Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
  • H10K71/10—Deposition of organic active material
  • H10K71/12—Deposition of organic active material using liquid deposition, e.g. spin coating
  • H10K71/13—Deposition of organic active material using liquid deposition, e.g. spin coating using printing techniques, e.g. ink-jet printing or screen printing
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
  • H10K71/10—Deposition of organic active material
  • H10K71/12—Deposition of organic active material using liquid deposition, e.g. spin coating
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
  • H10K71/10—Deposition of organic active material
  • H10K71/12—Deposition of organic active material using liquid deposition, e.g. spin coating
  • H10K71/13—Deposition of organic active material using liquid deposition, e.g. spin coating using printing techniques, e.g. ink-jet printing or screen printing
  • H10K71/135—Deposition of organic active material using liquid deposition, e.g. spin coating using printing techniques, e.g. ink-jet printing or screen printing using ink-jet printing
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
  • H10K71/10—Deposition of organic active material
  • H10K71/16—Deposition of organic active material using physical vapour deposition [PVD], e.g. vacuum deposition or sputtering
  • H10K71/166—Deposition of organic active material using physical vapour deposition [PVD], e.g. vacuum deposition or sputtering using selective deposition, e.g. using a mask
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
  • H10K71/20—Changing the shape of the active layer in the devices, e.g. patterning
  • H10K71/231—Changing the shape of the active layer in the devices, e.g. patterning by etching of existing layers
  • H10K71/233—Changing the shape of the active layer in the devices, e.g. patterning by etching of existing layers by photolithographic etching
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
  • H10K71/40—Thermal treatment, e.g. annealing in the presence of a solvent vapour
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K50/00—Organic light-emitting devices
  • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
  • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass

Definitions

• This disclosure relates in general to a process for making an electronic device. It further relates to the device made by the process. Description of the Related Art Electronic devices utilizing organic active materials are present in many different kinds of electronic equipment. In such devices, an organic active layer is sandwiched between two electrodes.
• OLED organic light emitting diode
• OLEDs are promising for display applications due to their high power-conversion efficiency and low processing costs.
• Such displays are especially promising for battery-powered, portable electronic devices, including cell-phones, personal digital assistants, handheld personal computers, and DVD players.
• These applications call for displays with high information content, full color, and fast video rate response time in addition to low power consumption.
• Containment structures are geometric obstacles to spreading: pixel wells, banks, etc. In order to be effective these structures must be large, comparable to the wet thickness of the deposited materials. When the emissive ink is printed into these structures it wets onto the structure surface, so thickness uniformity is reduced near the structure. Therefore the structure must be moved outside the emissive "pixel" region so the non-uniformities are not visible in operation. Due to limited space on the display (especially high-resolution displays) this reduces the available emissive area of the pixel.
• a process for forming a contained second layer over a first layer comprising: forming the first layer having a first surface energy; treating the first layer with a reactive surface-active composition to form a treated first layer having a second surface energy which is lower than the first surface energy; exposing the treated first layer with radiation; and forming the second layer.
• an organic electronic device comprising a first organic active layer and a second organic active layer positioned over an electrode, said process comprising: forming the first organic active layer having a first surface energy over the electrode; treating the first organic active layer with a reactive surface- active composition to form a treated first organic active layer having a second surface energy which is lower than the first surface energy; exposing the treated first organic active layer with radiation; and forming the second organic active layer.
• an organic electronic device comprising a first organic active layer and a second organic active layer positioned over an electrode, and further comprising a reactive surface-active composition between the first organic active layer and the second organic active layer.
• FIG. 1 includes a diagram illustrating contact angle.
• FIG. 2 includes an illustration of an organic electronic device.
• FIG. 3 includes an illustration of a substrate with anode lines.
• FIG. 4 includes an illustration of the substrate of FIG. 3 coated with a buffer material.
• FIG. 5 includes an illustration of the substrate of FIG. 4 further coated with a reactive surface-active composition.
• FIG 6 includes an illustration of the substrate of FIG. 5 after exposure and development.
• a process for forming a contained second layer over a first layer comprising: forming the first layer having a first surface energy; treating the first layer with a reactive surface-active composition to form a treated first layer having a second surface energy which is lower than the first surface energy; exposing the treated first layer with radiation; and applying the second layer over the treated and exposed first layer.
• active when referring to a layer or material, is intended to mean a layer or material that exhibits electronic or electro-radiative properties.
• an active material electronically facilitates the operation of the device.
• active materials include, but are not limited to, materials which conduct, inject, transport, or block a charge, where the charge can be either an electron or a hole, and materials which emit radiation or exhibit a change in concentration of electron-hole pairs when receiving radiation.
• inactive materials include, but are not limited to, planarization materials, insulating materials, and environmental barrier materials.
• the term "contained" when referring to a layer, is intended to mean that the layer does not spread significantly beyond the area where it is deposited.
• the layer can be contained by surface energy affects or a combination of surface energy affects and physical barrier structures.
• an electrode is intended to mean a member or structure configured to transport carriers within an electronic component.
• an electrode may be an anode, a cathode, a capacitor electrode, a gate electrode, etc.
• An electrode may include a part of a transistor, a capacitor, a resistor, an inductor, a diode, an electronic component, a power supply, or any combination thereof.
• organic electronic device is intended to mean a device including one or more organic semiconductor layers or materials.
• An organic electronic device includes, but is not limited to: (1) a device that converts electrical energy into radiation (e.g., a light-emitting diode, light emitting diode display, diode laser, or lighting panel), (2) a device that detects a signal using an electronic process (e.g., a photodetector, a photoconductive cell, a photoresistor, a photoswitch, a phototransistor, a phototube, an infrared (“IR”) detector, or a biosensors), (3) a device that converts radiation into electrical energy (e.g., a photovoltaic device or solar cell), (4) a device that includes one or more electronic components that include one or more organic semiconductor layers (e.g., a transistor or diode), or any combination of devices in items (1) through (4).
