WO2008131750A2

WO2008131750A2 - Light-emitting component and method for the production thereof

Info

Publication number: WO2008131750A2
Application number: PCT/DE2008/000732
Authority: WO
Inventors: Sebastian Reineke; Gregor Schwartz; Karl Leo; Karsten Walzer
Original assignee: Novaled Ag
Priority date: 2007-04-30
Filing date: 2008-04-30
Publication date: 2008-11-06
Also published as: WO2008131750A3

Abstract

The invention relates to a light-emitting component, particularly an organic light-emitting diode, comprising an electrode, a counter electrode and an organic region which is arranged between the electrode and the counter electrode and comprises a region emitting organic light. The invention also relates to methods for producing a component of this type.

Description

Light emitting device and method for manufacturing

The invention relates to technologies in the field of organic light emitting device, in particular organic light emitting diode.

Background of the invention

Organic light-emitting diodes or organic light-emitting diodes (OLEDs) are now generally recognized as having the potential, in the field of lighting technology, to offer an alternative to conventional light sources such as incandescent lamps or fluorescent tubes. Meanwhile, the achieved performance efficiencies (see, for example, D'Andrade et al., Adv., Mater., 16 (2004) 1585) are significantly higher than those of incandescent bulbs. Recent reports suggest that the efficiencies of fluorescent tubes can be surpassed. For highest power efficiencies, phosphorescent emitters are currently used because they are designed to convert 100% of the charged carriers into light, i. 100% quantum efficiency can be achieved.

Another important criterion in addition to the power efficiency for everyday applicability as a light source is the service life. It is already pointed out in document EP 1 705 727 A1 that always a certain amount of blue or blue-green light must be present for the white light generation. In this spectral range, however, the concept of phosphorescence emitters reaches its limits, as far as the stability of the emitter molecules or even more of the matrix material is concerned, since the excitation energies approach the binding energies of the molecular building blocks. Therefore, the approach was chosen to cover the blue to blue-green spectral range with a fluorescent emitter and the longer wavelength range with phosphorescent emitters.

Document EP 1 705 727 A1 describes a concept of how, in spite of the intrinsically limited 25% quantum efficiency of direct light emission of a fluorescent blue emitter, the overall efficiency of a white light OLED can be brought to 100% by using a fluorescent blue emitter with a triplet energy , which is higher than the triplet energy of at least one phosphorescent emitter used. By Diffusion of the non-radiating Triplettexzitonen by the blue emitting layer to another emission layer containing the phosphorescent emitter, and subsequent exothermic energy transfer and the Triplettexzitonen the blue emitter can be used for the light emission.

Although an OLED with this concept can in principle achieve 100% quantum efficiency, however, shows in the experimental realization that, especially at high luminance the quantum efficiency is greatly reduced because of the necessary high excitron and charge carrier concentrations. On the one hand, the long life of the non-radiating triplet excitons in the blue-emitting layer is necessary so that the excitons can diffuse to the adjacent layer containing the phosphorescent emitter. On the other hand, it leads to a strong accumulation of excitons in its main formation zone. This results in an increased non-radiative extinction of excitons, since with increasing exciton density an exciton is always able to return to the ground state by losing its energy in the further excitation of another exciton (exciton-exciton-annihilation). Quantum efficiency therefore decreases with increasing current density, which is generally known as a "roll-off of efficiency.

Conventional, electrically undoped organic light-emitting diodes (OLEDs), which are also referred to as organic light-emitting diodes, depending on the design have a reduced number of layers. Here, for example, functions of a hole transport layer and an electron and exciton block layer or a hole and exciton block layer and an electron transport layer may each be combined into one emission layer structure.

The preparation of the individual organic layers can take place by means of thermal evaporation, molecular beam epitaxy, spin-on from solutions and by deposition from the gas phase. Conventional methods, such as the evaporation of organic materials, allow only structuring in one dimension. The standard emission layer structure may consist of a mixed evaporation of a host or matrix material and the phosphorescent emitter dye, usually at concentrations between 1mol% and 20mol%. A light-emitting device with organic layers and emission of triplet-exciton states with increased efficiency is described in the document DE 102 24 021 B4, wherein the device has a layer order with a hole-injecting contact - the anode, one or more hole-injecting and hole-transporting Layers, a system of stacked layers in the light emitting zone, one or more electron injecting and electron transporting layers and an electron injecting contact - a cathode - wherein the light emitting zone consists of a series of heterojunctions which form interfaces between the stacked layers, in the system stacked layers alternately a layer of a material with hole-transporting or bipolar transport properties and a layer of another material with electron-transporting or bipolar transport properties angegan are arranged and wherein at least one of the materials is mixed with a triplet emitter dopant.

