Apparatus and Method for Delivering Organic Materials via Organic Vapor Jet Printing (OVJP)

Abstract

The present disclosure relates to devices and methods for delivering organic materials via organic vapor jet printing (OVJP). Embodiments of the disclosed subject matter provide a device having means with a micro-nozzle array disposed on a microfabricated jet die. The means may include a first gas distribution plate and a second opposing plate, wherein the microfabricated jet die is disposed between the first gas distribution plate and the second opposing plate, wherein the first gas distribution plate is irreversibly joined to the micro-nozzle array using an airtight seal, and wherein the first gas distribution plate includes a plurality of sealed flow paths. A manifold may be reversibly joined to the first gas distribution plate, wherein the microfabricated jet die and the first gas distribution plate and the second opposing plate are disposed between the manifolds. A heat conducting plate may have at least one window that provides a clearance fit for the means within a range of motion relative to the heat conducting plate.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims priority to U.S. Patent Application Serial No. 63 / 022,631, filed May 11, 2020, the entire content of which is incorporated herein by reference. Technical Field

[0003] The present invention relates to high-temperature, low-profile, bondable gas distribution plates and opposing plates for coupling a jet head to a larger gas delivery system for delivering organic materials via organic vapor jet printing (OVJP), and to devices and techniques including such gas distribution plates and opposing plates. Background Art

[0004] For various reasons, optoelectronic devices that utilize organic materials have become increasingly popular. Many of the materials used to fabricate such devices are relatively inexpensive, so organic optoelectronic devices have the potential for a cost advantage over inorganic devices. Additionally, the inherent properties of organic materials, such as their flexibility, can make them more suitable for certain applications, such as fabrication on flexible substrates. Examples of organic optoelectronic devices include organic light-emitting diodes / devices (OLEDs), organic phototransistors, organic photovoltaic cells, and organic photodetectors. For OLEDs, organic materials can have performance advantages over conventional materials. For example, the wavelength of light emitted by an organic emissive layer can generally be easily adjusted with appropriate dopants.

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

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

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

[0008] As used herein, "top" means furthest from the substrate, while "bottom" means closest to the substrate. When a first layer is described as being "disposed" "above" a second layer, the first layer is disposed further from the substrate. Unless it is specified that the first layer is "in contact with" the second layer, there may be other layers between the first layer and the second layer. For example, the cathode can be described as being "disposed" "above" the anode, although there are various organic layers therebetween.

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

[0010] When a ligand is believed to directly contribute to the photosensitive properties of an emissive material, the ligand can be called "photosensitive". When a ligand is believed not to contribute to the photosensitive properties of an emissive material, the ligand can be called "auxiliary", but an auxiliary ligand can modify the properties of a photosensitive ligand.

[0011] As used herein, and as would be generally understood by one of ordinary skill in the art, if the first energy level is closer to the vacuum level, then the first "highest occupied molecular orbital" (HOMO) or "lowest unoccupied molecular orbital" (LUMO) energy level is "greater than" or "higher than" the second HOMO or LUMO energy level. Since the ionization potential (IP) is measured as a negative energy relative to the vacuum level, a higher HOMO energy level corresponds to an IP with a smaller absolute value (less negative IP). Similarly, a higher LUMO energy level corresponds to an electron affinity (EA) with a smaller absolute value (less negative EA). On a conventional energy level diagram with the vacuum level at the top, the LUMO energy level of a material is higher than the HOMO energy level of the same material. A "higher" HOMO or LUMO energy level appears closer to the top of this diagram than a "lower" HOMO or LUMO energy level.

[0012] As used herein, and as would be generally understood by one of ordinary skill in the art, if the first work function has a higher absolute value, then the first work function is "greater than" or "higher than" the second work function. Since the work function is typically measured as a negative number relative to the vacuum level, this means that a "higher" work function is more negative. On a conventional energy level diagram with the vacuum level at the top, a "higher" work function is illustrated as being farther from the vacuum level in the downward direction. Thus, the definitions of the HOMO and LUMO energy levels follow different rules than the work function.

[0013] The present disclosure may describe layers, materials, regions, and devices in terms of the color of the light they emit. Generally speaking, as used herein, an emission region described as producing a specific color of light may include one or more emission layers arranged on top of each other in a stack.

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

[0015] As used herein, emission materials, layers, and regions can be distinguished from each other and from other structures based on the light initially generated by the material, layer, or region, as opposed to the light ultimately emitted by the same or a different structure. Initial light generation is typically the result of a change in energy levels that causes the emission of photons. For example, an organic emission material can initially generate blue light, which can be converted to red or green light by a color filter, quantum dots, or other structures, such that the complete emission stack or sub - pixel emits red or green light. In this case, even though the sub - pixel is a "red" or "green" component, the initially emitting material or layer can be referred to as a "blue" component.

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

[0017]

[0018] More details regarding OLEDs and the above definitions can be found in U.S. Patent No. 7,279,704, which is incorporated herein by reference in its entirety. SUMMARY OF THE INVENTION

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

[0020] According to one embodiment, a device may include means having a micro-nozzle array disposed on a microfabricated jet die. The device may include a first gas distribution plate and a second opposing plate, wherein the microfabricated jet die is disposed between the first gas distribution plate and the second opposing plate. The first gas distribution plate may be irreversibly bonded to the micro-nozzle array using an airtight seal, wherein the first gas distribution plate includes a plurality of sealed flow paths. A manifold may be reversibly bonded to the first gas distribution plate, wherein the microfabricated jet die, the first gas distribution plate, and the second opposing plate may be disposed between the manifold. The device may include a heat conducting plate in thermal contact with an active cooling source, wherein the heat conducting plate has at least one window extending through its entire thickness, and the first gas distribution plate and the second opposing plate of the device, a portion of the microfabricated jet die, and the micro-nozzle array protrude through the window such that the minor axis of the window cross-section provides a clearance fit for the device within its range of motion relative to the heat conducting plate. The device may include one or more thermal evaporation sources in fluid communication with the first gas distribution plate, wherein the manifold may be in fluid communication with the micro-nozzle array via the plurality of sealed flow paths within the first gas distribution plate.

[0021] The micro-nozzle array of the device can be disposed on the edge of the micro-machined jet die. The micro-nozzle array can be disposed on one side of the micro-jet die.

[0022] The micro-machined jet die of the device can include at least one of silicon, quartz, and / or metal.

[0023] The second opposing plate of the device can be a second gas distribution plate, wherein the manifold is hermetically sealed and joined to the first gas distribution plate.

[0024] At least one of the plurality of sealed flow paths of the device can be configured to carry a mixture of organic vapor and an inert carrier gas.

[0025] The first gas distribution plate of the device can have a section near the micro-nozzle array through which all the flow paths pass, and the aspect ratio of the depth of the section does not exceed 10% of the width or height of the section. As used throughout, the depth can be the direction perpendicular to one side of the micro-nozzle array.

[0026] The heat conducting plate of the device can shield the object acted on by the micro-nozzle array from the heat generated by the manifold and the plurality of evaporation sources.

[0027] The seal of the device can be a gasket or a joint. The micro-nozzle array of the device can be irreversibly joined to the first gas distribution plate and the second opposing plate using a glass frit, ceramic adhesive, bonding, and / or soft or hard solder compounds at a reflow temperature above 350 °C or above 500 °C to form a seal. The first gas distribution plate of the device can include a material having an average coefficient of thermal expansion less than 6×10 -6 K -1 between room temperature and the reflow temperature of the soft solder.

[0028] The first gas distribution plate and the second opposing plate of the device can be made of at least one of molybdenum, tungsten, kovar, aluminum nitride, and / or silicon nitride.

[0029] The device can include a heater thermally coupled to the micro-nozzle array, wherein the heater is configured to heat the micro-nozzle array. The micro-nozzle array can direct a convective jet of gas onto the surface of a substrate.

[0030] The micro-nozzle array and the substrate of the device can be configured to move relative to each other.

[0031] The micro-machined jet die and the micro-nozzle array of the device can contain silicon.