• a device that converts electrical energy into radiation e.g., a light-emit
• fluorinated when referring to an organic compound, is intended to mean that one or more of the hydrogen atoms in the compound have been replaced by fluorine.
• fluorine The term encompasses partially and fully fluorinated materials.
• radiation means adding energy in any form, including heat in any form, the entire electromagnetic spectrum, or subatomic particles, regardless of whether such radiation is in the form of rays, waves, or particles.
• reactive surface-active composition is intended to mean a composition that comprises at least one material which is radiation sensitive, and when the composition is applied to a layer, the surface energy of that layer is reduced. Exposure of the reactive surface-active composition to radiation results in the change in at least one physical property of the composition.
• RSA abbreviated
• radiation sensitive when referring to a material, is intended to mean that exposure to radiation results in at least one chemical, physical, or electrical property of the material.
• surface energy is the energy required to create a unit area of a surface from a material.
• a characteristic of surface energy is that liquid materials with a given surface energy will not wet surfaces with a lower surface energy.
• layer is used interchangeably with the term “film” and refers to a coating covering a desired area. The term is not limited by size. The area can be as large as an entire device or as small as a specific functional area such as the actual visual display, or as small as a single sub-pixel. Layers and films can be formed by any conventional deposition technique, including vapor deposition, liquid deposition (continuous and discontinuous techniques), and thermal transfer.
• liquid composition is intended to mean a liquid medium in which a material is dissolved to form a solution, a liquid medium in which a material is dispersed to form a dispersion, or a liquid medium in which a material is suspended to form a suspension or an emulsion.
• Liquid medium is intended to mean a material that is liquid without the addition of a solvent or carrier fluid, i.e., a material at a temperature above its solidification temperature.
• liquid containment structure is intended to mean a structure within or on a workpiece, wherein such one or more structures, by itself or collectively, serve a principal function of constraining or guiding a liquid within an area or region as it flows over the workpiece.
• a liquid containment structure can include cathode separators or a well structure.
• liquid medium is intended to mean a liquid material, including a pure liquid, a combination of liquids, a solution, a dispersion, a suspension, and an emulsion. Liquid medium is used regardless whether one or more solvents are present.
• the term “over” does not necessarily mean that a layer, member, or structure is immediately next to or in contact with another layer, member, or structure. There may be additional, intervening layers, members or structures.
• the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion.
• a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
• “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).
• the reactive surface-active composition (“RSA") is a radiation- sensitive composition. When exposed to radiation, at least one physical property and/or chemical property of the RSA is changed such that the exposed and unexposed areas can be physically differentiated. Treatment with the RSA lowers the surface energy of the material being treated.
• the RSA is a radiation-hardenable composition. In this case, when exposed to radiation, the RSA can become more soluble or dispersable in a liquid medium, less tacky, less soft, less flowable, less liftable, or less absorbable. Other physical properties may also be affected.
• the RSA is a radiation-softenable composition. In this case, when exposed to radiation, the RSA can become less soluble or dispersable in a liquid medium, more tacky, more soft, more flowable, more liftable, or more absorbable. Other physical properties may also be affected.
• the radiation can be any type of radiation to which results in a physical change in the RSA.
• the radiation is selected from infrared radiation, visible radiation, ultraviolet radiation, and combinations thereof.
• Physical differentiation between areas of the RSA exposed to radiation and areas not exposed to radiation, hereinafter referred to as "development,” can be accomplished by any known technique. Such techniques have been used extensively in the photoresist art. Examples of development techniques include, but are not limited to, treatment with a liquid medium, treatment with an absorbant material, treatment with a tacky material, and the like.
• the RSA consists essentially of one or more radiation-sensitive materials. In one embodiment, the RSA consists essentially of a material which, when exposed to radiation, hardens, or becomes less soluble, swellable, or dispersible in a liquid medium, or becomes less tacky or absorbable. In one embodiment, the RSA consists essentially of a material having radiation polymerizable groups. Examples of such groups include, but are not limited to olefins, acrylates, methacrylates and vinyl ethers. In one embodiment, the RSA material has two or more polymerizable groups which can result in crosslinking.
• the RSA consists essentially of a material which, when exposed to radiation, softens, or becomes more soluble, swellable, or dispersible in a liquid medium, or becomes more tacky or absorbable.
• the RSA consists essentially of at least one polymer which undergoes backbone degradation when exposed to deep UV radiation, having a wavelength in the range of 200-300 nm. Examples of polymers undergoing such degradation include, but are not limited to, . polyacrylates, poiymethacrylates, polyketones, polysulfones, copolymers thereof, and mixtures thereof.
• the RSA consists essentially of at least one reactive material and at least one radiation-sensitive material.
• the radiation-sensitive material when exposed to radiation, generates an active species that initiates the reaction of the reactive material.
• Examples of radiation-sensitive materials include, but are not limited to, those that generate free radicals, acids, or combinations thereof.
• the reactive material is polymerizable or crosslinkable. The material polymerization or crosslinking reaction is initiated or catalyzed by the active species.
• the radiation-sensitive material is generally present in amounts from 0.001% to 10.0% based on the total weight of the RSA.
• the RSA consists essentially of a material which, when exposed to radiation, hardens, or becomes less soluble, swellable, or dispersible in a liquid medium, or becomes less tacky or absorbable.
• the reactive material is an ethylenically unsaturated compound and the radiation-sensitive material generates free radicals.
