Height measurement and control of a vapor deposition system in a confined space

Abstract

The present application relates to height measurement and control of a vapor deposition system in a confined space. Embodiments of the disclosed subject matter provide an apparatus having a print head comprising a micro-nozzle array of depositors to deposit material on a substrate. A reflective optical device can reflect a signal output by at least one optical sensor and reflect the signal from a surface of the substrate to the optical sensor. A processor can determine a distance between the optical sensor and a target surface of the substrate. The apparatus can include one or more actuators coupled to the at least one print head to move the print head relative to an internal reference frame and adjust a position of the print head relative to the substrate. The sensor can be fixedly coupled to the internal reference frame with a mount. The print head can be configured to move on at least one linear or rotational axis of motion independently of the optical sensor.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to U.S. Patent Application No. 63 / 054,150 filed July 20, 2020, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to devices and techniques for manufacturing organic emissive devices, such as organic light emitting diodes, and devices and techniques comprising the same. The devices for manufacturing can bring the measurements closer to the printing zone and can provide thermal management for the sensors. BACKGROUND

[0004] Opto-electronic devices that make use of organic materials are becoming increasingly important for a number of reasons. Many of the materials used to make such devices are relatively inexpensive, so organic opto-electronic devices have the potential to be lower cost than other technology options. In addition, the inherent properties of organic materials, such as their flexibility, can make them well suited for particular applications, such as fabrication on a flexible substrate. Examples of organic opto-electronic devices include organic light emitting diodes / devices (OLEDs), organic phototransistors, organic photovoltaic cells, and organic light emitting detectors. For OLEDs, the organic materials can have performance advantages over conventional materials. For example, the wavelength at which an organic emissive layer emits light can generally be easily tuned with appropriate dopants.

[0005] OLEDs make use of thin organic films that emit light when a voltage is applied across the device. OLEDs are becoming an increasingly interesting technology for use in the display, lighting, and back-lighting 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 entirety.

[0006] One application for phosphorescent emissive molecules is a full color display. Industry standards for such displays include having invdividual sub-pixels that emit in response to red, green, and blue light, respectively. One option for a display panel is to have a number of these sub-pixels integrated into three arrays that are located on top of one another, with the different color sub-pixels arranged in repeating groups of red, green, and blue. The manufacturer can achieve variations in color by changing the relative proportions of red, green, and blue sub-pixels in each repeating group.

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

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

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

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

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

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

[0013] Layers, materials, regions, and devices can be described herein with reference to the color of light emitted thereby. In general, as used herein, an emissive region described as producing a particular color of light can include one or more emissive layers disposed in a stacked manner on one another.

[0014] As used herein, a "red" layer, material, region, or device refers to a layer, material, region, or device that emits light in the range of about 580-700 nm or that has the highest peak of its emission spectrum in that region. Similarly, a "green" layer, material, region, or device refers to a layer, material, region, or device that emits or has an emission spectrum with a peak wavelength in the range of about 500-600 nm; a "blue" layer, material, or device refers to a layer, material, or device that emits or has an emission spectrum with a peak wavelength in the range of about 400-500 nm; and a "yellow" layer, material, region, or device refers to a layer, material, region, or device 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 "deep blue" and "light blue" light. As used herein, in arrangements that provide independent "light blue" and "deep blue," the "deep blue" component refers to a component with a peak emission wavelength that is at least about 4 nm less than the peak emission wavelength of the "light blue" component. Typically, the peak emission wavelength of the "light blue" component is in the range of about 465-500 nm and the peak emission wavelength of the "deep blue" component is in the range of about 400-470 nm, although these ranges can vary for some configurations. Similarly, a color converting layer refers to a layer that converts or modifies light of one color to light with a wavelength specified for that color. For example, a "red" filter refers to a filter that forms light with a wavelength in the range of about 580-700 nm. Generally, there are two classes of color converting layers: color filters that modify the spectrum of light by removing unwanted wavelengths of light, and color converting layers that convert higher energy photons to lower energy. A "color" component refers to a component that, when activated or used, produces or otherwise emits light with a particular color as previously described. For example, "a first emission region of a first color" and "a second emission region of a second color different from the first color" describe two emission regions that emit two different colors as previously described when activated within a device.

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

[0016] In some cases, it can be preferable to describe the color of components such as emissive regions, sub-pixels, color conversion layers, etc. in terms of 1931 CIE coordinates. For example, a yellow emissive material can have multiple peak emission wavelengths, one in or near the edge of the "green" region, and one within 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. A shape in the 1931 CIE color space is constructed by following the locus between two color points and any other interior point. For example, the interior shape parameters for red, green, blue, and yellow can be defined as follows:

[0017]

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

[0019] According to an embodiment, an organic light emitting diode / device (OLED) is also provided. The OLED can include an anode, a cathode, and an organic layer disposed between the anode and the cathode. According to an embodiment, the organic light emitting device is incorporated into one or more devices selected from the group consisting of a consumer product, an electronic component module, and / or a lighting panel.

[0020] According to an embodiment, a device can include at least one print head having an array of micro-nozzles of a depositor to deposit material on a substrate. The device can include at least one optical sensor for the array of micro-nozzles of the depositor of each print head to output a signal. A reflective optical device can be disposed on the at least one print head to reflect the signal output by the at least one optical sensor and reflect the signal from a surface of the substrate to the optical sensor. A processor can be communicatively coupled to the at least one optical sensor to determine a distance between the at least one optical sensor and a target surface of the substrate based on a distance of offset between the depositor and the substrate and based on a distance between the at least one optical sensor and the reflective optical device. One or more actuators can be coupled to the at least one print head to move the at least one print head relative to an internal reference frame decoupled from an external chamber and adjust a position of the at least one print head relative to the substrate, wherein the processor can be communicatively coupled to the one or more actuators to move the at least one print head. At least one sensor of the device can be fixedly coupled to the internal reference frame with a mount, and the at least one print head can be configured to move independently of the at least one optical sensor on at least one linear or rotational axis of motion.

[0021] The reflective optical device can be a mirror, a prism, and / or a beamsplitter. The reflective optical device can be milled, ground, etched, deposited, or plated on a portion of the at least one print head.

[0022] The apparatus can include a cooling device thermally coupled to the mount to actively cool the mount of the at least one optical sensor. The mount can be an adjustable mount.

