HK1062903A - Thermal imaging processes and products of electroactive organic material - Google Patents

Description

Thermal imaging process and product of electroactive organic materials

Technical Field

The present invention relates to improved methods and products for performing thermal transfer imaging of electroactive materials, particularly laser-induced thermal transfer imaging.

Background

The use of thermal transfer methods in applications such as color correction is well known. Such thermal transfer methods include, for example, dye sublimation, dye transfer, melt transfer, and ablative material transfer, and typically utilize laser-induced thermal transfer of species. Such methods are described, for example, in Baldock, British patent No. 2083726; DeBoer, U.S. Pat. No. 4942141; kellogg, U.S. patent No. 5019549; evans, U.S. Pat. No. 4948776; foley et al, U.S. patent No. 5156938; ellis et al, U.S. patent No. 5171650; koshizuka et al, U.S. Pat. No. 4643917.

Laser-induced thermal transfer processes typically use a donor element comprising a layer of material to be transferred ("transfer layer") and a receiver element having a surface to receive the transferred material. The donor element and the receiver element are brought into proximity or contact with each other and then selectively exposed to laser radiation, typically infrared laser light. The exposed portions of the donor element generate heat upon absorption of the impinging laser radiation, causing these portions of the transfer layer to be transferred to the surface of the receiver element. Either the donor element or the receiver element substrate is transparent, or both are transparent. If the material of the transfer layer does not absorb the impinging laser radiation, the donor must also include a heating layer adjacent to the transfer layer and the supporting base member. The heating layer is a material that is capable of absorbing radiation, generating heat, and causing the transfer layer to transfer. The donor element can also include additional layers, such as an ink-jet layer between the heating layer and the transfer layer. The burst layer decomposes upon heating to form gas molecules that push the exposed portion of the transfer layer into the receiver element.

In digital processes, exposure occurs only in a small selected area of the assembly at a time, which limits the transfer of material from the donor element to the receiver element to only one pixel at a time. Computer control facilitates high precision and speed of transfer. Alternatively, in a similar process, the entire assembly may be irradiated and the desired portions of the thermal imaging layer selectively exposed using a mask. See, for example, U.S. patent nos. 5857709 and 5937272.

Organic electronic devices, such as light emitting devices, light detecting devices, and photovoltaic cells, can be formed from a thin layer of electroactive organic material sandwiched between two electrical contact layers. Electroactive organic materials are organic materials having properties such as electroluminescence, photosensitivity, charge transport and/or charge injection, conductivity (by hole or electron), and/or exciton blocking. The material may be a semiconductor material. At least one of the two electrical contact layers is light-transmissive so that light from the electroactive organic material layer passes through the electrical contact layer or light can pass through the electrical contact layer to the electroactive organic material layer. Other devices of similar construction include photoconductive cells, photo-resistive cells, photodiodes, photoswitches and transistors.

Organic electroluminescent materials capable of emitting light upon application of current between electrical contact layers include organic molecules such as anthracene, butadiene, coumarin derivatives, acridine and stilbene derivatives. See, for example, Tang, U.S. Pat. No. 4356429. Semiconducting conjugated polymers are also used as electroluminescent materials. See, for example, Fried et al, U.S. patent 5247190, Heeger et al, U.S. patent No.5408109, and Nakano et al, European patent application publication No 443861. The electroactive organic material may be modified to emit light at different wavelengths.

Photosensitive devices, such as photodetectors and photovoltaic cells, may also employ certain conjugated polymers and electroluminescent and photoluminescent materials to generate an electrical signal in response to radiant energy. With charge-trapping material, e.g. buckyball (C)₆₀) Electroluminescent materials mixed with their derivatives exhibit this photosensitivity. For example, see Yu, Gang et al report on Photonics WEST 3939 conference on San Jose, Calif. 1, 22-28, 2000, "photovoltaic cells and photodetectors made from semiconducting polymers: recent progress ".

Organic electronic devices have the advantages of good flexibility, low cost, and ease of manufacture, and (as above) have performance properties that can reach, and in some cases even exceed, conventional photosensitive devices. (same as above)

Organic semiconductor materials may also be used to form thin film transistors. The transistor can now be made entirely of organic material. Organic material transistors are cheaper than conventional transistors and can be used for low-level applications, because in low-level applications lower switching speeds are acceptable, whereas using conventional transistors is not economical. See, for example, Drury C.J. et al, "Low cost all Polymer Integrated circuits", appl.Phys.Lett., 73(1), 6 months 1998, pages 108-. In addition, organic transistors are flexible and may be advantageous in certain applications, such as controlling light emitting diodes on a curved surface of a monitor. Organic semiconductor materials (supra) include pentacene, polythiophene ethylene, thiophene oligomers, benzothiophene dimers, phthalocyanines, and polyacetylenes. See, for example, U.S. patent No. 5981970 to Dimitrakopoulos et al, U.S. patent No. 5625199 to Bauntech et al, U.S. patent No. 5347144 to Garnier et al, and Klauck, Hagen et al for "deposition: pentacene organic thin film transistors and integrated circuits ", Solid State Technology, 43(3), 3 months and 2 days, pages 63-75.

The electroactive organic material may be applied to one of the electrical contact layers or to a portion of the transistor by spin coating, casting, or ink jet printing. They can also be applied directly by vapour deposition processes, depending on the nature of the material. Electroactive polymer precursors may also be applied and transferred to the polymer, typically by heating. These methods are complex, slow, expensive, and not accurate enough, and when patterned using standard lithographic (wet development) techniques, expose the device to detrimental thermal and chemical processes.

Ink jet printing has been used to apply pixels of electroactive organic materials having diameters of about 350 and 100 microns. See, for example, U.S. Pat. No. 6087196, European patent 0880303A 1, WO99/66483 and WO 9943031. See also U.S. patent No. 5989945 for applying a resist using ink jet printing. It is stated that pixels having a diameter of about 35 microns have been used for conventional printing applications such as short-run color printing and verification of color reproduction.

Organic electronic devices, such as light emitting, light detecting and optoelectronic devices, typically include a layer of charge injection/transport material in close proximity to the electroluminescent organic material to facilitate charge transport (electron or hole transport) and/or energy gap matching of the electroactive organic material and the electrical contact layer. The charge injection/transport material has not yet been patterned. Therefore, a charge injection/transfer material having low conductivity must be used to avoid cross-talk between pixels.

Materials patterned using thermal transfer processes are generally faster and less expensive to pattern than materials patterned using similar processes in conjunction with wet development techniques. Thermal transfer processes, particularly laser-induced thermal transfer processes, also have higher precision. It is advantageous to apply the electroactive organic material using a thermal transfer process, particularly a laser induced thermal transfer process.

Summary of The Invention

The present invention is directed to a method of providing a patterned layer of an electroactive organic material comprising selectively subjecting a donor element comprising a transfer layer of a thermographic electroactive organic material to heat to remove an unwanted portion of the electroactive material from the transfer layer, thereby forming a patterned layer of the desired electroactive organic material on the donor element.