• Ethylenically unsaturated compounds include, but are not limited to, acrylates, methacrylates, vinyl compounds, and combinations thereof. Any of the known classes of radiation-sensitive materials that generate free radicals can be used.
• radiation-sensitive materials which generate free radicals include, but are not limited to, quinones, benzophenones, benzoin ethers, aryl ketones, peroxides, biim ⁇ dazoles, benzyl dimethyl ketal, hydroxyl alkyl phenyl acetophone, dialkoxy actophenone, trimethylbenzoyl phosphine oxide derivatives, aminoketones, benzoyl cyclohexanol, methyl thio phenyl morpholino ketones, morpholino phenyl amino ketones, alpha halogennoacetophenones, oxysulfonyl ketones, sulfonyl ketones, oxysulfonyl ketones, sulfonyl ketones, benzoyl oxime esters, thioxanthrones, camphorquinones, ketocoumarins, and Michler's ketone.
• the radiation sensitive material may be a mixture of compounds,
• the RSA is a compound having one or more crosslinkable groups.
• Crosslinkable groups can have moieties containing a double bond, a triple bond, a precursor capable of in situ formation of a double bond, or a heterocyclic addition polymerizable group.
• crosslinkable groups include benzocyclobutane, azide, oxiran, di(hydrocarbyl)amino, cyanate ester, hydroxyl, glycidyl ether, C1- 10 alkylacrylate, C1-10 alkylmethacrylate, alkenyl, alkenyloxy, alkynyl, maleimide, nadimide, tri(C1-4)alkylsiloxy, tri(C1-4)alkylsilyl, and halogenated derivatives thereof.
• the crosslinkable group is selected from the group consisting of vinylbenzyl, p- ethenylphenyl, perfluoroethenyl, perfluoroehtenyloxy, benzo-3,4- cyclobutan-1-yl, and p-(benzo-3,4-cyc!obutan-1-yl)phenyl.
• the reactive material can undergo polymerization initiated by acid, and the radiation-sensitive material generates acid. Examples of such reactive materials include, but are not limited to, epoxies. Examples of radiation-sensitive materials which generate acid, include, but are not limited to, sulfonium and iodonium salts, such as diphenyliodonium hexafluorophosphate.
• the RSA consists essentially of a material which, when exposed to radiation, softens, or becomes more soluble, swellable, or dispersible in a liquid medium, or becomes more tacky or absorbable.
• the reactive material is a phenolic resin and the radiation-sensitive material is a diazonaphthoquinone.
• the RSA comprises a fluorinated material. In one embodiment, the RSA comprises an unsaturated material having one or more fluoroalkyl groups. In one embodiment, the fluoroalkyl groups have from 2-20 carbon atoms. In one embodiment, the RSA is a fluorinated acrylate, a fluorinated ester, or a fluorinated olefin monomer. Examples of commercially available materials which can be used as RSA materials, include, but are not limited to, Zonyl® 8857A, a fluorinated unsaturated ester monomer available from E. I.
• the RSA is a fluorinated macromonomer.
• macromonomer refers to an oligomeric material having one or more reactive groups which are terminal or pendant from the chain.
• the macromonomer has a molecular weight greater than 1000; in some embodiments, greater than 2000; in some embodiments, greater than 5000.
• the backbone of the macromonomer includes ether segments and perfluoroether segments.
• the backbone of the macromonomer includes alkyl segments and perfluoroalkyl segments.
• the backbone of the macromonomer includes partially fluorinated alkyl or partially fluorinated ether segments.
• the macromonomer has one or two terminal polymerizable or crosslinkable groups.
• the RSA is an oligomeric or polymeric material having cleavable side chains, where the material with the side chains forms films with a different surface energy that the material without the side chains.
• the RSA has a non-fluorinated backbone and partially fluorinated or fully fluorinated side chains. The RSA with the side chains will form films with a lower surface energy than films made from the RSA without the side chains.
• the RSA can be can be applied to a first layer, exposed to radiation in a pattern to cleave the side chains, and developed to remove the side chains.
• the side chains are thermally fugitive and are cleaved by heating, as with an infrared laser.
• development may be coincidental with exposure in infrared radiation.
• development may be accomplished by the application of a vacuum or treatment with solvent.
• the side chains are cleavable by exposure to UV radiation.
• development may be coincidental with exposure to radiation, or accomplished by the application of a vacuum or treatment with solvent.
• the RSA comprises a material having a reactive group and second-type functional group.
• the second-type functional groups can be present to modify the physical processing properties or the photophysical properties of the RSA.
• groups which modify the processing properties include plasticizing groups, such as alkylene oxide groups.
• groups which modify the photophysical properties include charge transport groups, such as carbazole, triarylamino, or oxadiazole groups.
• the RSA reacts with the underlying area when exposed to radiation. The exact mechanism of this reaction will depend on the materials used. After exposure to radiation, the RSA is removed in the unexposed areas by a suitable development treatment. In some embodiments, the RSA is removed only in the unexposed areas.
• the RSA is partially removed in the exposed areas as well, leaving a thinner layer in those areas. In some embodiments, the RSA that remains in the exposed areas is less than 5 ⁇ A in thickness. In some embodiments, the RSA that remains in the exposed areas is essentially a monolayer in thickness. 3. Process
• a first layer is formed, the first layer is treated with a reactive surface-active composition ("RSA"), the treated first layer is exposed to radiation, and a second layer is formed over the treated and exposed first layer.
• the first layer is a substrate.
• the substrate can be inorganic or organic. Examples of substrates include, but are not limited to glasses, ceramics, and polymeric films, such as polyester and polyimide films.
• the first layer is an electrode.
• the electrode can be unpattemed, or patterned. In one embodiment, the electrode is patterned in parallel lines. The electrode can be on a substrate.