[0023] The processor can control the one or more actuators to move the at least one print head based on a first measured distance between the at least one sensor and the reflective optical device changing by a first predetermined amount, and / or a second measured distance between the reflective optical device and the substrate changing by a second predetermined amount.

[0024] The at least one actuator of the apparatus can include a first actuator and a second actuator. The at least one print head can have a first side and a second side, and the first actuator can be coupled to the first side and the second actuator can be coupled to the second side. The first actuator and the second actuator can control a position of the at least one print head such that a fly height gap between the at least one print head and the substrate can be controlled on the first side and the second side of the at least one print head having a micro- nozzle array of depositors. The first actuator and the second actuator can provide the at least one print head with a linear degree of freedom along a substrate normal and a rotational degree of freedom in a substrate plane.

[0025] The at least one optical sensor of the apparatus can include a first optical sensor and a second optical sensor, and the one or more actuators can include a first actuator and a second actuator. The first optical sensor can be disposed at a first end of the at least one print head, and the second optical sensor can be disposed at a second end of the at least one print head. The first optical sensor can determine a first displacement between the at least one print head and the substrate, and the second optical sensor can determine a second displacement between the at least one print head and the substrate. A first output of the first optical sensor can be used by the processor to control the first actuator, and a second output of the second optical sensor can be used by the processor to control the second actuator.

[0026] The at least one optical sensor can include a plurality of sensors for each actuator of the one or more actuators. The processor can control each actuator based on a plurality of signals received from the respective plurality of sensors.

[0027] The at least one print head can include a plurality of first print heads and a plurality of second print heads arranged to form a printbar. The plurality of first print heads can be offset from the plurality of second groups of print heads to form staggered rows on the printbar.

[0028] The at least one print head can extend through a temperature-controlled cold plate. The at least one optical sensor can be mounted on the temperature-controlled cold plate.

[0029] The apparatus can include at least one thermally coupled heater to heat the at least one print head. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 An organic light emitting device is shown.

[0031] Figure 2 An inverted organic light emitting device is shown without a separate electron transport layer.

[0032] Figure 3 A front view and an isometric view of an apparatus with a vertically mounted sensor aligned with the print plane is shown.

[0033] Figure 4 A front view and an isometric view of an apparatus with a vertically mounted sensor measuring the front or back surface of the substrate from the print head is shown.

[0034] Figure 5 An apparatus with a horizontally mounted sensor and light deflection element arrangement according to an embodiment of the disclosed subject matter is shown.

[0035] Figures 6A-6C A response of an apparatus according to an embodiment of the disclosed subject matter to changes in the measured height of a substrate surface is shown.

[0036] Figures 7A-7B A comparison of the reflection range of a horizontally mounted sensor with a 45 degree light deflection element ( Figure 7A ) to a 10 degree sensor mounted with a 40 degree light deflection element ( Figure 7B ) according to an embodiment of the disclosed subject matter is shown.

[0037] Figure 8 A change in the actual change in measured distance versus flying height under different sensor mounting angles and light deflection element pairings according to an embodiment of the disclosed subject matter is shown.

[0038] Figure 9 A print bar with multiple print heads including a measurement and control system according to an embodiment of the disclosed subject matter is shown. DETAILED DESCRIPTION

[0039] Generally, an OLED includes at least one organic layer disposed between and electrically connected to an anode and a cathode. When a current is applied, the anode injects holes and the cathode injects electrons into the organic layer(s). The injected holes and electrons each migrate toward the oppositely charged electrode. When an electron and hole localize on the same molecule, an "exciton," which is a localized electron-hole pair having an excited energy state, is formed. When the exciton relaxes, it releases energy that can be in the form of light (photoluminescence), heat (non-radiative relaxation), or electrical energy (radiative relaxation). In some cases, the exciton can localize on an excimer or an exciplex. Non- radiative relaxation is considered a loss path, and therefore, generally is undesirable.

[0040] Initial OLEDs used emissive molecules that emitted light from singlet states ("fluorescence"), e.g., as disclosed in U.S. Patent No. 4,769,292, which is hereby incorporated by reference in its entirety. Fluorescent emission generally is restricted to wavelengths shorter than about 630 nm because longer wavelengths fall outside the visible spectrum.

[0041] More recently, OLEDs having emissive materials that emit light from triplet states ("phosphorescence") have been demonstrated. Baldo et al., "Highly Efficient Phosphorescent Emission from Organic Electroluminescent Devices," Nature, vol. 395, 151-154, 1998 ("Baldo-I"); and Baldo et al., "Very high-efficiency green organic light-emitting devices based on electrophosphorescence," Appl. Phys. Lett., vol. 75, no. 3, pp. 4-6, 1999 ("Baldo-II"), which are incorporated by reference in their entireties. Phosphorescence is described in more detail in U.S. Patent No. 7,279,704 at columns 5-6, which is incorporated by reference.

[0042] Figure 1An organic light emitting device 100 is shown. The figures are not necessarily drawn to scale. The device 100 can 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 blocking layer 170. The cathode 160 is a composite cathode with a first conductive layer 162 and a second conductive layer 164. The device 100 can be fabricated by depositing the layers in order. The properties and functions of these various layers and example materials are more fully described in US 7,279,704, columns 6-10, which is incorporated by reference in its entirety.

[0043] More examples of each of these layers can be found. For example, a flexible and transparent substrate-anode combination is disclosed in U.S. Patent No. 5,844,363, which is incorporated by reference in its entirety. An example of a p-doped hole transport layer is m-MTDATA doped with F4-TCNQ at a 50:1 molar ratio, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated by reference in its entirety. Examples of light emitting and host materials are disclosed in U.S. Patent No. 6,303,238 to Thompson et al., which is incorporated by reference in its entirety. An example of an n-doped electron transport layer is BPhen doped with Li at a 1:1 molar ratio, as disclosed in U.S. Patent Application Publication No. 2003 / 0230980, which is incorporated by reference in its entirety. U.S. Patent Nos. 5,703,436 and 5,707,745, incorporated by reference in their entirety, disclose examples of cathodes including composite cathodes having a thin layer of metal, such as Mg:Ag, with an overlying transparent, conductive, sputter-deposited ITO layer. The theory and use of blocking layers are described in more detail in U.S. Patent No. 6,097,147 and U.S. Patent Application Publication No. 2003 / 0230980, which are incorporated by reference in their entirety. Examples of injection layers are provided in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated by reference in its entirety. Descriptions of protective layers can be found in U.S. Patent Application Publication No. 2004 / 0174116, which is incorporated by reference in its entirety.