Another embodiment of the present invention is directed to exposing a thermal imaging member to laser radiation for imaging purposes, wherein the imaging member includes a transfer layer comprised of a plurality of layers of an electroactive material, one of the layers being a layer of a charge injection/transport material, whereby the laser radiation removes the exposed portions of the transfer layer to form a desired patterned layer of the electroactive material and the charge injection/transport material on the thermal imaging member.

A third embodiment of the present invention is directed to selectively heating a donor element including a charge injection/transport material transfer layer to remove unwanted portions of the charge injection/transport material from the transfer layer, thereby forming a patterned layer of the desired charge injection/transport material on the donor element.

A fourth embodiment of the invention is directed to removing unwanted portions of the electroactive organic material from the transfer layer by subjecting the donor element, which includes the transfer layer of the thermographic electroactive organic material, to heat in an exposure pattern that is the reverse image of the desired pattern.

A fifth embodiment of the present invention is directed to a method for forming an organic electronic device, comprising providing a donor element comprising a patterned layer of an electroactive organic material; providing a substrate comprising a first electrical contact layer; transferring the patterned layer onto the substrate such that a first surface of the patterned layer is adjacent to the first electrical contact layer; and providing a second electrical contact layer adjacent to the second surface of the patterned layer.

A sixth embodiment is directed to an article of manufacture comprising a base member and a transfer layer supported on the base member and comprising a desired pattern of a desired electroactive organic material, wherein the transfer layer is selectively heated to remove an undesired portion of the electroactive organic material from the transfer layer to form the desired pattern.

A seventh embodiment is directed to an organic electronic device comprising a first electrical contact layer; a second electrical contact layer, and a pixelated pattern of an electroactive organic material located between the first and second electrical contact layers; wherein the pixelated pattern comprises at least 10000 pixels per square centimeter.

An eighth embodiment is directed to an organic electronic device, comprising a first electrical contact layer; a second electrical contact layer, and a pixelated pattern of an electroactive organic material located between the first and second electrical contact layers; wherein each pixel has a length of less than about 100 microns and a minimum of about 10 microns and each pixel has a width of less than about 100 microns and a minimum of about 10 microns.

We have found that current thermal transfer processes typically result in partial decomposition of the transfer layer material at the absorption interface. While this decomposition may be acceptable for most transfer processes where the thickness of the material to be transferred is 10000  or more, it may be problematic when the material is thin. For example, in organic electronic devices such as light emitting displays, photodetectors, photovoltaic cells, and semiconductor devices, the thickness of the layer of electroactive organic material is typically from about 100  to about 5000 . Decomposition of the electroactive organic material at the interface of the electroactive organic material and the heating layer can result in evaporation of a substantial portion of the material to be transferred. Thus some or all of the electroactive organic material being transferred may be damaged or degraded during thermal transfer, either by being subjected to higher temperatures in the presence of oxygen or by direct evaporation. A thermal transfer process that does not damage such thin electroactive organic material layers should be very useful.

The term "organic electronic device" as used herein refers to an electronic device in which any electroactive component is an organic material.

The term "adjacent" as used herein does not necessarily mean that one layer is immediately adjacent to another layer. Between two layers, which are said to be adjacent to each other, there may be an intermediate layer. The term "photoactive organic material" refers to any organic material that exhibits electroluminescent and/or photosensitive luminescence.

Brief description of the drawings

FIG. 1 is an exemplary donor element and optional acceptor element for use in the process of the present invention.

FIG. 2 illustrates the donor element and the receiver element of FIG. 1 combined and subjected to irradiation in accordance with the present invention.

FIG. 3 is a perspective view of the donor element and the receiver element of FIG. 2 after irradiation and separation, wherein the donor element includes the pattern layer to be transferred, in accordance with the present invention.

FIG. 4 shows the donor element and patterned receiver layer substrate of FIG. 3.

FIG. 5 illustrates the donor element and substrate of FIG. 4 after pattern layer transfer has been completed.

FIG. 6 illustrates a donor element including a transfer pattern layer and an anode substrate of an organic electronic device according to the present invention.

Fig. 7 shows the anode substrate of fig. 6 after the pattern layer has been transferred.

Fig. 8 shows the anode substrate of fig. 7 after the cathode is applied.

Detailed Description

In accordance with the present invention, undesired portions of the transfer layer of electroactive organic material carried over the donor element are subjected to thermal radiation to remove the undesired portions of the electroactive organic material from the transfer layer. The radiation pattern may be the reverse image of the desired pattern. Upon exposure of the transfer layer to radiation, the desired pattern of electroactive organic material remains on the donor element. The heat exposure to the unwanted portions of the electroactive organic material is localized and rapidly dissipates. Thus, the heat to which the desired pattern of electroactive organic material is subjected to radiation is not sufficient to cause decomposition of the material. The desired pattern can then be transferred to the substrate in a second step of the process without the use of excessive heat, by methods such as lamination, and thus without causing decomposition of the patterned layer. When preparing a multi-patterned layer of electroactive organic material according to the method of the present invention, the transfer layer of the donor element and the resulting first patterned layer on the donor element may further comprise a second patterned layer of electroactive organic material. In organic electronic devices comprising both a photoactive organic material and a charge injection/transport organic material, the photoactive organic material and the charge injection/transport material typically have the same pattern.

The donor element and optional acceptor element used in the first step of the process of the present invention are described below.

Donor element and receptor element

FIG. 1 is an exemplary donor element (10) and recipient element (20) for use in the process of the present invention.

As best seen in fig. 1 and 2, the donor (10) includes a thermographic transfer layer (12) including at least one layer of an electroactive organic material (13), a base element (14), and a heating layer (16) between the base element (14) and the transfer layer (12). The base element (14) provides support for the heating layer (16) and the transfer layer (12). The transfer layer (12) may also further comprise one or more layers of different electroactive organic materials. For example, layer (13) may be an electroluminescent material and optional layer (15) may be a charge injection/transport material. An optional layer (15) is shown on the side of the first electroactive organic material (13) opposite the heating layer (16). Furthermore, an optional layer (15) may also be located between the electroactive organic material layer (13) and the heating layer (16) (not shown), depending on the configuration on the substrate or the resulting device.

The receptor element (20) comprises a receptor carrier (22) and an optional adhesive coating (24).

The receiver element (20) is preferably adjacent to the transfer layer (12) of the donor element (10) to receive the unwanted irradiated portions of the electroactive organic material (13) in the first step of the process of the present invention.

The base member (14) of the donor element (10) and the receptor carrier (22) of the receptor element are dimensionally stable sheet-like materials. The donor element (14) and the recipient support (22) are preferably flexible to facilitate subsequent processing steps, as described further below. At least one of the base element (14) and the receptor carrier (22) is transparent to laser radiation (R) to expose the transfer layer (12) for irradiation, as will be described further below.

