinforcing layer, and / or the device may include a reinforcing layer disposed above the second electrode.

[0037] According to one embodiment, the device can be a consumer electronic device, such as a flat panel display, curved display, computer monitor, medical monitor, television, signboard, lamp for internal or external lighting and / or signaling, head-up display, fully transparent or partially transparent display, flexible display, rollable display, foldable display, stretchable display, laser printer, telephone, cellular phone, tablet computer, tablet phone, personal digital assistant (PDA), wearable device, laptop computer, digital camera, camcorder, viewfinder, microdisplay with a diagonal of less than 2 inches, 3D display, virtual reality or augmented reality display, vehicle, video wall comprising multiple displays tiled together, theater or stadium screen, optical communication device and / or signage. Attached Figure Description

[0038] Figure 1 An organic light-emitting device was displayed.

[0039] Figure 2 An inverted organic light-emitting device without an independent electron transport layer was demonstrated.

[0040] Figures 3A-3D An emitting device containing a self-absorbing layer is shown, wherein the self-absorbing layer may be located within the emitting layer of the device. Figure 3C and 3D ), or may not be located in the emitter layer of the device ( Figures 3A-3B ). Figure 3A and 3C An apparatus containing a reflective layer that forms a microcavity is shown according to embodiments of the disclosed subject matter, while Figure 3B and 3D A device is shown that includes a reflective layer that reflects light in the far field but is at least 10 micrometers away from the OLED layer, thereby producing incoherent reflection and thus avoiding the microcavity effect.

[0041] Figures 4A-4F It shows the situation in the emission layer ( Figure 4C-4F ) or in an independent layer ( Figures 4A-4B A tandem OLED containing a self-absorbing layer. According to embodiments of the disclosed subject matter, the tandem stack may contain a reflective layer that forms a microcavity. Figure 4A , 4C , 4E), or may contain a reflective layer that reflects light in the far field but is at least 10 micrometers away from the OLED layer, thereby producing incoherent reflection and thus avoiding the microcavity effect ( Figure 4B , 4D , 4F).

[0042] Figure 5 A graph showing the calculation of the cumulative plasmon coupling fraction as a function of the number of absorption / emission cycles in the device, according to embodiments of the disclosed subject matter.

[0043] Figures 6A-6B Devices comprising more than one SAE (Self-Absorbing Emitter) layer are demonstrated. According to embodiments of the disclosed subject matter, the device may contain a reflective layer forming a microcavity ( Figure 6A ), or may include a reflective layer that reflects light in the far field, thereby avoiding microcavity effects ( Figure 6B ).

[0044] Figures 7A-7B A device with an OLED is demonstrated, which may have two SAE layers, one inside the device and one outside the device. According to embodiments of the disclosed subject matter, the second SAE layer may be located directly above the top electrode. Figure 7A () or it can be part of the decoupling scheme () Figure 7B ).

[0045] Figure 8A A tandem OLED according to an embodiment of the disclosed subject matter is shown, wherein at least one emitter layer and an SAE layer are within a threshold distance of the enhancement layer.

[0046] Figure 8B A single-stack device according to an embodiment of the disclosed subject matter is shown, wherein the EML and one or more SAE layers are within a threshold distance of the enhancement layer. Detailed Implementation

[0047] Generally, an OLED comprises at least one organic layer disposed between and electrically connected to both the anode and cathode. When a current is applied, holes are injected into the anode and electrons into the organic layer from the cathode. The injected holes and electrons migrate toward their respective oppositely charged electrodes. 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 photoemission mechanism, light is emitted. In some cases, excitons may be localized on excimers or excited-state complexes. Non-radiative mechanisms (such as thermal relaxation) may also occur, but are generally considered undesirable.

[0048] Early OLEDs used emitting molecules that emitted light from a single state (“fluorescence”), as disclosed, for example, in U.S. Patent No. 4,769,292, which is incorporated herein by reference in its entirety. Fluorescence emission typically occurs within timeframes of less than 10 nanoseconds.

[0049] Recently, OLEDs with emitting materials that emit light from the triplet state (“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,” Applied Physics Letters, Vol. 75, 3, 4-6 (1999) (“Baldo-II”), are incorporated herein by reference in their entirety. Phosphorescence is described in more detail in columns 5-6 of U.S. Patent No. 7,279,704, which is incorporated herein by reference.

[0050] Figure 1 An organic light-emitting device 100 is shown. The figures are not necessarily drawn to scale. 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. Device 100 can be fabricated by sequentially depositing the layers. The properties and functions of these various layers, as well as example materials, are described in more detail in columns 6-10 of US 7,279,704, which is incorporated herein by reference.

[0051] Further examples of each of these layers are available. For instance, a flexible and transparent substrate-anode combination is disclosed in U.S. Patent No. 5,844,363, which is incorporated herein by reference in its entirety. An example of a p-doped hole transport layer is m-MTDATA doped with F4-TCNQ in a 50:1 molar ratio, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated herein by reference in its entirety. Examples of emitting and host materials are disclosed in U.S. Patent No. 6,303,238 to Thompson et al., which is incorporated herein by reference in its entirety. An example of an n-doped electron transport layer is BPhen doped with Li in a 1:1 molar ratio, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated herein by reference in its entirety. Examples of cathodes, comprising composite cathodes having a thin layer of metal (e.g., Mg:Ag) having an overlying transparent, conductive, sputtered ITO layer, are disclosed in their entirety in U.S. Patent Nos. 5,703,436 and 5,707,745, which are incorporated herein by reference in their entirety. Theories and uses 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 herein by reference in their entirety. Examples of implantation layers are provided in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated herein by reference in its entirety. A description of protective layers can be found in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated herein by reference in its entirety. Barrier layer 170 may be a single layer or multiple layers and may cover or surround other layers of the device. Barrier layer 170 may also surround substrate 110, and / or it may be disposed between the substrate and other layers of the device. A barrier layer, also known as an encapsulation, encapsulation layer, protective layer, or permeation barrier, typically provides protection against moisture, ambient air, and other similar materials permeating through other layers of a 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 herein by reference in its entirety.

[0052] Figure 2An inverted OLED 200 is shown. The device includes a substrate 210, a cathode 215, an emitter layer 220, a hole transport layer 225, and an anode 230. The device 200 can be fabricated by sequentially depositing these layers. Because the most common OLED configuration has a cathode disposed above the anode, and the device 200 has a cathode 215 disposed below the anode 230, the 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 the device 200. Figure 2 Provide an example of how some layers can be omitted from the structure of device 100.

[0053] Figure 1 and 2 The simple layered structures illustrated herein are provided by way of non-limiting examples, and it should be understood that embodiments of the invention can be used in conjunction with a variety of other structures. The specific materials and structures described are exemplary in nature, and other materials and structures can be used. Functional OLEDs can be obtained by combining the various layers described in different ways, or the layers can be omitted entirely based on design, performance, and cost factors. Other layers not specifically described may also be included. Materials other than those specifically described may be used. Although many examples provided herein describe various layers as comprising a single material, it should be understood that combinations of materials, such as mixtures of host and dopant, or more generally, mixtures, can be used. Furthermore, 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 emitter layer 220, and can be described as a hole transport layer or a hole injection layer. In one embodiment, an OLED may be described as having an “organic layer” disposed between a cathode and an anode. This organic layer may comprise a single layer, or may further comprise, for example, regarding Figure 1 and 2 Multiple layers of the different organic materials mentioned above.