[0044] Figure 2An inverted OLED 200 is shown. The device includes a substrate 210, a cathode 215, an emissive layer 220, a hole transport layer 225, and an anode 230. Device 200 can be fabricated by depositing the layers in order. Because the most common OLED configuration has a cathode disposed over an anode, and device 200 has a cathode 215 disposed under anode 230, device 200 can be referred to as an "inverted" OLED. Similar materials to those described with respect to device 100 can be used in the corresponding layers of device 200. Figure 2 One example of how some layers can be omitted from the structure of device 100 is provided.

[0045] Figure 1 and 2 The simple layered structure illustrated in FIGS. 1-2 is provided by way of non-limiting example, and it is understood that embodiments of the present application can be used in conjunction with a variety of other structures. The particular materials and structures described are exemplary in nature and other materials and structures can be used. Functional OLEDs can be obtained by combining the various layers described in different ways, or layers can be omitted entirely, based on design, performance, and cost factors. Other layers not specifically described can also be included. Materials other than those specifically described can be employed. As an example, the OLED can be described as having a single layer comprising a mixture of materials, such as a host and a dopant, or more generally a mixture of materials. In addition, the layers can have various sub-layers. The names given to the various layers herein are not intended to be strictly limiting. For example, in device 200, hole transport layer 225 transports holes and injects holes into emissive layer 220, and 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 a cathode and an anode. This organic layer can include a single layer, or can further include multiple layers of different organic materials as described, for example, with respect to FIGS. 1-2. Figure 1 and 2 The various layers can be deposited by a variety of techniques, including thermal evaporation, sputtering, chemical vapor deposition (CVD), metal-organic chemical vapor deposition (MOCVD), thermal oxidation, laser ablation, and plasma-enhanced chemical vapor deposition (PECVD). These techniques are well known to those skilled in the art.

[0046] Structures and materials other than those specifically described can also be used. For example, an OLED can comprise a polymeric OLED (PLED), such as disclosed in U.S. Patent No. 5,247,190 to Friend et al., which is incorporated by reference in its entirety. By way of another example, an OLED can be used that has a single organic layer. OLEDs can be stacked, such as described in U.S. Patent No. 5,707,745 to Forrest et al., which is incorporated by reference in its entirety. OLED structures can deviate from Figure 1 and 2The simple layered structure illustrated in the middle. For example, the substrate can include angled reflective surfaces to improve out-coupling, such as a table structure as described in U.S. Patent No. 6,091,195 to Forrest et al., and / or a dimple structure as described in U.S. Patent No. 5,834,893 to Bulovic et al., which are incorporated by reference in their entirety.

[0047] In some embodiments disclosed herein, the emissive layer or material, such as Figures 1-2 The emissive layer 135 and emissive layer 220 shown in the middle, respectively, can include quantum dots. Unless explicitly indicated to the contrary or indicated in light of the understanding of one of skill in the art in the context, an "emissive layer" or "emissive material" as disclosed herein can include organic emissive materials and / or emissive materials containing quantum dots or equivalent structures. Such emissive layers can include only quantum dot materials that convert light emitted by a separate emissive material or other emitter, or it can also include the separate emissive material or other emitter, or it can itself directly emit light by application of a current. Similarly, a color shifting layer, color filter, up-conversion or down-conversion layer or structure can include materials containing quantum dots, but such layers can not be considered "emissive layers" as disclosed herein. In general, an "emissive layer" or material is one that emits initial light that can be altered by another layer within the device that does not itself emit initial light, such as a color filter or other color shifting layer, and that can also re-emit light with different altered spectral content based on the initial light emitted by the emissive layer.

[0048] Unless otherwise described, any of the layers of the various embodiments can be deposited by any suitable method. For organic layers, preferred methods include thermal evaporation, ink-jet (as described in U.S. Pat. Nos. 6,013,982 and 6,087,196, which are incorporated by reference in their entireties), organic vapor phase deposition (OVPD) as described in U.S. Pat. No. 6,337,102 to Fifer et al., which is incorporated by reference in its entirety, and deposition by organic vapor jet printing (OVJP), as described in U.S. Pat. No. 7,431,968, which is incorporated by reference in its entirety. Other suitable deposition methods include spin coating and other solution based processes. Solution based processes are preferably conducted in a nitrogen or inert atmosphere. For other layers, preferred methods include thermal evaporation. Preferred patterning methods include deposition through a mask, cold welding (as described in U.S. Pat. Nos. 6,294,398 and 6,468,819, which are incorporated by reference in their entireties) and patterning associated with some of the deposition methods such as ink-jet and OVJD. Other methods can also be used. The materials to be deposited can be modified in order to impart desirable characteristics to the deposition process. For example, substituents can be used in small molecules to enhance their solution processability. Substituents such as alkyl and aryl groups, branched or unbranched, and preferably containing at least 3 carbons, can be used in small molecules to enhance their solution processability. Substituents with 20 or more carbons can be used, and from 3 to 20 carbons are a preferred range. Materials with asymmetric structures can have better solution processability than those with symmetric structures, because they can have lower recrystallization tendencies. Dendrimer substituents can be used to enhance the solution processability of small molecules.

[0049] Devices manufactured according to embodiments of the present invention may optionally further include a barrier layer. One use of the barrier layer is to protect the electrodes and organic layers from damage caused by exposure to harmful substances in an environment including moisture, vapor, and / or gases. The barrier layer may be deposited on, under, or beside a substrate or electrode, or on any other part of the device, including edges. The barrier layer may comprise a single layer or multiple layers. The barrier layer can be formed using various known chemical vapor deposition techniques and may comprise compositions having a single phase and compositions having multiple phases. Any suitable material or combination of materials may be used for the barrier layer. The barrier layer may contain inorganic or organic compounds, or both. Preferred barrier layers comprise a mixture of polymeric and non-polymeric materials, as described in U.S. Patent No. 7,968,146, PCT Patent Application Nos. PCT / US2007 / 023098 and PCT / US2009 / 042829, which are incorporated herein by reference in their entirety. For the process to be considered a "mixture," the aforementioned polymeric and non-polymeric materials constituting the barrier layer should be deposited and / or deposited simultaneously under the same reaction conditions. The weight ratio of polymeric to non-polymeric materials can range from 95:5 to 5:95. The polymeric and non-polymeric materials can be produced from the same precursor material. In one example, the mixture of polymeric and non-polymeric materials is essentially composed of polymeric silicon and inorganic silicon.