Examples of flexible transparent films suitable for use as the base member (14) include, for example, polyethylene terephthalate ("polyester"), polyethersulfone, polyimide, poly (vinyl alcohol-co-acetal), polyethylene, or cellulose esters such as cellulose acetate, and polyvinyl chloride. The base element (14) of the donor element (10) is preferably polyethylene terephthalate, which has been plasma treated to receive the heating layer (16). The same materials can be used for the receptor carrier (22). Opacifying materials such as polyethylene terephthalate, ivory paper or synthetic paper filled with white pigments such as titanium dioxide, such as Tyvek  spunbond polyolefin (available from e.i. du Pond DE neuro-Company, Wilmington, DE) may also be used as the receptor carrier (22).

Heating layer

As is clear from fig. 2, the heating layer (16) of the donor element (10) acts to absorb the laser radiation (R) and to subject the electroactive organic material of the transfer layer (12) to irradiation, thereby converting the radiation into heat. The heating layer is typically metal.

Nickel, aluminum, chromium, vanadium and alloys thereof are preferred metals for use as the heating layer (16). Electron beam deposited nickel is preferred because it has been found that oxygen plasma treated nickel can best assist in exfoliation of the electroactive organic material, as will be discussed further below.

Examples of other suitable materials are transition metal elements and metal elements of groups 13, 14, 15 (according to the new IUPAC edition, listed in handbook of chemistry and physics, 81 th edition (CRC press, Boca Raton, FL2000-2001), wherein the groups are numbered 1-18 from left to right in the periodic table), their alloys with each other, their alloys with elements of groups 1 and 2, which are capable of absorbing the laser wavelength. As is clear from fig. 4, the adhesion of the alloy of the transition metal element and the group 1 and 2 elements to the electroactive material is generally less, or can be treated to be less, than the adhesion of the electroactive organic material to the receiving surface of the substrate (30). Tungsten (W) is an example of a suitable transition metal.

Carbon and non-metallic elements of group 14 may be used.

Further, the heating layer may be an organic layer including an organic binder and an infrared absorber. Examples of suitable binders are those which decompose thermally at relatively low temperatures, such as polyvinyl chloride, chlorinated polyvinyl chloride and nitrocellulose. Examples of near infrared absorbers are carbon black and infrared dyes.

The thickness of the heating layer depends on the light absorption capacity of the metal used. For chromium, nickel vanadium or nickel, a layer of 80-100  is preferred. Aluminum heating layers of thickness 40-50  showed higher light absorption. If carbon is used, the thickness of the heating layer is approximately 500 a and 1000 a 1000  a.

While a single heating layer is preferred, multiple heating layers may be used, and the different layers may have the same or different compositions.

The heating layer (16) may be applied on the base element (14) by a physical vapour deposition technique. The term "physical vapor deposition" refers to various deposition processes performed in vacuum. For example, physical vapor deposition includes all forms of sputtering (including ion beam sputtering) and all forms of vapor deposition, such as electron beam evaporation and chemical vapor deposition. One particular form of physical vapor deposition that can be used in the present invention is rf magnetron sputtering. Nickel may be deposited onto the base element (14) by electron beam deposition. The aluminum may be applied by resistive heating. The chromium, nickel and nickel vanadium layers may be applied by sputtering or electron beam deposition.

As is clear from fig. 3-5, in order to assist in the transfer of the patterned layer (12') of electroactive organic material onto the predetermined substrate in the second step of the process, it is important that the degree of adhesion of the heating layer (16) to the electroactive organic material is less than the degree of adhesion of the electroactive organic material (13) or optional layer (15), if present, to the substrate, as described below. Therefore, it is preferable to provide a peelable layer (17) between the heating layer (16) and the electroactive organic material layer (12). The peelable layer (17) may be obtained by oxygen plasma treatment of the heating layer (16). It has been found that treatment with oxygen plasma for at least about 45 seconds, preferably about 90 seconds, facilitates transfer of the desired pattern of electroactive organic material to the substrate by lamination without damaging the electroactive organic material. An oxide layer may also be formed on the surface of the heating layer adjacent to the electroactive organic material layer. The oxide layer may have a thickness of several monolayers. Alternatively, the isolation layer having a monolayer thickness may also be applied directly to the heating layer surface, such as by bar coating. Suitable barrier layers include polydimethylsiloxane, available from Polysciences, inc. (Warrington, PA); isodichlorosilane perfluorodecane, available from GelestInc (Tullytoun, PA); hexamethyldisilazane (HMDS), available from Arch Chemicals, Inc (Norwalk, CT); dichlorosilane perfluorodecane, also available from Gelest Inc. and tridecafluoro-1, 1, 2, 2-tetrahydrooctyl-1-methyldichlorosilane, available from United Chemical Technologies, Inc. The peelable layer may also be a heat activated release material.

Electroactive organic materials

As can be clearly seen in fig. 1 and 2, the at least one electroactive organic material transfer layer (12) comprises any organic material having one or more of the following characteristics: electroluminescence, photosensitivity, charge transport and/or charge injection (hole or electron), conductivity and exciton blocking. The electroactive organic material may comprise an organic molecule or a polymer. It comprises an organic semiconductor material. The thickness of the electroactive organic material layer is typically between 100-. Specific electroactive organic materials that may be used in the process of the invention are discussed further below.

As mentioned above, the transfer layer of the electroactive organic material layer (12) may comprise one or more electroactive organic materials. For example, the transfer layer (12) may comprise a layer of electroluminescent material (13) and a layer of charge injection/transport material (15).

The charge injection/transport material facilitates the transport of charge (electron or hole transport) in the organic electronic device and/or the energy gap matching of the electroactive organic material and the electrical contact layer. Energy gap matching is the matching of the gap between the highest occupied valence band energy level and the lowest unoccupied conduction band energy level. Polyaniline and poly (dioxythiophene) are examples of charge injection/transport materials. Examples of other charge injection/transport materials are discussed further below.

Eruption layer

A burst layer (not shown) may optionally be included between the heating layer (16) and the electroactive organic material layer (12), as is well known in the art. The burst layer decomposes into gas molecules when heated in the region subjected to radiation, providing additional force to transfer unwanted portions of the electroactive organic material layer (12) to the receiver element (20). Polymers having lower decomposition temperatures (less than about 350 c, preferably less than about 325 c, and more preferably less than about 280 c) may be used. For the case of polymers having more than one decomposition temperature, the first decomposition temperature should be below 350 ℃. A suitable spray layer is disclosed in U.S. patent No.5766819, assigned to the assignee of the present invention. Thermal additives may also be added to the hair spray layer to amplify the effect of heat generation in the heating layer (16), as is known in the art and also described in U.S. patent No. 5766819. By providing an additional decomposition pathway to produce gaseous products, additional driving forces may be generated, thereby facilitating the transfer process.

If a burst layer is provided, the peelable layer (17) discussed above will facilitate transfer of the burst layer material from the heating layer (16) adjacent to the exposed portion of the heating layer (16).