[0032] The heat conducting plate may have a window lined with insulating material. The micro nozzle array and the first gas distribution plate may include at least a part of the device, and at least a part of the device protrudes through the window of the heat conducting plate such that the normal plane of the device is parallel to the depth dimension of the first gas distribution plate.

[0033] The first gas distribution plate and the second opposing plate of the device may include a resistive heater. The first gas distribution plate and the second opposing plate of the device may include one or more thermal insulating materials selected from quartz, borosilicate glass, alumina, and / or mica. At least one of the first gas distribution plate and the second opposing plate of the device may be configured to allow gas to be fed therethrough.

[0034] The device may include a deformable metal gasket, wherein the first gas distribution plate is sealed to the manifold using the deformable metal gasket. The deformable metal gasket may be reversibly sealed to the device. The deformable metal gasket may comprise a material integral with the manifold.

[0035] The first gas distribution plate of the device may comprise a plurality of etched or ground material layers, and the material layers are bonded together using a forming temperature higher than the reflow temperature of the material used to bond the micro nozzle array to the first gas distribution plate.

[0036] According to one embodiment, a device may include a device having a micro nozzle array. The device may include a first gas distribution plate, which is irreversibly joined to the micro nozzle array using an airtight seal, wherein the first gas distribution plate includes a plurality of sealed flow paths. One or more thermal evaporation sources of the device may be in fluid communication with the first gas distribution plate. The device may include a manifold, wherein the first gas distribution plate is reversibly joined to the manifold. The manifold may be in fluid communication with the micro nozzle array via a plurality of sealed flow paths within the first gas distribution plate. At least one of these flow paths may carry a mixture of organic vapor and an inert carrier gas. The first gas distribution plate may have a section close to the micro nozzle array, and all the flow paths pass through the section, and the depth of the section is not wider than the depth of the micro nozzle array at its connection point, wherein the depth may be a direction perpendicular to the plane of the micro nozzle array. The device may include a heat conducting plate, wherein the first gas distribution plate and the heat conducting plate are in thermal contact with an active cooling source. The heat conducting plate may have at least one window extending through its entire thickness, and the device may protrude through the window such that the short axis of the cross section of the window is at least the micro nozzle array of the device to provide a clearance fit within the range of movement of the device relative to the heat conducting plate, so that the heat conducting plate shields the object acted upon by the micro nozzle array from the heat generated by the manifold and the one or more thermal evaporation sources.

[0037] The seal of the device can be a gasket or a fitting. The micro-nozzle array of the device can be irreversibly joined and / or attached to the device using, for example, a glass frit, a ceramic binder, an adhesive, and / or a soft or hard solder compound at a reflow temperature that may be higher than 350 °C or higher than 500 °C. The first gas distribution plate can comprise a material having an average coefficient of thermal expansion of less than 6×10 -6 K -1 between room temperature and the reflow temperature of the soft solder. The device can comprise at least one of molybdenum, tungsten, kovar alloy, aluminum nitride, and / or silicon nitride.

[0038] The apparatus can include a heater thermally coupled to the micro-nozzle array, wherein the heater is configured to heat the micro-nozzle array.

[0039] The micro-nozzle array of the device can direct a convective jet of gas onto the surface of a substrate. The micro-nozzle array and the substrate are configured to move relative to each other. The micro-nozzle array can comprise silicon.

[0040] The heat conducting plate of the apparatus can comprise a window lined with an insulating material.

[0041] The device can include a deformable metal gasket, wherein the first gas distribution plate is sealed to the manifold using the deformable metal gasket. The deformable metal gasket can reversibly seal to the device. In some embodiments, the deformable metal gasket comprises a material integral with the manifold. Description of the Drawings

[0042] Figure 1 An organic light emitting device is shown.

[0043] Figure 2 An inverted organic light emitting device without a separate electron transport layer is shown.

[0044] Figure 3 An OVJP jet head is shown, wherein the micro-nozzle array is located on the edge of a microfabricated die.

[0045] Figure 4a An OVJP jet head having a micro-nozzle array located on the edge of a microfabricated die, which incorporates a gas distribution plate and a counter plate, is shown according to an embodiment of the disclosed subject matter.

[0046] Figure 4b An OVJP jet head having a micro-nozzle array located on the edge of a microfabricated die, which incorporates a gas distribution plate, is shown according to an embodiment of the disclosed subject matter, wherein the gas supply and exhaust are piped from the same side of the assembly.

[0047] FIG. 5a shows an OVJP ejection head with a micro-nozzle array located on the edge of a microfabricated die according to an embodiment of the disclosed subject matter. The microfabricated die includes a gas distribution plate and an opposing plate, with additional thermal insulation material around the window in the cooling plate.

[0048] FIG. 5b shows an OVJP ejection head with a micro-nozzle array located on the edge of a microfabricated die according to an embodiment of the disclosed subject matter. The microfabricated die includes a gas distribution plate and an opposing plate, with additional thermal insulation material forming a sheath around the gas distribution plate and the opposing plate.

[0049] Figure 6 Shows the thermal load applied to a substrate by an OVJP ejection head according to an embodiment of the disclosed subject matter.

[0050] Figure 7 Shows an alternative embodiment of an OVJP ejection head, where the micro-nozzle array is located on one side of the microfabricated die.

[0051] Figure 8 Shows an alternative embodiment of an OVJP ejection head according to an embodiment of the disclosed subject matter, where the micro-nozzle array is located on one side of a microfabricated die including a gas distribution plate and an opposing plate. DETAILED DESCRIPTION

[0052] Generally, an OLED includes at least one organic layer disposed between an anode and a cathode and electrically connected to the anode and the cathode. When a current is applied, the anode injects holes and the cathode injects electrons into one or more organic layers. The injected holes and electrons each migrate toward the electrodes of opposite charge. When an electron and a hole are located on the same molecule, an "exciton" is formed, which is a localized electron-hole pair with an excited energy state. When the exciton relaxes via a photoelectric emission mechanism, light is emitted. The exciton can be confined to an excimer or an exciplex. Non-radiative mechanisms (such as thermal relaxation) may also occur, but are generally considered undesirable.

[0053] Initial OLEDs used emissive molecules that emit light from their singlet state ("fluorescence"), as disclosed, for example, in U.S. Patent No. 4,769,292, which is incorporated herein by reference in its entirety. Fluorescent emission typically occurs within a time frame of less than 10 nanoseconds.

[0054] Recently, OLEDs with emissive materials that emit light from triplets (“phosphorescence”) have been demonstrated. Baldo et al., “Highly Efficient Phosphorescent Emission from Organic Electroluminescent Devices,” Nature, Vol. 395, 151 - 154, 1998; (“Baldo-I”) and Baldo et al., “Very high-efficiency green organic light-emitting devices based on electrophosphorescence,” Appl. Phys. Lett., Vol. 75, No. 3, 4 - 6 (1999) (“Baldo-II”) are incorporated herein by reference in their entirety. Phosphorescence is described in more detail in columns 5 - 6 of U.S. Patent No. 7,279,704, which is incorporated by reference.

[0055] Figure 1 FIG. 100 shows an organic light-emitting device. The drawings are not necessarily to scale. Device 100 may include a substrate 110, an anode 115, a hole injection layer 120, a hole transport layer 125, an electron blocking layer 130, an emissive layer 135, a hole blocking layer 140, an electron transport layer 145, an electron injection layer 150, a protective layer 155, a cathode 160, and a barrier layer 170. Cathode 160 is a composite cathode having a first conductive layer 162 and a second conductive layer 164. Device 100 can be fabricated by sequentially depositing the described layers. The characteristics and functions of these different layers, as well as example materials, are described in more detail in columns 6 - 10 of US 7,279,704, which is incorporated by reference.