[0050] In some embodiments, at least one of the anode, the cathode, or a new layer disposed above 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 excitation state energy from the emitter material to non-radiative modes of the surface plasmon polaritons. The enhancement layer is disposed at a distance from the organic emissive layer that does not exceed a threshold distance, 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 where 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 enhancement layer on the opposite side of the organic emissive layer. In some embodiments, the outcoupling layer is disposed on the emissive layer opposite the enhancement layer, but still able to outcouple energy from the surface plasmon modes 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 modes of the device into other modes, such as but not limited to organic waveguide modes, substrate modes, or another waveguide mode. If the energy is scattered into non-free space modes 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, oxide, and can include stacks and / or mixtures of these materials.

[0051] The enhancement layer changes the effective properties of the medium in which the emitter material resides, resulting in any or all of the following: reduced emissivity, altered emission line shape, emission intensity variation with angle, altered stability of the emitter material, altered efficiency of the OLED, and reduced roll-off efficiency of the OLED device. Placing the enhancement layer on the cathode side, the anode side, or both, results in an OLED device that takes advantage of any of the effects described above. In addition to the specific functional layers mentioned herein and illustrated in the various OLED examples shown in the figures, the OLEDs according to the present disclosure can also include any other functional layers commonly found in OLEDs.

[0052] The enhancement layer can comprise 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 permittivity 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. In general, a metamaterial is a medium composed of different materials in which the effect on the medium as a whole is different from the sum of its material parts. In particular, we define an optically active metamaterial as a material that simultaneously has a negative permittivity and a negative permeability. On the other hand, a hyperbolic metamaterial is an anisotropic medium in which the permittivity or permeability has different signs for different spatial directions. Optically active metamaterials and hyperbolic metamaterials are strictly distinguished from many other photonic structures, such as Distributed Bragg Reflectors ("DBRs"), because the medium should exhibit homogeneity in the direction of propagation on the length scale of the optical wavelength. Using terminology that will be understood by those skilled in the art: the permittivity of a metamaterial in the direction of propagation can be described using an effective medium approximation. Plasmonic materials and metamaterials provide methods for controlling the propagation of light, which can enhance OLED performance in a variety of ways.

[0053] In some embodiments, the enhancement layer is provided as a planar layer. In other embodiments, the enhancement layer has periodically, quasi-periodically, or randomly arranged wavelength-sized features, or has periodically, quasi-periodically, or randomly arranged subwavelength-sized features. In some embodiments, the wavelength-sized features and the subwavelength-sized features have sharp edges.

[0054] In some embodiments, the outcoupling layer has wavelength-sized features arranged periodically, quasi-periodically, or randomly, or has sub-wavelength-sized features arranged periodically, quasi-periodically, or randomly. In some embodiments, the 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 above a material. In these embodiments, the outcoupling can be adjusted 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 additional layers 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 of at least one of the following: a metal, a dielectric material, a semiconductor material, a metal alloy, a mixture of dielectric materials, a stack or a layering of one or more materials, and / or a core of one type of material coated with a shell of another 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 additional layers disposed on them. In some embodiments, the outcoupling layer can be used to adjust the polarization of the emission. Changing the size and periodicity of the outcoupling layer can select the type of polarization that is preferentially outcoupled to air. In some embodiments, the outcoupling layer also serves as an electrode for the device.

[0055] It is believed that the internal quantum efficiency (IQE) of fluorescent OLEDs can exceed the 25% spin-statistics limit by delayed fluorescence. As used herein, there are two types of delayed fluorescence, P-type delayed fluorescence and E-type delayed fluorescence. P-type delayed fluorescence results from triplet-triplet annihilation (TTA).

[0056] On the other hand, E-type delayed fluorescence does not rely on the collision of two triplets, but rather on the thermal population of a triplet to a singlet excited state. Compounds are needed that are capable of producing E-type delayed fluorescence in order to have a minimal singlet-triplet gap. Thermal energy can activate the transition back from a triplet to a singlet. This type of delayed fluorescence is also known as thermally activated delayed fluorescence (TADF). A notable feature of TADF is that the delayed component increases with temperature due to the increase in thermal energy. If the rate of reverse intersystem crossing is fast enough to minimize non-radiative decay from triplets, then the fraction of singlet excited states that are refilled can reach 75%. The total singlet fraction can be 100%, far exceeding the spin-statistics limit for electrically generated excitons.

[0057] E-type delayed fluorescence characteristics can be found in exciplex systems or in single compounds. Without being bound by theory, it is believed that E-type delayed fluorescence requires that the light emitting material have a small singlet-triplet energy gap (ΔES-T). Organic non-metal containing donor-acceptor light emitting materials can be able to achieve this. Emission from these materials is often characterized as donor-acceptor charge transfer (CT) type emission. The spatial separation of the HOMO and LUMO in these donor-acceptor type compounds often results in a small ΔES-T. These states can include CT states. Typically, donor-acceptor light emitting materials are constructed by linking an electron donor moiety (such as an amino or carbazole derivative) with an electron acceptor moiety (such as a N-containing six-membered aromatic ring).

