Doped single crystal OLED

Abstract

The present application provides an OLED doped with a single crystal, and specifically relates to a device comprising a light emitting diode having an emission surface wherein the emission surface comprises a doped organic solid crystal. The light emitting diode may include an organic light emitting diode (OLED). The doped organic solid crystal may be a single crystal.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 63 / 579,408, filed on August 29, 2023, and U.S. Non-Provisional Application No. 18 / 543,061, filed on December 18, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure relates generally to display systems, and more particularly to organic light emitting diode (OLED)-based displays, including micro-OLED-based displays, and methods of making the same. Background Art

[0004] The display system can include a display panel having an array of individual LED display elements defining an active area. The display system can also include a semiconductor backplane located below the display panel. The backplane can provide structural support for the LED display elements and electrical connections for transmitting control signals to the light-emitting diodes. It will be appreciated that the integration of the LED display elements with the backplane and control circuitry can affect pixel-level interconnections, including the size and density of the pixel array, and ultimately affect the quality, performance, and cost of the display system.

[0005] While light sources such as organic light-emitting diodes (OLEDs) are key components of displays in AR / VR systems, important performance metrics are the light source's quantum efficiency and light extraction efficiency, which measures how efficiently photons are generated within the diode and extracted from the device. Photons generated in OLEDs can be lost due to a number of phenomena, including surface plasmon polarization modes, waveguide (WG) modes, and absorption within the device. Summary of the Invention

[0006] One aspect of the present disclosure provides a device comprising a light emitting diode having an emissive layer, wherein the emissive layer comprises a doped organic solid crystal.

[0007] Another aspect of the present disclosure provides a light-emitting diode, which includes: an anode; a hole injection layer, the hole injection layer covering the anode; a hole transport layer, the hole transport layer covering the hole injection layer; an emission layer, the emission layer covering the hole transport layer; a blocking layer, the blocking layer covering the emission layer; an electron transport layer, the electron transport layer covering the blocking layer; and a cathode, the cathode covering the electron transport layer, wherein the emission layer includes doped organic solid crystals.

[0008] Another aspect of the present disclosure provides a method comprising: forming a main electrode; forming an organic solid crystal layer above the main electrode, wherein the organic solid crystal layer comprises an emissive dopant; and forming a sub-electrode above the organic solid crystal layer, wherein the sub-electrode at least partially overlaps with the main electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings illustrate several exemplary embodiments and are a part of the specification. Together with the following description, these drawings illustrate and explain various principles of the present disclosure.

[0010] Figure 1 A diagram of a head-mounted display (HMD) including a near-eye display (NED) according to some embodiments.

[0011] Figure 2 According to some embodiments Figure 1 Cross-sectional view of the HMD shown in .

[0012] Figure 3 An isometric view of a waveguide display according to various embodiments is shown.

[0013] Figure 4 Depicted is an exploded perspective view of a simplified OLED structure according to some embodiments.

[0014] Figure 5 is a schematic diagram of an OLED display architecture including a display driver integrated circuit (DDIC) mounted over the backside of a silicon backplane according to some embodiments.

[0015] Figure 6 is a cross-sectional view of a doped organic solid crystal emissive layer according to certain embodiments.

[0016] Figure 7 is a diagrammatic representation of example dopants suitable for forming a doped organic solid crystal emissive layer according to certain embodiments.

[0017] Figure 8 is an illustration of exemplary augmented reality glasses that may be used in conjunction with embodiments of the present disclosure.

[0018] Figure 9 is an illustration of an exemplary virtual reality headset that may be used in conjunction with embodiments of the present disclosure.

[0019] Throughout the drawings, the same reference numerals and descriptions indicate similar, but not necessarily identical, elements. Although the exemplary embodiments described herein are susceptible to various modifications and alternative forms, specific embodiments have been shown in the drawings by way of example and will be described in detail herein. However, the exemplary embodiments described herein are not intended to be limited to the specific forms disclosed. On the contrary, this disclosure covers all modifications, equivalents, and alternatives falling within the scope of the appended claims. DETAILED DESCRIPTION

[0020] Optical displays are ubiquitous in emerging technologies, including wearable devices, smartphones, tablets, laptops, desktop computers, and other display systems. Many display systems used in these technologies are based on light-emitting diodes (LEDs), including organic light-emitting diodes (OLEDs). The present disclosure relates generally to display systems, and more specifically to displays based on organic light-emitting diodes (OLEDs), including micro-OLED displays, and methods for their manufacture.

[0021] According to various embodiments, a display system may include a display panel having an array of individual LED display elements defining an active area. One or more LED display elements can be grouped to form pixels. Each of the plurality of pixels may include an organic light emitting diode (OLED) and suitable control circuitry configured to generate and distribute control signals to selectively illuminate the pixel to project an image.

[0022] The display system may also include a semiconductor backplane located beneath the display panel. The backplane provides structural support for the LED display elements and electrical connections to transmit control signals to the light-emitting diodes. It will be appreciated that the integration of the LED display elements with the backplane and control circuitry can impact pixel-level interconnects, including the size and density of the pixel array, and ultimately the quality, performance, and cost of the display system.

[0023] While light sources such as organic light-emitting diodes (OLEDs) are key components of displays in AR / VR systems, important performance metrics are the light source's quantum efficiency and light extraction efficiency, which measures how efficiently photons are generated within the diode and extracted from the device. Photons generated in OLEDs can be lost due to a number of phenomena, including surface plasmon polarization modes, waveguide (WG) modes, and absorption within the device.

[0024] Disclosed herein are OLED display structures including an emissive layer configured to improve light generation efficiency. According to various embodiments, the emissive layer can include one or more layers of appropriately doped organic solid crystals (OSCs). The crystal structure and resulting refractive index of the OSC layer (i.e., relative to the refractive index of the organic layers within the OLED, for example) can be used to improve the light extraction efficiency of the device, including the generation and emission of light having a preferred polarization.

[0025] Organic solid crystal thin films can be implemented as single-layer or multi-layer structures. Multilayer films comprising multiple layers of organic solid crystal materials can include multiple layers of biaxially oriented organic solid materials. Each biaxial layer can be characterized by three mutually orthogonal refractive indices (n1, n2, n3), where n1≠n2≠n3.

[0026] According to certain embodiments, multilayer organic solid films can be incorporated into light sources such as OLEDs to improve light extraction efficiency. By aligning (i.e., rotating) the layers in a plane relative to adjacent layers, such bi-directionally oriented multilayer films can achieve higher signal efficiency and greater ghost image suppression than architectures using comparable materials. Organic solid films can also be used as brightness enhancement layers in various projectors.

[0027] One or more source materials can be used to form organic solid films, including multilayer films. Example organic materials include various types of crystalline organic semiconductors. According to various embodiments, organic semiconductors can include small molecules, macromolecules, liquid crystals, organometallic compounds, oligomers and polymers. Organic semiconductors can include p-type, n-type or bipolar polycyclic aromatic hydrocarbons, such as carbon 60, anthracene, tetracene, phenanthrene, tolane, pyrene, corannulene, fluorene, biphenyl and terphenyl.

[0028] Exemplary compounds may include cyclic, linear, and / or branched structures, may be saturated or unsaturated, and may additionally include heteroatoms and / or saturated or unsaturated heterocycles, such as furan, pyrrole, thiophene, pyridine, pyrimidine, piperidine, quinoline, benzothiophene, benzopyran, bent and asymmetric acenes, 2,6-naphthalenedicarboxylic acid, and 2,6-dimethylcarboxylate.

[0029] Heteroatoms may include fluorine, chlorine, nitrogen, oxygen, sulfur, phosphorus, and various metals. Suitable starting materials for molding solid organic semiconductor materials may include pure organic compositions, melts, solutions, or suspensions containing one or more organic materials of the present disclosure.

[0030] In some embodiments, the organic solid crystal may include functional groups such as amines, alcohols, or carboxylic acids.

[0031] Structurally, the disclosed organic materials and thin films derived therefrom can be single crystals, polycrystalline, or glassy. Organic solid crystals can include tightly packed structures (e.g., organic molecules) that exhibit desired optical properties (such as high and tunable refractive index and high birefringence). Anisotropic organic solid materials can include preferred molecular stacking or preferred molecular orientation or alignment.

[0032] Such organic solid crystal (OSC) materials can provide functions including phase modulation, beam steering, wavefront shaping and correction, optical communications, optical computing, and holography. Due to their optical and mechanical properties, organic solid crystals can enable high-performance devices and can be incorporated into passive or active optical devices (including AR / VR headsets) and can replace comparative material systems (such as polymers, inorganic materials, and liquid crystals). In some aspects, organic solid crystals can have optical properties that rival those of inorganic crystals while exhibiting the processability and electrical response of liquid crystals.

[0033] Due to their relatively low melting points, organic solid crystals can be molded to form desired structures. The molding process allows for complex architectures and can be more economical than cutting, grinding, and polishing bulk crystals. In one example, a single crystal or polycrystalline shape (such as a sheet or cube) can be partially or completely melted into a desired form and then controlled cooled to form a single crystal with the new shape.