[0056] There are more examples of each of these layers. For example, a flexible and transparent substrate-anode combination is disclosed in U.S. Patent No. 5,844,363, which is incorporated herein by reference in its entirety. Examples of p-doped hole transport layers are doped with F in a molar ratio of 50:1 4m-MTDATA of -TCNQ, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated herein by reference in its entirety. Examples of the emissive material and the host material are disclosed in U.S. Patent No. 6,303,238 to Thompson et al., which is incorporated by reference in its entirety. An example of an n-doped electron transport layer is BPhen doped with Li in a 1:1 molar ratio, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated herein by reference in its entirety. U.S. Patent Nos. 5,703,436 and 5,707,745, which are incorporated by reference in their entireties, disclose examples of cathodes that include a composite cathode having a thin layer of metal (such as Mg:Ag) overlaid with a transparent, conductive, sputter-deposited ITO layer. The theory and use of the blocking layer are described in more detail in U.S. Patent No. 6,097,147 and U.S. Patent Application Publication No. 2003 / 0230980, which are incorporated by reference in their entireties. Examples of the injection layer are provided in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated herein by reference in its entirety. A description of the protective layer can be found in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated herein by reference in its entirety.

[0057] Figure 2 An inverted OLED 200 is shown. The device includes a substrate 210, a cathode 215, an emissive layer 220, a hole transport layer 225, and an anode 230. The device 200 can be fabricated by depositing the layers in sequence. Since the most common OLED configuration has the cathode disposed on the anode, and the device 200 has the cathode 215 disposed under the anode 230, the device 200 can be referred to as an "inverted" OLED. Materials similar to those described with respect to the device 100 can be used in the corresponding layers of the device 200. Figure 2 An example of how some layers can be omitted from the structure of the device 100 is provided.

[0058] Figure 1 and 2The simple layered structure shown is provided by way of non-limiting example, and it should be understood that embodiments of the present invention can be used in conjunction with a variety of other structures. The specific materials and structures described are exemplary in nature, and other materials and structures can be used. Functional OLEDs can be achieved by combining the described individual layers in different ways, based on design, performance, and cost factors, or certain layers can be omitted entirely. Other layers not specifically described can also be included. Materials other than those specifically described can be used. Although many of the examples provided herein describe the various layers as comprising a single material, it should be understood that combinations of materials (e.g., mixtures of host and dopant) or more generally, mixtures can be used. Additionally, layers can have various sub-layers. The names given to the individual layers herein are not intended to be strictly limiting. For example, in device 200, the hole transport layer 225 transports holes and injects holes into the emission layer 220, and can be described as a hole transport layer or a hole injection layer. In one embodiment, an OLED can be described as having an "organic layer" disposed between the cathode and the anode. Such an organic layer can comprise a single layer, or can further comprise, for example, multiple layers of different organic materials as described with respect to Figure 1 and 2 the different organic materials described.

[0059] Structures and materials not specifically described can also be used, such as OLEDs comprising polymeric materials (PLEDs), as disclosed in U.S. Patent No. 5,247,190 to Friend et al., which is incorporated herein by reference in its entirety. By way of another example, an OLED having a single organic layer can be used. OLEDs can be stacked, for example, as described in U.S. Patent No. 5,707,745 to Forrest et al., which is incorporated herein by reference. The OLED structure can deviate from Figure 1 and 2 the simple layered structure shown. For example, the substrate can include angled reflective surfaces to improve outcoupling, such as the mesa structure described in U.S. Patent No. 6,091,195 to Forrest et al., and / or the pit structure described in U.S. Patent No. 5,834,893 to Bulovic et al., which are incorporated herein by reference.

[0060] In some embodiments disclosed herein, the emission layer or material, such as Figures 1 - 2The emission layer 135 and the emission layer 220 shown respectively therein may include quantum dots. Unless explicitly indicated to the contrary or indicated as the case may be according to the understanding of those skilled in the art, an "emission layer" or "emission material" as disclosed herein may include an organic emission material and / or an emission material containing quantum dots or an equivalent structure. Such an emission layer may include only a quantum dot material that converts light emitted by a separate emission material or other emitter, or it may also include the separate emission material or other emitter, or it may itself emit light directly by applying an electric current. Similarly, a color-changing layer, a color filter, an up-conversion or down-conversion layer or structure may include a material containing quantum dots, but such a layer may not be regarded as an "emission layer" as disclosed herein. Generally speaking, an "emission layer" or material is an "emission layer" or material that emits initial light, which can be changed by another layer (such as a color filter or other color-changing layer) that does not emit initial light itself within the device, and can also re-emit changed light with different spectral content based on the initial light emitted by the emission layer.

[0061] Unless otherwise specified, any one of the layers of various embodiments can be deposited by any suitable method. For organic layers, preferred methods include thermal evaporation; inkjet printing, as described in U.S. Patent Nos. 6,013,982 and 6,087,196, which are incorporated herein by reference in their entirety; organic vapor deposition (OVPD), as described in U.S. Patent No. 6,337,102 issued to Forrest et al., which is incorporated herein by reference in its entirety; and deposition by organic vapor jet printing (OVJP), as described in U.S. Patent No. 7,431,968, which is incorporated herein by reference in its entirety. Other suitable deposition methods include spin coating and other solution-based processes. Solution-based processes are preferably carried out in nitrogen or an inert atmosphere. For other layers, the preferred method is thermal evaporation. Preferred patterning methods include deposition via a mask; cold welding, as described in U.S. Patent Nos. 6,294,398 and 6,468,819, which are incorporated herein by reference in their entirety; and patterning associated with certain deposition methods (such as inkjet printing and OVJD). Other methods can also be used. The materials to be deposited can be modified to make them compatible with the specific deposition method. For example, substituents such as alkyl and aryl groups that are branched or unbranched and preferably contain at least 3 carbons can be used in small molecules to enhance their ability to withstand solution processing. Substituents having 20 or more carbons can be used, and a range of 3 - 20 carbons is preferred. Materials with an asymmetric structure may have better solution processability than materials with a symmetric structure because asymmetric materials may have a lower tendency to recrystallize. Dendrimer substituents can be used to enhance the solution processability of small molecules.

[0062] Devices fabricated in accordance with embodiments of the present invention may further optionally include a barrier layer. One use of the barrier layer is to protect the electrodes and organic layers from damage by harmful substances in an environment that includes moisture, vapors, and / or gases, etc. The barrier layer may be deposited on the substrate, on the electrodes, under the substrate, under the electrodes, beside the substrate, beside the electrodes, or on any other part of the device (including the edges). The barrier layer may comprise a single layer or multiple layers. The barrier layer may be formed by various known chemical vapor deposition techniques and may include compositions having a single phase as well as compositions having multiple phases. Any suitable material or combination of materials may be used for the barrier layer. The barrier layer may be doped with inorganic or organic compounds or both. Preferred barrier layers include mixtures of polymeric and non-polymeric materials as described in U.S. Patent No. 7,968,146, PCT Patent Application Nos. PCT / US2007 / 023098 and PCT / US2009 / 042829, which are incorporated herein by reference in their entirety. For a material to be considered a "mixture", the above-described polymeric and non-polymeric materials that make up the barrier layer should be deposited under the same reaction conditions and / or simultaneously deposited. The weight ratio of the polymeric material to the non-polymeric material may be in the range of 95:5 to 5:95. The polymeric material and the non-polymeric material may be formed from the same precursor material. In one example, the mixture of the polymeric material and the non-polymeric material consists essentially of polymeric silicon and inorganic silicon.