[0058] Devices fabricated in accordance with embodiments of the disclosure can be incorporated into a wide variety of electronic apparatuses, such as electronic apparatuses that can be utilized in a variety of electronic products or intermediate components. Examples of such electronic products or intermediate components include display screens, lighting devices (such as discrete light source devices or lighting panels), and the like, which can be utilized by an end user product manufacturer. The electronic apparatuses can optionally include driving electronics and / or power supplies. Devices fabricated in accordance with embodiments of the disclosure can be incorporated into a wide variety of consumer products that have one or more electronic apparatuses (or units) incorporated therein. A consumer product is disclosed that includes an OLED that includes a compound of the disclosure in an organic layer in the OLED. The consumer product should include any kind of product that includes one or more of one or more light sources and / or some type of visual display. Some examples of such consumer products include flat panel displays, curved panel displays, computer monitors, medical monitors, televisions, billboards, interior or exterior lighting and / or signaling lights, heads-up displays, fully or partially transparent displays, flexible displays, rollable displays, foldable displays, stretchable displays, laser printers, telephones, cellular telephones, tablet computers, phablets, personal digital assistants (PDAs), wearable devices, laptop computers, digital cameras, video cameras, viewfinders, micro-displays with a diagonal less than 2 inches, 3-D displays, virtual reality or augmented reality displays, vehicles, video walls containing multiple displays tiled together, theater or stadium screens, and signs. Various control mechanisms can be used to control devices fabricated in accordance with the disclosure, including passive matrix and active matrix. It is intended that many of the devices 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 this temperature range (e.g., -40 °C to 80 °C).

[0059] The materials and structures described herein can be applied in devices other than OLEDs. For example, other optoelectronic devices such as organic solar cells and organic photodetectors can employ the materials and structures. More generally, organic devices such as organic transistors can employ the materials and structures.

[0060] In some embodiments, the OLED has one or more features selected from the group consisting of: flexible, rollable, foldable, stretchable, and bendable. In some embodiments, the OLED is transparent or semi-transparent. In some embodiments, the OLED further comprises a layer comprising carbon nanotubes.

[0061] In some embodiments, the OLED further comprises a layer comprising a delayed fluorescence emitter. In some embodiments, the OLED comprises an RGB pixel arrangement or a white plus color filter pixel arrangement. In some embodiments, the OLED is a mobile device, a handheld device, or a wearable device. In some embodiments, the OLED is a display panel 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 an illumination panel.

[0062] In some embodiments of the emissive region, the emissive region further comprises a host.

[0063] 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.

[0064] The OLEDs disclosed herein can be incorporated into one or more of consumer products, electronic component modules, and illumination panels. The organic layer can be an emissive layer, and the compound can be an emissive dopant in some embodiments, while the compound can be a non-emissive dopant in other embodiments.

[0065] 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) ambipolar, b) electron transporting, c) hole transporting, or d) a wide band gap material that plays little role in charge transport. In some embodiments, the host can include a metal complex. The host can be an inorganic compound.

[0066] Combinations with other materials

[0067] Materials described herein as useful for particular layers in an organic light emitting device can be used in combination with a wide variety of other materials present in devices. For example, the emissive dopants disclosed herein can be used in conjunction with a wide variety of hosts, transport layers, blocking layers, injection layers, electrodes and other layers that can be present. The materials described or referenced below are non-limiting examples from among the many that exist in the art and that can be used in combination with the compounds disclosed herein. One of skill in the art can readily identify other materials that can be useful in combination with the compounds disclosed herein.

[0068] 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.

[0069] Conducting dopants:

[0070] Charge transport layers can be doped with conducting dopants to substantially alter their charge carrier density, which in turn will alter their conductivity. The conductivity is increased by the creation of charge carriers in the matrix material, and depending on the type of dopant, a change in the Fermi level of a semiconductor can also be achieved. Hole transport layers can be doped with a p-type conducting dopant, and n-type conducting dopants are used in electron transport layers.

[0071] HIL / HTL:

[0072] The hole injection / transport materials used in the present application are not particularly limited, and any compound can be used as long as the compound is generally used as a hole injection / transport material.

[0073] EBL:

[0074] An electron blocking layer (EBL) can be used to reduce the number of electrons and / or excitons that leave an emissive layer. The presence of such a blocking layer in a device can result in a device with greater efficiency and / or longer lifetime as compared to a similar device without the blocking layer. Further, the blocking layer can be used to confine the emission to a desired area of the OLED. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and / or a higher triplet energy than the emitter closest to the EBL interface. In some embodiments, the EBL material has a higher LUMO (closer to the vacuum level) and / or a higher triplet energy than one or more of the hosts closest to the EBL interface. In one aspect, the compounds used in the EBL contain the same molecule or the same functional group as used in one of the hosts described below.

[0075] Hosts:

[0076] The light-emitting layer of the present organic EL device preferably contains at least a metal complex as a light-emitting material, and can contain a host material using a metal complex as a dopant material. Examples of the host material are not particularly limited, and any metal complex or organic compound can be used as long as the triplet energy of the host is greater than that of the dopant. Any host material can be used with any dopant as long as the triplet criterion is satisfied.

[0077] HBL:

[0078] A hole-blocking layer (HBL) can be used to reduce the number of holes and / or excitons leaving the emission layer. The presence of such a blocking layer in a device can result in substantially higher efficiency and / or longer lifetime compared to a similar device lacking the blocking layer. Furthermore, the blocking layer can be used to confine emission to a desired region of the OLED. In some embodiments, the HBL material has a lower HOMO (further from the vacuum level) and / or a higher triplet energy than the emitter closest to the HBL interface. In some embodiments, the HBL material has a lower HOMO (further from the vacuum level) and / or a higher triplet energy than one or more of the hosts closest to the HBL interface.

[0079] ETL:

[0080] An electron transport layer (ETL) can include a material capable of transporting electrons. The electron transport layer can be intrinsic (undoped) or doped. Doping can be used to enhance the conductivity. Examples of ETL materials are not particularly limited and can be any metal complex or organic compound, so long as it is typically used to transport electrons.

[0081] Charge generation layer (CGL)

[0082] In a tandem or stacked OLED, the CGL plays an important role in performance, which is composed of n-doped and p-doped layers for injecting electrons and holes, respectively. Electrons and holes are supplied by the CGL and electrodes. The consumed electrons and holes in the CGL are refilled by electrons and holes injected from the cathode and anode, respectively; then, the ambipolar current gradually reaches a steady state. Typical CGL materials include n- and p-conductivity dopants used in the transport layers.

[0083] Vapor jet deposition methods of manufacturing OLEDs can include a material dispensing system that can use an array of micro-nozzles arranged on a print bar. The gap between the nozzles and the substrate can be adjusted to achieve a desired thickness, width, and / or uniformity of the thin film of deposited material that results as the substrate and nozzles move relative to each other in a print pass. A displacement sensor can provide feedback to a controller and / or processor that can adjust the height of the print bar to maintain a desired gap between the nozzles and the substrate. The amount of offset between the sensor mounting location and the nozzles can be a predetermined distance. The difference between this predetermined distance and the measured distance between the nozzles and the substrate can be the gap. Because the substrate surface can not be flat in scale relative to the desired print gap, the gap can be measured close to the print zone.