• the first layer is deposited on a substrate.
• the first layer can be patterned or unpattemed.
• the first layer is an organic active layer in an electronic device.
• the first layer can be formed by any deposition technique, including vapor deposition techniques, liquid deposition techniques, and thermal transfer techniques.
• the first layer is deposited by a liquid deposition technique, followed by drying.
• a first material is dissolved or dispersed in a liquid medium.
• the liquid deposition method may be continuous or discontinuous.
• Continuous liquid deposition techniques include but are not limited to, spin coating, roll coating, curtain coating, dip coating, slot-die coating, spray coating, and continuous nozzle coating.
• Discontinuous liquid deposition techniques include, but are not limited to, ink jet printing, gravure printing, flexographic printing and screen printing.
• the first layer is deposited by a continuous liquid deposition technique.
• the drying step can take place at room temperature or at elevated temperatures, so long as the first material and any underlying materials are not damaged.
• the first layer is treated with an RSA. The treatment can be coincidental with or subsequent to the formation of the first layer.
• the RSA treatment is coincidental with the formation of the first organic active layer.
• the RSA is added to the liquid composition used to form the first layer.
• the RSA migrates to the air interface, i.e., the top surface, of the first layer in order to reduce the surface energy of the system.
• the RSA treatment is subsequent to the formation of the first layer. In one embodiment, the RSA is applied as a separate layer overlying, and in direct contact with, the first layer.
• the RSA is applied without adding it to a solvent. In one embodiment, the RSA is applied by vapor deposition. In one embodiment, the RSA is a liquid at room temperature and is applied by liquid deposition over the first layer. The liquid RSA may be film- forming or it may be absorbed or adsorbed onto the surface of the first layer. In one embodiment, the liquid RSA is cooled to a temperature below its melting point in order to form a second layer over the first layer. In one embodiment, the RSA is not a liquid at room temperature and is heated to a temperature above its melting point, deposited on the first layer, and cooled to room temperature to form a second layer over the first layer. For the liquid deposition, any of the methods described above may be used.
• the RSA is deposited from a second liquid composition.
• the liquid deposition method can be continuous or discontinuous, as described above.
• the RSA liquid composition is deposited using a continuous liquid deposition method.
• the choice of liquid medium for depositing the RSA will depend on the exact nature of the RSA material itself.
• the RSA is a fluorinated material and the liquid medium is a fluorinated liquid. Examples of fluorinated liquids include, but are not limited to, perfluorooctane, trifluorotoluene, and hexafluoroxylene.
• the RSA treatment comprises a first step of forming a sacrificial layer over the first layer, and a second step of applying an RSA layer over the sacrificial layer.
• the sacrificial layer is one which is more easily removed than the RSA layer by whatever development treatment is selected. Thus, after exposure to radiation, as discussed below, the RSA layer and the sacrificial layer are removed in either the exposed or unexposed areas in the development step.
• the sacrificial layer is intended to facilitate complete removal of the RSA layer is the selected areas and to protect the underlying first layer from any adverse affects from the reactive species in the RSA layer. After the RSA treatment, the treated first layer is exposed to radiation.
• the type of radiation used will depend upon the sensitivity of the RSA as discussed above.
• the exposure can be a blanket, overall exposure, or the exposure can be patternwise.
• the term "patternwise" indicates that only selected portions of a material or layer are exposed. Patternwise exposure can be achieved using any known imaging technique. In one embodiment, the pattern is achieved by exposing through a mask. In one embodiment, the pattern is achieved by exposing only select portions with a laser. The time of exposure can range from seconds to minutes, depending upon the specific chemistry of the RSA used. When lasers are used, much shorter exposure times are used for each individual area, depending upon the power of the laser.
• the exposure step can be carried out in air or in an inert atmosphere, depending upon the sensitivity of the materials.
• the radiation is selected from the group consisting of ultra-violet radiation (10-390 nm), visible radiation (390-770 nm), infrared radiation (770-10 6 nm), and combinations thereof, including simultaneous and serial treatments.
• the radiation is thermal radiation.
• the exposure to radiation is carried out by heating. The temperature and duration for the heating step is such that at least one physical property of the RSA is changed, without damaging any underlying layers of the light-emitting areas.
• the heating temperature is less than 250 0 C. In one embodiment, the heating temperature is less than 150 0 C.
• the radiation is ultraviolet or visible radiation. In one embodiment, the radiation is applied patternwise, resulting in exposed regions of RSA and unexposed regions of RSA.
• the first layer is treated to remove either the exposed or unexposed regions of the RSA.
• Patternwise exposure to radiation and treatment to remove exposed or unexposed regions is well known in the art of photoresists.
• the exposure of the RSA to radiation results in a change in the solubility or dispersibility of the RSA in solvents.
• this can be followed by a wet development treatment.
• the treatment usually involves washing with a solvent which dissolves, disperses or lifts off one type of area.
• the patternwise exposure to radiation results in insolubilization of the exposed areas of the RSA, and treatment with solvent results in removal of the unexposed areas of the RSA.
• the exposure of the RSA to visible or UV radiation results in a reaction which decreases the volatility of the RSA in exposed areas.
• a thermal development treatment involves heating to a temperature above the volatilization or sublimation temperature of the unexposed material and below the temperature at which the material is thermally reactive.
• the material would be heated at a temperature above the sublimation temperature and below the thermal polymerization temperature.
• the exposure of the RSA to radiation results in a change in the temperature at which the material melts, softens or flows.
• a dry development treatment can include contacting an outermost surface of the element with an absorbent surface to absorb or wick away the softer portions. This dry development can be carried out at an elevated temperature, so long as it does not further affect the properties of the originally unexposed areas.