[0034] For example, the process of molding optically anisotropic crystalline or partially crystalline films can include the manipulation of the thermodynamics and kinetics of nucleation and crystal growth. In certain embodiments, the temperature of the nucleation zone closest to the mold during molding can be less than the melting onset temperature (T m ), while the temperature away from the nucleation zone can be greater than the melting onset temperature. Such a temperature gradient paradigm can be achieved by a spatially applied thermal gradient, optionally combined with a selective melting process (e.g., laser, soldering iron, etc.), thereby removing excess nuclei and leaving only a small number of nuclei (e.g., a single nucleus) for crystal growth.

[0035] To promote nucleation and crystal growth, selected temperatures and temperature gradients can be applied to the crystallization front of the nascent film. For example, the temperature and temperature gradient adjacent to the crystallization front can be determined based on the selected raw materials (i.e., molding composition), including their melting temperature, thermal stability, and rheological properties.

[0036] Suitable molds for molding organic solid films can be made of a mold having a melting starting temperature (T m ) Higher softening temperature or glass transition temperature (Tg The mold may include any suitable material, such as silicon, silicon dioxide, fused silica, quartz, glass, nickel, silicone, siloxane, perfluoropolyether, polytetrafluoroethylene, perfluoroalkoxyalkane, polyimide, polyethylene naphthalate, polyvinylidene fluoride, and polyphenylene sulfide.

[0037] Epitaxial or non-epitaxial growth processes can be used to form an organic solid crystal (OSC) layer on a suitable substrate or on a mold. A seed crystal for promoting crystal nucleation and an anti-nucleation layer configured to locally inhibit nucleation can jointly promote the formation of a limited number of crystal nuclei in one or more designated locations, which in turn can promote the formation of larger, continuous organic solid crystals. In some embodiments, the nucleation-promoting layer or the seed crystal itself can be configured as a thin film.

[0038] Example nucleation promoting materials or seed materials can include one or more metals or inorganic elements or compounds, such as Pt, Ag, Au, Al, Pb, indium tin oxide, and SiO2. Another example nucleation promoting material or seed material can include organic compounds, such as polyimides, polyamides, polyurethanes, polyureas, polythioureas, polyethylenes, polysulfonates, polyolefins, and mixtures and combinations thereof. In some examples, the nucleation promoting material can be configured as a textured layer or alignment layer (such as a rubbed polyimide or a photoalignment layer), which can be configured to induce directionality or preferred orientation for the over-formed organic solid crystal film.

[0039] An example method for making an organic solid crystal thin film includes providing a mold; forming a layer of nucleation-promoting material over at least a portion of a surface of the mold; and depositing a layer of molten feedstock over the surface of the mold and in contact with the layer of nucleation-promoting material while maintaining a temperature gradient across the layer of molten feedstock.

[0040] The anti-nucleation layer may include a dielectric material. In another embodiment, the anti-nucleation layer may include an amorphous material. In an example process, crystal nucleation may occur independently of the substrate or mold.

[0041] In some embodiments, a surface treatment or release layer disposed above a substrate or mold can be used to control the nucleation and growth of organic solid crystals (OSCs) and subsequently facilitate separation and harvesting of bulk crystals or thin films. For example, a coating having a solubility parameter that is mismatched with the deposition chemistry can be applied to the substrate (e.g., entirely or partially) to inhibit interaction between the substrate and the crystalline layer during the deposition process.

[0042] Example surface treatment coatings may include oleophobic coatings or hydrophobic coatings. A thin layer (e.g., a single layer or a double layer) of oleophobic or hydrophobic material may be used to condition the substrate or mold prior to the epitaxial process. The coating material may be selected based on the substrate and / or the organic crystalline material. Other example surface treatment coating materials include siloxanes, fluorosilicone, phenylsiloxane, fluorinated coatings, polyvinyl alcohol and other OH-containing coatings, acrylic acid, polyurethane, polyester, and polyimide.

[0043] In some embodiments, a release agent may be applied to the inner surface of the mold and / or combined with the molding composition. Surface treatment of the inner surface of the mold may include chemical bonding or physical adsorption of small molecules or polymers / oligomers having linear, branched, dendritic, or cyclic structures functionalized or terminated with, for example, fluorinated groups, silicone groups, or hydrocarbon groups.

[0044] A buffer layer can be formed over the deposition surface of a substrate or mold. The buffer layer can include small molecules similar to or even identical to those that make up an organic solid crystal (e.g., anthracene single crystal). The buffer layer can be used to tune one or more properties of the deposition / growth surface of the substrate or mold, including surface energy, wettability, crystallinity, or molecular orientation.

[0045] Another exemplary method for producing an organic solid crystal thin film includes: forming a molecular feedstock layer above a mold surface, the molecular feedstock comprising crystalline organic molecules; forming a selected number of crystal nuclei from the organic molecules within a nucleation region of the molecular feedstock layer; and growing the selected number of crystal nuclei to form the organic solid crystal thin film. In some embodiments, the selected number of crystal nuclei may be one. Crystal growth may be controlled using isothermal processing, slow cooling, and zone annealing.

[0046] In some embodiments, additives can be used to promote the growth of single crystals and / or their release from the mold. In some embodiments, in addition to the precursor for the organic solid crystal (i.e., the crystalline organic molecule), the molecular raw material can include an additive selected from polymers, oligomers, and small molecules, wherein the additive can have a melting start temperature that is at least 20°C lower than the melting start temperature of the organic solid crystal precursor, for example, 20°C, 30°C, or even 40°C lower than the melting start temperature of the molding composition. Additives can promote crystal growth and the formation of larger crystal sizes. In some embodiments, additives can be combined with the molding process to improve the properties of the molded organic solid film, including its surface roughness.

[0047] During molding, and according to specific embodiments, the cover plate can be applied to the free surface of the organic solid crystal film. The cover plate can be tilted at a certain angle relative to the major surface of the film. Force can be applied to the cover plate to produce capillary force (capillary force), which promotes the mass transfer of molten raw materials, that is, between the cover plate and the substrate and in the direction of the crystallization front of the grown crystalline film. In some embodiments, such as by the vertical orientation of the deposition system, gravity can contribute to the mass transfer and transportation of molten raw materials to the crystallization front. Suitable materials for cover plate and substrate can independently include silicon dioxide, fused silica, high refractive index glass, high refractive index inorganic crystal and high melting temperature polymer (for example, siloxane, polyimide, PTFE, PFA etc.), although other material components are considered.

[0048] According to certain embodiments, a method of forming an organic solid crystal (OSC) may include: contacting an organic precursor (i.e., a crystalline organic molecule) with a non-volatile dielectric material; forming a layer including the organic precursor over a surface of a substrate or mold; and treating the organic precursor to form an organic crystalline phase, wherein the organic crystalline phase may include a preferred orientation of the molecules.

[0049] The act of contacting the organic precursor with the non-volatile dielectric material may include forming a homogeneous mixture of the organic precursor and the non-volatile dielectric material. In another embodiment, the act of contacting the organic precursor with the non-volatile dielectric material may include: forming a layer of the non-volatile dielectric material over a surface of the substrate or mold; and forming the organic precursor layer over the layer of the non-volatile dielectric material.

[0050] In some embodiments, a non-volatile dielectric material can be disposed between the mold surface and the organic precursor and can be adapted to reduce the surface roughness of the molded organic film and facilitate its release from the mold while locally inhibiting the nucleation of a crystalline phase. Example non-volatile dielectric materials include liquids such as silicone oils, fluorinated polymers, polyolefins, and / or polyethylene glycol. Another example non-volatile dielectric material can include a crystalline material having a melting temperature lower than that of the organic precursor material. In some embodiments, the mold surface can be pretreated to improve the wettability and / or adhesion of the non-volatile dielectric material.

[0051] The substrate or mold may include a surface that can be configured to provide a desired shape to the molded organic solid film. For example, the substrate or mold surface can be planar, concave or convex, and can include a three-dimensional architecture (such as a surface relief grating), or configured to form a curvature (e.g., a compound curvature) of a microlens, microprism, or prismatic lens. According to some embodiments, the geometric shape of the substrate or mold can be transferred and incorporated into the surface of the over-formed organic solid crystal film. For convenience, unless the context indicates otherwise, the terms "substrate" and "mold" can be used interchangeably herein.

[0052] The deposition surface of the substrate or mold may include a functional layer configured to be transferred to the organic solid crystal after the organic solid crystal is formed and separated from the substrate or mold. The functional layer may include an interference coating, an AR coating, an enhanced reflectivity coating, a bandpass coating, a bandstop coating, a blanket electrode, or a patterned electrode. As an example, the electrode may include any suitable conductive material, such as a metal, a transparent conductive oxide (TCO) (e.g., indium tin oxide or indium gallium zinc oxide), or a metal mesh or nanowire matrix (e.g., including metal nanowires or carbon nanotubes).

[0053] In place of molding, or in addition to molding, another example deposition method for forming organic solid crystals includes: vapor growth, solid state growth, melt-type growth, solution growth, etc., optionally in combination with a suitable substrate and / or seed crystal. The substrate can be organic or inorganic. As an example, thin film solid organic materials can be manufactured using one or more processes selected from chemical vapor deposition and physical vapor deposition. Another coating process (for example, a coating process from a solution or melt) can include 3D printing, inkjet printing, gravure printing, doctor blading, and spin coating, etc. Such a process can induce shearing during coating, and therefore can contribute to the preferred orientation of crystallites (crystallites) or molecular alignment and crystallites and / or molecules in the organic solid crystal film. Another example method can include pulling a self-supporting crystal from the melt. According to some embodiments, solid phase, liquid phase, or vapor deposition process can include an epitaxial process.