[0084] Organic vapor jet printing (OVJP) is a thermal printing process, and the surface of the substrate can move as it is subjected to thermal loading from the hot vapor jet and in proximity to the hot print bar, which can have a predetermined temperature range. As the sensor can measure the gap close to the print zone, embodiments of the disclosed subject matter can maintain the gap between the array of micro-nozzles and the substrate at a precise tolerance (e.g., a predetermined tolerance range). As the operating temperature range of the sensor can be less than the operating temperature range of the print bar, embodiments of the disclosed subject matter can thermally manage the sensor. Embodiments of the disclosed subject matter can measure closer to the print zone and can provide thermal management for the sensor.

[0085] Embodiments of the disclosed subject matter can monitor the distance between the substrate and the micro-nozzle array-based depositor in the print head of the OVJP system. In some embodiments, different types of sensors can be used to determine the distance between the nozzles and the surface, such as optical sensors and capacitive sensors. In one embodiment, an array of optical displacement sensors (e.g., multiple sensors) can be used with each micro-nozzle array. Light signals can be reflected orthogonally from a target surface on the substrate and can return to the sensor. A processor can calculate the distance from the sensor to the substrate surface. The processor can use this value, along with a predetermined offset between the mounting height of the nozzles and the sensor, to determine the gap of the nozzles to the substrate. This gap can be referred to as the flight height.

[0086] Figure 3A front view and an isometric view of an apparatus with vertically mounted sensors aligned with the printing plane and a mounting arrangement according to an embodiment of the disclosed subject matter is shown. The print head 101 can include a micro-nozzle array of depositors 102 positioned over a substrate 103. The position of the print head 101 can be controlled by a plurality of actuators 104 (e.g., a plurality of actuators) to adjust the height of each side of the print head 101. Optical sensors 105 can be rigidly attached to the first and second sides of the print head 101 by a standoff 106. The distance 107 between the substrate 103 and the depositors 102 can be calculated from the difference between the measured distance from the sensors 105 to the substrate 108 and the offset distance 109 between each sensor 105 and the depositors 102. As shown in Figure 3 , the sensors 105 can be mounted along the same plane as the depositor array 102, or as shown in Figure 4 , the sensors 105 can be in front of and / or behind the depositor array 102.

[0087] Figures 3-4 A vertical orientation view of the print head 101 is shown, where the substrate 103 is translated perpendicular to the page in Figure 3 and along the horizontal direction in Figure 4 . Figures 3-4 The sensors 105 shown in Figures 3-4 may have a 2 mm diameter body, which can be the smallest diameter that can be used in the embodiment shown. The operating temperature of the print head 101 can be hundreds of degrees Celsius higher than the maximum operating temperature of the sensors 105. The standoff 106 (i.e., rigid fastener) that connects the sensors 105 to the print head 101 can prevent the sensors 105 from overheating. In practice, the standoff 106 can keep the sensors 105 more than 5 mm away from the print zone to thermally isolate the sensors 105. The error in the measurement can be introduced at 5 mm away from the print zone.

[0088] Figure 5 An apparatus with horizontally mounted sensors and mirror arrangement according to an embodiment of the disclosed subject matter is shown. In this embodiment, the apparatus can include a reflective optical device 301, such as a mirror, prism, and / or beamsplitter, and a horizontally mounted sensor 302. When using a reflective optical device 301, the body of the sensor 302 can not be connected to the print head 101 by a standoff (e.g., the standoff 106 shown in Figures 3-4 . In fact, the sensor 302 can be fixed in place relative to the internal reference frame 303 as the print head 101 moves vertically with the motion of the actuators that connect the print head 101 to the fixed frame 303. Fixing the position of the optical sensor 302 probe can provide cooling and / or thermal management for the sensor 302, improving the accuracy and repeatability of the displacement measurement while reducing the likelihood of damaging the sensor 302. In Figure 5The measurement by the sensor 302 can be the cumulative distance of both the distance 304 between the sensor 302 and the specular optical device 301 and the distance 305 between the specular optical device 301 and the substrate 103. The offset distance between the nozzle height and the distance measured by the sensor 304 can be used by the processor 306 for the calculation of the flying height. The processor 306 can be communicatively coupled to the actuator 104 and the sensor 302. The processor can control the actuator 104 based on the output signal from the sensor 302.

[0089] Figures 6A-6C The response of the display device to changes in the substrate surface position is shown in arbitrary units. Figure 6A The initial configuration of the display device is shown, where the sensor measures 27 units, while the actual flying height 401 is 4 units. The range 402 from the sensor to the mirror is 11 units, while the range 403 from the mirror to the substrate is 16 units. The sum of the ranges can be the distance output by the sensor. The offset between the sensor and the nozzle can be the difference between these distances (i.e., 27 - 4 = 23 units). This offset can be used by the processor to report the correct flying height.

[0090] When the device observes a change in the measurement of -2 units, as shown in Figure 6B the processor and / or the sensor can control the actuator 404 to adjust the position of the print head upward by 2 units. Figure 6C The print head after the position adjustment is shown. The measurement can be at the original set point of 27 units, while the distance between the depositor and the substrate can be at the original value of 4 units. The position of the sensor can be fixed, so the point at which the sensor beam intersects the reflective optical device 405 can change as the print head moves. The measured distance can change as the length of the path between the sensor and the reflective optical device, and the reflective optical device and the substrate, changes. The length of the path between the substrate and the reflective optical device can not change in Figures 6B-6C the length of the path between the sensor and the reflective optical device can lengthen by 2 units as the print head rises. As long as the total path length remains constant, the distance between the depositor array and the substrate can remain constant. If the print head encounters a descent instead of an ascent, the opposite can occur. The length of the path between the reflective optical device and the substrate can initially increase, and the print head can move downward accordingly. This downward motion can not change the optical path length between the print head and the substrate, but can shorten the path length between the reflective optical device and the sensor until the target value is restored. The predetermined acquisition rate of the sensor can be such that the response time of these changes can be measured in milliseconds.