[0063] In some embodiments, at least one of an anode, a cathode, or a new layer disposed on the organic emissive layer acts as an enhancement layer. The enhancement layer comprises a plasmonic material that exhibits surface plasmon resonance, which non-radiatively couples to the emitter material and transfers excited state energy from the emitter material to a non-radiative mode of surface plasmon polaritons. The enhancement layer is provided at a threshold distance not exceeding that of the organic emissive layer, where, due to the presence of the enhancement layer, the emitter material has a total non-radiative decay rate constant and a total radiative decay rate constant, and the threshold distance is the distance at which the total non-radiative decay rate constant equals the total radiative decay rate constant. In some embodiments, the OLED further comprises an outcoupling layer. In some embodiments, the outcoupling layer is disposed on the opposite side of the organic emissive layer from the enhancement layer. In some embodiments, the outcoupling layer is disposed on the side of the emissive layer opposite the enhancement layer but still outcouples energy from the surface plasmon mode of the enhancement layer. The outcoupling layer scatters energy from the surface plasmon polaritons. In some embodiments, this energy is scattered as photons into free space. In other embodiments, the energy is scattered from the surface plasmon mode into other modes of the device, such as (but not limited to) an organic waveguide mode, a substrate mode, or another waveguide mode. If the energy is scattered into a non-free space mode of the OLED, other outcoupling schemes can be incorporated to extract the energy into free space. In some embodiments, one or more intervening layers can be disposed between the enhancement layer and the outcoupling layer. Examples of intervening layers can be dielectric materials, including organic, inorganic, perovskite, oxides, and can include stacks and / or mixtures of these materials.

[0064] The enhancement layer modifies the effective properties of the medium in which the emitter material resides, thereby causing any one or all of the following: reduced emissivity, altered emission line shape, angular variation of emission intensity, stability of the emitter material, variation in OLED efficiency, and reduced OLED device efficiency roll-off. Placing the enhancement layer on the cathode side, the anode side, or both results in an OLED device that exploits any of the effects mentioned above. In addition to the specific functional layers described in the various OLED examples mentioned herein and illustrated in the figures, the OLEDs according to the present disclosure can also include any of the other functional layers commonly seen in OLEDs.

[0065] The enhancement layer can be composed of a plasmonic material, an optically active metamaterial, or a hyperbolic metamaterial. As used herein, a plasmonic material is a material in which the real part of the dielectric constant crosses zero in the visible or ultraviolet region of the electromagnetic spectrum. In some embodiments, the plasmonic material includes at least one metal. In such embodiments, the metal can include at least one of Ag, Al, Au, Ir, Pt, Ni, Cu, W, Ta, Fe, Cr, Mg, Ga, Rh, Ti, Ru, Pd, In, Bi, Ca, alloys or mixtures of these materials, and stacks of these materials. Generally speaking, a metamaterial is a medium composed of different materials, where the medium as a whole behaves differently from the sum of its material components. Specifically, we define an optically active metamaterial as a material having both a negative dielectric constant and a negative magnetic permeability. On the other hand, a hyperbolic metamaterial is an anisotropic medium in which the dielectric constant or magnetic permeability has different signs for different spatial directions. Optically active metamaterials and hyperbolic metamaterials are strictly distinct from many other photonic structures, such as Distributed Bragg Reflectors (“DBR”), because the medium should appear uniform in the direction of propagation for the length scale of the light wavelength. Using terms that can be understood by those skilled in the art: the dielectric constant of the metamaterial in the direction of propagation can be described by an effective medium approximation. Plasmonic materials and metamaterials provide methods of controlling light propagation that can enhance OLED performance in various ways.

[0066] In some embodiments, the enhancement layer is provided as a planar layer. In other embodiments, the enhancement layer has wavelength-sized features arranged periodically, quasi-periodically, or randomly, or sub-wavelength-sized features arranged periodically, quasi-periodically, or randomly. In some embodiments, the wavelength-sized features and sub-wavelength-sized features have sharp edges.

[0067] In some embodiments, the outcoupling layer has wavelength-sized features arranged periodically, quasi-periodically, or randomly, or sub-wavelength-sized features arranged periodically, quasi-periodically, or randomly. In some embodiments, the outcoupling layer can be composed of a plurality of nanoparticles, and in other embodiments, the outcoupling layer is composed of a plurality of nanoparticles disposed on a material. In these embodiments, outcoupling can be tuned by at least one of the following: changing the size of the plurality of nanoparticles, changing the shape of the plurality of nanoparticles, changing the material of the plurality of nanoparticles, adjusting the thickness of the material, changing the refractive index of the material or an additional layer disposed on the plurality of nanoparticles, changing the thickness of the enhancement layer, and / or changing the material of the enhancement layer. The plurality of nanoparticles of the device can be formed by at least one of the following: metal, dielectric material, semiconductor material, metal alloy, mixture of dielectric materials, stack or layer of one or more materials, and / or core of one type of material coated with a shell of a different type of material. In some embodiments, the outcoupling layer is composed of at least metal nanoparticles, where the metal is selected from the group consisting of: Ag, Al, Au, Ir, Pt, Ni, Cu, W, Ta, Fe, Cr, Mg, Ga, Rh, Ti, Ru, Pd, In, Bi, Ca, alloys or mixtures of these materials, and stacks of these materials. The plurality of nanoparticles can have an additional layer disposed thereon. In some embodiments, the polarization of the emission can be tuned using the outcoupling layer. Changing the dimensions and periodicity of the outcoupling layer can select a preferred type of polarization outcoupled to air. In some embodiments, the outcoupling layer also serves as an electrode of the device.

[0068] It is believed that the internal quantum efficiency (IQE) of fluorescent OLEDs can exceed the spin statistical limit by 25% via delayed fluorescence. As used herein, there are two types of delayed fluorescence, namely P-type delayed fluorescence and E-type delayed fluorescence. P-type delayed fluorescence is generated by triplet-triplet annihilation (TTA).

[0069] On the other hand, E-type delayed fluorescence does not rely on the collision of two triplets, but rather on the thermal population between the triplet and the singlet excited state. Compounds capable of generating E-type delayed fluorescence are needed in order to have a very small singlet-triplet gap. Thermal energy can activate the transition from the triplet state back to the singlet state. This type of delayed fluorescence is also referred to as thermally activated delayed fluorescence (TADF). A notable feature of TADF is that the delayed component increases with increasing temperature due to the increase in thermal energy. If the reverse intersystem crossing rate is fast enough to minimize non-radiative decay from the triplet state, the proportion of singlet excited states filled in reverse can reach 75%. The total singlet fraction can be 100%, far exceeding the spin statistical limit of electro-generated excitons.

[0070] E-type delayed fluorescence characteristics can be seen in exciplex systems or single compounds. Without being bound by theory, it is believed that E-type delayed fluorescence requires the luminescent material to have a small singlet-triplet energy gap (ΔES-T). Organometallic donor-acceptor luminescent materials may be able to achieve this. The emission of these materials is typically characterized as donor-acceptor charge transfer (CT) type emission. The spatial separation of the HOMO and LUMO in these donor-acceptor type compounds usually results in a small ΔES-T. These states can include CT states. Generally, donor-acceptor luminescent materials are constructed by connecting an electron donor moiety (such as an amino or carbazole derivative) to an electron acceptor moiety (such as an N-containing six-membered aromatic ring).

[0071] Devices manufactured according to embodiments of the present invention can be incorporated into a variety of electronic component modules (or units) that can be incorporated into a variety of electronic products or intermediate components. Examples of such electronic products or intermediate components include display screens that can be used by end-user product manufacturers, lighting devices, such as discrete light source devices or lighting panels, etc. The electronic component module may optionally include driving electronic devices and / or power supplies. Devices manufactured according to embodiments of the present invention can be incorporated into a variety of consumer products in which one or more of the electronic component modules (or units) are incorporated. A consumer product comprising an OLED is disclosed, wherein the organic layer of the OLED includes a compound of the present invention. Such consumer products should include any kind of product that includes one or more of a light source and / or a visual display of some type. Some examples of such consumer products include flat panel displays, curved displays, computer monitors, medical monitors, televisions, billboards, lights for internal or external lighting and / or signaling, head-up displays, fully transparent or partially transparent displays, flexible displays, rollable displays, foldable displays, stretchable displays, laser printers, telephones, cellular phones, tablets, phablets, personal digital assistants (PDAs), wearable devices, laptop computers, digital cameras, video cameras, viewfinders, microdisplays with a diagonal of less than 2 inches, 3-D displays, virtual reality or augmented reality displays, vehicles, video walls comprising a plurality of tiled-together displays, theater or stadium screens, and signs. A variety of control mechanisms can be used to control the devices manufactured according to the present invention, including passive matrix and active matrix. Many of the devices are intended to be used in a temperature range comfortable for humans, such as 18 °C to 30 °C, and more preferably at room temperature (20 - 25 °C), but can be used outside of this temperature range (e.g., -40 °C to 80 °C).