One problem is that with the stacking sequences of different mixing systems within the light emission zone, although an increase in the external quantum efficiency can be achieved, but with these structures no reduced efficiency drop can be observed at high luminance. In addition, the stacking sequences of the mixing systems lead to increased recombination efficiency by trapping charge carriers at the interfaces of the heterojunctions.

Phosphorescent light-emitting components are known, in particular also in the embodiment as OLEDs. In known components, the external quantum efficiency decreases significantly at high brightnesses. The main reason for the decline in efficiency is the nature of phosphorescent emitter molecules, which, unlike conventional fluorescent dyes, emit from the electronic triplet state. The quantum-mechanically forbidden transition with total spin one becomes accessible to light emission through the use of heavy metals such as platinum or iridium as the central atom. The excited states, called excitons, have a mean lifetime that is orders of magnitude longer, even for modern phosphorescent emitter molecules, than for fluorescent dyes. For this reason, the triplet excitons are much more susceptible to all conceivable quenching mechanisms that cause the extinction of such excited State without the state can be the emission. Consequently, the quantum efficiency at high excitation densities or brightnesses decreases significantly.

The largest developmental leap in the field of organic light-emitting diodes in a thin-film OLED has been made by Tang et al., Appl. Phys. Lett. 51 (1987) 913, wherein the introduction of phosphorescent molecules has been provided as emitter molecules (see Baldo et al., Nature 395 (1998) 151). These have the distinct advantage of enabling an internal conversion efficiency of 100%. The use of heavy metals such as platinum or iridium as the central atom in this molecule strongly influences the electronic structure, which in this case results in both the emission from the triplet state and the intermolecular transfer rate from singlet to triplet state (ISC). "Intersystem crossing") and can be highly efficient (see Tsuboi, Journ. Lumin 119-120 (2006) 288).

In organic light-emitting diodes, the charge carriers, namely electrons and holes, are statistically injected with respect to their spin, so that as a result the excited states, also referred to as excitons, form with random spin distribution. Due to the spin multiplicity of one to three in the singlet and triplet state, only about 25% of the excitons are formed on average in the singlet state (see Baldo et al., Phys. Rev. B 60 (1999) 14422). In conventional fluorescent OLEDs, this is the limit for internal conversion efficiency, i. 25%. In phosphorescent molecules, both excitation states, singlet and triplet, are redirected to the triplet state (ISC) or formed so that the molecules are potential materials for internal 100% quantum efficiency in OLEDs. A disadvantage of the molecules is the long lifetime of the excited state compared to fluorescent dyes. Even for state-of-the-art phosphorescent molecules, the lifetime is several orders of magnitude higher, in the order of a few microseconds, cf. for this purpose, the emission from the singlet state with lifetimes of a few nanoseconds (Kawamura et al., J. Journ. Appl. Phys. 43 (2004) 7729).

In contrast to most fluorescence OLEDs whose emission zone is a pure layer of the fluorescent dye, phosphorescent dyes diluted in a host material are mixed in order to avoid so-called aggregate quenching (see Kawamura et al., Phys. Rev. Lett. 2006) 017404). Here, it is important that the host material has a higher triplet energy than or at least as high triplet energy as the emitter dye to exclude the energy transfer of the emitter triplet excitons on the host molecules as a possible loss channel. Furthermore, the emission layers require relatively high concentrations of the emitter dye (~ 5-10 mol%) because the energy transfer from the host material to the emitter molecule is slower and shorter-range. The energy transfer is a Dexter process (see Dexter, Journ. Chem. Phys. 21 (1953) 836). This in turn is detrimental to the absolute efficiency, since it can already come to the aforementioned aggregate quenching at the concentrations. At concentration, exciton diffusion directly on the emitter molecules is readily possible.