[0054] As used herein, the terms "epitaxial," "epitaxial," and / or "epitaxial growth and / or deposition" refer to the nucleation and growth of organic solid crystals on a deposition surface, wherein the growing layer of organic solid crystals is assumed to have the same crystallographic habit as the material of the deposition surface. For example, in an epitaxial deposition process, the chemical reactants can be controlled and the system parameters can be set so that the deposited atoms or molecules land on the deposition surface and remain sufficiently mobile via surface diffusion to orient themselves according to the crystallographic orientation of the atoms or molecules at the deposition surface. Epitaxial processes can be homogeneous or heterogeneous.

[0055] According to various embodiments, doping and related techniques can be used to tune the optical and electro-optical properties of organic solid crystals. For example, doping can affect one or more of the polarization, photoluminescence, and electroluminescence of the organic solid crystal. Introducing a dopant (i.e., an impurity) into an organic solid crystal can affect, for example, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) bands, and thus affect its band gap, induced dipole moment, and / or molecular / crystal polarization.

[0056] Doping can be performed in situ, i.e., during epitaxial growth. For example, the dopant can be incorporated into the raw material. In exemplary embodiments, doping can be used to modify the electronic structure and, thereby, at least one optical property of the organic solid crystal without damaging the molecular packing or the crystal structure itself.

[0057] Doping alters the electron and hole carrier concentrations of the host material at thermal equilibrium. Doped organic solid crystals can be either p-type or n-type. As used herein, "p-type" refers to the addition of impurities that create a valence electron deficit in the organic solid crystal, while "n-type" refers to the addition of impurities that create free electrons in the organic solid crystal. Without wishing to be bound by theory, doping can affect "π-stacking" and "π-π interactions" in the organic solid crystal.

[0058] Example dopants include Lewis acids (electron acceptors) and Lewis bases (electron donors). Specific examples include charge neutral and ionic species (e.g., Bronsted Acids and Bronsted bases), in combination with the above-mentioned processes, can be incorporated into organic solid crystals by solution growth or vapor phase co-deposition. In certain embodiments, the dopant can include organic molecules, organic ions, inorganic molecules, or inorganic ions. The doping distribution can be homogeneous or limited to a specific region (e.g., depth or area) of the organic solid crystal.

[0059] During nucleation and growth, one or more of substrate temperature, deposition pressure, solvent vapor pressure, or non-solvent vapor pressure can be used to control the orientation of the in-plane axes of the OSC film. The high refractive index and high birefringence organic solid films can be supported by a substrate or mold, or removed therefrom to form a self-supporting film. The substrate (if used) can be rigid or deformable.

[0060] The example process can be integrated with a real-time feedback loop configured to evaluate one or more properties of the organic solid crystal and adjust one or more process variables accordingly, including melt temperature, mold temperature, rate at which feedstock is injected into the mold, etc.

[0061] After deposition, the OSC film can be segmented and polished to obtain the desired size specifications and surface quality. For example, segmentation can include diamond turning, but other cutting methods can also be used. Polishing can include chemical mechanical polishing. In some embodiments, chemical or mechanical surface treatment can be used to create structures on the surface of the OSC film. Example surface treatment methods include diamond turning and photolithography and etching processes. In some embodiments, a cover plate or substrate with a reciprocal structure can be used to create surface structures in the OSC film.

[0062] The organic film can include a planar, convex or concave surface. In some embodiments, the surface can include a three-dimensional architecture, such as a periodic surface relief grating. In another embodiment, the film can be configured as a microlens or a prismatic lens. For example, a polarization optical device can include a microlens that selectively focuses one polarization of light on another polarization. In some embodiments, the structured surface can be formed in situ, that is, during the crystal growth of the organic solid crystal film above a suitably shaped mold. In another embodiment, the structured surface can be formed after crystal growth, for example using additive or subtractive processing, such as 3D printing or lithography and etching. Nucleation and growth kinetics and chemical selection can be selected to produce a solid organic crystal film having an area (lateral) size of at least about 1 cm.

[0063] The organic crystalline phase can be monocrystalline or polycrystalline. In some embodiments, the organic crystalline phase can include amorphous regions. In some embodiments, the organic crystalline phase can be substantially crystalline. The organic crystalline phase can be characterized in that the refractive index along at least one major axis at 589 nm is at least about 1.5. As an example, the refractive index of the organic crystalline phase at 589 nm and along at least one major axis can be at least about 1.5, at least about 1.6, at least about 1.7, at least about 1.8, at least about 1.9, at least about 2.0, at least about 2.1, at least about 2.2, at least about 2.3, at least about 2.4, at least about 2.5 or at least about 2.6, including ranges between any of the aforementioned values.

[0064] In some embodiments, the organic crystalline phase may be characterized by a birefringence (Δn) of at least about 0.05, where n1≠n2≠n3, e.g., at least about 0.05, at least about 0.1, at least about 0.2, at least about 0.3, at least about 0.4, or at least about 0.5, including ranges between any of the foregoing values. In some embodiments, the birefringent organic crystalline phase may be characterized by a birefringence of less than about 0.05, e.g., less than about 0.05, less than about 0.1, less than about 0.05, less than about 0.02, less than about 0.01, less than about 0.005, less than about 0.002, or less than about 0.001 (including ranges between any of the foregoing values).

[0065] Table 1 shows, for example, triaxial ellipsometry data for isotropic and anisotropic organic molecules. The data includes predicted and measured refractive index and birefringence values for 1,2,3-trichlorobenzene (1,2,3-TCB), 1,2-diphenylacetylene (1,2-DPE), and phenazine. For each organic material composition, the shown refractive index and birefringence values are greater than the predicted values, compared to values calculated based on the HOMO-LUMO gap.

[0066] Table 1. Refractive index and birefringence data of example organic semiconductors

[0067]

[0068] Organic solid films (including multilayer organic solid films) can be optically transparent and exhibit low bulk haze. As used herein, for a given thickness, a "transparent" or "optically transparent" material or element can have a transmittance of at least about 60%, for example, about 60%, 65%, 70%, 75%, 80%, 90%, 95%, 97%, 98%, 99% or 99.5% (including ranges between any of the aforementioned values) in the visible and / or near-IR spectrum and a bulk haze of less than about 5%, for example, a bulk haze of about 0.1, 0.2, 0.4, 1, 2 or 4% (including ranges between any of the aforementioned values). Transparent materials typically exhibit very low light absorption and minimal light scattering.

[0069] As used herein, the terms "haze" and "clarity" may refer to optical phenomena related to the transmission of light through a material and may be due to, for example, refraction of light within the material, e.g., due to secondary phases or porosity and / or reflection of light from one or more surfaces of the material. It will be appreciated that haze may be related to the amount of light that experiences wide-angle scattering (i.e., angles greater than 2.5° from normal) and loss of transmission contrast, while clarity may be related to the amount of light that experiences narrow-angle scattering (i.e., angles less than 2.5° from normal) and the resulting loss of optical clarity or "see-through quality."

[0070] In some embodiments, one or more organic solid crystal thin film layers can be cut and stacked to form a multilayer. Multilayer film can be formed by arranging (clock) and stacking each layer in a clockwise direction. That is to say, in the example "arranged in a clockwise direction" multilayer stack, the range of the refractive index orientation error of the angle between the continuous layers can be about 1 ° to about 90 °, such as 1 °, 2 °, 5 °, 10 °, 20 °, 30 °, 40 °, 45 °, 50 °, 60 °, 70 °, 80 ° or 90 °, including the range between any value in the aforementioned values.

[0071] In an example multilayer architecture, the thickness of each layer can be determined by the average of the in-plane refractive indices (n2 and n3), where (n2 + n3) / 2 can be greater than about 1.5, e.g., greater than 1.5, greater than 1.55, or greater than 1.6. In general, the thickness of a given layer can be inversely proportional to the arithmetic mean of its in-plane indices. Similarly, the total number of layers in a multilayer stack can be determined by the in-plane birefringence (|n3 - n2|), which can be greater than about 0.05, e.g., greater than 0.05, greater than 0.1, or greater than 0.2.

[0072] In a multilayer architecture, the thickness of each OSC layer can be constant or variable. In some examples, the OSC layer thickness can vary throughout the stack. The OSC layer thickness can vary continuously, for example, as the thickness of each successive layer increases throughout the multilayer.

[0073] According to some embodiments, for a given biaxially oriented organic solid material layer within a multilayer stack, the out-of-plane refractive index (n1) can be determined by the relationship is associated with the in-plane refractive indices (n2 and n3), where represents the rotation angle of the refractive index vector between adjacent layers. The variation in n1 can be less than ±0.7, less than ±0.6, less than ±0.5, less than ±0.4, less than ±0.3, or less than ±0.2.

[0074] According to some embodiments, the multilayer may include an OSC material layer and a secondary material layer arranged in a repeating structure of ABAB... The secondary material layer may include one or more of an amorphous polymer, an amorphous inorganic compound, or a liquid crystal.