[0072] The materials and structures described herein can be applied to devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors can use the materials and structures. More generally, organic devices such as organic transistors can employ the materials and structures.

[0073] In some embodiments, the OLED has one or more characteristics selected from the group consisting of flexible, rollable, foldable, stretchable, and bendable. In some embodiments, the OLED is transparent or semi-transparent. In some embodiments, the OLED further includes a layer comprising carbon nanotubes.

[0074] In some embodiments, the OLED further includes a layer containing a delayed fluorescence emitter. In some embodiments, the OLED includes an RGB pixel arrangement or a white plus color filter pixel arrangement. In some embodiments, the OLED is a mobile device, a handheld device, or a wearable device. In some embodiments, the OLED is a display panel with a diagonal less than 10 inches or an area less than 50 square inches. In some embodiments, the OLED is a display panel with a diagonal of at least 10 inches or an area of at least 50 square inches. In some embodiments, the OLED is a lighting panel.

[0075] In some embodiments of the emission region, the emission region further includes a host.

[0076] In some embodiments, the compound can be an emissive dopant. In some embodiments, the compound can generate emission via phosphorescence, fluorescence, thermally activated delayed fluorescence (i.e., TADF, also known as E-type delayed fluorescence), triplet-triplet annihilation, or a combination of these processes.

[0077] The OLEDs disclosed herein can be incorporated into one or more consumer products, electronic component modules, and lighting panels. The organic layer can be an emissive layer, and the compound can be an emissive dopant in some embodiments and a non-emissive dopant in other embodiments.

[0078] The organic layer can also include a host. In some embodiments, two or more hosts are preferred. In some embodiments, the host used can be a) bipolar, b) electron transporting, c) hole transporting, or d) wide bandgap material that plays a minor role in charge transport. In some embodiments, the host can include a metal complex. The host can be an inorganic compound.

[0079] Combinations with other materials

[0080] The materials described herein as being specific layers that can be used in an organic light emitting device can be used in combination with a variety of other materials present in the device. For example, the light emitting dopants disclosed herein can be used in combination with a variety of hosts, transport layers, blocking layers, injection layers, electrodes, and other layers that may be present. The materials described or mentioned below are non-limiting examples of materials that can be used in combination with the compounds disclosed herein, and one of ordinary skill in the art can readily consult the literature to identify other materials that can be used in combination.

[0081] The different emissive and non-emissive layers and arrangements disclosed herein can use different materials. Examples of suitable materials are disclosed in U.S. Patent Application Publication No. 2017 / 0229663, which is incorporated by reference in its entirety.

[0082] Conductive dopants:

[0083] The charge transport layer can be doped with a conductive dopant to substantially change its charge carrier density, which in turn will change its conductivity. Conductivity is increased by generating charge carriers in the matrix material, and depending on the type of dopant, a change in the Fermi level of the semiconductor can also be achieved. The hole transport layer can be doped with a p-type conductive dopant, and an n-type conductive dopant is used in the electron transport layer.

[0084] HIL / HTL:

[0085] The hole injection / transport materials used in the present invention are not particularly limited, and any compound can be used as long as the compound is typically used as a hole injection / transport material.

[0086] EBL:

[0087] An electron blocking layer (EBL) can be used to reduce the number of electrons and / or excitons leaving the emissive layer. The presence of such a blocking layer in the device can result in substantially higher efficiency and / or longer lifetime compared to a similar device without a blocking layer. Additionally, a blocking layer can be used to confine emission to the desired region of the OLED. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and / or higher triplet energy compared to the emitter closest to the EBL interface. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and / or higher triplet energy compared to one or more of the hosts closest to the EBL interface. In one aspect, the compound used in the EBL contains the same molecule or the same functional group as one of the hosts described below.

[0088] Host:

[0089] The light-emitting layer of the organic EL device of the present invention preferably contains at least a metal complex as a light-emitting material, and may contain a matrix material using a metal complex as a dopant material. Examples of the matrix material are not particularly limited, and any metal complex or organic compound can be used as long as the triplet energy of the matrix is greater than the triplet energy of the dopant. Any host material can be used with any dopant as long as the triplet criterion is satisfied.

[0090] HBL:

[0091] A hole blocking layer (HBL) can be used to reduce the number of holes and / or excitons leaving the emissive layer. The presence of the blocking layer in the device can result in generally higher efficiency and / or longer lifetime compared to a similar device lacking the blocking layer. Additionally, a blocking layer can be used to confine emission to the desired region of the OLED. In some embodiments, the HBL material has a lower HOMO (farther from the vacuum level) and / or a higher triplet energy compared to the emitter closest to the HBL interface. In some embodiments, the HBL material has a lower HOMO (farther from the vacuum level) and / or a higher triplet energy compared to one or more of the hosts closest to the HBL interface.

[0092] ETL:

[0093] The electron transport layer (ETL) can include materials capable of transporting electrons. The electron transport layer can be intrinsic (undoped) or doped. Doping can be used to enhance conductivity. Examples of ETL materials are not particularly limited, and any metal complex or organic compound can be used as long as it is typically used to transport electrons.

[0094] Charge generation layer (CGL)

[0095] In a tandem or stacked OLED, the CGL plays an important role in performance and is composed of an n-doped layer and a p-doped layer for injecting electrons and holes, respectively. Electrons and holes are supplied by the CGL and the electrodes. The electrons and holes consumed in the CGL are refilled by electrons and holes injected from the cathode and anode, respectively; subsequently, the bipolar current gradually reaches a steady state. Typical CGL materials include n- and p-conductive dopants used in the transport layer.

[0096] Embodiments of the disclosed subject matter provide a high-temperature, low-profile, bondable gas distribution plate and an opposing plate for coupling a jet head to a larger gas delivery system for delivering organic materials via organic vapor jet printing (OVJP). The bonded assembly allows for efficient delivery of hot materials to the surface of the substrate with minimal thermal load on the substrate.

[0097] In such as Figure 3In the illustrated example OVJP system, the microfabricated die 301 contains a micro-nozzle array 302 along its lower edge. The die 301 is typically made of silicon, but other materials can also be used. The die 301 is clamped between two heated plates 303. At least one of the plates of the fixture is connected to a heated manifold 304 that feeds organic vapors entrained in an inert carrier gas into the die via an operating line 305 that extends from the manifold 304 through the plate 303 to one or more through-holes in one side of the die 301. At least one of the plates 303 of the fixture has an exhaust line 306 that connects the through-holes in the die 301 to a low-pressure reservoir to draw process gases and excess organic vapors from the printing area. A heater 307 can be connected to one or more of the plates 303 of the fixture and to the manifold 304. The microfabricated die 301 and the means for containing the die and connecting it to the heated manifold 304 are referred to as a printhead.

[0098] The temperature of the substrate affects the morphology of the deposited film. To control the morphology, it is important to control the heat load on the surface. A temperature control plate or a cooling plate is placed between the printhead and the substrate 308. The cooling plate has a thicker portion 309 to allow heat to conduct effectively to the coolant circuit, but has a thinner portion 310 near the micro-nozzle array. This thinner portion 310 is not as effective at insulating as the thicker portion 309, but the form factor requirements of the fixture assembly require material to be removed from the cooling plate to accommodate the fixture so that the micro-nozzle array can be close to the substrate 308. The micro-nozzle array must be kept at a high temperature, so only a short distance of the tip of the die can protrude from the fixture. Requirements for thermal uniformity, airtightness, and mechanical stiffness limit how small the fixture can be made. The window in the cooling plate must be wide enough to accommodate a portion of the fixture surrounding the die 301. Thus, only part of the fixture is shielded from the substrate 308, and its shielded section is shielded only by a thinner-than-ideal portion of the cooling plate.