Adhesive coating

As best seen in fig. 1-3, the adhesive coating (24) of the receiver member (20) facilitates adhesion of the irradiated portion of the transfer layer (12) to the receiver member (20). The adhesion of the adhesive coating (24) should not be so high as to prevent unexposed portions of the transfer layer (12) from being removed from the transfer layer (12) by the adhesive coating (24), as is well known in the art. The adhesive coating (24) may be a suitable polycarbonate, polyurethane, polyester, polyvinyl chloride, styrene/acrylonitrile copolymer, poly (caprolactam), copolymer of vinyl acetate with ethylene and/or vinyl chloride, (meth) acrylate homopolymer (e.g., butyl methacrylate), and copolymers and mixtures thereof.

The method of the invention

In the first step of the preferred embodiment of the method of the invention, the uncovered surface of the transfer layer (12) of one or more layers of electroactive organic materials (13), (15) of the donor (10) is contacted with the adhesive layer (22) of the receiver element (20) to form an assembly (25), as best shown in FIG. 2. Alternatively, the donor element (10) and the receptor element (20) may be taped together and adhered to an imaging device. Pins/clips may also be used. As yet another alternative, the donor element (10) can be laminated to the receiver element (20). In addition, the receptor member surface may be roughened during application by laminating a matte polyethylene coversheet to promote contact with the receptor member (20) to facilitate removal of air between the donor member (10) and the receptor member (20).

Unwanted portions of the thermographic transfer layer (12) of the electroactive organic material are then irradiated with radiation (R) in the form of heat or light through the donor element (10). If the recipient support (22) is transparent, the donor element may also be irradiated through the recipient support (not shown). As described above, the irradiation pattern is the reverse image of the desired pattern. The heating layer (16) absorbs the radiation (R) and generates heat that vaporizes unwanted portions of the transfer layer (12) to cause transfer of unwanted portions of material on the transfer layer (12) in the donor element (10) to the receiver element (20).

After irradiation, the donor element (10) is separated from the receiver element (20). This can be done by simply peeling the two elements apart. The peel force required is typically small; the donor vector (10) can be easily detached from the recipient element (20). Any conventional manual or automated separation technique may be used.

After separation of the donor element (10) and the receiver element (20), the desired pattern (12') of the first electroactive organic material (13) and the optional second electroactive organic material (15) remains on the donor element (10), while the irradiated undesired portion (12 ") of the transfer layer (12) remains on the receiver element (20), as best shown in FIG. 3.

As is clear from fig. 2, the radiation (R) is preferably provided by a laser. The laser radiation may be about 1J/cm²Preferably about 75 to 440mJ/cm²The laser fluence of (2). Other techniques that generate sufficient heat to cause transfer of the electroactive organic material may be employed. For example, a thermal print head or a metal tip microscopic array having a diameter of about 50 nanometers (such as those used in atomic force microscopy) or about 5 microns may also be used. To generate heat, a current is passed through the metal tip. Higher imaging accuracy can be achieved with a thin metal tip than with a laser.

Various types of lasers can be used to irradiate the thermographic transfer layer (12) of electroactive organic material. The laser is preferably in the infrared, near infrared or visible region. Diode lasers emitting in the 750-870nm range are particularly advantageous, with their significant advantages of small size, low cost, stability, reliability, ruggedness, and ease of modulation. Diode lasers emitting in the 780-850nm range are preferred. Such lasers are commercially available, for example, from Spectra Diode Laboratories, San Jose, Calif. Other types of lasers may be used, as is well known in the art, so long as the absorption of the heating layer (16) matches the emission wavelength of the laser.

If both the donor element (10) and the receiver element (20) are flexible, the combination (25) may be conveniently mounted on a drum for imaging with a laser.

After a patterned layer (12 ') is formed over the first electroactive organic material (13) and the optional second electroactive organic material (15) on the donor element (10) and the donor element (10) is separated from the receiver element (20) (if used), as best shown in FIG. 3, the donor element (10), including the patterned layer (12'), is brought into contact with a predetermined substrate (30), as best shown in FIG. 4. The substrate (30) may include a base element (32) and an adhesive coating (34) that enhances adhesion of the patterned layer (12') to the substrate. The adhesive coating (34) may be any of the materials discussed above with respect to the adhesive coating (22) of the receiver element (20). As mentioned above, it is important that the adhesion of the receiving surface of the substrate (30) to the electroactive organic material of the desired pattern (12 ') is greater than the adhesion of the pattern (12') to the heating layer (16) of the band peelable layer (17). The substrate (30) may be part of an electronic organic device (such as an anode or cathode of a light emitting display), a light detecting device, or a photovoltaic cell, as will be described further below. The substrate may also be part of a transistor.

The desired pattern (12') is preferably transferred to the substrate by lamination. Roll lamination may be utilized for lamination to roll or press lamination as is well known in the art. Preferably roll-to-roll Waterprof^Laminator (Dupont, Wilmington, manufactured by DE) completes the lamination. If roll-to-roll lamination is used, both the donor element (10) and the substrate (30) must be flexible. In press lamination, neither need be flexible. Pressures of approximately 5000-10000 pounds per square inch (approximately 500-1000 kilograms per square centimeter) may be used in press lamination.

After separation of the donor element (10) from the substrate (30), the desired pattern (12') of the first electroactive organic material (13) and, optionally, the second electroactive material (15) is transferred to the substrate, as best seen in FIG. 5.

The process may be repeated for different donor elements to impart a pattern of different electroactive organic materials on the same surface of the substrate (30), adjacent to each other.

The method of the present invention is particularly useful for transferring layers of electroactive organic materials as thin as 100  -5000 , where significant degradation of the transferred layer occurs when the layer is transferred using conventional thermal transfer techniques. Thicker layers of electroactive organic materials may also be transferred using the methods of the present invention.

Organic electronic device

As discussed above, the desired substrate for use as the receptor element (20) in the methods of the present invention can be, for example, an optical emitter, an optical detector, or an anode of a photovoltaic organic electronic device. Fig. 6-8 illustrate the formation of such devices.

As is clearly shown in fig. 6, the anode substrate (100) of such an organic electronic device typically comprises a carrier element (102) and a transparent first electrical contact layer (104). A donor element (10) for making an organic layer of an organic electronic device of the present invention comprises a desired patterned layer (12 '), the patterned layer (12') overlying a first layer of electroactive organic material (13) and a second layer of electroactive organic material (15) for transfer to a first electrical contact layer (104). The first electroactive layer is preferably a layer of photoactive organic material and the second electroactive layer is preferably a layer of charge injection/transport material. A desired patterned layer (12') of a first electroactive organic material (13) and a second electroactive organic material (15) is formed over the donor element (10) by the process described above with respect to fig. 1-3. The desired patterned layer (12') of the first electroactive organic material (13) and the second electroactive organic material (15) is preferably applied to the first electrical contact layer (104) by a lamination process also as described above with reference to fig. 4-5.