[0075] The multilayer may additionally include pairs of conductive electrodes positioned to apply a voltage or current to the OSC material layer located between the electrodes. In some embodiments, the electrodes may be arranged to independently apply a voltage or current to each OSC layer. In some embodiments, the electrodes may be arranged to apply a voltage or current to different groups of layers within the multilayer. The refractive index or OSC film may be manipulated by the applied voltage, current, or stress.

[0076] Organic solid crystals with actively tunable refractive index and birefringence are disclosed. Methods of fabricating such organic solid crystals can control their surface roughness independently of surface features (e.g., gratings, etc.) and can include forming optical elements such as reflective polarizers from them.

[0077] According to various embodiments, optical elements comprising organic solid crystals (OSCs) can be integrated into optical components or devices (such as OFETs, OPVs, OLEDs, etc.), and can be incorporated into structures or devices such as waveguides, Fresnel lenses (e.g., cylindrical Fresnel lenses or spherical Fresnel lenses), gratings, photonic integrated circuits, birefringence compensation layers, reflective polarizers, and index matching layers (LED / OLED). In certain embodiments, the grating architecture can be tuned along one, two, or three dimensions. The optical element can include a single or multilayer OSC architecture.

[0078] As will be appreciated, one or more properties of an organic solid crystal can be tailored for a particular application. For example, for many optical applications, it can be advantageous to control the crystallite size, surface roughness, mechanical strength and toughness, and the orientation of crystallites and / or molecules within an organic solid crystal film. In a multilayer architecture, the composition, structure, and properties of each organic layer can be independently selected.

[0079] Organic solid crystals (e.g., OSC films) can be incorporated into passive and active optical waveguides, resonators, lasers, optical modulators, and the like. Other example active optical devices include projectors and projection optics, ophthalmic high-refractive-index lenses, eye trackers, gradient-index optical devices, Pancharatnam-Berry phase (PBP) lenses, microscopes, pupil-steering elements, optical computers, optical fibers, rewritable optical data storage, all-optical logic gates, multi-wavelength optical data processors, optical transistors, and the like. According to another embodiment, organic solid crystals (e.g., OSC films) can be incorporated into passive optical devices such as waveguides, reflective polarizers, and refractive / diffractive lenses. Related optical elements for passive optical devices may include waveguides, polarization-selective gratings, Fresnel lenses, microlenses, geometric lenses, PBP lenses, and multilayer films.

[0080] According to certain embodiments, the doped organic solid crystal can be incorporated into the emissive layer of a light-emitting diode. The organic solid crystal can operate as a charge transport medium and can be doped with any suitable luminescent guest, such as a phosphor (e.g., a fluorescent material or a phosphorescent material) or a fluorophore. Without wishing to be bound by theory, the OSC material can orient the luminescent guest in a manner that effectively emits light having a selective polarization. Thus, such an LED can directly emit s-polarized light or p-polarized light without filtering the emitted light to obtain the desired polarization.

[0081] Suitable phosphors and fluorophores emit from triplet excited states. For example, phosphors include metal complexes such as platinum-complexed porphyrins PtOEP (platinum-octaethyl-porphyrin), Ir(ppy2)(acac) (bis[2-(2-pyridinyl-N)phenyl-C](acetylacetonato)iridium(III), and Ir(p-CF3-ppy)3 (tris[2-(2-pyridinyl-kN)-5-(trifluoromethyl)phenyl-kC]iridium), although other compositions are contemplated. Example fluorophores include quantum dots and organic dyes such as fluorescein, rhodamine, and aminomethylcoumarin acetate (AMCA). The choice of phosphor / fluorophore can be determined by the desired absorption / emission properties of the host organic solid crystal and / or the emissive layer. For example, the choice of phosphor or fluorophore can be determined by the shape, packing, and / or crystal structure of the host organic solid crystal and / or the desired absorption or emission color within the visible light spectrum.

[0082] As will be appreciated, the LED-based displays described herein may include micro-LEDs. In addition, the LED-based displays may include organic LEDs (OLEDs), including micro-OLEDs. The LED-based displays may be incorporated into various devices, such as wearable near-eye displays (NEDs). The disclosed methods and structures may be used to manufacture low-cost, high-resolution displays having commercially relevant form factors (e.g., having one or more lateral dimensions greater than about 1.6 inches).

[0083] According to the general principles described herein, features from any of the above embodiments may be used in combination with each other. These and other embodiments, features and advantages will be more fully understood by reading the following detailed description in conjunction with the accompanying drawings and claims.

[0084] The following will refer to Figure 1-9 A detailed description of OLED devices and systems and methods for their manufacture is provided. According to certain embodiments, the light extraction efficiency and quantum efficiency of the disclosed devices and systems can be improved by co-integration of an emissive layer comprising doped organic solid crystals (OSCs). Figure 1-3The discussion involves an example near-eye display (NED). Figure 4-7 The related discussion includes descriptions of OLEDs and OLED packages in combination with doped OSC emissive layers according to various embodiments. Figure 8 and Figure 9 Related discussions relate to various virtual reality platforms that may include display devices as described herein.

[0085] Figure 1 is a diagram of a near-eye display (NED) 100 according to some embodiments. The NED 100 can present media to a user. Examples of media that can be presented by the NED 100 include one or more images, video, audio, or some combination thereof. In some embodiments, the audio can be presented via an external device (e.g., speakers and / or headphones) that receives audio information from the NED 100, a console (not shown), or both, and presents audio data to the user based on the audio information. The NED 100 is typically configured to operate as a virtual reality (VR) NED. However, in some embodiments, the NED 100 can be modified to also operate as an augmented reality (AR) NED, a mixed reality (MR) NED, or some combination thereof. For example, in some embodiments, the NED 100 can augment a view of a physical, real-world environment with computer-generated elements (e.g., still images, video, sound, etc.).

[0086] Figure 1 The NED 100 shown in FIG. 1 may include a frame 105 and a display 110. The frame 105 may include one or more optical elements that together display media to a user. That is, the display 110 may be configured for a user to view content presented by the NED 100. Figure 2 As described, the display 110 may include at least one source component to generate image light to present optical media to the user's eyes. The source component may include, for example, a source, an optical system, or some combination thereof.

[0087] It should be understood that Figure 1 is merely an example of a virtual reality system, and the display system described herein may be incorporated into other such systems. In some embodiments, Figure 1 It can also be called a head-mounted display (HMD).

[0088] According to some embodiments of the present disclosure, Figure 2 for Figure 12. The cross section 200 of the NED 100 is shown in FIG. The cross section 200 may include at least one display assembly 210 and an exit pupil 230. The exit pupil 230 is where the eyeball 220 may be positioned when the user wears the NED 100. In some embodiments, the frame 105 may represent the frame of glasses. For illustrative purposes, Figure 2 The cross section 200 is shown in association with a single eyeball 220 and a single display assembly 210, but in an alternative embodiment not shown, Figure 2 Another display assembly, separate from or integrated with the display assembly 210 shown in FIG, can provide image light to the user's other eye.

[0089] The display assembly 210 can be configured to direct image light to the eyeball 220 through the exit pupil 230. The display assembly 210 can be composed of one or more materials (e.g., plastic, glass, etc.) having one or more refractive indices, which effectively reduces the weight of the NED 100 and widens the field of view.

[0090] In an alternative configuration, the NED 100 may include one or more optical elements (not shown) between the display assembly 210 and the eyeball 220. By way of various examples, the optical elements may be used to correct aberrations in image light emitted from the display assembly 210, amplify image light emitted from the display assembly 210, perform some other optical conditioning of image light emitted from the display assembly 210, or a combination thereof. Example optical elements may include an aperture, a Fresnel lens, a convex lens, a concave lens, a filter, or any other suitable optical element that can affect image light.

[0091] In some embodiments, the display assembly 210 can include a source assembly to generate image light to present the media to the user's eyes. The source assembly can include, for example, a light source, an optical system, or some combination thereof. According to various embodiments, the source assembly can include a light emitting diode (LED), such as an organic light emitting diode (OLED).

[0092] Figure 3 An isometric view of a waveguide display 300 is illustrated according to some embodiments. The waveguide display 300 can be a component of the NED 100 (e.g., the display component 210). In alternative embodiments, the waveguide display 300 can form part of some other NED or other system that directs image light to a specific location.

[0093] The waveguide display 300 may include a source component 310, an output waveguide 320, and a controller 330. For illustration purposes, Figure 3The waveguide display 300 is shown associated with a single eye 220, but in some embodiments, another waveguide display that is separate (or partially separate) from the waveguide display 300 can provide image light to the user's other eye. For example, in a partially separate system, one or more components can be shared between the waveguide displays for each eye.

[0094] The source assembly 310 generates image light. The source assembly 310 may include a source 340, a light conditioning assembly 360, and a scanning mirror assembly 370. The source assembly 310 may generate image light 345 and output it to the coupling element 350 of the output waveguide 320.

[0095] Source 340 may include a light source that generates at least coherent image light 345 or partially coherent image light 345. Source 340 may emit light according to one or more lighting parameters received from controller 330. Source 340 may include one or more source elements, including but not limited to light emitting diodes, such as micro OLEDs, as described below with reference to Figures 4 to 9 Described in detail.