[0099] Embodiments of the disclosed subject matter reduce the heat load applied to the substrate by the OVJP mechanism by providing a gas distribution plate that allows as much of the assembly as possible to remain shielded by a thick cooling plate during operation.

[0100] Embodiments of the disclosed subject matter provide high-temperature, low-profile, bondable gas distribution plates and opposing plates for connecting microfluidic devices made of silicon or other materials to larger gas delivery systems. The gas distribution plates and opposing plates can have a low profile in the depth direction while being relatively tall and wide. This arrangement can provide a minimum cross-sectional area of the heated printhead facing the substrate while allowing a thick cooling plate to surround the gas distribution plates and opposing plates and thermally isolate the rest of the heated OVJP assembly from the substrate.

[0101] When attempting to seal a fluid connection at the interface of two parts, operating at high temperatures in a high-purity vacuum environment can pose challenges. Conventional polymer seals have a maximum operating temperature of approximately 300 °C, and many are much lower. Even when using high-temperature-rated polymers, outgassing can be a problem. Although metal seals can operate at high temperatures, metal and polymer seals typically use additional fixtures during assembly, such as bolt connections, which increase the physical size of the gas distribution plate and the opposing plate. Heat transfer within the OVJP mechanism can be controlled because some components of the OVJP mechanism may be hot while other components may be heat-sensitive. Other dimensions in the fixtures increase the thermal load on the system components, which may be undesirable. The gas distribution plate and the opposing plate disclosed herein can be used as a passage device to move fluid from one hot region through a window in a cooling plate and into another region, and can reduce the thermal load on the system. This allows the substrate to be most effectively shielded from the heat generated by the evaporation source and the connection manifold.

[0102] The gas distribution plate and the opposing plate disclosed herein can be used in organic vapor jet printing (OVJP). OVJP is a system in which organic materials are communicated to a substrate via a hot carrier gas, where a micro-nozzle array needs to be connected to a macroscopic assembly to heat the material and entrain it in a vapor stream. The vapor stream cannot be cooled along its path, and the processing equipment may not transfer excessive heat to the substrate. By reducing the size of the portion of the printhead assembly exposed to the substrate and using a shielded or cooled interface, the thermal load can be more easily managed.

[0103] Figure 4aAn apparatus according to an embodiment of the disclosed subject matter is shown. A micro-nozzle array 401, which may be similar to a micro-nozzle array in a plane perpendicular to its orifices and may have one or more delivery orifices in fluid communication with an inert carrier gas and an organic vapor stream. The delivery orifices may meet on either side with exhaust orifices in fluid communication with an exhaust pipeline. The micro-nozzle array 401 may be disposed at an edge of a silicon die 402, and the silicon die is disposed between plates 403. The plates 403 may include a first gas distribution plate and a second opposing plate. The micro-nozzle array 401, the silicon die 402, and the plates 403 may project through a cooling plate 404. The micro-nozzle array 401 may be close to a substrate 410 where deposition will be targeted. The die 402 may be irreversibly sealed to one or more of the gas distribution plate and the opposing plate using methods such as frit, ceramic adhesive, bonding, soldering, or brazing. In some embodiments, the die 402 may be attached to the gas distribution plate. The gas distribution plate of the plates 403 may be mechanically attached to an interface manifold block 405, and one or more fluid paths 406 may be sealed using a high-temperature seal in a gland feature 407. At least one of the plates 403 has a channel 408 that may feed an organic vapor entrained in an inert carrier gas from a manifold connected to one or more organic vapor sublimation sources 411 into the die 402. At least one of the plates 403 may include an exhaust pipeline 409 that connects a through-hole on the die 402 to a low-pressure reservoir 412 to draw process gases and excess organic vapor from the printing area.

[0104] Figure 4b is shown Figure 4a an alternative arrangement where the organic vapor channel 408 and the exhaust pipeline 409 may be led out through the same plate 403. The opposing plate 403a and the manifold block 405a may not include any internal channels and thus may not use a hermetic seal at their interfaces.

[0105] FIG. 5a shows Figure 4a an alternative arrangement of the embodiment shown in. The arrangement shown in FIG. 5a may include a thermal insulation material 501, such as quartz or borosilicate glass, which may be attached to the perimeter of a window in the cooling plate 404. The thermal insulation material 501 may be used to maintain a temperature gradient such that the plate 403 remains hot while the cooling plate 404 remains cold. That is, the plate 403 may have a predetermined hot temperature that is greater than the predetermined cold temperature of the cooling plate 403. An alternative embodiment is shown in FIG. 5b where a thermal insulation sheet may overcoat and / or cover the outer surfaces of the plate 403 and the microfabricated die assembly. In Figures 5a - 5b the embodiment shown, the embodiment shown in FIG. 5a may be preferred because it reduces the cross-sectional size of the heated ejection head close to the substrate 410.

[0106] The plate 403 may include stacked and bonded channels and / or holes. The bonding may be vacuum brazing, diffusion bonding, soldering, glass frit, ceramic adhesive, etc. The bonding may allow for complex internal geometries that may reduce the profile of the plate 403. The final bonded portion may have multiple leak-proof fluid channels, each channel connecting an inlet to an outlet hole. If soldering, brazing, or welding techniques are used to fabricate one or more of the plates 403, the forming temperature may be greater than the temperature of the hard solder or soft solder used to attach the plate 403 to the die 402 including the micro-nozzle array 401. The material used for the plate 403 may match the coefficient of thermal expansion (CTE) of silicon to avoid cracking of the silicon due to different expansions of the mating materials. Some examples of materials that match the CTE of silicon may include molybdenum, tungsten, quartz, kovar alloy, aluminum nitride, etc. The average CTE between room temperature and the liquid of the material used to solder or braze the micro-nozzle array 401 to the gas distribution plate and the opposing plate may be less than 6×10 -6 K -1 . By matching the expansions, the silicon die 402 and the plate 403 can be bonded to eliminate another sealing interface.

[0107] The silicon die 402 including the micro-nozzle array 401 may be indirectly heated by a heater attached to a clamping plate in a manner similar to the heater 307 of one or more of the plates 303 that may be connected to the Figure 3 fixture shown. Surface-to-surface metal contacts may have a higher thermal resistance than welded contacts, so the fixture must be heated to a much higher temperature than the temperature required at the tip of the silicon die 402. Embodiments of the disclosed subject matter may compensate by heating the heater to a higher temperature set point. The bonding interface between the silicon die 402 and the plate 403 may provide more efficient heat conduction, and the heater temperature may be reduced accordingly. This may further reduce the heat load on the substrate 410 and the cooling requirements of the OVJP tool.

[0108] Heat transfer to the substrate may be restricted by a temperature control plate mounted between the thermal assembly and the substrate. Areas of the temperature control plate may be cut out so that the micro-nozzles and their support structures may pass through and be close to the substrate without exposing all of the thermal components. Since the bonding also removes the fasteners required to clamp and seal the silicon at its gas interface, the overall size of these structures may be reduced. Therefore, smaller cutout windows may be formed in the plate, further reducing the heat load on the substrate.

[0109] Figure 6 Heat transfer from a conventionally mounted ejection head to a substrate is shown versus using Figure 4aComparison of heat transfer of the disclosed embodiments of the present invention to a substrate. The temperature of the ejection head can be indicated in degrees Celsius on the horizontal axis 601, while the heat transfer rate of the substrate at a distance of 50 μm from the tip of the ejection head to the micro-nozzle array can be indicated in watts using the vertical axis 602. The gray dashed line 603 can show Figure 3 the relationship between the heat transfer rate and temperature of an OVJP ejection head of a standard configuration as shown, while the gray solid line 604 can show the relationship between the heat transfer rate and temperature of an OVJP ejection head using an embodiment of the disclosed subject matter as shown Figure 4a . Figure 4a The device shown can reduce the heat load on the substrate by approximately 12% over its operating range. This may be due to the lower thermal mass and cross-section of the plate 303 compared to the current fixture and the smaller window in the cooling plate 404 allowed by the plate 403, which can enable the cooling plate 404 to better shield the substrate 410 from the heat generated by the sublimation source and the manifold connecting the sublimation source to the plate 403. The absence of milled depressions in the cooling plate 404 to accommodate clamping hardware can improve the thermal insulation between the substrate and the heated OVJP assembly. The pipelines 605 and 606 shown in Figure 8 are discussed in connection with the embodiment shown Figure 6 .