Organic components with a mixed system of host material and phosphorescent emitter dye further contain blocker or block layers adjacent to the emission zone, since even with the long lifetime, the average diffusion length of the excitons increases, which are intended to confine both charge carriers and triplet excitons into the emission zone. To achieve the latter, the layers must have a much higher triplet energy than that of the emitter dye (Tβiocker »temitter / ~ 0.4eV) (see Goushi et al., Journ. Appl. Phys., 95 (2004) 7798).

The long lifetime makes the excited triplet states very susceptible to all quenching mechanisms, which are triplet-triplet annihilation (TTA), triplet-carrier quenching, and field-induced dissociation of the excitons into free charge carriers, especially at high excitation densities (see Reineke et al., Phys Rev. B 75 (2007) 125328). Here, the triplet-triplet annihilation is the dominant process. The process can in principle be done by two different mechanisms: (a) by diffusion of the triplet excitons until two excited states are close enough to annihilate, and (b) by long-range interaction, based on the Förster energy transfer model.

If two excited states are so close that the electronic orbitals overlap and interact, the extinction step can also take place by the so-called Dexter energy transfer. In the latter case, the extinction happens in one step. The process is determined only by the so-called Försterradius the emitting molecule, which defines the maximum distance between two excited states, in the erasure still takes place (see Staroske et al., Phys. Rev. Lett 98 (2007) 197402). The latter process, in contrast to the diffusion-based mechanism, does not depend on the concentration of the emitter molecules, the Förster-based mechanism being an intrinsic limit for the triplet-triplet quenching TTA in the OLEDs, since it is determined solely by the optical properties of the materials used becomes. In other words, the diffusion-based extinguishing mechanism is always intrinsically accompanied by the ranger-based extinction.

In order to minimize the efficiency decline in phosphorescent OLEDs, the approaches outlined below were chosen.

Attempts have been made to minimize the intrinsic lifetime of the excited triplet state on the emitter molecule. Here, it seems, development is exhausted, modern emitters have triplet lifetimes of a microsecond and less. The heavy metal has a very strong influence on the properties and finds today's optimum with iridium (see Baldo et al., Nature 395 (1998) 151; Baldo et al., Phys. Rev. B 62 (2000) 10967).

It has also been proposed to minimize the lifetime of the excited state by ambient defining optical properties. The lifetime can be reduced by up to 50% by introducing a higher quality OLED microcavity (Huang et al., Appl. Phys. Lett. 89 (2006) 263512).

Finally, it has been proposed to minimize the exciton density required for a given brightness by widening the recombination zone in the emission zone. This can be achieved, for example, by the approach of the double emission layer (He, Appl. Phys. Lett. 85 (2004) 3911).

In organic light-emitting components, there are some studies for the so-called emission layer, ie the area of light generation, in which the emission zone by quantum well structures, but usually using fluorescent dyes is constructed. There are sometimes drastic efficiency improvements, which has as a major cause that the recombination efficiency is increased, for example by better charge carrier capture (Huang, Appl. Phys. Lett 73 (1998) 3348; Xie, Appl. Phys. Lett. 80 (2002). 1477). Since the efficiency decrease in fluorescent OLEDs is only insignificantly determined by bimolecular processes due to the short life of the singlet state, these structures do not achieve any improvements in the efficiency decrease.

Phosphorescent OLEDs whose emission zone has a quantum well structure are described in Cheng et al, Jpn. J. Appl. Phys. 42 (2003) L376. Here, the known triplet emitter 2,3,7,8,12,13,17,18-octaethyl-21H23 H-porphin platinum (II) (PtOEP) is used. Compared to a standard structure, the quantum well structure has an increase in external quantum efficiency by a factor of about two. The quantum well structure shows a greater decrease in the quantum efficiency at high brightnesses, so that the structures given at current densities of about 200mA / cm ² ultimately have almost identical efficiency values. The effect is explained by the saturation of the emitter molecules.

The spatial separation of different areas of mixed systems of host material and emitter dye has another advantage in itself. The separation largely decouples any energy transfer, also and especially at low excitation densities, between the centers. Typical phosphorescent emitters have Förster radii of less than 2nm, allowing Förster-based energy transfer between neighboring molecules

Distances of this magnitude can be prevented (Kawamura et al., Phys. Rev. Lett. 96 (2006) 017404).