[0096] The output waveguide 320 can be configured as an optical waveguide that outputs image light to the user's eye 220. The output waveguide 320 receives image light 345 via one or more coupling elements 350 and directs the received input image light 345 to one or more decoupling elements 360. In some embodiments, the coupling element 350 couples the image light 345 from the source assembly 310 into the output waveguide 320. The coupling element 350 can be or include a diffraction grating, a holographic grating, some other element that couples the image light 345 into the output waveguide 320, or some combination thereof. For example, in embodiments where the coupling element 350 is a diffraction grating, the pitch of the diffraction grating can be selected so that total internal reflection occurs and the image light 345 propagates internally toward the decoupling element 360. For example, the pitch of the diffraction grating can be in the range of approximately 300 nm to approximately 600 nm.

[0097] The decoupling element 360 decouples the totally internally reflected image light from the output waveguide 320. The decoupling element 360 can be or include a diffraction grating, a holographic grating, some other element that decouples the image light from the output waveguide 320, or some combination thereof. For example, in an embodiment where the decoupling element 360 is a diffraction grating, the pitch of the diffraction grating can be selected to cause the incident image light to exit the output waveguide 320. The orientation and position of the image light 345 exiting the output waveguide 320 can be controlled by changing the orientation and position of the image light 345 entering the coupling element 350.

[0098] The output waveguide 320 can be composed of one or more materials that promote total internal reflection of the image light 345. The output waveguide 320 can be composed of, for example, silicon, glass, or a polymer, or some combination thereof. The output waveguide 320 can have a relatively small form factor, such as for use in a head-mounted display. For example, the output waveguide 320 can be approximately 30 mm wide along the x-dimension, approximately 50 mm long along the y-dimension, and 0.5-1 mm thick along the z-dimension. In some embodiments, the output waveguide 320 can be a planar (2D) optical waveguide.

[0099] Controller 330 can be used to control the scanning operation of source component 310. In some embodiments, controller 330 can determine the scanning instructions of source component 310 based at least on one or more display instructions. Display instructions may include instructions for rendering one or more images. In some embodiments, display instructions may include image files (e.g., bitmaps). Display instructions can be received from, for example, a console of a virtual reality system (not shown). Scanning instructions may include instructions for source component 310 to generate image light 345. Scanning instructions may include, for example, the type of image light source (e.g., monochrome, multi-color), the scanning rate, the orientation of the scanning mirror assembly 370, and / or one or more lighting parameters. Controller 330 may include a combination of hardware, software, and / or firmware not shown here so as not to obscure other aspects of the present disclosure.

[0100] According to some embodiments, source 340 may include a light emitting diode (LED), such as an organic light emitting diode (OLED). An organic light emitting diode (OLED) is a light emitting diode (LED) having an emissive electro-emissive layer, which may include a thin film of an organic compound that emits light in response to an electric current. The organic layer is typically located between a pair of conductive electrodes. One or both electrodes may be transparent.

[0101] As will be understood, OLED displays can be driven using either a passive-matrix (PMOLED) or active-matrix (AMOLED) control scheme. In a PMOLED scheme, each row (and line) in the display can be controlled sequentially, while AMOLED control typically uses a thin-film transistor backplane to directly access and turn individual pixels on or off, which allows for higher resolution and larger display areas.

[0102] Figure 4A simplified structure of an OLED according to some embodiments is depicted in FIG. As shown in the exploded view, OLED 400 may include, from bottom to top, a substrate 410, an anode 420, a hole injection layer 430, a hole transport layer 440, an emissive layer 450, a blocking layer 460, an electron transport layer 470, and a cathode 480. In some embodiments, substrate (or backplane) 410 may include single crystal silicon or polycrystalline silicon or other suitable semiconductors (e.g., germanium).

[0103] Anode 420 and cathode 480 may include any suitable conductive material or materials, such as transparent conductive oxides (TCOs, e.g., indium tin oxide (ITO) and zinc oxide (ZnO). Anode 420 and cathode 480 are configured to inject holes and electrons, respectively, into one or more organic layers within emissive layer 450 during device operation.

[0104] A hole injection layer 430 disposed above the anode 420 receives holes from the anode 420 and is configured to inject the holes deeper into the device, while an adjacent hole transport layer 440 can support the transport of holes to the emissive layer 450. The emissive layer 450 converts electrical energy into light. The emissive layer 450 can include one or more organic molecules or luminescent fluorescent dyes or dopants, which can be dispersed in a suitable matrix as known to those skilled in the art.

[0105] Blocking layer 460 may improve device function by confining electrons (carriers) to emissive layer 450. Electron transport layer 470 may support the transport of electrons from cathode 480 to emissive layer 450.

[0106] In some embodiments, the generation of red, green, and blue colors (to render a full-color image) can include forming red, green, and blue OLED sub-pixels in each pixel of the display. Alternatively, the OLED 400 can be adapted to generate white light in each pixel. The white light can be passed through a color filter to generate red, green, and blue sub-pixels.

[0107] Any suitable deposition process or processes may be used to form the OLED 400. For example, physical vapor deposition (PVD), chemical vapor deposition (CVD), evaporation, spray coating, spin coating, atomic layer deposition (ALD), etc. may be used to fabricate one or more layers constituting the OLED. Alternatively, a thermal evaporator, a sputtering system, 3D printing, stamping, etc. may be used to fabricate the OLED 400.

[0108] According to some embodiments, OLED 400 may be a micro-OLED. According to various examples, a "micro-OLED" may refer to an OLED having a small active light emitting area (eg, less than 2,000 μm in some embodiments). 2 , in other embodiments less than 20 μm 2 or less than 10μm 2 ) of a particular type of OLED. In some embodiments, the emitting surface of the micro-OLED can have a diameter of less than about 2 μm. Such micro-OLEDs can also have collimated light output, which can increase the brightness level of light emitted from a small active light-emitting area.

[0109] Figure 5 An example OLED device is schematically shown in FIG. According to some embodiments, an OLED device 500 (e.g., a micro OLED chip) may include a display active area 530 having an active matrix 532 (such as OLED 400) disposed on a single crystal (e.g., silicon) backplane 520. The combined display / backplane architecture (i.e., display element 540) may be coupled directly or indirectly (e.g., at or near interface A) to a display driver integrated circuit (DDIC) 510. As shown, the DDIC 510 may include an array of drive transistors 512, which, as will be understood by those skilled in the art, may be formed using conventional CMOS processes. One or more display driver integrated circuits may be formed over a single crystal (e.g., silicon) substrate.

[0110] In some embodiments, at least one area dimension (i.e., length or width) of the display active area 530 can be greater than about 1.3 inches, for example, about 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.25, 2.5, 2.75, or 3 inches, including ranges between any of the foregoing values, although larger area displays are contemplated.

[0111] The silicon backplane 520 may include a single crystal or polycrystalline silicon layer 523 having through silicon vias 525 for electrically connecting the DDIC 510 to the display active area 530. In some embodiments, the display active area 530 may also include a transparent capping layer 534, a color filter 536, and a cover glass 538 disposed over an upper emitting surface 533 of an active matrix 532. The active matrix 532 including the emitting surface 533 may include doped organic solid crystals.

[0112] According to various embodiments, the display active area 530 and underlying silicon backplane 520 can be fabricated separately from the DDIC 510 and subsequently bonded to the DDIC 510, which can simplify the formation of the OLED active area, including the active matrix 532, color filters 536, etc.

[0113] DDIC 510 can be bonded directly to the back side of the silicon backplane opposite the active matrix 532. In another embodiment, a chip-on-flex (COF) packaging technology can be used to integrate display element 540 with DDIC 510, optionally via a data selector (i.e., multiplexer) array (not shown), to form OLED device 500. As used herein, in some examples, the term "multiplexer" or "data selector" can refer to a device suitable for combining or selecting from multiple analog or digital input signals, which are transmitted to a single output. A multiplexer can be used to increase the amount of data that can be transmitted within a certain amount of space, time, and bandwidth.

[0114] Reference Figure 6 , shows a simplified cross-sectional view of an emissive layer 650 containing an OSC. The emissive layer 650 can include an organic solid crystal matrix 652 and dopants 654 distributed throughout the matrix. The dopants 654 can be aligned within the matrix 652 in a manner effective to produce light emission with a selective polarization.

[0115] Reference Figure 7 , shown as an example phosphor. In this material, phosphorescence can be generated by emission from a triplet excited state, where the electrons in the excited orbital have the same spin orientation as the n ground state electrons.

[0116] Disclosed are light emitting diodes (LEDs) having an emissive layer formed from doped organic crystals. Example dopants include luminescent phosphors or fluorophores that can be configured to emit light having a selected polarization. In certain embodiments, the phosphors can be oriented by the organic crystals in a manner effective to produce a selective polarization (e.g., p or s) at the operating wavelength. Example organic crystalline materials include small molecules, macromolecules, liquid crystals, organometallic compounds, oligomers, and polymers, and can include organic semiconductors such as polycyclic aromatic compounds, for example, anthracene and phenanthrene.

[0117] Methods for making organic crystals can include growing crystals from melts or solutions, and chemical or physical vapor deposition using suitable precursors. Doping can be performed in situ, where the type and amount of dopant can be selected to influence the crystal structure and optical properties of the organic crystal material. Example dopants include metal complexes, such as platinum-complexed porphyrins PtOEP (platinum-octaethyl-porphyrin).