[0110] As shown Figure 7 , the OVJP micro-nozzle array can have orifices that cut into the surface rather than the edge of the micro-machined die. The orifices can be present on the lower surface of the die 701 connected to the manifold 702 by a connection 703, which can be a soldering connection, a brazing connection, an adhesive, a glass frit, a ceramic adhesive, or other suitable connection. The surface of the micro-nozzle array can be in a plane perpendicular to its orifices and can have one or more delivery orifices that are in fluid communication with an inert carrier gas and an organic vapor stream. The delivery orifices can meet on either side with exhaust orifices that are in fluid communication with an exhaust pipeline. In some embodiments, the surface of the micro-nozzle array can have a different arrangement of delivery orifices and exhaust orifices. The micro-nozzle configuration can include delivery orifices and exhaust orifices as edges. The configuration shown in Figure 7 can include an ejection head that has an increased cross-sectional area facing the substrate, which can provide a greater heat transfer rate to the substrate. Compared to the edge configuration discussed above, the higher heat transfer rate can be offset by a greater material deposition rate, such that the dose of heat received per unit substrate area can be approximately the same or lower. The manifold 702 can be joined to the micro-nozzle array using soldering or brazing techniques as disclosed in U.S. Patent No. 9,700,901. The manifold 702 can expose additional surface area to the substrate 706 for heat transfer and may require a distinct window through the cooling plate 707.

[0111] Figure 8shows a structure on the edge similar to that Figure 3 shown in, but Figure 8 the configuration in can be manufactured such that the plate presents less cross-sectional area to the substrate for heat transfer. Die 801 can be directly connected to plate 802 through seal 803, and the seal can be a soldering seal, a brazing seal, an adhesive, a glass frit, a ceramic adhesive seal or other suitable seal. Plate 802 can include a first gas distribution plate and a second opposing plate. Plate 802 can extend through a window that cuts through a thicker portion of cooling plate 804, and the window is more capable of absorbing heat from the evaporation source and the manifold connecting the evaporation source to plate 802. The plate can include one or more delivery operation pipelines 805, and the delivery operation pipelines transfer organic vapors entrained in an inert carrier gas from the evaporation source to the micro-nozzle array. The plate can also include an exhaust pipeline 806, and the exhaust pipeline is in a depressurized state relative to the chamber and extracts gas from below the die. Compared with one of the previous configurations as Figure 3 shown, the compact gas distribution plate and the opposing plate can significantly reduce the heat transferred to the substrate.

[0112] Figure 6 shows a graph of the heat transferred to the substrate versus the jet head temperature. The dark dashed line 605 is for the jet head directly connected to the Figure 8 shown plate 802, while the dark solid line 606 is for the jet head for the configuration including cooling plate 804. Figure 8 The cooling plate 804 of can reduce the heat load on the substrate by reducing the heated cross-sectional area to which the substrate is exposed. The configuration can allow for more thermal shielding around the micro-nozzle array. A total heat transfer reduction of 11% can be expected.

[0113] The first gas distribution plate and the second opposing plate can provide a solid surface, so that a mechanical seal (such as a metal O-ring) is used to seal the fluid path between the plate and the mating part or interface. Using such a seal on bare silicon may result in high stress concentration and is most likely to rupture before the seal reaches full seat pressure. Some embodiments of the disclosed subject matter can include a soft deformable metal disposable gasket material that fuses to the plate at its detachable connection to the OVJP manifold.

[0114] In some printing and coating applications, it may be desirable to have a depositor array that matches the width of the substrate so that full coverage can be achieved in a single pass. The channels of the plate (e.g., the gas distribution plate and the opposing plate) may be arranged in a linear pattern to form a long and thin gas distribution plate and opposing plate, and the plate can be coupled to one or more microfluidic devices.

[0115] Above, for example, in combination with Figure 6The printhead under discussion was modeled using the laminar flow and heat transfer packages in COMSOL Multiphysics. A nitrogen environment and a room temperature heat bath were assumed in all cases, with the micro-nozzle array located 50 μm above the substrate and 1 mm below the type of fixture being evaluated. The cooling plate and the substrate platen were also at a temperature of 20 °C, and the platen carried a 0.7 mm thick glass substrate. The cooling plate was 1 mm above the substrate. Four fixtures were evaluated.

[0116] Embodiments of the disclosed subject matter can provide an apparatus that includes a device having a micro-nozzle array disposed on a micro-machined jet die. The micro-nozzle array of the device can be disposed on an edge of the micro-machined jet die. The micro-nozzle array can be disposed on one side of the micro-jet die. The micro-machined jet die of the device can include at least one of silicon, quartz, and / or metal. The apparatus can include a first gas distribution plate and a second opposing plate, wherein the micro-machined jet die is disposed between the first gas distribution plate and the second opposing plate. The first gas distribution plate can be irreversibly joined to the micro-nozzle array using an airtight seal, wherein the first gas distribution plate includes a plurality of sealed flow paths. A manifold can be reversibly joined to the first gas distribution plate, wherein the micro-machined jet die, the first gas distribution plate, and the second opposing plate can be disposed between the manifold. The apparatus can include a heat conducting plate in thermal contact with an active cooling source, wherein the heat conducting plate has at least one window extending through its entire thickness, and the first gas distribution plate and the second opposing plate of the device, a portion of the micro-machined jet die, and the micro-nozzle array project through the window such that the minor axis of the window cross-section provides a clearance fit for the device within its range of motion relative to the heat conducting plate. The apparatus can include one or more thermal evaporation sources in fluid communication with the first gas distribution plate, wherein the manifold can be in fluid communication with the micro-nozzle array via the plurality of sealed flow paths within the first gas distribution plate.

[0117] In some embodiments, the micro-nozzle array of the device can be disposed on an edge of the micro-machined jet die. The micro-nozzle array can be disposed on one side of the micro-jet die. The micro-machined jet die of the device can include at least one of silicon, quartz, and / or metal. The micro-nozzle array and the substrate of the apparatus can be configured to move relative to each other. The micro-machined jet die and the micro-nozzle array of the device can comprise silicon.

[0118] The second opposing plate of the device can be a second gas distribution plate. The manifold can be joined to the first gas distribution plate using an airtight seal.

[0119] At least one of the plurality of sealed flow paths of the device may be configured to carry a mixture of organic vapor and an inert carrier gas.

[0120] The first gas distribution plate of the device may have a section close to the micro-nozzle array, all the flow paths pass through the section, and the aspect ratio of the depth of the section does not exceed 10% of the width or height of the section, where the depth may be the direction perpendicular to one side of the micro-nozzle array.

[0121] The heat conducting plate of the device may shield the object acted on by the micro-nozzle array from the heat generated by the manifold and the plurality of evaporation sources. The heat conducting plate may have a window lined with an insulating material such as quartz, borosilicate glass, etc. The micro-nozzle array and the first gas distribution plate may include at least a part of the device, and the at least a part protrudes through the window of the heat conducting plate such that the normal plane of the device is parallel to the depth dimension of the first gas distribution plate.

[0122] The seal of the device may be a gasket or a joint. The micro-nozzle array of the device may be irreversibly joined to the first gas distribution plate and the second opposing plate using a glass frit, a ceramic adhesive, and / or a soft solder or hard solder compound at a reflow temperature above 350 °C or above 500 °C to form a seal. That is, in some embodiments, a non-metallic seal such as a high-temperature glass frit or a ceramic adhesive may be used. The first gas distribution plate of the device may include a material having an average coefficient of thermal expansion less than 6×10 -6 K -1 between room temperature and the reflow temperature of the soft solder.

[0123] The first gas distribution plate and the second opposing plate of the device may be made of at least one of molybdenum, tungsten, kovar alloy, aluminum nitride, and / or silicon nitride.