As is clearly shown in fig. 7 and 8, after the transfer of the desired patterned layer (12') of the first electroactive organic material (13) and the second electroactive organic material (15) onto the first electrical contact layer (104), the cathode portion (125) of the organic electronic device is applied. The cathode portion (125) comprises a second electrical contact layer (114) applied on the electroactive organic material (13) of the patterned layer (12'). A second carrier element (120) is then applied on the second electrical contact layer (114) to form the organic electronic device (200), as is clearly shown in fig. 8.

Alternatively, the first electroactive organic material may be applied in a pattern from one donor element and the second electroactive organic material (15) may then be applied in a pattern from a second donor element. In this case, each donor element comprises a transfer layer (12) of a single type of electroactive organic material.

Although not preferred, the charge injection/transport material (15) may also be applied to the anode substrate (100) by conventional techniques, such as coating techniques. As discussed above, the preferred embodiment of the present invention can reduce cross talk between pixels, making it possible to utilize charge injection/transfer with high conductivity.

The elements of the organic electronic device (200) will now be described in more detail.

Anode and cathode carrier elements

If the organic electronic device is to be flexible, for example a light emitting device mounted on a curved surface such as a computer screen, the first carrier element (102) and the second carrier element (20) of the anode part (100) are preferably of a composite structure comprising at least one layer of a flexible polymer film and at least one layer of a flexible barrier material, as described in patent application No. pct/US00/11534, filed on 17.4.2000, assigned to the assignee of the present invention. As described in this patent application, the flexible barrier material protects the electrical contact layer (104) (114) and the patterned layer (12') of the first and second electroactive organic materials (13, 15) from exposure to oxygen, water vapor and heat in subsequent processing steps. Preferably, there are two layers of flexible polymeric material film (102a), (120a) on opposite sides of the flexible barrier material layer (102b), (120b), as best seen in fig. 6 and 8.

Suitable flexible polymeric films include polyethylene terephthalate, polyethylene naphthalate, polyamide, and combinations thereof, polyolefins, polyamides, polyacrylonitriles, polymethacrylcyanides, perfluorinated and partially fluorinated polymers, polycarbonates, polyvinyl chloride, polyurethanes, polypropylene resins, epoxy resins, and varnish resins. The support thickness is typically about 1 to 10 mils (about 25 to 250 microns).

In a light-emitting device, a light-detecting device or an optoelectronic device, at least one of the carrier elements needs to be light-transmissive in order for light to be able to pass through. Light transmission barrier materials include nitrides, fluorides, carbides, glasses, and inorganic oxides. Silicon nitride, aluminum oxide and silicon oxide are preferred. Suitable materials are described in detail in patent application No. PCT/US 00/11534. In the embodiment shown in fig. 8, the carrier element (102) of the anode portion (100) comprises a light-transmissive barrier material through which light is emitted or received. For example, silicon nitride having a thickness of about 200-500 nm may be used. The polymer films (102a), (120a) may be sealed to the barrier material layers (102b), (102b) by an adhesive.

The carrier elements (102), (120) may extend beyond the boundaries of the adjacent electrical contact layers (104) (114), respectively, and the perimeter lines of the carrier elements (102), (120) may be sealed together, for example by an adhesive, completely surrounding the electrical contact layers (104) (114) and the pattern of electroactive organic material. Portions of the electrical contact layers (104) (114) that are required to be connected to drive or provide signals to receiving circuitry may extend through the carrier elements (102), (120).

If the organic electronic device does not require flexibility, the carrier element (102) may be glass, as is well known in the art, for example, as described in U.S. Pat. No.5073446 to Nahamura et al, U.S. Pat. No.5482896 to Tony, and U.S. Pat. No.5073446 to Scozza et al.

First electric contact layer

In this example, the substrate (100) is an anode portion of an organic electronic device (200) through which light may be emitted or received. Thus, the first electrical contact layer (104) is a transparent material. Conductive mixed metal oxides of groups 2, 3, 4, such as indium tin oxide, or conductive polymers such as polyaniline or poly (dioxythiophene) can be used. Indium tin oxide ("ITO") is preferred.

A mixed metal oxide, such as indium tin oxide, may be applied to one surface of the base element (102) by vapor deposition techniques as discussed above. Polyaniline and other conductive polymers can be applied by spin coating, rod coating, and ribbon coating methods.

The first electrical contact layer may be patterned as desired. For example, the first electrical contact layer (104) may be a series of parallel strips forming electrode lines so that individual pixels of the pattern (12') of the first electroactive organic material (13) find their place on the display. The second electrical contact layer (114), discussed further below, may also be a series of parallel strips that form electrode lines perpendicular to the electrode lines of the first electrical contact layer (104) that make up the matrix, as is well known in the art. In this organic electronic device (200), a pattern (12') of a first electroactive organic material (13) is positioned in accordance with a first electrical contact layer (104) so as to correspond to an overlapping portion of the first and second electrical contact layers (104) in a matrix.

A patterned mask or photoresist may be placed on the carrier element (102) before the material of the first electrical contact layer (104) is applied, whereby the first electrical contact layer is applied on the carrier element (102) in a desired pattern. Alternatively, the first electrical contact layer is applied as a complete layer and subsequently patterned using, for example, photoresist and wet chemical etching methods.

The thickness of the first electrical contact layer is typically about 500 a 5000  a.

The first electrical contact layer (114) may include extensions (not shown) to connect the device to an external circuit. Other methods of connecting the circuits, such as through vias, may also be provided. The openings for the through-holes may be formed separately in each layer during assembly of the device or may be formed by drilling through all layers after assembly of the device. The vias are then plated by well-known techniques, such as those described in Sinnadurai, handbook of microelectronic packaging and connection technology (electro chemical Publications Ltd., 1985). If a via is used, its opening should be completely sealed around the connection line to protect the active layer from exposure to the external environment.

Charge injection/transport layer

In a preferred embodiment, the first electroactive layer is a layer of photoactive organic material and the second electroactive layer is a layer of charge injection/transport material. The charge injection/transport layer (15) facilitates the band gap matching of the charge transport (electron or hole transport) and/or photoactive organic material layer (13) with the first electrical contact layer (104). If both the photoactive organic material (13) and the charge injection/transport material (15) are applied to the heating layer (16) of the donor element (10), as in this preferred embodiment, the wetting action of the charge injection/transport material (15) on the photoactive organic material (13) should be sufficient to form a continuous film. If the charge injection/transport material (15) is placed on the anode portion (100) by conventional techniques and the patterned layer (12') of photoactive organic material (13) is transferred onto the charge injection/transport material (15), the adhesion of the charge injection/transport material (15) to the photoactive organic material (13) must be stronger than the adhesion of the photoactive organic material (13) to the heating layer metal (16) (and the associated isolation layer (17) of the donor (10)).