[0118] Example Implementation

[0119] Embodiment 1: A device comprising a light emitting diode having an emitting surface, wherein the emitting surface comprises a doped organic solid crystal.

[0120] Embodiment 2: The device of embodiment 1, wherein the light emitting diode is an OLED.

[0121] Embodiment 3: The device of any one of Embodiments 1 and 2, wherein the emissive layer is disposed between the anode and the cathode.

[0122] Embodiment 4: The apparatus of any one of embodiments 1 to 3, wherein the organic solid crystal comprises a single crystal.

[0123] Embodiment 5: The apparatus according to any one of embodiments 1 to 4, wherein the organic solid crystal comprises a hydrocarbon compound selected from the group consisting of anthracene, tetracene, phenanthrene, tolan, pyrene, cyclopentene, fluorene, biphenyl, and terphenyl.

[0124] Embodiment 6: The apparatus according to any one of embodiments 1 to 5, wherein the organic solid crystal comprises a saturated or unsaturated heterocyclic or polycyclic aromatic hydrocarbon selected from the group consisting of furan, pyrrole, thiophene, pyridine, pyrimidine, piperidine, quinoline, benzothiophene, benzopyran, bent and asymmetric acene, 2,6-naphthalenedicarboxylic acid, and 2,6-dimethylcarboxylate.

[0125] Embodiment 7: The apparatus of any one of embodiments 1 to 6, wherein the organic solid crystal comprises a functional group selected from the group consisting of an amine, an alcohol, and a carboxylic acid.

[0126] Embodiment 8: The device according to any one of embodiments 1 to 7, wherein the organic solid crystal comprises a dopant selected from the group consisting of platinum-octaethyl-porphyrin, bis[2-(2-pyridyl-N)phenyl-C](acetylacetonate)iridium(III) (Ir(ppy2)(acac)), tris[2-(-2-pyridyl-kN)-5-(trifluoromethyl)phenyl-kC]iridium (Ir(p-CF3-ppy)3), fluorescein, rhodamine, and aminomethylcoumarin acetate.

[0127] Embodiment 9: The apparatus of any one of embodiments 1 to 8, wherein the dopant concentration within the organic solid crystal ranges from about 0.01 wt.% to about 50 wt.%.

[0128] Embodiment 10: The device of any one of Embodiments 1 to 9, wherein the dopant is configured to affect optical properties of the light emitting diode.

[0129] Embodiment 11: The device of any one of Embodiments 1 to 10, wherein the dopant is aligned within the organic solid crystal in a manner effective to produce light emission having a selective polarization.

[0130] Embodiment 12: A light-emitting diode, comprising: an anode; a hole injection layer, the hole injection layer covering the anode; a hole transport layer, the hole transport layer covering the hole injection layer; an emission layer, the emission layer covering the hole transport layer; a blocking layer, the blocking layer covering the emission layer; an electron transport layer, the electron transport layer covering the blocking layer; and a cathode, the cathode covering the electron transport layer, wherein the emission layer comprises doped organic solid crystals.

[0131] Embodiment 13: The light-emitting diode according to embodiment 12, wherein the organic solid crystal comprises a single crystal.

[0132] Embodiment 14: The light-emitting diode according to any one of Embodiments 12 and 13, wherein the organic solid crystal comprises a hydrocarbon compound selected from the group consisting of anthracene, tetracene, phenanthrene, tolanthracene, pyrene, cyclopentene, fluorene, biphenyl, and terphenyl.

[0133] Embodiment 15: The light-emitting diode according to any one of embodiments 12 to 14, wherein the organic solid crystal comprises a hydrocarbon selected from the group consisting of furan, pyrrole, thiophene, pyridine, pyrimidine, piperidine, quinoline, benzothiophene, benzopyran, bent and asymmetric acene, 2,6-naphthalene dicarboxylic acid, and 2,6-dimethylcarboxylate.

[0134] Embodiment 16: The light emitting diode according to any one of Embodiments 12 to 15, wherein the organic solid crystal comprises a functional group selected from the group consisting of amines, alcohols, and carboxylic acids.

[0135] Embodiment 17: The device of any one of Embodiments 12 to 16, wherein the organic solid crystal comprises a dopant selected from the group consisting of platinum-octaethyl-porphyrin, bis[2-(2-pyridyl-N)phenyl-C](acetylacetonate)iridium(III) (Ir(ppy2)(acac)), tris[2-(-2-pyridyl-kN)-5-(trifluoromethyl)phenyl-kC]iridium (Ir(p-CF3-ppy)3), fluorescein, rhodamine, and aminomethylcoumarin acetate.

[0136] Example 18: A method comprising: forming a main electrode; forming an organic solid crystal layer above the main electrode, the organic solid crystal layer comprising an emissive dopant; forming a sub-electrode above the organic solid crystal layer, the sub-electrode at least partially overlapping the main electrode.

[0137] Embodiment 19: The method according to embodiment 18, wherein the organic solid crystal layer comprises a single crystal.

[0138] Embodiment 20: The method of any one of Embodiments 18 and 19, wherein the emissive dopant comprises a phosphor or a fluorophore.

[0139] Embodiments of the present disclosure may include or be implemented in combination with various types of artificial reality systems. Artificial reality is a form of reality that has been adjusted in some way before being presented to a user, which may include, for example, virtual reality, augmented reality, mixed reality, hybrid reality, or some combination and / or derivative thereof. Artificial reality content may include content that is entirely computer-generated or computer-generated content combined with captured (e.g., real-world) content. Artificial reality content may include video, audio, tactile feedback, or some combination thereof, any of which may be presented in a single channel or in multiple channels (such as stereoscopic video that produces a three-dimensional 3D effect to the audience). In addition, in some embodiments, artificial reality may also be associated with applications, products, accessories, services, or some combination thereof that are used, for example, to create content in artificial reality and / or otherwise be used in artificial reality (e.g., to perform activities therein).

[0140] Artificial reality systems can be implemented in a variety of different form factors and configurations. Some artificial reality systems can be designed to operate without a near-eye display (NED). Other artificial reality systems can include a NED that also provides a view of the real world (such as, for example, Figure 8 visibility of the augmented reality system 800 in FIG, or visually immersing the user in an artificial reality (such as, for example, Figure 9 900 in the virtual reality system. While some artificial reality devices may be self-contained systems, other artificial reality devices may communicate and / or coordinate with external devices to provide an artificial reality experience to a user. Examples of such external devices include handheld controllers, mobile devices, desktop computers, devices worn by the user, devices worn by one or more other users, and / or any other suitable external systems.

[0141] Steering Figure 8 , an augmented reality system 800 may include an eyewear device 802 having a frame 810 configured to hold a left display device 815(A) and a right display device 815(B) in front of a user's eyes. Display devices 815(A) and 815(B) may function together or independently to present an image or group of images to the user. Although the augmented reality system 800 includes two displays, embodiments of the present disclosure may be implemented in an augmented reality system having a single NED or more than two NEDs.

[0142] In some embodiments, the augmented reality system 800 may include one or more sensors, such as sensor 840. Sensor 840 can generate measurement signals in response to the movement of the augmented reality system 800, and the sensor can be located on substantially any part of the frame 810. Sensor 840 can represent one or more of a variety of different sensing mechanisms, such as a positioning sensor, an inertial measurement unit (IMU), a depth camera assembly, a structured light emitter and / or detector, or any combination thereof. In some embodiments, the augmented reality system 800 may or may not include sensor 840 or may include more than one sensor. In embodiments where sensor 840 includes an IMU, the IMU can generate calibration data based on the measurement signals from sensor 840. Examples of sensor 840 can include, but are not limited to, accelerometers, gyroscopes, magnetometers, other suitable types of sensors that detect movement, sensors for error correction of the IMU, or some combination thereof.

[0143] In some examples, the augmented reality system 800 may also include a microphone array having a plurality of acoustic transducers 820(A)-820(J), collectively referred to as acoustic transducers 820. Acoustic transducers 820 may represent transducers that detect changes in air pressure caused by sound waves. Each acoustic transducer 820 may be configured to detect sound and convert the detected sound into an electronic format (e.g., analog or digital format). Figure 8 The microphone array in can include, for example, ten acoustic transducers: acoustic transducers 820(A) and 820(B), which can be designed to be placed in the user's respective ears; acoustic transducers 820(C), 820(D), 820(E), 820(F), 820(G) and 820(H), which can be positioned at different locations on the frame 810; and / or acoustic transducers 820(I) and 820(J), which can be positioned on the respective neckbands 805.

[0144] In some embodiments, one or more of the acoustic transducers 820(A)-(J) can be used as an output transducer (e.g., a speaker). For example, the acoustic transducers 820(A) and / or 820(B) can be earbuds or any other suitable type of earbuds or speakers.

[0145] The configuration of the acoustic transducers 820 of the microphone array can vary. Figure 8820, but the number of acoustic transducers 820 can be greater or less than ten. In some embodiments, using a greater number of acoustic transducers 820 can increase the amount of audio information collected and / or the sensitivity and accuracy of the audio information. Conversely, using a lower number of acoustic transducers 820 can reduce the computing power required by the associated controller 850 to process the collected audio information. In addition, the position of each acoustic transducer 820 of the microphone array can vary. For example, the position of the acoustic transducer 820 can include a defined position on the user, a defined coordinate on the frame 810, an orientation associated with each acoustic transducer 820, or some combination thereof.

