Material for a functional layer of an organic electronic component, method for the production thereof, and use thereof

Translation of description of equivalent WO 03107453 A2

p0001description

p0002Material for a functional layer of an organic electronic component manufacturing processes and use of this

p0003The invention relates to a material for a functional layer of an organic electronic component, in particular one, from which both a conductive, a semi-conductive layer and an insulating function can be formed.

p0004There are materials for functional layers based on PEDOT-PSS [poly (3, 4-ethylenedioxythiophene) poly (styrene- sulfonate)] or PA I (polyaniline) -PSS known. These materials provide functional layers as thin films of the respective functional polymer.

p0005So far, it is necessary for the respective functional layer a specially suitable material by applying techniques such as spin coating, etc. to be processed. It is disadvantageous that, in particular for the mass production of "disposable electronics such as electronic cash chips, ID tags, etc., for such a component multiple functional polymers are used, which must be processed in each case under different conditions.

p0006Object of the present invention is therefore to provide a material that is suitable for all functional layers of an electronic component, so that the manufacturing techniques simplify and thus can be more cost-effective.

p0007There is a general recognition of the invention that a mixture of different fractions of a single functional polymer has an adjustable by the mixing ratio conductivity, the rheological properties of the mixture are unimpaired by the mixing ratio of the fractions. The invention relates to a material for forming a functional layer of an electronic component with adjustable conductivity, said material at least a mixture of feed comprising two fractions of a functional polymer, namely a first fraction which is based on a dispersion of the functional polymer in a first solvent, in which the functional polymer is at least partially dispersed and a second fraction of functional polymer which is based on a genuine th solution of the functional polymer in a second solvent, wherein the two fractions processed together, dispersed and / or dissolved and the mixing ratio of at least two fractions in connection with the thickness of the functional layer, the conductivity of the function layer formed from this material can be adjusted. Furthermore, subject of the invention is a method for preparing a material for a functional layer of an electronic component in which a mixture of two different fractions of a functional polymer is optionally combined in a solvent.

p0008According to one embodiment of the method a dispersion of the functional polymer and a solution of the functional polymer is added to a high boiling solvent, then by distillation, the lower boiling solvent removed so that ultimately form the different fractions of functional polymer in the high boiling solvent substantially the material. Here, one embodiment of the method that each said high boiling solvent it- tel is in equal parts, as the Group is present, added.

p0009According to an advantageous embodiment, the material is substantially free from the solvent and / or dispersing medium of the underlying fractions and / or comprises an additional, third solvent. The material can include any further additives and additives, as for these types the materials available and / or are useful as defoamers or wetting agents etc.

p0010As "Material * is present always called magnetic material according to the invention for forming a functional layer of an organic electronic component.

p0011According to another embodiment, the two groups are respectively in dry matter before the dispersion / solution.

p0012The two fractions designate two modifications, ie two presumably different states of a substance.

p0013According to an advantageous embodiment, the Funktionspo- lymer PEDOT or PANI.

p0014According to an advantageous embodiment, the functional polymer is present as a copolymer or mixture, the PSS comprises polystyrene sulfonate anions.

p0015According to one embodiment, the first solvent is water or other component with a high polarity in which the functional polymer is substantially insoluble.

p0016According to one embodiment of the invention, the second solvent is ethanol or other low boiling, polar solvent is preferably a polar-protic, the hydrogen bonds can form ..

p0017The term "low boiling solvent * to be here understood that have up to 150 ° C boiling point.

p0018In one embodiment, the third solvent is different from the first and / or the second solvent.

p0019According to an advantageous embodiment, an other alcohol used as the third solvent is ethylene glycol or ' sets, in particular mixtures of several alcohols, and / or alcohols with a carbon content of C4 to CIO, branched and unbranched, and polyhydric alcohols, or mixtures thereof, and mixtures with water, more preferably glycol and glycerol.

p0020The term "solution" is used when individual polymer particles are substantially surrounded by solvent molecules and it stands in contrast to the term "dispersion * denoting the state conglomerate in the individual polymer particles and form, for example, cluster, but do not knock or drop off, but substantially in the dispersed and not precipitate, so larger solid agglomerations form. Whether a component is referred to herein as a solvent or as a dispersing agent depends only on how the functional polymer each in question behaves in this medium. To consider the conditions that prevail during the preparation, storage and / or processing respectively.