Examples of hole transport materials for layers are summarized, for example, in Y.Wang, Kirk-Othmer encyclopedia of chemical technology (4 th edition), Vol.18, p.837-. Both hole transporting molecules and polymers may be used.

Commonly used hole-transporting molecules are: n, N ' -diphenyl-N, N ' -bis (3-methylphenyl) [1, 1 ' -diphenyl ] -4, 4 ' -diamine (TPD), 1-bis [ (di-4-tolylamino) phenyl ] cyclohexane (TAPC), N, N ' -bis (4-methylphenyl) -N, N ' -bis (4-ethylphenyl) - [1, 1 ' - (3, 3 ' -dimethyl) diphenyl ] -4, 4 ' -diamine (ETPD), tetrakis- (3-methylphenyl) -N, N, N ', N ' -2, 5-Phenylenediamine (PDA), a-phenyl-4-N, N-diphenylaminostyrene (TPS), p- (diethylamino) benzaldehyde Diphenylhydrazine (DEH), Triphenylamine (TPA), bis [4- (N, N '-diethylamino) -2-tolyl ] (4-tolyl) methane (MPMP), 1-phenyl-3- [ p- (diethylamino) styryl ] -5- [ p- (diethylamino) phenyl ] pyrazoline (PPR or DEASP), 1, 2-trans-bis (9H-carbazol-9-yl) cyclobutane (DCZB), N' -tetrakis (4-tolyl) - (1, 1 '-diphenyl) -4, 4' -diamine (TTB), and porphyrin compounds such as copper phthalocyanine.

Commonly used hole-transporting polymers are polyvinylcarbazole, (phenylmethyl) polysilane, polyaniline, poly (dioxythiophene) (preferably poly (3, 4-ethylenedioxythiophene) "PEDOT"), and doped forms thereof. Hole-transporting polymers can also be obtained by incorporating hole-transporting molecules such as those mentioned above into polymers such as polystyrene and polycarbonate.

Examples of charge transport materials for the charge injection layer include oxa (oxinoid) metal chelates, such as Alq₃(ii) a Phenanthroline-based compounds, such as 2, 9-dimethyl-4, 7-diphenyl-1, 10-phenanthroline (DDPA) or 4, 7-diphenyl-1, 10-phenanthroline (DPA); and pyrrole compounds such as 2- (4-diphenyl) -5- (4-tert-butylphenyl) -1, 3, 4-oxadiazole (TAZ). The charge injection layer (106) can be used both to assist electron transport and as a buffer or confinement layer to prevent exciton annihilation at the layer interface. This layer preferably improves electron mobility and reduces exciton annihilation.

Polyaniline and PEDOT may be spin coated onto the first electrical contact layer (104).

The thickness of the charge injection layer may be about 100-.

Photoactive organic materials

In a preferred embodiment where the first electroactive layer is a layer of photoactive organic material and the second electroactive layer is a layer of charge injection/transport material, the specific photoactive organic material of the pattern (12') depends on the type of electronic organic device (200). In light emitting devices, such as light emitting displays, photoactive organic materials are light emitting materials that are activated by application of a sufficient voltage. In photosensitive devices such as light cells or photovoltaic cells, electroactive organic materials are layers of materials that respond to radiant energy and produce a signal with or without an applied bias.

When the organic electronic device (200) shown in fig. 8 is a light emitting device, the light emitting material may be any organic electroluminescent material or other organic light emitting material. Anthracene, naphthalene, phenanthrene, pyrene, chrysene, perylene, butadiene such as 1, 4-diphenylbutadiene and tetraphenylbutadiene/coumarin derivatives, acridine and stilbene such as trans-stilbene may also be used, as described in Tang, U.S. patent 4356429 and Van Slyke, et al, U.S. patent No. 4539507. Oxa metal chelates such as AlQ3, as described in U.S. patent No.5047687 to Van Slyke, may also be used.

Alternatively, semiconducting conjugated polymers may be used, as described in Friend et al, U.S. Pat. No.5247190, Heeger et al, U.S. Pat. No.5408109, and Nakano et al, U.S. Pat. No. 5317169. Examples of such polymers include poly (p-phenylacetylene) and poly (2, 7- (9, 9-dialkylfluorene)) known as PPV. PPV is preferred because it has a lifetime exceeding that of polyfluorenes. Mixtures of electroactive materials, such as mixtures of light emitting polymers, may also be used.

When the electronic organic device (200) shown in fig. 8 is a photodetector or photovoltaic cell, the electroactive organic material can be a material layer that responds to radiant energy and generates a signal with or without an applied bias. Materials that respond to radiant energy and produce a signal with or without an applied bias voltage (as is the case in certain light-conducting cells or photocells) include materials that chemically react under the action of light to produce a signal. Specific examples include, but are not limited to, MEH-PPV ("coupler made of semiconducting polymer", G.Yu, K.Pakbaz, A.J.Heeger, Journal of electronic materials, Vol.23, p.925-928 (1994)); the complexes of MEH-PPV with CN-PPV ("high efficiency photodiodes made from interpenetrating polymer networks", J.J.M.Hall et al (Cambridge group), Nature, Vol.376, pp.498-500, 1995).

Materials responsive to radiant energy and capable of generating a signal with or without an applied bias (as in light)In the case of sinks, photoresistors, photoswitches, phototransistors, light pipes) include, for example, a number of conjugated polymers and electroluminescent materials mixed with charge-trapping materials, such as fullerenes (C)₆₀) Yu et al "photovoltaic cells and photodetectors made from semiconducting polymers: recent progress ", reported on Photonics WEST, 3939 meeting, San Jose, Calif., on 1 month, 22-28 days 2000.

The desired pattern (12') of photoactive organic material (13) may be a series of pixels. "Pixel" refers to the smallest addressable element on the display. According to the method of the present invention, at least about 10000 pixels per square centimeter can be transferred to the anode substrate (100). Each pixel may be square with a length and width less than about 100 microns. Pixels each 5 microns in length and width and integer multiples thereof can be imaged using a laser beam directed at 5 microns in imaging beam. As shown in example I below, we successfully patterned and transferred lines and spaces as small as 30 microns, indicating that it is possible to pattern pixels of 30 microns x 30 microns. It is believed that pixels as small as 10 microns by 10 microns can be patterned using the method of the present invention.

The thickness of the layer of photoactive organic material is typically 100 a-500 a 500 , preferably about 500 a-2000 a 2000 .

Second electric contact layer

The second electrical contact layer (114) of the cathode portion (125) is positioned adjacent to the patterned layer (12 ') of the first electroactive organic material (13) such that the patterned layer (12') is positioned between the first electrical contact layer (104) and the second electrical contact layer (114).

The second electrical contact layer (114) of the cathode portion (125) may be any metal or nonmetal having a lower work function than the first electrical contact layer (104) of the anode portion of the device (200). The material for the second electrical contact layer may be selected from group 1 alkali metals (e.g., Li, Cs), group 2 (alkaline earth) metals, lanthanides, and actinides. Such as aluminum, indium, calcium, barium, magnesium, and ytterbium, and combinations thereof, may also be used. Ytterbium and aluminum are preferred.