[0054] Structures and materials not specifically described can also be used, such as OLEDs (PLEDs) containing polymeric materials, as disclosed in, for example, U.S. Patent No. 5,247,190 to Friend et al., which is incorporated herein by reference in its entirety. By another example, OLEDs with a single organic layer can be used. OLEDs can be stacked, for example as described in, for example, U.S. Patent No. 5,707,745 to Forrest et al., which is incorporated herein by reference in its entirety. OLED structures can deviate from... Figure 1 and 2The simple layered structure described herein. For example, the substrate may include angled reflective surfaces to improve out-coupling, such as the tabletop structure described in U.S. Patent No. 6,091,195 to Forrest et al., and / or the recessed structure described in U.S. Patent No. 5,834,893 to Bulovic et al., which are incorporated herein by reference in their entirety.

[0055] In some embodiments disclosed herein, the emission layer or material (e.g. Figure 1-2 The emitting layers 135 and 220 shown herein may include quantum dots. Unless explicitly indicated otherwise or as understood by one of ordinary skill in the art, the term "emitting layer" or "emitting material" as disclosed herein may include organic emitting materials and / or emitting materials containing quantum dots or equivalent structures. Generally, an emitting layer comprises emitting material within a host matrix. Such an emitting layer may comprise only quantum dot material that converts light emitted by a separate emitting material or other emitting body, or it may also comprise a separate emitting material or other emitting body, or it may emit light directly by applying an electric current. Similarly, color-changing layers, color filters, upconversion or downconversion layers, or structures may comprise materials containing quantum dots, but such layers are not considered "emitting layers" as disclosed herein. Typically, an "emitting layer" or material is a material that emits initial light based on injected charge, wherein the initial light may be altered by another layer (e.g., a color filter or other color-changing layer) that does not itself emit initial light within the device, but may re-emit altered light with different spectral content based on absorption and downconversion of the initial light emitted by the emitting layer to lower energy light emission. In some embodiments disclosed herein, color-changing layers, color filters, up-conversion and / or down-conversion layers may be disposed outside the OLED device, for example, above or below the electrodes of the OLED device.

[0056] Unless otherwise specified, any of the layers in the various embodiments may be deposited by any suitable method. For organic layers, preferred methods include thermal evaporation, inkjet printing (as described in U.S. Patent Nos. 6,013,982 and 6,087,196, which are incorporated herein by reference in their entirety), organic vapor deposition (OVPD) (as described in U.S. Patent No. 6,337,102 by Forrest et al., which are incorporated herein by reference in their entirety), and deposition by organic vapor jet printing (OVJP) (as described in U.S. Patent No. 7,431,968, which is incorporated herein by reference in its entirety). Other suitable deposition methods include spin coating and other solution-based processes. Solution-based processes are preferably performed in a nitrogen or inert atmosphere. For other layers, preferred methods include thermal evaporation. Preferred patterning methods include deposition via a mask, cold soldering (as described in U.S. Patents 6,294,398 and 6,468,819, which are incorporated herein 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 suit a particular deposition method. For example, branched or unbranched substituents, preferably containing at least three carbons, such as alkyl and aryl groups, may be used in small molecules to enhance their solution handling ability. Substituents having 20 or more carbons may be used, with 3 to 20 carbons being a preferred range. Materials with asymmetric structures may have better solution handleability than those with symmetric structures because asymmetric materials may have a lower tendency to recrystallize. Dendritic polymer substituents may be used to enhance the solution handling ability of small molecules.

[0057] Devices manufactured according to embodiments of the present invention may optionally further include a barrier layer. One use of the barrier layer is to protect the electrodes and organic layers from damage caused by exposure to harmful substances in an environment including moisture, vapor, and / or gases. The barrier layer may be deposited on, under, or beside a substrate or electrode, or on any other part of the device, including edges. The barrier layer may comprise a single layer or multiple layers. The barrier layer can be formed using various known chemical vapor deposition techniques and may comprise compositions having a single phase and compositions having multiple phases. Any suitable material or combination of materials may be used for the barrier layer. The barrier layer may contain inorganic or organic compounds, or both. Preferred barrier layers comprise a mixture of polymeric and non-polymeric materials, as described in U.S. Patent No. 7,968,146, PCT Patent Application Nos. PCT / US2007 / 023098 and PCT / US2009 / 042829, which are incorporated herein by reference in their entirety. For the process to be considered a "mixture," the aforementioned polymeric and non-polymeric materials constituting the barrier layer should be deposited and / or deposited simultaneously under the same reaction conditions. The weight ratio of polymeric to non-polymeric materials can range from 95:5 to 5:95. The polymeric and non-polymeric materials can be produced from the same precursor material. In one example, the mixture of polymeric and non-polymeric materials is essentially composed of polymeric silicon and inorganic silicon.

[0058] In some embodiments, at least one of the anode, cathode, or a new layer disposed above the organic emitting layer serves as a reinforcement layer. The reinforcement layer comprises a plasmonic material exhibiting surface plasmon resonance, which is nonradiatively coupled to the emitting material and transfers excited-state energy from the emitting material to the nonradiative modes of the surface plasmon polaritons. The reinforcement layer is provided at a threshold distance from the organic emitting layer, wherein the emitting material has a total nonradiative decay rate constant and a total radiative decay rate constant due to the presence of the reinforcement layer, and the threshold distance is a distance where the total nonradiative decay rate constant is equal to the total radiative decay rate constant. In some embodiments, the OLED further comprises an excoupling layer, as disclosed in U.S. Patent No. 9,960,386, which is incorporated herein by reference in its entirety. In some embodiments, the excoupling layer is disposed above the reinforcement layer on the opposite side of the organic emitting layer. In some embodiments, the excoupling layer is disposed on the opposite side of the emitting layer from the reinforcement layer, but still allows energy to be decoupled from the surface plasmon polariton modes of the reinforcement layer. The excoupling layer scatters or extracts energy from the surface plasmon polaritons. In some embodiments, this energy is scattered into free space in the form of photons. In other embodiments, energy is scattered or extracted from the surface plasmon modes of the device into other modes, such as, but not limited to, organic waveguide modes, substrate modes, or another waveguide mode. If energy is scattered or extracted into the non-free-space modes of the OLED, other decoupling schemes can be incorporated to extract energy into free space. In some embodiments, one or more dielectric spacer layers may be disposed between the reinforcement layer and the decoupling layer. The plasmon stack may include a dielectric spacer material (i.e., a dielectric spacer layer) whose refractive index is selected based on the color of light emitted by the organic emitting material. In one embodiment, the dielectric spacer material (i.e., the dielectric spacer layer) may be located between the reinforcement layer and the nanoparticles in the plasmon stack. In an alternative embodiment, the dielectric spacer material may be located between two electrodes in the plasmon stack. In yet another embodiment, the dielectric spacer material may be located on either side of either electrode, outside the plasmon stack. In yet another embodiment, the dielectric spacer material may be located between the reinforcement layer and the decoupling layer or may be integrated within the decoupling layer. In some embodiments, the dielectric spacer layer may be present only in plasmonic stacked subpixels, only in non-platinonic stacked subpixels, or in both. Examples of materials suitable for the dielectric spacer layer include dielectric materials, including organic, inorganic, perovskite, and oxide materials, and may include stacks and / or mixtures of these materials.