Emission layer structures have been described in which all emitter dyes are incorporated in a host or matrix material having different concentrations (D'Andrade, Adv. Mat. 16 (2004) 624). The presented emission layer structure reaches about 16 lm / W at 100 cd / m ² and 11.1 ml / W at 1000 cd / m ² . This corresponds to an efficiency reduction to 69% of the value at 100 cd / m ^2. Summary of the invention

The invention has for its object to provide an improved light-emitting device with high efficiency, even at high luminance and a method for manufacturing.

This object is achieved by a light-emitting device according to independent claim 1. Furthermore, an organic light-emitting component according to independent claim 31 and a method for producing according to independent claim 49 are provided. Advantageous embodiments of the invention are the subject of dependent subclaims.

According to one aspect, the invention encompasses the idea of a light-emitting component, in particular an organic light-emitting diode, having an electrode and a counterelectrode and an organic region arranged between the electrode and the counterelectrode with an organic light-emitting region which comprises at least one emission layer and which during application an electrical voltage is applied to the electrode and the counter electrode emitting light in several color ranges in the visible spectral range, optionally up to white light, the emission layer at least one predominantly in the blue or blue-green spectral light emitting fluorescent emitter and at least one predominantly in the non-blue spectral light emitting phosphorescent emitter, in the emission layer for the at least one fluorescent emitter a triplet energy for an energy level of a triplet state size r is equal to or approximately equal to (within 0, IeV) a triplet energy for an energy level of a triplet state of the at least one phosphorescent emitter, and the organic light emitting region comprises at least 5% of the generated light in the visible spectral region as singlet state fluorescent light at least one fluorescent emitter is formed releasably in the emission layer.

Surprisingly, it has been found that a light-emitting organic component according to this embodiment has a very small drop in quantum efficiency with increasing current. The invention thus has compared to the prior art, in particular over the Document EP 1 705 727 A1, has the advantage that a highly efficient and at the same time long-lasting light-emitting component for light emission in several color ranges in the visible spectral range up to white light is created even at high luminances, as are necessary in lighting technology. The observed small drop in quantum efficiency can be explained as follows: The problem that at the high current densities necessary for high luminance a large accumulation of triplet excitons in the fluorescent emission layer arises, which leads to the so-called "roll-off ^{1 of} the efficiency is direct admixture of one or more phosphorescent emitter dissolved, since thus formed on one or all of the fluorescent emitter Triplettexzitonen be transferred directly to the or the phosphorescent emitter and the accumulation can not even arise.

Another important advantage of the invention is the simpler manufacture of the device, since less layers are to be applied by mixing the emitter.

It turns out that with careful design of the organic light emitting device further optimization is possible. Too high a concentration of the phosphorescent emitter in the emission layer also promotes the transfer of singlet excitons from the fluorescent emitter. This is, to some degree, an undesirable effect, as it can no longer produce fluorescent light from the singlet excitons. Experiments have shown that a concentration of the phosphorescent emitter of about 0.25 weight percent in the fluorescent emitter in the emission layer of the device leads to a balanced emission of fluorescent and phosphorescent light. This is a technically well controllable concentration (see, for example, Shao et al., Appl. Phys. Lett. 86, 073510 (2005)). Of course, the actual concentration to be set of the phosphorescent emitter can also be chosen to be larger or smaller, depending on the emitters used and the desired color impression of the emitted light.

The proportion of fluorescent light is adjusted via the concentration ratio of fluorescent and phosphorescent material in the emission layer. The more fluorescent emitter is contained, the higher the proportion of fluorescent light in the total light emission. Experimentally, the fluorescent light can then be measured by recording an electroluminescence spectrum and determining the intensity component of the emitter which fluoresces in the blue spectral region.

A preferred embodiment of the invention provides that the emission layer consists of a solid layer of the at least one fluorescent emitter used as the matrix material, in which the at least one phosphorescent emitter is embedded. In this embodiment, the invention also stands out in particular from the state of the art for multicolor-emitting polymer OLEDs, where the emission layer generally consists of a polymer with good charge carrier conduction properties, to which several types of emitter molecules are admixed (see, for example, Shih et al., Appl. Phys Lett., 88, 251110 (2006)), since here no matrix exclusively responsible for the charge carrier transport is used, but this function is taken over by the fluorescent emitter.

In an expedient embodiment of the invention it can be provided that the emission layer consists of an organic material into which the at least one fluorescent emitter with a concentration between 0.1 and 50 mol% and the at least one phosphorescent emitter are embedded.