• the first layer After treatment with the RSA, and exposure to radiation, the first layer has a lower surface energy than prior to treatment. In the case where part of the RSA is removed after exposure to radiation, the areas of the first layer that are covered by the RSA will have a lower surface energy that the areas that are not covered by the RSA.
• contact angle is intended to mean the angle ⁇ shown in Figure 1.
• angle ⁇ is defined by the intersection of the plane of the surface and a line from the outer edge of the droplet to the surface.
• angle ⁇ is measured after the droplet has reached an equilibrium position on the surface after being applied, i.e. "static contact angle". A variety of manufacturers make equipment capable of measuring contact angles.
• the second layer is then applied over the RSA-treated first layer.
• the second layer can be applied by any deposition technique.
• the second layer is applied by a liquid deposition technique.
• a liquid composition comprises a second material dissolved or dispersed in a liquid medium, applied over the RSA-treated first layer, and dried to form the second layer.
• the liquid composition is chosen to have a surface energy that is greater than the surface energy of the RSA-treated first layer, but approximately the same as or less than the surface energy of the untreated first layer.
• the liquid composition will wet the untreated first layer, but will be repelled from the RSA-treated areas.
• the liquid may spread onto the RSA-treated area, but it will de-wet.
• the RSA is patterned and the second layer is applied using a continuous liquid deposition technique. In one embodiment, the second layer is applied using a discontinuous liquid deposition technique. In one embodiment, the RSA is unpattemed and the second layer is applied using a discontinuous liquid deposition technique.
• the first layer is applied over a liquid containment structure. It may be desired to use a structure that is inadequate for complete containment, but that still allows adjustment of thickness uniformity of the printed layer. In this case it may be desirable to control wetting onto the thickness-tuning structure, providing both containment and uniformity. It is then desirable to be able to modulate the contact angle of the emissive ink. Most surface treatments used for containment (e.g., CF4 plasma) do not provide this level of control.
• the first layer is applied over a so-called bank structure. Bank structures are typically formed from photoresists, organic materials (e.g., polyimides), or inorganic materials (oxides, nitrides, and the like).
• Bank structures may be used for containing the first layer in its liquid form, preventing color mixing; and/or for improving the thickness uniformity of the first layer as it is dried from its liquid form; and/or for protecting underlying features from contact by the liquid.
• Such underlying features can include conductive traces, gaps between conductive traces, thin film transistors, electrodes, and the like. It is often desirable to form regions on the bank structures possessing different surface energies to achieve two or more purposes (e.g., preventing color mixing and also improving thickness uniformity).
• One approach is to provide a bank structure with multiple layers, each layer having a different surface energy.
• a more cost effective way to achieve this modulation of surface energy is to control surface energy via modulation of the radiation used to cure a RSA.
• This modulation of curing radiation can be in the form of energy dosage (power * exposure time), or by exposing the RSA through a photomask pattern that simulates a different surface energy (e.g., expose through a half-tone density mask).
• the first and second layers are organic active layers.
• the first organic active layer is formed over a first electrode, the first organic active layer is treated with a reactive surface-active composition to reduce the surface energy of the layer, and the second organic active layer is formed over the treated first organic active layer.
• the first organic active layer is formed by liquid deposition of a liquid composition comprising the first organic active material and a liquid medium.
• the liquid composition is deposited over the first electrode, and then dried to form a layer.
• the first organic active layer is formed by a continuous liquid deposition method. Such methods may result in higher yields and lower equipment costs.
• the RSA treatment is subsequent to the formation of the first organic active layer.
• the RSA is is applied as a separate layer overlying, and in direct contact with, the first organic active layer.
• the RSA is deposited from a second liquid composition.
• the liquid deposition method can be continuous or discontinuous, as described above.
• the RSA liquid composition is deposited using a continuous liquid deposition method.
• the thickness of the RSA layer can depend upon the ultimate end use of the material. In some embodiments, the RSA layer is at least 100A in thickness. In some embodiments, the RSA layer is in the range of 100- 3000A; in some embodiments 1000-2000A.
• the treated first organic active layer is exposed to radiation.
• the type of radiation used will depend upon the sensitivity of the RSA as discussed above.
• the exposure can be a blanket, overall exposure, or the exposure can be patternwise.
• the exposure of the RSA to radiation results in a change in solubility or dispersibility of the RSA in a liquid medium.
• the exposure is carried out patternwise. This can be followed by treating the RSA with a liquid medium, to remove either the exposed or unexposed portions of the RSA.
• the RSA is radiation-hardenable and the unexposed portions are removed by the liquid medium.
• FIG. 2 is an exemplary electronic device, an organic light-emitting diode (OLED) display that includes at least two organic active layers positioned between two electrical contact layers.
• the electronic device 100 includes one or more layers 120 and 130 to facilitate the injection of holes from the anode layer 110 into the photoactive layer 140.
• the layer 120 adjacent the anode is called the hole injection layer or buffer layer.
• the layer 130 adjacent to the photoactive layer is called the hole transport layer.
• An optional electron transport layer 150 is located between the photoactive layer 140 and a cathode layer 160.
• the photoactive layer 140 can be a light-emitting layer that is activated by an applied voltage (such as in a light-emitting diode or light-emitting electrochemical cell), a layer of material that responds to radiant energy and generates a signal with or without an applied bias voltage (such as in a photodetector).
• an applied voltage such as in a light-emitting diode or light-emitting electrochemical cell
• a layer of material that responds to radiant energy and generates a signal with or without an applied bias voltage (such as in a photodetector).
• the device is not limited with respect to system, driving method, and utility mode.