[0091] Figures 7A-7B A horizontally mounted sensor with a 45-degree reflective optical device is shown, in accordance with an embodiment of the disclosed subject matter.Figure 7A Comparison of the range of reflection of a 10 degree sensor (as shown in FIG. 5) with a 40 degree reflective optics mount. Figure 7B

[0092] When the sensor is mounted horizontally, the choice of mounting position can be difficult, as shown in FIG. 6. In order to have the measurement point as close as possible to the print area, the reflective optics 501 can be positioned close to the depositor array, and thus also close to the substrate 502. The centerline 503 of the sensor can be mounted horizontally at a height 504 greater than its radius to avoid contacting the substrate 502, and the reflective optics 501 can be placed closer to the substrate than this. Figure 7A It is shown that by using a mounting angle 505 of 10 degrees, with a 40 degree reflective optics 501, the measurement point can be closer to the print area. This configuration can keep the body of the sensor away from the hot print head assembly and the substrate 502. Figure 7B

[0093] Figure 7B It is shown that when the sensor is at any angle between horizontal and vertical, the processor can adjust the measured signal of the sensor according to a calibrated "zeroed" position. The units are normalized in FIG. 7 to show that with a change in flight height of 1 arbitrary unit (AU), the range length 507 can increase by 1 arbitrary unit before reaching the surface of the reflective optics, and there can be a smaller vertical travel 508 of 0.174 arbitrary units. Thus, the sensor can have a change in height of 1 - 0.174 = 0.826 arbitrary units. Figure 7B

[0094] Figure 8 It is shown that the change in actual change in distance measured relative to flight height under different sensor mounting angles and reflective optics pairings according to embodiments of the disclosed subject matter. The vertical axis 601 shows the change in measured optical path length, while the horizontal axis 602 shows the actual change in flight height. Each line shows the case of a sensor mounted in the plane of the substrate with a 45 degree reflective optics (e.g., line 603); a sensor mounted 10 degrees above the surface of the substrate with a 40 degree reflective optics (e.g., line 604); a sensor mounted 20 degrees above the surface of the substrate with a 35 degree reflective optics (e.g., line 605); and a sensor mounted 30 degrees above the surface of the substrate with a 30 degree reflective optics (e.g., line 606). Adjustment of the tilted mounted sensor can reduce the change in measured displacement change relative to the actual displacement change. While the processor of the device can account for the change in adjustment, this can still reduce the accuracy of the displacement measurement of the sensor. In embodiments of the disclosed subject matter, the sensor can be mounted as close to horizontal or vertical as possible to minimize these effects.

[0095] Figure 9 ​​​A printbar including a plurality of print heads according to an embodiment of the disclosed subject matter is shown. Figure 9 The printbar assembly of FIG. 1 is shown looking down on a substrate. The plurality of print heads 701 can be arranged in rows (e.g., two rows, as shown in Figure 9 FIG. 1) to form staggered rows that eliminate the overlay gap on the substrate moving in a direction 702 perpendicular to a row of print heads 701 under the print heads 701. Each print head 701 can have a reflective optical device 703 on each end of its outer surface. An optical sensor 704 can be aligned with each reflective optical device 703 to track the displacement between the depositors at the bottom of the print heads 701 and the substrate at the location at which they are located. This information can be provided to a processor that can use actuators to adjust the printbar to maintain a constant fly height between each print head 701 in the printbar and the substrate.

[0096] Embodiments of the disclosed subject matter improve the reliability of the measurement by moving the measurement point to a location closer to the substrate, which is an area previously inaccessible. The sensor can be mounted further away from the thermal assembly including the print heads, which significantly reduces the thermal load to the sensor and its mount. Embodiments of the disclosed subject matter improve the life of the sensor and maintain stable, reliable measurements. A device having the features of embodiments of the disclosed subject matter can be scaled because the sensor is not mounted along the same nozzle plane, as shown in Figure 3 FIG. 1. In fact, it can be mounted above the front or back substrate surface.

[0097] Embodiments of the disclosed subject matter described above in connection with Figures 5-9 may include a device having at least one print head (e.g., print head 101 shown in Figure 5 FIG. 1) including an array of micro-nozzles of a depositor (e.g., depositor 102 shown in Figure 5 FIG. 1) to deposit material on a substrate (e.g., substrate 103 shown in Figure 5 FIG. 1; Figures 7A-7B FIG. 1; and a substrate 502 shown in Figure 5 FIG. 1) to output a signal. Figure 9 FIG. 1) to output a signal.

[0098] a reflective optical device (e.g., reflective optical device 301 shown in Figure 5 FIG. 1; Figures 7A-7B FIG. 1; and a reflective optical device 501 shown in Figure 9A reflective optical device 703) shown in FIG. 6 can be disposed on at least one print head to reflect a signal output by at least one optical sensor and reflect the signal from a surface of a substrate to a sensor. The reflective optical device can be a mirror, a prism, or a beamsplitter. The reflective optical device can be milled, ground, etched, deposited, or plated on a portion of at least one print head.

[0099] A processor (e.g., Figure 5 A processor 306) shown in FIG. 6 can be communicatively coupled to at least one optical sensor to determine a distance between at least one optical sensor and a target surface of a substrate based on an offset distance between a depositor and the substrate and based on a distance between at least one optical sensor and a reflective optical device. The processor can be communicatively coupled to an actuator to control movement of the actuator based on a signal received from the optical sensor.

[0100] One or more actuators (e.g., Figure 5 An actuator 104) shown in FIG. 6 can be coupled to at least one print head to move the at least one print head relative to an internal reference frame (e.g., Figure 5 An internal reference frame 303) shown in FIG. 6 can be configured such that it does not bend. An external chamber can enclose and / or surround the print head, sensor, reflective optical device, actuator, substrate, and internal reference frame. At least one sensor can be fixedly coupled to the internal reference frame with a mount. At least one print head can be configured to move independently of at least one optical sensor on at least one linear or rotational axis of motion. For example, the actuator can move the at least one print head independently of the optical sensor.

[0101] The processor can be configured to control one or more actuators to move at least one print head based on a first measured distance between at least one sensor and a reflective optical device changing by a first predetermined amount and / or a second measured distance between the reflective optical device and a substrate changing by a second predetermined amount.