An advantageous embodiment of the invention provides that the organic light emitting region is at least 10% proportion of the generated light in the visible spectral range as fluorescent light of singlet states of the at least one fluorescent emitter in the emission layer is made.

Preferably, a development of the invention provides that the organic light-emitting region is at least 15% proportion of the generated light in the visible spectral range as fluorescent light of singlet states of the at least one fluorescent emitter in the emission layer formed.

In an advantageous embodiment of the invention can be provided that the organic light emitting area is at least 20% proportion of the generated light in the visible spectral range as fluorescent light of singlet states of the at least one fluorescent emitter in the emission layer made. A further development of the invention can provide that the organic light-emitting region forms at least 25% of the generated light in the visible spectral range as fluorescent light of singlet states of the at least one fluorescent emitter in the emission layer. In connection with white light spectra, the smaller a component is in the blue spectral range, that is to say for the components described here the fluorescent light component, the lower the color temperature of the electroluminescence spectrum. However, when high-efficiency emitters with near-100% luminescence efficiencies are used, the invention only allows high quantum efficiencies (close to 100% internal). In other words, an electroluminescence spectrum with a 25% proportion of fluorescent light in the blue spectral range corresponds to the spectrum with the highest color temperature and at the same time the highest possible quantum efficiency when using highly efficient emitters with luminescence efficiencies close to 100%. If the fluorescence component is more than 25%, the color temperature becomes higher, but the quantum efficiency decreases.

A preferred development of the invention provides that the organic light-emitting region comprises a further emission layer with at least one phosphorescent emitter which emits light predominantly in the non-blue spectral range.

In an expedient embodiment of the invention, it can be provided that the emission layer and the further emission layer are formed adjoining one another.

An advantageous embodiment of the invention provides that the emission layer and the further emission layer are formed so as to transport holes, and that a distance between one of the surfaces of the emission layer facing the cathode and a surface of the cathode facing the emission layer is smaller than a distance between one of the cathodes facing surface of the further emission layer and the further emission layer facing surface of the cathode.

Preferably, a development of the invention provides that the emission layer and the further emission layer are formed transporting electrons and that a distance between one of the counter electrode facing the anode surface of the Emission layer and one of the emission layer facing surface of the anode is smaller than a distance between an anode surface facing the further emission layer and the further emission layer facing surface of the anode.

In an advantageous embodiment of the invention can be provided that the emission layer is formed transporting electrons and the further emission layer is formed holes transporting and that a distance between one of the electrode formed as a cathode surface facing the emission layer and the emission layer facing surface of the cathode smaller than is a distance between a surface of the further emission layer facing the cathode and a surface of the cathode facing the further emission layer.

A development of the invention can provide that the emission layer is formed transporting holes and the further emission layer is formed transporting electrons and that a distance between one of the counter electrode formed as an anode facing surface of the emission layer and one of the emission layer facing

Surface of the anode smaller than a distance between one of the anode facing

Surface of the further emission layer and one of the further emission layer facing surface of the anode.

A preferred embodiment of the invention provides that a hole block layer is arranged between the emission layer and the cathode, wherein the hole block layer is transporting electrons and an organic material of the hole block layer has a HOMO level which is at least about 0.3 eV lower than a HOMO. Level of the fluorescent emitter in the emission layer. It has been shown that an energy barrier of less than 0.3 eV is not sufficient to effectively block holes.

In an expedient embodiment of the invention, it can be provided that an electron block layer is arranged between the emission layer and the anode, wherein the electron block layer is hole transporting and an organic material of the electron block layer has a LUMO level which is at least about 0.3 eV is higher than a LUMO level of the fluorescent emitter in the emission layer. It has been shown that an energy barrier of less than 0.3 eV is usually insufficient to effectively block electrons.

An advantageous embodiment of the invention provides that a minimum energy of singlet excitons and triplet excitons in the hole block layer or in the electron block layer is greater than a minimum energy of singlet excitons and triplet excitons in the emission layer.

Preferably, a development of the invention provides that the emission layer and / or the further emission layer are formed in multiple layers.

In an advantageous embodiment of the invention can be provided that the emission layer has a thickness between about 10 nm and about 100 nm. Layers with a thickness of at least about 10 nm are still technically manageable. Layers with a thickness of more than 100 nm lead to an excessive voltage drop.