• the photoactive layer 140 is made up different areas of at least three different colors. The areas of different color can be formed by printing the separate colored areas. Alternatively, it can be accomplished by forming an overall layer and doping different areas of the layer with emissive materials with different colors. Such a process has been described in, for example.published U.S. patent application 2004-009
• the new process described herein can be used to apply an organic layer (second layer) to an electrode layer (first layer).
• first layer is the anode 110
• second layer is the buffer layer 120.
• the new process described herein can be used for any successive pairs of organic layers in the device, where the second layer is to be contained in a specific area.
• the second organic active layer is the photoactive layer 140
• the first organic active layer is the device layer applied just before layer 140.
• the device is constructed beginning with the anode layer.
• the RSA treatment would be applied to layer 130 prior to applying the photoactive layer 140.
• the RSA treatment would be applied to layer 120.
• the RSA treatment would be applied to the electron transport layer 150 prior to applying the photoactive layer 140.
• the second organic active layer is the hole transport layer 130
• the first organic active layer is the device layer applied just before layer 130.
• the RSA treatment would be applied to buffer layer 120 prior to applying the hole transport layer 130.
• the anode 110 is formed in a pattern of parallel stripes.
• the buffer layer 120 and, optionally, the hole transport layer 130 are formed as continuous layers over the anode 110.
• the RSA is applied as a separate layer directly over layer 130 (when present) or layer 120 (when layer 130 is not present).
• the RSA is exposed in a pattern such that the areas between the anode stripes and the outer edges of the anode stripes are exposed.
• the layers in the device can be made of any materials which are known to be useful in such layers.
• the device may include a support or substrate (not shown) that can be adjacent to the anode layer 110 or the cathode layer 150. Most frequently, the support is adjacent the anode layer 110.
• the support can be flexible or rigid, organic or inorganic. Generally, glass or flexible organic films are used as a support.
• the anode layer 110 is an electrode that is more efficient for injecting holes compared to the cathode layer 160.
• the anode can include materials containing a metal, mixed metal, alloy, metal oxide or mixed oxide.
• Suitable materials include the mixed oxides of the Group 2 elements (i.e., Be, Mg, Ca, Sr, Ba, Ra), the Group 11 elements, the elements in Groups 4, 5, and 6, and the Group 8-10 transition elements.
• mixed oxides of Groups 12, 13 and 14 elements such as indium-tin-oxide, may be used.
• the phrase "mixed oxide” refers to oxides having two or more different cations selected from the Group 2 elements or the Groups 12, 13, or 14 elements.
• Some non-limiting, specific examples of materials for anode layer 110 include, but are not limited to, indium-tin-oxide ("ITO"), aluminum-tin-oxide, gold, silver, copper, and nickel.
• the anode may also comprise an organic material such as polyaniline, polythiophene, or polypyrrole.
• the anode layer 110 may be formed by a chemical or physical vapor deposition process or spin-cast process.
• Chemical vapor deposition may be performed as a plasma-enhanced chemical vapor deposition ("PECVD") or metal organic chemical vapor deposition ("MOCVD”).
• Physical vapor deposition can include all forms of sputtering, including ion beam sputtering, as well as e-beam evaporation and resistance evaporation.
• Specific forms of physical vapor deposition include rf magnetron sputtering and inductively-coupled plasma physical vapor deposition ("IMP-PVD"). These deposition techniques are well known within the semiconductor fabrication arts.
• the anode layer 110 is patterned during a lithographic operation.
• the pattern may vary as desired.
• the layers can be formed in a pattern by, for example, positioning a patterned mask or resist on the first flexible composite barrier structure prior to applying the first electrical contact layer material.
• the layers can be applied as an overall layer (also called blanket deposit) and subsequently patterned using, for example, a patterned resist layer and wet chemical or dry etching techniques. Other processes for patterning that are well known in the art can also be used.
• the anode layer 110 typically is formed into substantially parallel strips having lengths that extend in substantially the same direction.
• the buffer layer 120 functions to facilitate injection of holes into the photoactive layer and to smoothen the anode surface to prevent shorts in the device.
• the buffer layer is typically formed with polymeric materials, such as polyaniline (PANI) or polyethylenedioxythiophe ⁇ e (PEDOT), which are often doped with protonic acids.
• the protonic acids can be, for example, poly(styrenesulfonic acid), poly(2-acrylamido-2-methyl-1- propanesulfonic acid), and the like.
• the buffer layer 120 can comprise charge transfer compounds, and the like, such as copper phthalocyanine and the tetrathiafulvalene-tetracyanoquinodimethane system (TTF-TCNQ).
• TTF-TCNQ tetrathiafulvalene-tetracyanoquinodimethane system
• the buffer layer 120 is made from a dispersion of a conducting polymer and a colloid-forming polymeric acid. Such materials have been described in, for example, published
• the buffer layer 120 can be applied by any deposition technique.
• the buffer layer is applied by a solution deposition method, as described above.
• the buffer layer is applied by a continuous solution deposition method. Examples of hole transport materials for optional layer 130 have been summarized for example, in Kirk-Othmer Encyclopedia of Chemical Technology, Fourth Edition, Vol. 18, p. 837-860, 1996, by Y. Wang. Both hole transporting molecules and polymers can be used.
• Commonly used hole transporting molecules include, but are not limited to: 4,4 ⁇ 4"-tris(N,N- diphenyl-amino)-t ⁇ phenylamine (TDATA); 4,4',4"-tris(N-3-methylphenyl-N- phenyl-amino)-triphenylamine (MTDATA); N,N'-diphenyl-N,N'-bis(3- methylphenyl)-[1.1 '-biphenyl]-4,4'-diamine (TPD); 1 , 1 -bis[(di-4-tolylamino) phenyljcyclohexane (TAPC); N,N 1 -bis(4-methylphenyl)-N,N'-bis(4- ethylphenyl)-[1.1'- ⁇ .S'-dimethyObiphenylH ⁇ '-diarnine (ETPD); tetrakis-(3- methylphenyO-N.N
• hole transporting polymers include, but are not limited to, polyvinylcarbazole, (phenylmethyl)polysilane, poly(dioxythiophenes), polyanilines, and polypyrroles. It is also possible to obtain hole transporting polymers by doping hole transporting molecules such as those mentioned above into polymers such as polystyrene and polycarbonate.