[0124] The device may include a heater thermally coupled to the micro-nozzle array, wherein the heater is configured to heat the micro-nozzle array. The micro-nozzle array may direct a convective jet of gas onto the surface of a substrate.

[0125] The first gas distribution plate and the second opposing plate of the device may include a resistive heater. The first gas distribution plate and the second opposing plate of the device may include one or more thermal insulation materials selected from quartz, borosilicate glass, alumina, and / or mica. At least one of the first gas distribution plate and the second opposing plate of the device may be configured to allow gas to be fed through.

[0126] The device may include a deformable metal gasket, wherein the first gas distribution plate is sealed to the manifold using the deformable metal gasket. The deformable metal gasket may be reversibly sealed to the device. The deformable metal gasket may comprise a material integral with the manifold.

[0127] The first gas distribution plate of the device may comprise a plurality of etched or ground material layers, which are bonded together using a forming temperature higher than the reflow temperature of the material used to bond the micro-nozzle array to the first gas distribution plate.

[0128] Embodiments of the disclosed subject matter may provide a device that includes a device having a micro-nozzle array. The device may include a first gas distribution plate that is irreversibly joined to the micro-nozzle array using an airtight seal, wherein the first gas distribution plate includes a plurality of sealed flow paths. One or more thermal evaporation sources of the device may be in fluid communication with the first gas distribution plate. The device may include a manifold, wherein the first gas distribution plate is reversibly joined to the manifold. The manifold may be in fluid communication with the micro-nozzle array via a plurality of sealed flow paths within the first gas distribution plate. At least one of these flow paths may carry a mixture of organic vapor and an inert carrier gas. The first gas distribution plate may have a section adjacent to the micro-nozzle array through which all the flow paths pass, and the depth of the section is not wider than the depth of the micro-nozzle array at its connection point. The device may include a heat conducting plate, wherein the first gas distribution plate and the heat conducting plate are in thermal contact with an active cooling source. The heat conducting plate may have at least one window extending through its entire thickness, through which the device may protrude, such that the minor axis of the cross-section of the window provides a clearance fit for at least the micro-nozzle array of the device within the range of movement of the device relative to the heat conducting plate, so that the heat conducting plate shields the object acted upon by the micro-nozzle array from the heat generated by the manifold and the one or more thermal evaporation sources.

[0129] The seal of the device may be a gasket or a joint. The micro-nozzle array of the device may be irreversibly joined to the device using, for example, glass frit, ceramic adhesive, and / or soft or hard solder compounds at a reflow temperature that may be higher than 350 °C or higher than 500 °C. The first gas distribution plate may comprise a material having an average coefficient of thermal expansion of less than 6×10 -6 K -1 between room temperature and the reflow temperature of the soft solder. The device may comprise at least one of molybdenum, tungsten, kovar alloy, aluminum nitride, and / or silicon nitride.

[0130] The device may include a deformable metal gasket, wherein the first gas distribution plate is sealed to the manifold using the deformable metal gasket. The deformable metal gasket may be reversibly sealed to the device. In some embodiments, the deformable metal gasket comprises a material integral with the manifold.

[0131] The device may include a heater thermally coupled to the micro-nozzle array, wherein the heater is configured to heat the micro-nozzle array.

[0132] The micro-nozzle array of the device may direct a convective jet of gas onto the surface of a substrate. The micro-nozzle array and the substrate are configured to move relative to each other. The micro-nozzle array may comprise silicon.

[0133] The heat conducting plate of the device may include a window lined with an insulating material such as quartz, borosilicate glass, etc.

[0134] It should be understood that the various embodiments described herein are merely examples and are not intended to limit the scope of the invention. For example, many of the materials and structures described herein may be replaced with other materials and structures without departing from the spirit of the invention. The invention as claimed may thus include variations of the specific examples and preferred embodiments described herein, as will be apparent to those skilled in the art. It should be understood that the various theories as to why the invention works are not intended to be limiting.

Claims

1. A device comprising: A device, the device comprising: A micro-nozzle array disposed on a micro-machined jet core; A first gas distribution plate and a second opposing plate, wherein the micro-machined jet core is disposed between the first gas distribution plate and the second opposing plate, wherein the first gas distribution plate is irreversibly joined to the micro-nozzle array using an airtight seal, and wherein the first gas distribution plate includes a plurality of sealed flow paths; and A manifold reversibly joined to the first gas distribution plate, wherein the micro-machined jet core, the first gas distribution plate, and the second opposing plate are disposed between the manifold; and A heat conducting plate in thermal contact with an active cooling source, wherein the heat conducting plate has at least one window extending through its entire thickness, and a portion of the first gas distribution plate and the second opposing plate of the device, a portion of the micro-machined jet core, and the micro-nozzle array protrude through the window such that the minor axis of the cross-section of the window provides a clearance fit for the device within the range of motion relative to the heat conducting plate; One or more thermal evaporation sources in fluid communication with the first gas distribution plate, wherein the manifold is in fluid communication with the micro-nozzle array via the plurality of sealed flow paths within the first gas distribution plate.

2. The device according to claim 1, wherein the micro-nozzle array is disposed on an edge of the micro-machined jet core.

3. The device according to claim 1, wherein the micro-nozzle array is disposed on one surface of the micro-machined jet core.

4. The device according to claim 1, wherein the second opposing plate is a second gas distribution plate, and wherein the manifold is joined to the first gas distribution plate using an airtight seal.

5. The device according to claim 1, further comprising: A heater thermally coupled to the micro-nozzle array, wherein the heater is configured to heat the micro-nozzle array.

6. The device according to claim 1, wherein the micro-nozzle array and the substrate are configured to move relative to each other.

7. The device according to claim 1, wherein the heat conducting plate comprises a window lined with an insulating material.

8. The device according to claim 7, wherein the micro-nozzle array and the first gas distribution plate comprise at least a portion of the device, and the at least a portion protrudes through the window of the heat conducting plate such that the normal plane of the device is parallel to the depth dimension of the first gas distribution plate.

9. The device according to claim 1, wherein the first gas distribution plate and the second opposing plate include resistive heaters.

10. The device according to claim 1, further comprising: A deformable metal gasket, wherein the first gas distribution plate is sealed to the manifold using the deformable metal gasket.

11. A device comprising: A device, the device comprising: A micro-nozzle array; A first gas distribution plate irreversibly joined to the micro-nozzle array using an airtight seal, wherein the first gas distribution plate includes a plurality of sealed flow paths; One or more thermal evaporation sources in fluid communication with the first gas distribution plate; and A manifold, wherein the first gas distribution plate is reversibly engaged to the manifold, wherein the manifold is in fluid communication with the micro-nozzle array via a plurality of sealed flow paths within the first gas distribution plate, wherein at least one of these flow paths carries a mixture of organic vapor and an inert carrier gas, and wherein the first gas distribution plate has a section adjacent to the micro-nozzle array through which all the flow paths pass, and the depth of the section is not wider than the depth of the micro-nozzle array at its connection point, and A heat conducting plate, wherein the first gas distribution plate and the heat conducting plate are in thermal contact with an active cooling source, and wherein the heat conducting plate has at least one window extending through its entire thickness, through which the device can protrude so that the minor axis of the cross-section of the window provides a clearance fit for at least the micro-nozzle array of the device within the range of movement of the device relative to the heat conducting plate, such that the heat conducting plate shields the object acted upon by the micro-nozzle array from the heat generated by the manifold and the one or more thermal evaporation sources.

12. The apparatus according to claim 11, further comprising: A heater thermally coupled to the micro-nozzle array, wherein the heater is configured to heat the micro-nozzle array.

13. The apparatus according to claim 11, wherein the micro-nozzle array and the substrate are configured to move relative to each other.

14. The apparatus according to claim 11, wherein the heat conducting plate comprises a window lined with an insulating material.

15. The apparatus according to claim 11, further comprising: A deformable metal gasket, wherein the first gas distribution plate is sealed to the manifold using the deformable metal gasket.

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