[0059] The enhancement layer modifies the effective properties of the medium in which the emitter material resides, thereby causing any or all of the following: reduced emissivity, modification of emission spectral shape, changes in emission intensity and viewing angle, changes in the stability of the emitter material, changes in OLED efficiency, and reduced efficiency degradation of the OLED device. Placing the enhancement layer on the cathode side, anode side, or both sides produces an OLED device that utilizes any of the above effects. In addition to the specific functional layers mentioned herein and illustrated in the various OLED examples shown in the figures, the OLED according to the invention may also include any of the other functional layers commonly found in OLEDs.

[0060] The reinforcing layer can be composed of plasmonic materials, optically active metamaterials, or hyperbolic metamaterials. As used herein, plasmonic materials are materials whose real portion of the dielectric constant crosses zero in the visible or ultraviolet region of the electromagnetic spectrum. In some embodiments, the plasmonic material comprises 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. Generally, metamaterials are media composed of different materials, wherein the medium as a whole acts differently than the sum of its material parts. Specifically, we define optically active metamaterials as materials having both a negative dielectric constant and negative permeability. On the other hand, hyperbolic metamaterials are anisotropic media, wherein the permittivity or permeability has different signs for different spatial orientations. Optically active metamaterials and hyperbolic metamaterials are strictly distinguished from many other photonic structures, such as distributed Bragg reflectors (DBRs), because the medium must be uniform along the length scale of the light wavelength in the direction of propagation. Using terminology understood by those skilled in the art, the dielectric constant of the metamaterial in the direction of propagation can be approximated by an effective medium. Plasmon materials and metamaterials offer methods for controlling light propagation that can enhance OLED performance in a variety of ways.

[0061] 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-periodicly, or randomly, or subwavelength-sized features arranged periodically, quasi-periodicly, or randomly. In some embodiments, the wavelength-sized features and subwavelength-sized features have sharp edges.

[0062] In some embodiments, the decoupling layer is characterized by a wavelength size arranged periodically, quasi-periodicly, or randomly, or by a subwavelength size arranged periodically, quasi-periodicly, or randomly. In some embodiments, the decoupling layer may be composed of multiple nanoparticles, and in other embodiments, the decoupling layer is composed of multiple nanoparticles disposed on top of a material. In these embodiments, decoupling can be tuned by at least one of the following: changing the size of the multiple nanoparticles, changing the shape of the multiple nanoparticles, changing the material of the multiple nanoparticles, adjusting the thickness of the material, changing the refractive index of the material or an additional layer disposed on the multiple nanoparticles, changing the thickness of the reinforcing layer, and / or changing the material of the reinforcing layer. The multiple nanoparticles of the device may be formed from at least one of the following: a metal, a dielectric material, a semiconductor material, a metal alloy, a mixture of dielectric materials, a stack or layer of one or more materials, and / or a core of one type of material, wherein the core is coated with a shell of a different type of material. In some embodiments, the decoupling 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 may have additional layers disposed on them. In some embodiments, the polarization of the emission can be tuned using the decoupling layer. Changing the dimension and periodicity of the decoupling layer can select a type of polarization that preferentially decouples to air. In some embodiments, the decoupling layer also functions as an electrode of the device.

[0063] It is believed that the internal quantum efficiency (IQE) of fluorescent OLEDs can exceed the 25% spin statistical limit through delayed fluorescence. As used in this paper, there are two types of delayed fluorescence: P-type delayed fluorescence and E-type delayed fluorescence. P-type delayed fluorescence is generated by triplet-triplet annihilation (TTA).

[0064] On the other hand, E-type delayed fluorescence does not depend on the collision of two triplet states, but rather on the thermal population between the triplet and singlet excited states. Compounds capable of producing E-type delayed fluorescence are required to have a very small singlet-triple gap. Thermal energy can activate transitions from the triplet state back to the singlet state. This type of delayed fluorescence is also called thermally activated delayed fluorescence (TADF). A significant characteristic of TADF is that the delayed component increases with increasing temperature due to increased thermal energy. If the reverse intersystem crossing rate is fast enough to minimize nonradiative decay from the triplet state, the fraction of singlet excited states that are refilled can reach 75%. The total singlet fraction can be 100%, far exceeding the spin statistical limit of electrically generated excitons.

[0065] E-type delayed fluorescence can be observed in excited complex systems or single compounds. Unbound by theory, it is believed that E-type delayed fluorescence requires the luminescent material to have a small singlet-triplet band gap (ΔES-T). Organic, metal-free donor-acceptor luminescent materials may be able to achieve this. The emission of these materials is typically characterized by donor-acceptor charge transfer (CT) emission. Spatial separation of the HOMO and LUMO in these donor-acceptor compounds usually results in a small ΔES-T. These states may involve CT states. Typically, donor-acceptor luminescent materials are constructed by linking an electron donor moiety (e.g., an amino or carbazole derivative) with an electron acceptor moiety (e.g., an N-containing six-membered aromatic ring).

[0066] Devices manufactured according to embodiments of the present invention can be incorporated into a wide variety of electronic component modules (or units), which can be incorporated into a variety of electronic products or intermediate components. Examples of such electronic products or intermediate components include displays, lighting devices (such as discrete light source devices or lighting panels), etc., which can be utilized by end-user product manufacturers. The electronic component module may optionally include driving electronics and / or a power supply. Devices manufactured according to embodiments of the present invention can be incorporated into a wide variety of consumer products having one or more electronic component modules (or units) incorporated therein. A consumer product incorporating an OLED is disclosed, wherein the OLED comprises compounds of the present disclosure in its organic layer. The consumer product should include any type of product containing one or more light sources and / or one or more of some type of visual display. Examples of the consumer products described include flat panel displays, curved displays, computer monitors, medical monitors, televisions, billboards, lights for internal or external lighting and / or signaling, head-up displays, fully transparent 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, camcorders, viewfinders, microdisplays with a diagonal of less than 2 inches, 3D displays, virtual reality or augmented reality displays, vehicles, video walls comprising multiple tiled displays, theater or stadium screens, optical communication devices, and / or signage. Various control mechanisms, including passive and active matrices, can be used to control the devices manufactured according to the invention. Many of the devices are intended for use in temperature ranges comfortable for humans, such as 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).

[0067] 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 utilize the materials and structures described herein. More generally, organic devices such as organic transistors can utilize the materials and structures described herein.

[0068] 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 including carbon nanotubes.

[0069] In some embodiments, the OLED further comprises a layer including a delayed phosphor emitter. In some embodiments, the OLED comprises an RGB pixel arrangement or a white pixel arrangement with a color filter. 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 with 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 with 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.

[0070] In some embodiments of the launch area, the launch area further includes a body.

[0071] In some embodiments, the compound may be an emission dopant. In some embodiments, the compound may generate emission via phosphorescence, fluorescence, thermally activated delayed fluorescence (TADF, also known as E-type delayed fluorescence), triplet-triplet annihilation, or a combination of these processes.

[0072] The OLEDs disclosed herein can be incorporated into one or more consumer products, electronic component modules, and lighting panels. The organic layer can be an emission layer, and the compound can be an emission dopant in some embodiments, while in other embodiments it can be a non-emission dopant.

[0073] 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 minor role in charge transport. In some embodiments, the host may include a metal complex. The host may be an inorganic compound.

[0074] Combination with other materials

[0075] The materials described herein for use in specific layers of organic light-emitting devices can be used in combination with a wide variety of other materials present in the device. For example, the emission dopants disclosed herein can be used in combination with a wide variety of possible host layers, transport layers, blocking layers, injection layers, electrodes, and other layers. 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.