[0146] The acoustic transducers 820(A) and 820(B) can be positioned on different parts of the user's ear, such as behind the pinna, behind the tragus, and / or in the auricle or fossa. Alternatively, in addition to the acoustic transducer 820 in the ear canal, there can be additional acoustic transducers 820 on or around the ear. Positioning the acoustic transducers 820 adjacent to the user's ear canal can enable the microphone array to collect information about how sound reaches the ear canal. By positioning at least two of the acoustic transducers 820 on either side of the user's head (e.g., as binaural microphones), the augmented reality device 800 can simulate binaural hearing and capture a 3D stereo sound field around the user's head. In some embodiments, acoustic transducers 820(A) and 820(B) may be connected to augmented reality system 800 via a wired connection 830, and in other embodiments, acoustic transducers 820(A) and 820(B) may be connected to augmented reality system 800 via a wireless connection (e.g., a Bluetooth connection). In other embodiments, acoustic transducers 820(A) and 820(B) may not be used in conjunction with augmented reality system 800 at all.

[0147] The acoustic transducers 820 on the frame 810 can be positioned in a variety of different ways, including along the length of the temples, across the bridge, above or below the display devices 815(A) and 815(B), or some combination thereof. The acoustic transducers 820 can be oriented so that the microphone array can detect sound in a wide range of directions around the user wearing the augmented reality system 800. In some embodiments, an optimization process can be performed during the manufacture of the augmented reality system 800 to determine the relative positioning of each acoustic transducer 820 in the microphone array.

[0148] In some examples, augmented reality system 800 can include or be connected to an external device (e.g., a paired device), such as neckband 805. Neckband 805 generally represents any type or form of paired device. Therefore, the following discussion of neckband 805 also applies to various other paired devices, such as charging cases, smart watches, smartphones, wristbands, other wearable devices, handheld controllers, tablet computers, laptop computers, other external computing devices, etc.

[0149] As shown, the neckband 805 can be coupled to the eyeglass device 802 via one or more connectors. The connectors can be wired or wireless and can include electrical and / or non-electrical (e.g., structural) components. In some cases, the eyeglass device 802 and the neckband 805 can operate independently without any wired or wireless connection between them. Although Figure 8 Components of the eyeglass device 802 and neckband 805 are shown in exemplary locations on the eyeglass device 802 and neckband 805, but these components may be positioned in other locations and / or distributed differently on the eyeglass device 802 and / or neckband 805. In some embodiments, components of the eyeglass device 802 and neckband 805 may be located on one or more additional peripheral devices that are paired with the eyeglass device 802, the neckband 805, or some combination thereof.

[0150] Pairing an external device (such as a neckband 805) with the augmented reality eyewear device can enable the eyewear device to achieve the form factor of a pair of glasses while still providing sufficient battery and computing power for expanded capabilities. Some or all of the battery power, computing resources and / or additional features of the augmented reality system 800 can be provided by the paired device or shared between the paired device and the eyewear device, thereby reducing the weight, heat distribution and form factor of the overall eyewear device while still maintaining the desired functionality. For example, the neckband 805 can allow components that would originally be included on the eyewear device to be included in the neckband 805 because the user can carry more weight on their shoulders than they would on their head. The neckband 805 can also have a larger surface area through which heat is diffused and dispersed to the surrounding environment. Therefore, the neckband 805 can allow for a larger battery and computing capacity than would be possible on a standalone eyewear device. Because the weight carried in the neckband 805 can be less intrusive to the user than the weight carried in the eyeglass device 802, the user can tolerate wearing the lighter eyeglass device and carrying or wearing the paired device for longer periods of time than the user can tolerate wearing a heavy standalone eyeglass device, thereby enabling the user to more fully integrate the artificial reality environment into their daily activities.

[0151] The neckband 805 can be communicatively coupled to the eyewear device 802 and / or other devices. These other devices can provide certain functions (e.g., tracking, positioning, depth mapping, processing, storage, etc.) to the augmented reality system 800. Figure 8 In an embodiment, the neckband 805 may include two acoustic transducers (e.g., 820(I) and 820(J)) that are part of a microphone array (or may form their own microphone subarray). The neckband 805 may also include a controller 825 and a power supply 835.

[0152] The acoustic transducers 820(I) and 820(J) of the neckband 805 may be configured to detect sound and convert the detected sound into an electronic format (analog or digital). Figure 8 In an embodiment, acoustic transducers 820(I) and 820(J) can be positioned on the neckband 805, thereby increasing the distance between the neckband acoustic transducers 820(I) and 820(J) and the other acoustic transducers 820 positioned on the eyeglass device 802. In some cases, increasing the distance between the acoustic transducers 820 of the microphone array can improve the accuracy of beamforming performed by the microphone array. For example, if acoustic transducers 820(C) and 820(D) detect a sound, and the distance between acoustic transducers 820(C) and 820(D) is greater than, for example, the distance between acoustic transducers 820(D) and 820(E), the source location of the detected sound can be determined more accurately than if the sound were detected by acoustic transducers 820(D) and 820(E).

[0153] The controller 825 of the neckband 805 can process information generated by sensors on the neckband 805 and / or the augmented reality system 800. For example, the controller 825 can process information from the microphone array describing sounds detected by the microphone array. For each detected sound, the controller 825 can perform a direction-of-arrival (DOA) estimate to estimate the direction from which the detected sound arrived at the microphone array. When the microphone array detects a sound, the controller 825 can populate an audio data set with this information. In embodiments where the augmented reality system 800 includes an inertial measurement unit, the controller 825 can calculate all inertial and spatial calculations based on the IMU located on the eyewear device 802. A connector can transmit information between the augmented reality system 800 and the neckband 805, and between the augmented reality system 800 and the controller 825. The information can be in the form of optical data, electrical data, wireless data, or any other transmittable data form. Moving the processing of information generated by the augmented reality system 800 to the neckband 805 can reduce the weight and heat of the eyewear device 802, making it more comfortable for the user.

[0154] The power supply 835 in the neckband 805 can provide power to the eyewear device 802 and / or the neckband 805. The power supply 835 can include, but is not limited to, lithium-ion batteries, lithium-polymer batteries, lithium primary batteries, alkaline batteries, or any other form of power storage. In some cases, the power supply 835 can be a wired power source. Including the power supply 835 on the neckband 805 rather than on the eyewear device 802 can help better distribute the weight and heat generated by the power supply 835.

[0155] As mentioned, some artificial reality systems can essentially replace one or more of the user's sensory perceptions of the real world with a virtual experience, rather than mixing the artificial reality with actual reality. An example of this type of system is a head-mounted display system, such as Figure 9 The virtual reality system 900 in FIG. 1 covers most or all of the user's field of view. The virtual reality system 900 may include a front rigid body 902 and a strap 904 shaped to fit around the user's head. The virtual reality system 900 may also include output audio transducers 906 (A) and 906 (B). Figure 9 Not shown, but front rigid body 902 may include one or more electronic components, including one or more electronic displays, one or more inertial measurement units (IMUs), one or more tracking transmitters or detectors, and / or any other suitable device or system for creating an artificial reality experience.

[0156] Artificial reality systems may include various types of visual feedback mechanisms. For example, the display devices in the augmented reality system 800 and / or the virtual reality system 900 may include one or more liquid crystal displays (LCDs), light emitting diode (LED) displays, micro-LED displays, organic LED (OLED) displays, digital light project (DLP) micro-displays, liquid crystal on silicon (LCoS) micro-displays, and / or any other suitable type of display screen. These artificial reality systems may include a single display screen for both eyes or may provide a display screen for each eye, which may allow for additional flexibility for zoom adjustment or for correcting a user's refractive error. Some of these artificial reality systems may also include an optical subsystem having one or more lenses (e.g., concave or convex lenses, Fresnel lenses, adjustable liquid lenses, etc.) through which a user can view the display screen. These optical subsystems may be used for various purposes, including collimation (e.g., making an object appear to be at a greater distance than its physical distance), magnification (e.g., making an object appear larger than its actual size), and / or transmission (e.g., to the viewer's eyes) of light. These optical subsystems can be used in non-pupil-forming architectures (such as a single-lens configuration, which directly collimates light but causes so-called pincushion distortion) and / or pupil-forming architectures (such as a multi-lens configuration, which produces so-called barrel distortion to offset pincushion distortion).

[0157] In addition to or instead of using a display screen, some artificial reality systems described herein may include one or more projection systems. For example, a display device in the augmented reality system 800 and / or virtual reality system 900 may include a micro-LED projector that projects light into the display device (using, for example, a waveguide), such as a transparent combiner lens that allows ambient light to pass through. The display device can refract the projected light into the user's pupil and can enable the user to view both the artificial reality content and the real world simultaneously. The display device can use any of a variety of different optical components to achieve this, including waveguide components (e.g., holographic, planar, diffractive, polarizing and / or reflective waveguide elements), light manipulation surfaces and elements (such as diffractive, reflective and refractive elements and gratings), coupling elements, etc. The artificial reality system can also be configured with any other suitable type or form of image projection system, such as a retinal projector for a virtual retinal display.