• the hole transport materia) comprises a cross-linkable oligomeric or polymeric material. After the formation of the hole transport layer, the material is treated with radiation to effect cross-linking. In some embodiments, the radiation is thermal radiation.
• the hole transport layer 130 can be applied by any deposition technique.
• the hole transport layer is applied by a solution deposition method, as described above. In one embodiment, the hole transport layer is applied by a continuous solution deposition method.
• Any organic electroluminescent (“EL") material can be used in the photoactive layer 140, including, but not limited to, small molecule organic fluorescent compounds, fluorescent and phosphorescent metal complexes, conjugated polymers, and mixtures thereof. Examples of fluorescent compounds include, but are not limited to, pyrene, perylene, rubrene, coumarin, derivatives thereof, and mixtures thereof.
• metal complexes include, but are not limited to, metal chelated oxinoid compounds, such as tris(8-hydroxyquinolato)aluminum (Alq3); cyclometalated iridium and platinum electroluminescent compounds, such as complexes of iridium with phenylpyridine, phenylquinoline, or phenylpyrimidine ligands as disclosed in Petrov et al., U.S. Patent 6,670,645 and Published PCT Applications WO 03/063555 and WO 2004/016710, and organometallic complexes described in, for example, Published PCT Applications WO 03/008424, WO 03/091688, and WO 03/040257, and mixtures thereof.
• metal chelated oxinoid compounds such as tris(8-hydroxyquinolato)aluminum (Alq3)
• cyclometalated iridium and platinum electroluminescent compounds such as complexes of iridium with phenylpyridine
• Electroluminescent emissive layers comprising a charge carrying host material and a metal complex have been described by Thompson et al., in U.S. Patent 6,303,238, and by Burrows and Thompson in published PCT applications WO 00/70655 and WO 01/41512.
• conjugated polymers include, but are not limited to poly(phenylenevinylenes), polyfluorenes, poly(spirobifluorenes), polythiophenes, poly(p-phenylenes), copolymers thereof, and mixtures thereof.
• the photoactive layer 140 can be applied by any deposition technique.
• the photoactive layer is applied by a solution deposition method, as described above.
• the photoactive layer is applied by a continuous solution deposition method.
• Optional layer 150 can function both to facilitate electron injection/transport, and can also serve as a confinement layer to prevent quenching reactions at layer interfaces. More specifically, layer 150 may promote electron mobility and reduce the likelihood of a quenching reaction if layers 140 and 160 would otherwise be in direct contact.
• optional layer 150 examples include, but are not limited to, metal-chelated oxinoid compounds (e.g., Alq3 or the like); phenanthroline- based compounds (e.g., 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline ( 11 DDPA"), 4,7-diphenyl-1,10-phenanthroline (“DPA”), or the like); azole compounds (e.g., 2-(4-biphenylyl)-5-(4-t-butylphenyl)-1 ,3,4-oxadiazole (“PBD” or the like), 3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1 ,2,4- triazole (“TAZ” or the like); other similar compounds; or any one or more combinations thereof.
• optional layer 150 may be inorganic and comprise BaO, LiF, Li ⁇ O, or the like.
• the cathode 160 is an electrode that is particularly efficient for injecting electrons or negative charge carriers.
• the cathode layer 160 can be any metal or nonmetal having a lower work function than the first electrical contact layer (in this case, the anode layer 110).
• the term "lower work function” is intended to mean a material having a work function no greater than about 4.4 eV.
• "higher work function” is intended to mean a material having a work function of at least approximately 4.4 eV.
• Materials for the cathode Jayer can be selected from alkali metals of Group 1 (e.g., Li, Na, K, Rb, Cs 1 ), the Group 2 metals (e.g., Mg, Ca 1 Ba 1 or the like), the Group 12 metals, the lanthanides (e.g., Ce, Sm, Eu, or the like), and the actinides (e.g., Th, U, or the like). Materials such as aluminum, indium, yttrium, and combinations thereof, may also be used.
• Group 1 e.g., Li, Na, K, Rb, Cs 1
• the Group 2 metals e.g., Mg, Ca 1 Ba 1 or the like
• the lanthanides e.g., Ce, Sm, Eu, or the like
• actinides e.g., Th, U, or the like.
• Materials such as aluminum, indium, yttrium, and combinations thereof, may also be used.
• cathode layer 160 examples include, but are not limited to, barium, lithium, cerium, cesium, europium, rubidium, yttrium, magnesium, samarium, and alloys and combinations thereof.
• the cathode layer 160 is usually formed by a chemical or physical vapor deposition process.
• additional layer(s) may be present within organic electronic devices.
• the RSA treatment step of the new process described herein may be after the formation of the anode 110, after the formation of the buffer layer 120, after the hole transport layer 130, or any combination thereof.
• the RSA treatment step of the new process described herein may be after the formation of the cathode 160, the electron transport layer 150, or any combination thereof.
• the different layers may have any suitable-thickness.
• Inorganic anode layer 110 is usually no greater than approximately 500 nm, for example, approximately 10-200 nm; buffer layer 120, and hole transport layer 130 are each usually no greater than approximately 250 nm, for example, approximately 50-200 nm; photoactive layer 140, is usually no greater than approximately 1000 nm, for example, approximately 50-80 nm; optional layer 150 is usually no greater than approximately 100 nm, for example, approximately 20-80 nm; and cathode layer 160 is usually no greater than approximately 100 nm, for example, approximately 1-50 nm. Jf the anode layer 110 or the cathode layer 160 needs to transmit at least some light, the thickness of such layer may not exceed approximately 100 nm.