[0076] The various emitting and non-emitting layers and arrangements disclosed herein can be made of different materials. Examples of suitable materials are disclosed in U.S. Patent Application Publication No. 2017 / 0229663, which is incorporated herein by reference in its entirety.

[0077] Conductive dopants:

[0078] Charge transport layers can be doped with conductive dopants to substantially alter their charge carrier density, which in turn changes their conductivity. Conductivity is increased by creating charge carriers in the matrix material and, depending on the type of dopant, can also achieve changes in the Fermi level of the semiconductor. Hole transport layers can be doped with p-type conductive dopants, while n-type conductive dopants are used in electron transport layers.

[0079] HIL / HTL:

[0080] The hole injection / transport materials used in this invention are not particularly limited, and any compound can be used, as long as the compound is commonly used as a hole injection / transport material.

[0081] EBL:

[0082] An electron blocking layer (EBL) can be used to reduce the number of electrons and / or excitons leaving the emitter layer. The presence of such a blocking layer in a device can result in generally higher efficiency and / or longer lifetime compared to similar devices lacking a blocking layer. Furthermore, the blocking layer can be used to confine emission to a desired area of ​​the OLED. In some embodiments, the EBL material has a higher LUMO (closer to vacuum level) and / or higher triplet energy compared to the emitter closest to the EBL interface. In some embodiments, the EBL material has a higher LUMO and / or higher triplet energy compared to one or more of the bodies closest to the EBL interface. In one aspect, the compound used in the EBL contains the same molecules or the same functional groups as those used in one of the bodies described below.

[0083] main body:

[0084] The light-emitting layer of the organic EL device of the present invention preferably contains at least a metal complex as the light-emitting material, and may contain a host material using a metal complex as a dopant material. Examples of the host material are not particularly limited, and any metal complex or organic compound can be used, as long as the triplet energy of the host is greater than that of the dopant. Any host material can be used with any dopant, as long as the triplet criterion is satisfied.

[0085] HBL:

[0086] Hole blocking layers (HBLs) can be used to reduce the number of holes and / or excitons leaving the emitter layer. The presence of such blocking layers in a device can result in generally higher efficiency and / or longer lifetime compared to similar devices lacking a blocking layer. Furthermore, blocking layers can be used to confine emission to a desired area of ​​the OLED. In some embodiments, the HBL material has a lower HOMO (farthest from vacuum level) and / or higher triplet energy compared to the emitter closest to the HBL interface. In some embodiments, the HBL material has a lower HOMO and / or higher triplet energy compared to one or more of the bodies closest to the HBL interface.

[0087] ETL:

[0088] An electron transport layer (ETL) may comprise a material capable of transporting electrons. The ETL may be intrinsic (undoped) or doped. Doping can be used to enhance conductivity. Examples of ETL materials are not particularly limited, and any metal complex or organic compound may be used, provided it is typically used for electron transport.

[0089] Charge generation layer (CGL)

[0090] In tandem or stacked OLEDs, the conduction layer (CGL) plays a fundamental role in performance. It consists of an n-doped layer and a p-doped layer, respectively, for injecting electrons and holes. Electrons and holes are supplied by the CGL and the electrodes. Electrons and holes consumed in the CGL are refilled by electrons and holes injected from the cathode and anode, respectively; subsequently, the bipolar current gradually reaches a steady state. Typical CGL materials include n- and p-conductive dopants used in the transport layer.

[0091] The enhancement layer described above may comprise a plasmonic material exhibiting surface plasmon resonances, nonradiatively coupled to the emitter material. In some embodiments, the emitter may be coupled to surface plasmon modes via near-field interactions. In other embodiments, the emitter may be coupled to surface plasmon modes via far-field optical interactions. The coupling process between the emitter and the surface plasmons allows excited-state energy to be transferred from the emitter material to nonradiative and / or radiative modes of the surface plasmon polaritons.

[0092] Organic light-emitting diodes (OLEDs) are typically designed with emitters that have high photoluminescence quantum yields and materials that have low absorption for photons generated within the OLED stack. This ensures that photons generated by the radiative recombination of excitons are not reabsorbed but are emitted as light to the outside of the device. However, conventional OLEDs are limited by the refractive index contrast between the organic layer and air, which restricts light extraction efficiency.

[0093] Plasmonic OLEDs, incorporating one or more plasmonic enhancement layers, couple excited-state energy to surface plasmonic modes in nearby enhancement layers. This can be accomplished through near-field or far-field coupling, and the plasmonic energy is subsequently converted into light. In the case of nanoparticle-based decoupling (NPO) schemes (i.e., decoupling layers containing nanoparticles), light can be generated directly in the air, thus circumventing the light extraction efficiency limitations imposed on conventional OLEDs. Since plasmonic decoupling efficiency has the potential to be much higher than that of conventional OLEDs, it is important to maximize the amount of excited-state energy that can be coupled into the plasmonic modes; this can be referred to as induction coupling.

[0094] The main factor limiting plasmon coupling efficiency stems from the fact that excitons located at a certain distance from the enhancement layer will have a subunit probability of exciting surface plasmon polaritons (SPPs). Practical device considerations, such as device short circuits and charge balance, require the emitter layer (EML) to be spaced a finite distance from the enhancement layer. Excitons that do not form SPPs can radiatively recombine and emit photons within the device. Instead of allowing photons to escape from the device or be trapped in waveguide modes, embodiments of the disclosed subject matter provide OLED devices comprising one or more materials that reabsorb the emitted light and couple the energy directly or through one or more intermediate materials into plasmon modes. As used throughout, such materials may be referred to as self-absorbing materials (SAMs), and layers containing SAMs may be referred to as self-absorbing layers (SALs). An emitter that absorbs its own emission is called a self-absorbing emitter (SAE). A SAE may be at least some or all of the absorbed light emitted by the SAM. SAMs, SALs, and / or SAEs may also absorb ambient light entering the device, which may also be coupled in the same manner.

[0095] In one embodiment, SAM and / or SAE may comprise: phthalocyanines, including variants such as boron chloride phthalocyanine, boron chloride-2,3-naphthyl phthalocyanine, boron hexachloride phthalocyanine, etc.; porphyrin dyes; coumarin dyes; photochromic dyes; perylene dyes; anthocyanin and / or aryl cyanine dyes; dipyrrole methylene dyes; dibenzopyran dyes; quinacridones; DIPYR (dipyridamole) dyes; BODIPY (Boron-dipyrrolemethylene) dyes; phosphors; fluorophores; thermally activated delayed fluorescence (TADF) materials; quantum dots; perovskite materials; boron-dipyrrolemethylene; rhodamine; fluorescein; fluorescein isothiocyanate; calcein; ethidium bromide; phycoerythrin; carboxylated naphthofluorescein; hexachlorofluorescein; tetramethylrhodamine; phenylethynylpyrene; or quantum-confined nanocrystals of cadmium selenide, cadmium sulfide, cadmium telluride, core-shell cadmium selenide-zinc sulfide, core-shell cadmium selenide-zinc selenide, lead sulfide, zinc selenide, etc.; 2D materials, such as molybdenum disulfide (MoS2), molybdenum diselenide (MoSe2), tungsten disulfide (WS2), tungsten diselenide (WSe2), etc. In preferred embodiments, SAM and / or SAE contain materials with a concentration greater than 10 within the desired filtration range. 4 cm -1 More preferably greater than 10 5 cm -1 Materials with peak absorption coefficients.