[0158] The artificial reality systems described herein may also include various types of computer vision components and subsystems. For example, the augmented reality system 800 and / or the virtual reality system 900 may include one or more optical sensors, such as two-dimensional (2D) or 3D cameras, structured light emitters and detectors, time-of-flight depth sensors, single-beam or scanning laser rangefinders, 3D LiDAR sensors, and / or any other suitable type or form of optical sensor. The artificial reality system may process data from one or more of these sensors to identify the user's location, to map the real world, to provide the user with context about the real-world environment, and / or to perform various other functions.

[0159] The artificial reality systems described herein may also include one or more input and / or output audio transducers. The output audio transducer may include a voice coil speaker, a ribbon speaker, an electrostatic speaker, a piezoelectric speaker, a bone conduction transducer, a cartilage conduction transducer, an ear tragus vibration transducer, and / or any other suitable type or form of audio transducer. Similarly, the input audio transducer may include a condenser microphone, a dynamic microphone, a ribbon microphone, and / or any other type or form of input transducer. In some embodiments, a single transducer may be used for both audio input and audio output.

[0160] In some embodiments, the artificial reality system described herein may also include a tactile (i.e., haptic) feedback system that can be incorporated into headgear, gloves, tights, handheld controllers, environmental equipment (e.g., chairs, floor mats, etc.), and / or any other type of device or system. The tactile feedback system can provide various types of skin feedback, including vibration, force, traction, texture, and / or temperature. The tactile feedback system can also provide various types of kinesthetic feedback, such as motion and compliance. Tactile feedback can be implemented using motors, piezoelectric actuators, fluid systems, and / or various other types of feedback mechanisms. The tactile feedback system can be implemented independently of other artificial reality devices, within other artificial reality devices, and / or in combination with other artificial reality devices.

[0161] By providing tactile, auditory content and / or visual content, artificial reality systems can create complete virtual experiences or enhance the user's real-world experience in various contexts and environments. For example, artificial reality systems can help or expand the user's perception, memory or cognition in a specific environment. Some systems can enhance the user's interaction with other people in the real world, or can achieve more immersive interaction with other people in the virtual world. Artificial reality systems can also be used for educational purposes (e.g., for teaching or training in schools, hospitals, government organizations, military organizations, commercial enterprises, etc.), entertainment purposes (e.g., for playing video games, listening to music, watching video content, etc.), and / or for accessibility purposes (e.g., as hearing aids, visual aids, etc.). The embodiments disclosed herein can implement or enhance the user's artificial reality experience in one or more of these contexts and environments and / or other contexts and environments.

[0162] The process parameters and step sequences described and / or illustrated herein are provided as examples only and may be modified as needed. For example, although the steps illustrated and / or described herein may be illustrated or discussed in a particular order, these steps do not necessarily need to be performed in the order illustrated or discussed. The various exemplary methods described and / or illustrated herein may also omit one or more of the steps described or illustrated herein, or include additional steps in addition to the steps disclosed.

[0163] The foregoing description has been provided to enable others skilled in the art to best utilize the various aspects of the exemplary embodiments disclosed herein. This exemplary description is not intended to be exhaustive or limited to any precise form disclosed. Many modifications and variations are possible without departing from the spirit and scope of the present disclosure. The embodiments disclosed herein should be considered in all respects as illustrative and not restrictive. Reference should be made to the appended claims and their equivalents when determining the scope of the present disclosure.

[0164] As used herein, in certain embodiments, the term "about" with respect to a particular numerical value or range of numerical values can mean and include the stated numerical value and all values within 10% of the stated numerical value. Thus, as an example, in certain embodiments, reference to the numerical value "50" as "about 50" can include values equal to 50 ± 5, i.e., values within the range of 45 to 55.

[0165] As used herein, the term "substantially" with reference to a given parameter, property, or condition can mean and encompass that one skilled in the art would understand that the given parameter, property, or condition is met to a small degree of variance, such as within acceptable manufacturing tolerances. As an example, depending on the particular parameter, property, or condition that is substantially met, the parameter, property, or condition may be met by at least about 90%, at least about 95%, or even at least about 99%.

[0166] Unless otherwise indicated, the terms "connected to" and "coupled to" (and their derivatives) as used in the specification and claims should be interpreted as allowing both direct and indirect (i.e., via other elements or components) connections. Furthermore, the terms "a" or "an" as used in the specification and claims should be interpreted as meaning "at least one." Finally, for ease of use, the terms "including" and "having" (and their derivatives) as used in the specification and claims are interchangeable with the word "comprising" and have the same meaning.

[0167] It should be understood that when an element, such as a layer or region, is referred to as being formed, deposited, or disposed “on” or “over” another element, it can be directly on at least a portion of the other element, or one or more intervening elements may also be present. Conversely, when an element is referred to as being “directly on” or “directly over” another element, it can be on at least a portion of the other element with no intervening elements present.

[0168] Although the transition phrase "comprising" may be used to disclose various features, elements, or steps of a particular embodiment, it should be understood that alternative embodiments, including those that may be described using the transition phrases "consisting of" or "consisting essentially of," are implicitly implied. Thus, for example, implicit alternative embodiments of an OSC layer that contains or includes anthracene include embodiments in which the OSC layer consists essentially of anthracene and embodiments in which the OSC layer consists of anthracene.

Claims

1. A display device comprising a light emitting diode having an emission layer, wherein: The emission layer includes doped organic solid crystals.

2. The display device according to claim 1, wherein The light emitting diode is an OLED.

3. The display device according to claim 1, wherein The emission layer is disposed between the anode and the cathode. The display device according to claim 1 , wherein: The organic solid crystal includes a single crystal.

5. The display device according to claim 1, wherein The organic solid crystal includes a hydrocarbon compound selected from the group consisting of anthracene, tetracene, phenanthrene, tolan, pyrene, cyclopentene, fluorene, biphenyl and terphenyl. The display device according to claim 1 , wherein: The organic solid crystal includes hydrocarbons selected from the group consisting of furan, pyrrole, thiophene, pyridine, pyrimidine, piperidine, quinoline, benzothiophene, benzopyran, bent and unsymmetrical acene, 2,6-naphthalene dicarboxylic acid, and 2,6-dimethylcarboxylate.

7. The display device according to claim 1, wherein The organic solid crystal includes a functional group selected from the group consisting of an amine, an alcohol, and a carboxylic acid.

8. The display device according to claim 1, wherein The organic solid crystal includes a dopant selected from the group consisting of platinum-octaethyl-porphyrin, bis[2-(2-pyridyl-N)phenyl-C](acetylacetonate)iridium(III), tris[2-(-2-pyridyl-kN)-5-(trifluoromethyl)phenyl-kC]iridium, fluorescein, rhodamine and aminomethylcoumarin acetate.

9. The display device according to claim 8, wherein The dopant concentration within the organic solid crystal is in a range of about 0.01 wt. % to about 50 wt. %.

10. The display device according to claim 8, wherein The dopant is configured to affect an optical property of the light emitting diode.

11. The display device according to claim 8, wherein The dopant is aligned within the organic solid crystal in a manner effective to produce light emission having a selective polarization.

12. A light emitting diode, comprising: anode; a hole injection layer, the hole injection layer covering the anode; a hole transport layer, the hole transport layer covering the hole injection layer; an emission layer, the emission layer covering the hole transport layer; a blocking layer, the blocking layer covering the emitting layer; an electron transport layer, the electron transport layer covering the blocking layer; as well as A cathode is disposed on the electron transport layer, wherein the emission layer comprises doped organic solid crystals.

13. The light emitting diode according to claim 12, wherein: The organic solid crystal includes a single crystal.

14. The light emitting diode according to claim 12, wherein The organic solid crystal includes a hydrocarbon compound selected from the group consisting of anthracene, tetracene, phenanthrene, tolan, pyrene, cyclopentene, fluorene, biphenyl and terphenyl.

15. The light emitting diode according to claim 12, wherein The organic solid crystal includes hydrocarbons selected from the group consisting of furan, pyrrole, thiophene, pyridine, pyrimidine, piperidine, quinoline, benzothiophene, benzopyran, bent and unsymmetrical acene, 2,6-naphthalene dicarboxylic acid, and 2,6-dimethylcarboxylate.

16. The light emitting diode according to claim 12, wherein The organic solid crystal includes a functional group selected from the group consisting of an amine, an alcohol, and a carboxylic acid.

17. The light emitting diode according to claim 12, wherein: The organic solid crystal includes a dopant selected from the group consisting of platinum-octaethyl-porphyrin, bis[2-(2-pyridyl-N)phenyl-C](acetylacetonate)iridium(III), tris[2-(-2-pyridyl-kN)-5-(trifluoromethyl)phenyl-kC]iridium, fluorescein, rhodamine and aminomethylcoumarin acetate.

18. A method for manufacturing a display device, the method comprising: forming a main electrode; forming an organic solid crystal layer above the main electrode, the organic solid crystal layer including an emissive dopant; A sub-electrode is formed over the organic solid crystal layer and at least partially overlaps the main electrode.

19. The method according to claim 18, wherein The organic solid crystal layer includes a single crystal.

20. The method according to claim 18, wherein The emissive dopant includes a phosphor or a fluorophore.

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