[0102] The at least one actuator can comprise a first actuator and a second actuator. The at least one print head can have a first side and a second side, and the first actuator can be coupled to the first side and the second actuator can be coupled to the second side. The first actuator and the second actuator can control a position of the at least one print head such that a fly height gap between the at least one print head and a substrate is controlled on the first side and the second side of the at least one print head having an array of micro-nozzles of a depositor. The first actuator and the second actuator can provide the at least one print head with a linear degree of freedom along a substrate normal and a rotational degree of freedom in a substrate plane.

[0103] In some embodiments, a cooling device can be thermally coupled to a mount of the sensor. The cooling device can actively cool the mount of the at least one optical sensor. The sensor mount can be an adjustable mount, which can be configured to change an orientation of the sensor.

[0104] In some embodiments, the at least one optical sensor can include a first optical sensor and a second optical sensor, and the one or more actuators include a first actuator and a second actuator. The first optical sensor can be disposed at a first end of the at least one print head, and the second optical sensor is disposed at a second end of the at least one print head. The first optical sensor can determine a first displacement between the at least one print head and the substrate, and the second optical sensor determines a second displacement between the at least one print head and the substrate.

[0105] A first output of the first optical sensor can be used by the processor to control the first actuator, and a second output of the second optical sensor is used by the processor to control the second actuator.

[0106] In some embodiments, the at least one optical sensor can include a plurality of sensors for each actuator of the one or more actuators. The processor can control each actuator based on a plurality of signals received from the respective plurality of sensors.

[0107] The at least one print head can include a plurality of first print heads and a plurality of second print heads arranged to form a print bar. The plurality of first print heads can be offset from the plurality of second groups of print heads to form staggered rows on the print bar.

[0108] In some embodiments, the at least one print head can extend through a temperature controlled cold plate. The at least one optical sensor can be mounted on the temperature controlled cold plate.

[0109] It should be understood that the various embodiments described herein are by way of example only, and are not intended to limit the scope of the invention. For example, many of the materials and structures described herein can be substituted with other materials and structures without deviating from the spirit of the invention. The present invention as claimed is therefore intended to include, to the extent permitted by law, equivalents of the specific examples and preferred embodiments described herein. It should be understood that no theory of operation is intended to limit the present invention.

Claims

1. A manufacturing apparatus for manufacturing an organic emissive device, or for manufacturing an apparatus comprising an organic emissive device, wherein the manufacturing apparatus comprises: at least one print head comprising a micro-nozzle array of a depositor to deposit material on a substrate; at least one optical sensor for the micro-nozzle array of the depositor of each print head to output a signal; a reflective optical device disposed on the at least one print head to reflect the signal output by the at least one optical sensor and reflect the signal from a surface of the substrate to the optical sensor; a processor communicatively coupled to the at least one optical sensor to determine a distance between the at least one optical sensor and a target surface of the substrate based on a distance of offset between the depositor and the substrate and based on a distance between the at least one optical sensor and the reflective optical device; and one or more actuators coupled to the at least one print head to move the at least one print head relative to an internal reference frame decoupled from an external chamber and adjust a position of the at least one print head relative to the substrate, wherein the processor can be communicatively coupled to the one or more actuators to move the at least one print head, wherein the at least one sensor is fixedly coupled to the internal reference frame, and wherein the at least one print head can be configured to move on at least one linear or rotational axis of motion independently of the at least one optical sensor.

2. The manufacturing apparatus of claim 1, wherein the reflective optical device is at least one selected from the group consisting of a mirror, a prism, and a beamsplitter.

3. The manufacturing apparatus of claim 1, wherein the reflective optical device is milled, ground, etched, deposited, or plated on a portion of the at least one print head.

4. The manufacturing apparatus of claim 1, further comprising: a cooling device thermally coupled to the mount to actively cool the mount of the at least one optical sensor.

5. The manufacturing apparatus of claim 1, wherein the mount comprises an adjustable mount.

6. The manufacturing apparatus of claim 1, wherein the processor controls the one or more actuators to move the at least one print head based on at least one selected from the group consisting of: a first measured distance between the at least one sensor and the reflective optical device changes by a first predetermined amount; and a second measured distance between the reflective optical device and the substrate changes by a second predetermined amount.

7. The manufacturing apparatus of claim 1, wherein the at least one actuator comprises a first actuator and a second actuator, wherein the at least one print head has a first side and a second side, and the first actuator is coupled to the first side and the second actuator is coupled to the second side, and wherein the first actuator is configured to move the at least one print head in a first direction and the second actuator is configured to move the at least one print head in a second direction. wherein the first and second actuators control a position of the at least one print head such that a fly height gap between the at least one print head and the substrate is controlled on a first and second side of the at least one print head having a micro-nozzle array of the depositor.

8. The manufacturing device of claim 1, wherein the at least one optical sensor comprises a first optical sensor and a second optical sensor, and the one or more actuators comprises a first actuator and a second actuator, wherein the first optical sensor is disposed at a first end of the at least one print head and the second optical sensor is disposed at a second end of the at least one print head, wherein the first optical sensor determines a first displacement between the at least one print head and the substrate and the second optical sensor determines a second displacement between the at least one print head and the substrate, and wherein a first output of the first optical sensor is used by the processor to control the first actuator and a second output of the second optical sensor is used by the processor to control the second actuator.

9. The manufacturing device of claim 1, wherein at least one optical sensor comprises a plurality of sensors for each actuator of the one or more actuators, and wherein the processor controls each actuator based on a plurality of signals received from the plurality of sensors.

10. The manufacturing device of claim 1, wherein the at least one print head comprises a plurality of first print heads and a plurality of second print heads arranged to form a print bar.

11. The manufacturing device of claim 10, wherein the plurality of first print heads and the plurality of second groups of print heads are offset to form staggered rows on the print bar.

12. The manufacturing device of claim 1, wherein the at least one print head extends through a temperature controlled cold plate.

13. The manufacturing device of claim 12, wherein the at least one optical sensor is mounted on the temperature controlled cold plate.

14. The manufacturing device of claim 1, further comprising: at least one thermally coupled heater to heat the at least one print head.

15. A consumer electronic device manufactured by the manufacturing device of any of claims 1-14.

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