[0096] In at least some of the embodiments disclosed herein, the SAM can be any material that absorbs light emitted from within the OLED stack and / or absorbs ambient light entering a device including the OLED stack. The amount of light absorbed can be at least 1%, 3%, 5%, 10%, at least 15%, etc.

[0097] In one embodiment, the SAM may have a Stokes shift of less than 100 nm. In some embodiments described herein, the SAM may absorb light but may not emit light, and therefore the SAM may not have a Stokes shift. Instead, the SAM may absorb OLED light and subsequently transfer energy (via Förster resonant energy transfer (FRET) or Dexter electron transfer (DET)), plasmon coupling, or any other energy transfer mechanism to another emitter. In some embodiments, the device may include a material for absorption and a material for emission, wherein the material may overlap with its absorption and emission spectra. In these embodiments, two materials may be selected such that the peak absorption wavelength of one material is precisely aligned with or has some other predetermined offset from the peak emission wavelength of the other material, rather than relying on a single material having a Stokes shift. In one embodiment, the material for absorption and the material for emission are visible in the SAL. In one embodiment, the SAL may include a first SAL layer and a second SAL layer, the first SAL layer including the material for absorption and the second SAL layer including the material for emission. In one embodiment, the SAL may include a first SAL layer, the first SAL layer comprising both the absorbent material and the emitter material mixed within the first SAL layer.

[0098] In some embodiments described herein, the SAM can be disposed between electrodes. In some embodiments, the SAM can contribute 0.1% to 100% of the energy transferred to the surface plasmon mode, which may not occur for other absorption structures. Plasmons can be collective oscillations of the electron density in a metal relative to stationary positive ions. This oscillation may occur when an electric field is applied to the metal, which may cause electrons to move to a first side, exposing positive ions on a second side. When the electric field is removed or reversed in direction, the electrons may move back to the first side, or may oscillate back and forth when an oscillating electric field is applied. Surface plasmons can be coherent electronic oscillations confined to the metal surface or metal-dielectric interface. When surface plasmons are coupled with photons, the interaction with electromagnetic energy can induce excitation modes of quasiparticles, or surface plasmon polaritons, which can propagate along the metal surface or metal-dielectric interface.

[0099] The device architecture in embodiments of the disclosed subject matter may include a reflective layer comprising a metal or dielectric material or a combination thereof, which reflects non-plasmic coupled light back to the SAL for reabsorption. The reflective layer may be placed to create a microcavity (e.g., Figure 3AAs shown in the diagram, this means that the position of the layer causes coherent reflection of light. This can be tuned to resonate near the emission wavelength, particularly detuned from the emission wavelength (e.g., the antinode of the cavity), or tuned to the peak absorption wavelength of SAM and / or SAL. In other embodiments, the reflective layer can be placed far enough away from the emission source to avoid incoherent reflection from the microcavity, and can utilize far-field specular reflection (e.g., as shown in the diagram). Figure 3B (As shown in the diagram). Once the photons are guided back to the SAL, they can be reabsorbed by the SAM, and those excitons can have another opportunity to couple into plasmonic modes. This process of reabsorption by the SAM to generate excitons and subsequently coupling them into plasmonic modes or to emissions from the SAM can be repeated until almost all excited-state energy has been transferred to plasmonic modes.

[0100] To minimize losses, the emitter in the SAM process can possess a high photoluminescence quantum yield (PLQY), and the absorbing material can have a large extinction coefficient. In some embodiments, the emitter can be both an absorbing and emitting material. Therefore, the emitter can exhibit strong self-absorption. For strong self-absorption, there may be a very small Stokes shift between the absorption and emission peaks and / or significant tail overlap between the absorption and emission spectra of the emitter. For example, for a strong self-absorption emitter with unit PLQY and 50% plasmon insertion efficiency, seven emit / reabsorption cycles may be required to achieve a plasmon insertion efficiency greater than 99%: (1) 50% SPP excitation and 50% photon generation; (2) reabsorption of the remaining 50% of photons to form excitons and another 50% of those to form SPPs, increasing the SPP fraction to a total of 75% after including insertion from step 1; (3) process (2) can be repeated to increase the SPP fraction to 87.5%; then (4) to 93.75%; then (5) to 96.875%; then (6) to approximately 98.5%; then (7) to greater than 99%. This is achieved by Figure 5 Line 500 is shown in the diagram. For an SAE with 90% PLQY and 50% plasmon coupling efficiency (i.e., a Purcell factor of 2), plasmon coupling can converge to 95% coupling within 11 cycles. As long as PLQY is close to unit, plasmon coupling can be low and can still produce near-unit plasmon coupling after many cycles. For example, an SAE with unit PLQY and 10% plasmon coupling efficiency can still converge to greater than 99% plasmon coupling after 45 cycles, such as... Figure 5Line 502 is shown in the diagram. These example calculations assume that each photon incident on the SAE can be absorbed and generate an exciton. For an SAE where the absorption intensity (or extinction coefficient) does not produce a unit photon absorption, the number of cycles can be increased accordingly. For example, if an average of 2 interactions with the photon is required to generate an absorption event, the number of cycles calculated above may double. If an average of 10 interactions with the photon is required to generate an absorption event, the number of cycles may increase by an order of magnitude. The maximum inclination fraction achievable for a given number of cycles is given by the following relationship:

[0101] Coupling=100∙in [1+PLQY∙∑(1-in) a [In percentage]

[0102] Where in is the coupling fraction, and the sum occurs over all a from a=1 to the number of cycles after the first electro-emission event. The coupling fraction after the first electro-emission event can be the coupling fraction itself. As the number of cycles approaches infinity, the geometric series converges, and the relation simplifies to:

[0103] Maximum input coupling = 100∙in [1+PLQY(1 / in-1)], in percentage.

[0104] If the inclination fraction or PLQY is in units, then the maximum inclination fraction can be in units. For an emitter with 50% inclination and 90% PLQY, the maximum inclination fraction can be 95%. For an emitter with 20% inclination and 80% PLQY, the maximum inclination fraction can be 84%.

[0105] In another preferred embodiment, the SAM can be a host that absorbs light generated by the emitter. In this embodiment, the process can still function as long as there is an energy difference between the host in its singlet state and the final emitter sufficient to drive the exciton to the emitter, preferably greater than 0.02 eV. Foster resonance energy transfer (FRET) can be driven by spectral overlap. The overlap integral is related to the extinction coefficient, which has M... -1 cm -1 The unit is M. The overlap integral itself (i.e., the overlap between the donor emission spectrum and the acceptor absorption spectrum) is expressed in M. -1 cm -1 nm 4 The unit is 10. In some embodiments, the overlap integral may have 10. 9 Up to 10 16 M -1 cm -1 nm 4 The range, or more preferably having 10 10 Up to 10 15M -1 cm -1 nm 4 The range.

[0106] For plasmonic OLEDs, assuming unit internal quantum efficiency, the external quantum efficiency (EQE) can be equal to the product of the plasmonic input efficiency and the plasmonic output efficiency. Using this method, the plasmonic input efficiency can approach 100%. This means that the EQE can approach the plasmonic output efficiency, which can be greater than 60% or even 80%.