p0021The term "organic material" or "functional material" or * functional polymer "herein encompasses all types of organic, organometallic and / or organic-inorganic plastic materials (hybrids), particularly those in English, for example with" referred to plastics. "This is to all kinds of materials except the semiconductors used for conventional diodes form (germanium, silicon) and the typical metallic conductors. A restriction in the dogmatic sense to organic material as carbon-containing tendes material is accordingly not intended, but is also thought of the widespread use of eg silicones. Furthermore, the term is no limitation on the molecular size, particularly to polymeric and / or oligomeric materials are, but it is certainly also the use of "small molecules" possible. the word element

p0022"Polymer" in the functional polymer is historically and makes no statement as to the existence of actual lent polymeric compound and no indication of whether it is a polymer blend or a copolymer or not.

p0023As dry matter here a fabric is referred to, which is free of solvent substantially.

p0024As "organic electronic component * is here, for example, a transistor, a diode, an optocoupler, a solar cell, an organic light-emitting diode, organic lighting, a display (active and passive matrix), a conductive fabric, an antistatic coating, or an optoelectronic component designated.

p0025In Further, en the invention is illustrated by way of Preparation:

p0026Here the conductivity is first modified by many orders of magnitude without changing the solvent environment. In this example, both come a mixture of two different PEDOT solutions (with the same solvent, for example,

p0027Ethylene glycol) are used, which due to their history (which is a solution of water-based solution containing other made of ethanol-based solution) have different conductivities. The solution consisting of water-based PEDOT (WPEDOT) obtained has a resistivity of 10^Λ2 ohm cm, consisting of ethanol-based PEDOT (EPEDOT) won one of 10 7 ohm-cm.

p0028Since the necessary surface conductivity is in components most important, by means of adjustment of the layer thickness (between 5 nm and 500 microns) the surface conductivity can be varied by as much as 10 orders of magnitude. In general, a surface resistance is then specified. For example, the ITO used for LCDs, OLEDs or solar cells as the anode one nen sheet resistance of 20 ohm / square. A PEDOT mixed with 10 s / cm (equivalent to 10^"1 Ohm cm resistivity) achieved with 5 microns thickness this conductive properties. For the preparation of the starting materials and WPEDOT EPEDOT the original solutions are, for example, commercially ertrieben inter alia from HC Starck, the same volume of ethylene glycol was added and then distilled off the original solvent in a rotary evaporator. Since ethylene glycol is distilled until 200 ° C, then remains a pure glycolic PEDOT solution. Since the origin of materials and WPEDOT EPEDOT are different in nature, the conductivity is drastically reduced by ethylene glycol by replacing the water in the case of WPEDOT, which is due to the dispersive nature of WPEDOT. In the case of EPEDOT, wherein there is a real solution, the conductivity is not changed by the replacement of ethanol by ethylene glycol. This creates two glycolic PEDOT variations with 5 orders of magnitude different conductivity. By mixing (diaphragm) of the two solutions can now each be set between conductivity (see Figure 1).

p0029The present invention is the problem of targeted fine tuning ( "Tuning *) the conductivity of the polymer film over many orders of magnitude while maintaining the optimum for the coating process solutions sungs- or dispersion characteristics described initially, to be resolved. By this invention, it is possible to use a polymer film whose conductivity can be arbitrarily selected within a wide range, with an inexpensive coating methods such. As screen printing, patterned or large areas apply at high resolution on a substrate. This is possible because the conductivity of the polymer is varied by different mixing ratios of the first and second group of functional polymer and / or by the choice of the third solvent, added admit without additives. This tension and viscosity remain unchanged surface and get the printability of the polymer. This will make it the first time to an organic electronic device, such as a transistor, to build from various mixtures of a single material. This leads to the so-called full-PEDOT transistor conductive PEDOT, semiconducting and insulating than anything PEDOT PEDOT, its production is cheaper by orders of magnitude known to date.

p0030The invention relates to a material (polymer mixture) to form a thin layer (5 nm to 500 .mu.m) with adjustable conductivity. The material comprises at least a mixture of two different fractions of a functional polymer, preferably in a solvent.

p0031The invention relates to a material for application of thin organic layers having a configurable conductivity. The material comprises at least a mixture of two different fractions of a functional polymer, preferably in a solvent, and is for example as a functional layer of an organic electronic component by means of different deposition techniques are used.