The second electrical contact layer (114) may be applied by a physical vapor deposition process over the pattern (12') of electroactive organic material and patterned using conventional techniques, as described above for the first electrical contact layer (104). The second electrical contact layer (114) may form a series of parallel stripe patterns perpendicular to the parallel stripes of the first electrical contact layer (104).

The second electrical contact layer (104) is typically 500 a 5000  a thick. If the cathode is barium or calcium, the thickness is about 50  a. Such electrical contact layers are typically covered with aluminum such that the overall thickness of the cathode is in the range of 500-. If the cathode is ytterbium or aluminum, then no capping layer is required and the monolayer itself has a thickness in the range of 500-5000 .

The carrier element (120) may be fixed to the second electrical contact layer (114) by means of an adhesive.

As discussed above with respect to the first electrical contact layer (104), the second contact layer (114) may also include extensions or vias (not shown) for connection to external circuitry.

Multi-step transfer process

As mentioned above, the method of the present invention may be repeated multiple times with different donor elements to apply different electroactive organic materials or patterns of electroactive materials adjacent to each other on the same layer of the substrate. Patterns of different electroactive organic materials may be applied to remain on the same layer, as is well known in the art. In a light emitting display device, different organic electroluminescent materials emitting different colors of light in different wavelength bands may be applied at locations corresponding to different overlapping portions of the first and second electrical contact layers (104) (114) to produce a color display. Electroluminescent materials that exhibit green, yellow, red and orange colors have been developed as described in U.S. patent No.5877695 to Kubes et al. The conjugated polymer poly-p-phenylacetylene ("PPV") emits a yellow-green color after gaining energy, while various variants of PPV emit red and blue light. Hydroquinone-aluminum compounds can also emit light of various colors. Polymers emitting light of different colors are available from Covion organic semiconductors BmbH (Frankfurt, Germany).

Thus, a color display having a high pixel density, a small pixel size and a high emission efficiency can be manufactured according to the method of the present invention.

Examples

Example I

Nickel vanadium, from Vacuum deposite Incorporated, Louisville, KY, was coated as a heating layer of 80  on the surface of a donor element comprising a polyester base element 8 inches by 4 inches (20.32cm by 10.16cm) thick (0.00635mm) to a light transmission of 40%.

The coated base element was cleaned by dipping it in a dish containing acetone for 30 seconds to 1 minute and then rinsed with an acetone spray bottle. The coated base element was then washed in a dish of water, wiped off, placed in a basin of water, and transferred to a clean laboratory for air drying.

The nickel vanadium coated base element was blow dried with nitrogen and then placed in the center of the plasma chamber. The plasma chamber was evacuated and then oxygen was introduced into the chamber until the pressure reached 0.5 torr. The oxygen plasma was generated using a radio frequency source operating at 80 watts. The nickel vanadium coated base member was exposed to oxygen plasma for 90 seconds to reduce the adhesion of the nickel vanadium coating to the electroactive organic material.

This electroactive organic material was then applied to the surface of the metal coated donor element by hand coating with 1.5 ml of a 0.5% solution of poly (9, 9-dialkylfluorene-2, 7-diyl) in 0.5% toluene using a number 0 Meyer rod, and then dried in air for 5 minutes to complete the donor element. Poly (9, 9-dialkylfluorene-2, 7-diyl) is a light-emitting polymer. The light emitting polymer layer is about 7000  thick. A plurality of donor elements are prepared.

After drying, the phosphor-coated donor element surface was contacted with 4 inch x 8 inch (10.16cm x 17.78cm) polycaprolactam receptor. The donor element/receptor assembly was glued to a 30X 40 inch (76.2cm X101.6 cm) aluminum plate which was then automatically loaded into a CREO3244 Spectrum random setter irradiation instrument as a standard offset plate. The instrument was purchased from Creo-Scitex, Inc., Vancouver, Canada. The apparatus comprises a drum of 81.2cm length and 91cm circumference. A 40 watt infrared diode laser emits radiation with a pulse width of 830 nm and 1 microsecond through a light valve that divides the radiation into an array of 240 overlapping 5 x 2 micron spots.

The assembly was exposed to constant laser power in a pattern through a polyester base element at a series of drum speeds varying between 100-200RPM (sensitivity of 100-300 mJ/cm)²) The pattern comprises a series of parallel 30 micron vertical lines and spaces that are the reverse image of the desired pattern.

The desired pattern of a series of parallel 30 micron vertical lines of light emitting polymer on the donor element, which are spaced at 30 micron intervals, can be observed under a microscope at 50 x magnification.

Example II

In this embodiment, a patterned electro-active material is applied to the anode portion of the light emitting display.

To prepare a donor element comprising a 2 mil (0.00325mm) polyester base element and a heating layer of e-beam deposited nickel, nickel was purchased from Vaccum Deposit incorporated. The nickel was deposited to a light transmission of 35%. The base member, on which the nickel has been deposited, is washed successively with acetone, methanol and water, dried with ionized nitrogen and treated with oxygen plasma for 90 seconds, as described in example I. The luminescent polymer of example I was then applied as described in example I to complete the donor element. The donor element was contacted with a polycaprolactam receptor and the assembly was then exposed to a CREO3244 trestter instrument as described in example I to form a patterned layer of light emitting polymer on the donor element.

The substrate comprised a 2 inch by 2 inch (5.08cm by 5.08cm), 7 mil (0.036285mm) thick polyester base member and indium applied to the base member by sputteringA tin oxide electrical contact layer. The coated substrate was purchased from south wall Technologies, inc, Palo Alto, CA, under the trade name Altair^TM0-60-HS. The indium tin oxide layer was 7 mils (0.03682mm) thick. The indium tin oxide resistivity was 60 ohm/cm.

The charge injection layer material comprised Baytron  P, poly (3, 4-ethylenedioxythiophene) ("PEDOT") and an aqueous solution of polystyrene ("PSS") having a total solids content of 1.3% by weight, available from Bayer (Leverkusen, Germany). Baytron  P is a hole injection material. Baytron  P was mixed with a dilute solution of polystyrene sulfonic acid ("PSSA") to give a solution containing 2% solids. 87.00 grams of this solution was prepared by mixing 60 grams of Baytron  P, 3.2 grams of PSSA (30% water), and 23.80 grams of water.

The charge injection/transport material was applied to the indium tin oxide electrical contact by loading 2 ml of the solution in a syringe and then feeding the solution through a 0.45 micron filter into a spin coater. The solution was spun in a spin coater at 2000RPM for 90 seconds. The applied substrate was removed from the spin coater and dried on a hot plate at 100 ℃ for 60 seconds. The resulting charge injection layer film had a film thickness of 1000 .