[0107] The devices in embodiments of the disclosed subject matter may include one or more emitters, and each emitter may be, but is not limited to, a phosphor, a fluorophore, a thermally activated delayed fluorescent emitter (TADF), a perovskite (including nanoscale perovskite materials), and / or a quantum dot. Self-absorbing emitters may be electrically excited and / or may be present in a device stack, optically pumped only by non-plasmic coupling emission from independently electrically excited emitters in another layer or the same layer. Examples of this arrangement are shown in Figures 3A-3D This may be advantageous for several reasons. For SAEs in independent, non-electrically pumped layers where no excitons are expected to form due to charge recombination, it may not be necessary to design the SAE molecules to be stable against charge or excited states, including triplet excited states, since SAE excitons can be optically pumped and thus separated from the charge and excited states in the EML. In the case where the SAE is situated in a transport layer, barrier layer, or injection layer, charge may still be present near the SAE. In this case, it may be preferable to design the energy levels of the SAE to minimize the possibility of charge on the molecule or only specific charges. For example, SAE materials deposited in an ETL may only need to be designed to be electronically stable, since holes are not expected to be present within the ETL. However, charge may be present on the molecule, but only with one charge sign (i.e., an electron or a hole, but not both). Furthermore, the SAE molecule may only need to match one energy level, for example, the lowest unoccupied molecular orbital (LUMO) if located in an electron transport layer (ETL), or the highest occupied molecular orbital (HOMO) if located in a hole transport layer (HTL). Therefore, the molecular design of SAEs can be simplified, and characteristics such as high PLQY, strong self-absorption, and / or high extinction coefficients can be prioritized. In one example embodiment, the EML can be electrically pumped, and non-plasmic coupled emission can excite the SAE, which subsequently couples a portion of the energy into plasmonic modes. The non-plasmic coupled emission can be reflected from the reflective layer and can be reabsorbed by the SAE. This process can be repeated until unity plasmonic coupling is achieved.

[0108] SAEs can be located in any device layer, such as a transport layer, barrier layer, injection layer, emitter layer, capping layer, and / or some other layer not between the two electrodes (i.e., cathode and anode) of the device. SAEs can be doped into the host material, which may or may not absorb emission, or can exist as a pure layer. Some SAEs can increase their self-absorption intensity upon aggregation, thus potentially requiring high concentrations or pure layers.

[0109] Plasmon OLEDs incorporating device stacks that are thinner than those in conventional OLED designs are not uncommon. Typically, the EML and / or transport layer will be thinner, such as less than 50 nm thick, more preferably less than 30 nm thick, and most preferably less than 20 nm thick, to position the excited-state energy close to the enhancement layer. However, for OLEDs with SAEs, near-unit plasmon coupling can be generated within approximately 50 emission / reabsorption cycles, even if the plasmon coupling efficiency per excitation event of the SAE molecules is less than 10%, provided that the SAE has unit PLQY and each photon is absorbed to generate an exciton. In a preferred embodiment, the SAE can be positioned sufficiently close to the enhancement layer to facilitate at least moderate coupling to plasmon modes. For example, the SAE layer can be spaced from the enhancement layer by less than 1000 nm, less than 500 nm, less than 250 nm, less than 150 nm, more preferably less than 100 nm, and most preferably less than 50 nm. For devices in embodiments of the disclosed subject matter where the SAE is not located in the EML, the EML and transport layer can be of any desired thickness, including conventional bottom or top emitter configuration thicknesses, which are typically 30-50 nm for the EML and 20 nm to 200 nm for the HTL and / or ETL. This circumvents the well-known OLED stability penalty of thin EMLs. Furthermore, the lack of rigidity requirements for cavity and / or device stack tuning improves the manufacturability of the arrangement of the disclosed subject matter, particularly in tandem and microcavity structures, as greater tolerances for layer thickness variations across the substrate can be acceptable. The ability of the devices of the disclosed subject matter to utilize thinner layers enables lower operating voltages and thus provides increased power efficiency.

[0110] The device arrangements in the embodiments of the disclosed subject matter are compatible with stacked or tandem OLEDs. In these devices, light generated by tandem OLED stacks can be trapped within the device because the opaque reflective layer and most of the opaque enhancement layer have typical transmittance of less than 40%, more typically less than 25%, or even 10% in the visible light range. If the trapped light is not directly absorbed by the SAE, it can be absorbed by the SAL and transferred to the emitter or SAE, whereby the energy can be coupled into plasmonic modes (with near-unit cumulative efficiency, as previously discussed), and subsequently converted into light via a decoupling scheme. The decoupling scheme can be, for example, a decoupling layer comprising, for example, nanoparticles, gratings, corrugated surfaces, or any number of other configurations exhibiting plasmon decoupling into light. Since the number of photons generated within the device can increase with the number of stacks in a tandem device, the EQE of the OLED can be high, and can even exceed 100%. It is predicted that each subunit can contribute an EQE equal to the decoupling efficiency of the plasmonic decoupling mechanism. For example, a triple-stacked tandem OLED incorporating the architecture of embodiments of the disclosed subject matter and achieving 60% plasmonic decoupling efficiency can have an expected EQE of 180%. Since the device can have efficiencies exceeding those possible with conventional tandem architectures, the device of the disclosed subject matter can achieve even greater operational stability improvements than conventional tandem OLEDs. Furthermore, since it is not necessary to select the thickness of the tandem stack layers to maximize conventional photonic decoupling efficiency, thinner layers can be used, which can have the effect of reducing operating voltage and improving power efficiency. This improves manufacturability by eliminating rigidity requirements on the device cavity, allowing for free variation in layer thickness without compromising device performance or affecting emission characteristics such as color and intensity shifts relative to angle, as these characteristics are largely determined by the plasmonic decoupling scheme. These device structures will also be more tolerant of layer thickness variations across the display panel. For example, if the device's HTL varies by 10% across a 13'' display, the impact on overall device performance is likely minimal. Even with a 10% variation in the distance from the SAM layer to the enhancement layer, the expected change in Purcell is less than 5%, thus having a negligible impact on the number of reabsorption events required to achieve maximum coupling. Furthermore, plasmonic decoupling schemes can be designed to reduce ambient light reflection, such as nanoparticle-based decoupling schemes that diffusely scatter ambient light, thereby improving manufacturability at the panel level by reducing the need for polarizers and / or other methods to reduce ambient light reflection. In a preferred embodiment, only one SAE layer may exist in the cascaded device, such as... Figures 4A-4F As shown in the diagram. In some embodiments, multiple SAE layers may be preferred. The cascaded arrangement can be as follows: Figure 4A The diagram shows the incorporation of microcavities, or as shown in the diagram. Figure 4B The diagram shown does not have microcavities.

[0111] The SAM and / or SAE within the device can be used to reduce ambient light reflection from the OLED active region. Since photoexcitation of the SAM in the device generates excitons, which are then coupled to plasmons and scattered as photons, ambient light can be used to increase the brightness of the OLED pixels. This can be advantageous, especially in outdoor conditions where brighter OLED pixels are necessary due to competition with bright ambient sunlight. To maintain high contrast, pixels in the "off" state can be reverse-biased.

[0112] The architecture of embodiments of the disclosed subject matter offers several advantages over the architecture of conventional single-stack or tandem devices. For example, a device incorporating an outcoupling layer with nanoparticles on the top side of an OLED can achieve a Lambertian emission profile with less color shift angle than a conventional top-emitting OLED. For devices with large cavities, such as tandem OLEDs, the complexity of the cavity design can be reduced because photons can be absorbed by the SAE and pass through plasmon modes instead of being emitted from the cavity into free space.