• Example 1 demonstrates an RSA treatment that is coincidental with the formation of the first layer.
• the first layer is an organic active layer.
• Coating 1 A first organic active layer of Material A (a cross-linkable hole transport material from Sumitomo Chemical CoI, Tokyo, Japan) was spin-coated from p-xy)ene onto a glass slide.
• Material A a cross-linkable hole transport material from Sumitomo Chemical CoI, Tokyo, Japan
• a first organic active layer was made from a solution containing 95% Material A and 5% of a fluorinated unsaturated ester monomer as an RSA (Zonyl® 8857A, from E. I. du Pont de Nemours and Company, Wilmington, DE) by spin-coating onto a glass slide. Both coatings were dried at 130C on a hot plate in air. Spin coating conditions were adjusted to provide films with similar thickness after drying. The coated materials were thermally cured in a convection oven with a nitrogen atmosphere at 200 0 C for 30 minutes.
• Example 2 demonstrates an RSA treatment that is subsequent to the formation of the first layer.
• the first layer is an organic active layer.
• Coatings of Material A were prepared on glass slides and cured at 200 0 C for 30 minutes in a convection oven with a nitrogen atmosphere.
• a solution of a fluorinated acrylate monomer as an RSA was spin-coated onto the cured Material A surface.
• the RSA solution was about 20% solids in hexafluoropropoxybenzene.
• the RSA was cured by heating at 130 0 C on a hot plate in air. Any unc ⁇ red RSA was rinsed off by soaking in trifluorotoluene in a petri dish for 15 minutes, and dried at ambient temperature in air.
• the contact angle of the cured, uncoated Material A was measured as about 9 degrees using anisole.
• the contact angle of the cured, uncoated Material A was identical within experimental error if the surface was simply rinsed with trifluorotoluene (no RSA coating).
• the contact angle was identical within experimental error if the RSA was coated onto the Material A and washed off with trifluorotoluene without reacting the RSA in the oven.
• the contact angle of the oven-cured RSA surface was 27 degrees. This demonstrates that the RSA can be applied and removed without affecting the underlying surface energy, and the difference vs. the cured film can be readily measured.
• Example 3 demonstrates an RSA treatment that is subsequent to the formation of the first layer.
• the first layer is an organic active layer.
• Glass slides were coated with Material A and thermally cured as described above. On some slides the Material A was overcoated with a solution of RSA (Zonyl® TA-N) as described above, and the RSA was dried at ambient. The thickness of the RSA coating was determined to be about 100 Angstrom (A) using a VEECO - NT3300 inteferometric profilometer. The RSA was exposed to actinic radiation (365-405 nm, 2.7 Joule/cm ⁇ 2) in air; half this glass slide was masked off to prevent exposure.
• actinic radiation 365-405 nm, 2.7 Joule/cm ⁇ 2
• Example 4 demonstrates an RSA treatment that is subsequent to the formation of the first layer. This example also demonstrates containment as it would be practiced during printing of an emissive ink. The example is shown in FIGs 3 through 6.
• a layer 220 of Material A was coated over the array of lines and cured at 200 0 C in a convection oven with an nitrogen atmosphere for 30 minutes, as shown in FIG. 4.
• the Material A-coated ITO lines are shown as 211.
• a coating 230 of Zonyl® TA-N was applied over the Material A on one substrate by spin coating from hexafluoropropoxybenzene, and dried in air, as shown in FIG. 5.
• FIG. 6 shows the piece after development, with RSA-covered areas 230 and Material A-covered areas over the ITO, 211 and Material A-covered areas over the glass, 220.
• An emissive ink comprising BH119 and BH215 (both from Idemitsu) in a ratio of 8:92, at 1.5% total solids, in anisole, was printed onto the ITO lines using a MicroFab printer, at ambient.
• the drop volume was about 40-45 picoliters, and the drop spacing was 0.08 mm, creating continuous lines of printing.
• the printed lines spread about 200-300 microns; that is, the ink spread across 3 ITO lines. This would have resulted in unacceptable color mixing in an actual printing process.
• the ink was contained entirely within the region treated with the RSA, and would have resulted in a high quality printed device.
• Example 5 demonstrates an RSA treatment that is subsequent to the formation of the first layer.
• Coatings of Material A were prepared and thermally cured as described above. These were then overcoated with RSA coatings of Zonyl® TA-N as described above. The RSA coatings received blanket exposures up to about 4 J/cm ⁇ 2. The coatings were washed in trifluorotoluene after exposure, and contact angles were measured with anisole. The anisole contact angle was modulated from about 9 degrees (Material A surface) to 40-45 degrees. No significant difference was observed if the exposures were performed in air or an inert atmosphere.
• Example 6 demonstrates an RSA treatment that is subsequent to the formation of the first layer, where removal of unexposed region is accomplished via sublimation.
• Coatings of Material A were prepared and thermally cured as described above. These were then overcoated with RSA coatings of heneicosafluorododecylacrylate by spin coating from a 3% wt/vol solution in perfluorooctance.
• One of the RSA coatings received a blanket UV exposure of about 1.5 J/cm 2 ; the other coating did not receive a UV exposure.
• the two coatings were baked at 195 C for 20 minutes on a hot plate in air, and contact angles were measured with anisole. The anisole contact angle was about 55 degrees on the RSA coating that had been exposed to UV radiation. The anisole contact angle was 10 degrees on the coating that had not been exposed to UV radiation.

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