The light emitting polymer pattern layer on the donor element is transferred to the charge injection layer by lamination. Lamination was accomplished using a roll-to-roll Waterprof  laminator available from DuPont (Wilmington, DE). Both rolls of the laminator were set at 125 ℃ and the rotation speed was 100 mm/min.

Parallel stripes of light emitting polymer 30 microns wide, 1000 microns thick, and 30 microns apart, observed under a microscope at 50 x magnification, have been transferred to the charge injection layer to form the anode of the light emitting display.

As will be described in one embodiment below, a cathode may be deposited on the anode substrate to form a light emitting display.

Example III

In this embodiment, a patterned light emitting display is formed.

The donor element comprises a1 mil (0.0254mm) polyester base element. The heating layer was formed by depositing VacuumDeposit Incorporated nickel on the base member using an electron beam so that the light transmittance was 35%. The base element and heating layer were cleaned, dried and oxygen plasma treated as described in example I. The luminescent polymer of example I was applied on the nickel layer. This element was contacted with a polycaprolactam receptor and irradiated with a CREO3244 trestter instrument, also as described in example I. After irradiation, the donor element was left with the desired pattern, which was formed by a series of parallel rectangular strips 30 microns thick spaced 30 microns apart, extending from a larger rectangular portion.

The first electrical contact layer was formed by sputtering indium tin oxide onto a polyester substrate, as described in example II, to form the anode portion of the display. The charge injection layer was then prepared using XICP-OSO1, an organic-based conductive polyaniline solution under development, available from Monsanto company, for general introduction in U.S. Pat. No. 5863465. XICP-OSO1 contains about 48.16 wt% xylene, 12.62 wt% butyl fiber solvent (i.e., 2-butoxyethanol), and 41.4 wt% conductive Polyaniline (PANI), which is a derivative of polyaniline in combination with dinonylnaphthalene sulfonic acid (DNNSA). Butyl Celluar was purchased from Sigma Aldrich Corporation (Milwaukee, Wis.). Xylene was also purchased from Aldrich, 99% pure.

In this example, a 2.60 wt% PANI/DSSA solution was prepared by mixing 0.9624 g of XICP-OSO1 and 14.3594 g of xylene (EMscience, purity: 98.5%). The 2.60 wt% PANI/DSSA solution was loaded into a syringe and then sent through a 0.45 micron filter to a spin coater. The solution was spun in a spin coater at 1500RPM for 90 seconds. The spin-coated substrate was taken out of the spin coater and dried on a hot plate at 100 ℃ for 60 seconds. The resulting charge injection layer film had a film thickness of 1000 .

Using Waterprofof^The laminator laminated the light emitting polymer pattern layer formed above onto the charge injection layer, both rollers set at 125 ℃ and a rotation speed of 400 mm/min. After the donor element is taken out, putThe desired pattern of the surface of the charge injection layer was observed under a microscope at 50 times larger.

A 2mm x 2mm aluminum electrical contact layer was then deposited by resistive method through a mask with 20 2 x 2mm openings onto the transferred pattern of light emitting polymer to form a first contact layer, 1500 a thick 1500 .

The device was tested by first washing selected areas of the organic material with a solvent to form contact pads, then supplying energy from a dc power supply and measuring the light output with a photometer. The change in applied voltage in 6 different regions of the luminous intensity and current density was measured. As a result, it was found that the light emission intensity increased with an increase in applied voltage, as expected.

Claims (14)

1. A method of providing a patterned layer of an electroactive organic material, the method comprising:

the donor element containing the thermographic electroactive organic material transfer layer is selectively heated to remove unwanted portions of the electroactive organic material from the transfer layer, thereby forming a patterned layer of the desired electroactive organic material on the donor element.

2. The method of claim 1 further comprising transferring the graphic layer from the donor element to a substrate, the transferring preferably being by lamination.

3. The method of claim 2, further comprising, prior to the irradiating step, positioning the transfer layer of the donor element adjacent to the receiver element such that the removed undesired portion of the electroactive organic material layer is transferred to the receiver element.

4. The method of claim 2 wherein the donor element further comprises a base element and a heating layer disposed between the base element and the electroactive organic material layer, the heating layer preferably being a metal.

5. The method of claim 1 wherein the donor element further comprises means for facilitating transfer of the patterned layer from the heating layer to the substrate, preferably by providing a release material on the metal surface adjacent the layer of electroactive organic material, the release material being selected from the group consisting of polydimethylsiloxane, isodichlorosilane perfluorodecane, hexamethyldisilazane, dichlorosilane perfluorodecane, and tridecafluoro-1, 1, 2, 2-tetrahydrooctyl-1-methyldichlorosilane.

6. The method of claim 2 wherein the transferring step includes providing an adhesion between the patterning layer and the donor element that is less than the adhesion between the patterning layer and the substrate.

7. The method of claim 2, wherein the electroactive organic material comprises first and second layers of electroactive organic material, one of said layers being a layer of charge injection/transport material, and wherein selectively exposing the donor element to heat removes unwanted portions of the first and second electroactive organic materials, thereby forming two desired patterned layers of electroactive organic material on the donor element,

wherein the substrate preferably comprises a first electrical contact layer,

wherein the charge injection/transport material layer is preferably obtained by forming a coating layer from a conductive polyaniline solution containing xylene, 2-butoxyethanol and conductive polyaniline.

8. The method of claim 2, including selectively exposing the donor element to laser radiation to heat, or to heat by the action of a thermal print head and an array of conductive metal tips.

9. An article of manufacture produced comprising:

a base element;

a transfer layer comprising a desired pattern of electroactive organic material supported on a base element, wherein the transfer layer has been patterned by selectively heating to remove undesired portions of the electroactive organic material from the transfer layer, the transfer layer preferably comprising a patterned layer of a first and a second electroactive organic material.

10. The article of claim 9, wherein one of the first and second patterned layers is a charge injection/transport material, the charge injection/transport material layer preferably being formed as a coating from a solution of a conductive polyaniline comprising xylene, 2-butoxyethanol, and the conductive polyaniline.

11. The article of claim 9 further comprising a heating layer, preferably metal, between the base member and the transfer layer.

12. The article of claim 9, further comprising means between the transfer layer and the heating layer for facilitating transfer of the transfer layer.

13. An organic electronic device, the device comprising:

a first electrical contact layer;

a second electrical contact layer;

a pixelated pattern of an electroactive organic material located between the first and second electrical contact layers; the pixelated pattern is at least 10000 pixels per square centimeter.

14. An organic electronic device, the device comprising:

a first electrical contact layer;

a second electrical contact layer;

a pixelated pattern of an electroactive organic material located between the first and second electrical contact layers;

wherein each pixel has a length of less than about 100 microns and a minimum of about 10 microns, and each pixel has a width of less than about 100 microns and a minimum of about 10 microns; preferably, each pixel has a length of less than about 50 microns and a width of less than about 50 microns; preferably, each pixel has a length of less than about 30 microns and a width of less than about 30 microns.