[0113] In some embodiments, it may be preferable to position the EML and / or SAM / SAE layers within a threshold distance of the enhancement layer, which can reduce excited-state transient lifetime and produce a more stable device, such as Figure 8B As illustrated in the example embodiment. In the case of cascaded stacking, at least one of the EML and / or SAM / SAE layers can be within the threshold distance of the enhancement layer, such as... Figure 8A As illustrated in the example embodiments. Furthermore, device stability can be improved by adjusting the EML thickness independently of the SAE layer. Thickening the EML typically increases device stability by increasing the volume that excitons may occupy, thereby reducing the likelihood of destabilizing excited-state interactions. The advantage of the architecture of the disclosed subject matter is that device stability can be increased by adjusting the EML thickness without concern for matching optical decoupling nodes or causing color shifts in the device, which are typically required for conventional devices emitting light directly from an OLED stack.

[0114] The transition dipole moments (TDMs) of the SAE and emitter can be selected to meet various desired conditions. For an SAE inside an EML with another emitter, it may be desirable to preferentially align the two TDMs horizontally or vertically to enhance the energy transfer efficiency to the SAE. This can occur through far-field photon emission and reabsorption, or nonradiative energy transfer such as Foster resonance energy transfer (FRET) or Dexter electron transfer (DET). In a preferred embodiment where the SAE can be located in a layer separate from the EML, it may be preferred to horizontally align the TDM of the emitter in the EML so that photons bounce off the reflective layer at near-normal incidence and are subsequently reabsorbed by the SAE. In another preferred embodiment, the TDM of the emitter in the EML can be vertically oriented such that it effectively couples photons into waveguide modes, which can then be absorbed by the SAE. In yet another preferred embodiment, the SAE can be vertically oriented to have increased plasmon coupling efficiency. Depending on the wavelength of the light emitted from the organic emitting material, ideal far-field plasmon coupling occurs when photons are incident on the reinforcement layer at an angle of 39–45 degrees relative to the plane of the reinforcement layer. This corresponds to a VDR of 0.33–0.65 for the organic emitting material.

[0115] The disclosed architecture is compatible with sensitized OLEDs, where excited-state energy can be transferred from the sensitizer to the emitter. The SAE can be located within the sensitized EML or in a separate layer and can be used to increase device efficiency. In one embodiment, the emitter in the EML can act as the "sensitizer," and the SAE can act as the "acceptor." Positioning the SAE in a layer separate from the EML can provide advantages over conventional sensitized devices because there may be no energy transfer loss via DET, as the two emitters can be separated over a greater distance than the distance that DET might occur.

[0116] SAEs can be arranged with narrow line shapes to improve color purity. SAEs can be arranged to achieve strong spectral overlap with the resonance of the plasmon decoupling scheme to obtain high decoupling efficiency. The decoupling scheme can be designed to customize the emission profile, particularly the color shift versus angle and intensity versus angle. In the case of decoupling layers with nanoparticles, the nanoparticles can be arranged in random, quasi-periodic, or ordered arrays, where the spectral overlap is tuned to SAE emission or detuned to SAE emission to modify the emission and angular profiles.

[0117] The device can incorporate one or more SAEs in the same or different layers, for example Figures 6A-6BThe arrangement is shown. This may be desirable to incorporate the benefits of different SAE characteristics. In one example embodiment, one SAE in the layer further away from the enhancement layer can be configured with a horizontally aligned TDM to bounce emitted light away from the reflector layer at near-normal incidence, thereby reducing waveguide load and “redirecting” the waveguide light (by absorption and re-emission) at a more perpendicular angle to the substrate, while the second SAE closer to the enhancement layer can have a more vertically aligned TDM to improve plasmon coupling efficiency.

[0118] In one embodiment, one or more of the SAE layers may not be located between the device electrodes. For example, such as Figure 7A As shown, two SAE layers can exist, one of which is located on top of the transparent electrode. In this example embodiment, SAE layer 1 can have a horizontal TDM (i.e., a vertical dipole ratio (VDR) less than 0.33, less than 0.25, or less than 0.2) to effectively redirect waveguide light through the transparent electrode to excite SAE layer 2. SAE layer 2 can emit light into the air. SAE layer 2 can be excited by an evanescent wave formed at the electrode / air interface due to the waveguide light from SAE layer 1. To increase the photon extraction efficiency into the air, SAE layer 2 can be made extremely thin, preferably less than 10 nm, more preferably less than 5 nm, and most preferably less than 1 nm. When the distance between SAE layer 1 and SAE layer 2 is small, preferably less than 20 nm, more preferably less than 10 nm, and most preferably less than 5 nm, energy transfer between SAE layer 1 and SAE layer 2 can be maximized. When the spacing is less than 5 nm, Foster resonant energy transfer (FRET) can facilitate energy transfer between the SAE layers. Figure 7B In this configuration, SAE layer 2 can be located within the spacer layer as part of the plasmon-to-photon decoupling structure. This can improve the plasmon-to-photon conversion efficiency because SAE layer 2 can be pumped by the enhancement layer and can be subjected to a large electric field in the spacer layer region, and thus undergoes an increased Purcell effect.

[0119] Five preferred embodiments in which the emitter can act as a SAM are present. A first exemplary embodiment may have an electrically pumped phosphor in an EML and an optically pumped SAE in a separate layer. A second exemplary embodiment may have an electrically pumped TADF in an EML and an optically pumped SAE in a separate layer. A third exemplary embodiment may have an electrically pumped TADF in an EML, which is also an SAE. A fourth exemplary embodiment may have an electrically pumped fluorophore in an EML and an optically pumped SAE in a separate layer. A fifth exemplary embodiment may have an electrically pumped fluorophore in an EML, which is also an SAE.

[0120] Five preferred embodiments may exist in which the host cell acts as the SAM. A first exemplary embodiment may include an electrically pumped phosphor in the EML and an optically pumped SAM host in a separate layer, capable of transferring energy to the emitter. A second exemplary embodiment may include an electrically pumped TADF in the EML and an optically pumped SAM host in a separate layer, capable of transferring energy to the emitter. A third exemplary embodiment may include an electrically pumped TADF doped into the SAM host in the EML. A fourth exemplary embodiment may include an electrically pumped phosphor in the EML and an optically pumped SAM host in a separate layer, capable of transferring energy to the emitter. A fifth exemplary embodiment may include an electrically pumped phosphor doped into the SAM host in the EML.

[0121] In embodiments without an enhancement layer, reabsorption may cause photons to be re-emitted to the light escape cone, potentially increasing OLED efficiency. In one example embodiment, waveguide light may be reabsorbed by an SAE (or a SAM body that transfers energy to the emitter), wherein the SAE (or emitter) may have a TDM with preferential horizontal orientation.

[0122] As described above Figure 3A-8B As shown, the apparatus of the disclosed subject matter may include a substrate, a first electrode disposed over the substrate, and a first organic emitting layer (EML) disposed over the first electrode, wherein the first EML includes a first emitting material. A second electrode may be disposed over the first EML. The enhancement layer may include a plasmonic material exhibiting surface plasmon resonance nonradiatively coupled to the first emitting material. A first surface-emitting amplified beam (SAM) may be disposed over the substrate, wherein the first SAM may include a material that absorbs at least a portion of the light emitted by the first EML.

[0123] In some embodiments, the second electrode may include a reinforcement layer comprising a plasmonic material exhibiting surface plasmon resonance coupled to the first emitting material.

[0124] In some embodiments, the plasmonic material may be able to transfer excited-state energy from a first emitting material to surface plasmon polaritons in the reinforcing layer. The SAM may be able to emit light, couple energy into plasmonic modes, and / or transfer energy to another material.

[0125] In some embodiments, the first EML of the device may include a first SAM. In other embodiments, the first emissive material of the device may be a first SAM.

[0126] The first electrode of the device may be a reflective electrode, and the first SAM may be disposed above or within the first EML. In some embodiments, the first and second electrodes may form a microcavity structure tuned to the emission spectrum of the emitting material. In other embodiments, the first and second electrodes may form a microcavity structure detuned to the wavelength emission of the emitter in the microcavity.

[0127] The first electrode of the device can be a transparent electrode, and the first SAM can be positioned above or within the first EML, for example... Figure 3B and 3D As shown in the diagram. The device may further include a reflector disposed on the side of the substrate opposite to the first electrode. The reflector may be positioned at a distance of at least 10 µm from the first EML.

[0128] In some embodiments, the SAM need not be a threshold distance enhancement layer to achieve high plasmon inclination fraction.

[0129] The device may include an outcoupling layer disposed above a first SAM. The outcoupling layer may include a plasmon-to-photon outcoupling layer. The outcoupling layer of the device may include an enhancement layer and a plurality of nanoparticles disposed above the enhancement layer.

[0130] In some embodiments, the photoluminescence quantum yield (PLQY) of the device's SAM can be at least 80%. In some embodiments where the SAM is the main component, the PLQY can be close to zero. The relationship between the radiative rate (kR) and the non-radiative rate (kNR) of the first SAM or first EML of the device can be kR ≥ 4 * kNR.

[0131] The device may include a second SAM positioned above the second electrode, for example Figures 7A-7B As shown in the diagram. In some embodiments, a transparent top electrode may be present, so the device may not have a microcavity. In some embodiments, the top electrode may be reflective, and the device may have a microcavity. However... Figure 7B The device may not have a microcavity because the reflector is too far away. If this arrangement is modified to have a microcavity, then the microcavity may become detuned.

[0132] The first and second electrodes can form a microcavity structure tunable for the emission spectrum of the emitting material. The first emitting layer of the device may be part of a first organic light-emitting diode (OLED) stack and may include a second emitting layer, which may be part of a second OLED stack, wherein the first emitting layer is closer to the enhancement layer than the second emitting layer, and wherein the first emitting layer is within a threshold distance. The first emitting material may have a total nonradiative decay rate constant. Total radiation attenuation rate constant The total nonradiative attenuation rate constant attributed to the enhancement layer and the total radiation attenuation rate constant attributed to the enhancement layer The reinforcing layer can be positioned at a distance from the first emissive material not exceeding a threshold distance, and the threshold distance is... The distance.

[0133] In some embodiments, the device may include a charge-generating layer disposed above a first EML and a second EML disposed above the charge-generating layer, the second EML including a second emission material, such as... Figures 4A-4B As shown in the figure. In some embodiments, the first EML of the device may include a SAM, and in another embodiment, the second EML of the device may include a SAM. At least two of the first electrode, the second electrode, and the charge generation layer may form a microcavity structure tuned or detuned for the emission spectrum of the first emission material and / or the second emission material (see, for example...). Figure 4A , 4C and 4E).

[0134] The device may include a second SAM disposed above the first SAM and between the first electrode and the second electrode, for example Figures 6A-6B As shown in the diagram. The first and second electrodes can form a microcavity structure that is tuned or detuned for the emission spectrum of the emitting material, for example... Figure 6A As shown in the image.

[0135] In some embodiments, the material of the first SAM of the device can absorb at least 1%, 5%, 10%, 25%, 50%, and up to 100% of the light emitted by the EML. The material of the first SAM of the device can absorb greater than 0.3%, greater than 1%, greater than 3%, greater than 5%, greater than 10%, greater than 20%, greater than 50%, and / or greater than 90% of the light emitted by the EML. That is, whenever a photon interacts with the material, the material of the SAM can absorb a non-zero amount of light emitted by the EML.

[0136] In some embodiments, the SAM of the device may have at least one of the following characteristics: the Stokes shift between the absorption spectrum and the emission spectrum of the SAM is less than or equal to 100 nm; the extinction coefficient of the highest absorption band of the SAM is greater than or equal to 10. 3 M -1 ˑ cm -1The system comprises a multi-carbon ring or heterocyclic system containing at least two fused rings; SAM is doped at a concentration greater than or equal to 0.5% by volume; SAM is uniformly doped into the first EML and is capable of accepting energy transferred from one or more components of the first EML; SAM is doped at the interface between the first EML and the barrier layer (BL) and is capable of accepting energy transferred from one or more components of the first EML or BL; and / or SAM is doped into the electron transport layer (ETL) and is capable of accepting energy transferred from one or more components of the ETL.

[0137] In some embodiments, the first electrode of the device may include a reinforcing layer, the second electrode may include a reinforcing layer, and / or the device may include a reinforcing layer disposed above the second electrode.

[0138] It should be understood that the various embodiments described herein are merely examples and are not intended to limit the scope of the invention. For instance, many of the materials and structures described herein can be substituted with other materials and structures without departing from the spirit of the invention. The claimed invention may therefore include variations of the specific examples and preferred embodiments described herein, as will be apparent to those skilled in the art. It should be understood that various theories regarding why the invention works are not intended to be limiting.

Claims

1. An apparatus comprising: Substrate; A first electrode disposed on the substrate; A first organic emission layer (EML) disposed above the first electrode, the first EML containing a first emission material; A second electrode positioned above the first EML; as well as A first self-absorbing material SAM is stacked with the substrate, the first SAM comprising a material that transfers at least a portion of the energy from the first EML to the first SAM.

2. The apparatus of claim 1, wherein the second electrode comprises a reinforcement layer, and wherein the reinforcement layer comprises a plasmonic material coupled to the first emitting material to exhibit surface plasmonic resonance.

3. The apparatus of claim 2, wherein the plasmonic material is capable of transferring excited-state energy from the first emitting material to the nonradiative mode of the surface plasmon polaritons of the reinforcing layer.

4. The apparatus of claim 2, wherein the plasmonic material is capable of nonradiative or radiative transfer of excited state energy.

5. The device of claim 2, wherein the SAM is capable of at least one of the following: emitting light, coupling energy to a plasmonic mode of the enhancement layer of the device, and transferring energy to another material.

6. The apparatus of claim 2, further comprising: The outcoupling layer is placed above the first SAM.

7. The apparatus of claim 1, wherein the first EML comprises the first SAM.

8. The apparatus of claim 7, wherein the first emission material is the first SAM.

9. The apparatus of claim 1, wherein the first electrode is a transparent electrode and the first SAM is disposed above or within the first EML.

10. The apparatus of claim 9, further comprising a reflector disposed on the side of the substrate opposite to the first electrode.

11. The apparatus of claim 10, wherein the reflector is positioned at a distance of at least 10 µm from the first EML.

12. The apparatus of claim 11, wherein the first SAM is disposed between the reflector and the substrate.

13. The apparatus of claim 1, wherein the photoluminescence quantum yield PLQY of the first SAM is at least 80%.

14. A consumer electronic device comprising the means according to claim 1.

15. The consumer electronic device of claim 14, wherein the device is at least one type selected from the group consisting of: flat panel displays, curved displays, computer monitors, medical monitors, televisions, billboards, lights for internal or external lighting and / or signaling, head-up displays, fully transparent 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, camcorders, viewfinders, microdisplays with a diagonal of less than 2 inches, 3D displays, virtual reality or augmented reality displays, vehicles, video walls comprising multiple displays tiled together, theater or stadium screens, optical communication devices, and signs.

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