A development of the invention can provide that the organic light-emitting region is formed emitting white light, wherein the at least one phosphorescent emitter in the emission layer and / or in the further emission layer emitter emitting in the red, orange, yellow or green spectral emitter is.

A preferred embodiment of the invention provides that a respective doped organic layer is formed between the organic light emitting region and the electrode and / or between the organic light emitting region and the counter electrode.

In an expedient embodiment of the invention, provision can be made for the respective doped organic layer to be a layer doped with an acceptor material or n-doped with a donor material.

An advantageous embodiment of the invention provides that the at least one fluorescent emitter in the emission layer, a metal-organic compound or a Complex compound with a metal with an atomic number is less than 40. This ensures that there is no strong spin-orbit coupling for the material.

A preferred embodiment of the invention provides that the at least one fluorescent emitter in the emission layer comprises an electron-withdrawing substituent from one of the following classes: halogens such as fluorine, chlorine, bromine or iodine; CN; halogenated or cyano-substituted alkanes or alkenes, in particular trifluoromethyl, pentafluoroethyl,

Cyanovinyl, dicyanovinyl, tricyanovinyl; halogenated or cyano-substituted aryl radicals, in particular pentafluorophenyl; and boryl radicals, in particular dialkylboryl, dialkylboryl having substituents on the alkyl groups, diarylboryl or diarylboryl having substituents on the

Aryl groups.

In an advantageous embodiment of the invention it can be provided that the at least one fluorescent emitter in the emission layer comprises an electron-donating substituent of one of the following classes: alkyl radicals such as methyl, ethyl, tert-butyl, isopropyl; alkoxy; Aryl radicals with or without substituents on the aryl, in particular tolyl and mesithyl; and amino groups, in particular NH 2, dialkylamine, diarylamine and diarlyamine having substituents on the aryl.

A development of the invention can provide that the fluorescent at least one emitter in the emission layer comprises a functional group having an electron acceptor property from one of the following classes: oxadiazole, triazole, benzothiadiazoles, benzimidazoles and N-aryl-benzimidazoles, bipyridine, cyanovinyl , Quinolines, triarylboryl, silol units, in particular derivative groups of silacyclopentadiene, cyclooctatetraene, quinoid structures and ketones, including quinolines, thiophene derivatives, pyrazolines, pentaaryl-cyclopentadiene, benzothiadiazoles, oligo-para-phenyl with electron-withdrawing substituents and fluorene and spiro Bifluorene with electron-withdrawing substituents.

A preferred embodiment of the invention provides that the fluorescent at least one emitter in the emission layer comprises a functional group having an electron donor property from one of the following classes: triarylamines, oligo-para-phenyl or oligo-meta-phenyl, carbazoles, Fluorene or spiro-bifluorenes, phenylene-vinylene units, naphthalene, anthracene, perylene, pyrene and thiophene. In an expedient embodiment of the invention, it can be provided that the following features are formed: the electrode is formed as an optically reflective electrode, a charge carrier transport layer having a layer thickness d1 is arranged between the emission zone and the optically reflecting electrode, and for the layer thickness dl = (λbi _au / 4) -ET, where ET is the penetration depth of electromagnetic waves into the optically reflecting electrode and λ _b i _{au is} a wavelength in the blue spectral range from 380nm to 500nm.

The description of an effective penetration depth ET is made by means of phase shift Φκathode of the light in the reflection. This shift depends on the cathode material (metal) and the wavelength and is calculated from the optical constants of the adjacent materials (see, for example, Dodabalapur et al., Journal of Applied Physics, 80, 6954 (1996)): z = λ / 4 - | (* Φκathode λy4π) | with Φ Thode _Ka = arctan (2n _o k _m / (n _o -n ² _m ² _m ² -k)). U ₀ is the real part and k _{0 is} the imaginary part of the complex refractive index of the organic layers, n _m is the real part and k _{m is} the imaginary part of the complex refractive index of the material of which the cathode is made.

An advantageous embodiment of the invention provides that the organic region is formed with a layer thickness dOB, for which applies: dOB = dOBl + dOB2-dAnode, where dOBl = (2 * n + 1) * 0.25 * λ _b iau and dOB2 = m * 0.5 * λ _b i _au and where dOBl is a distance of

Emission layer from a cathode, n integer n is greater than or equal to zero, dOB2 is one

Distance of the emission layer from an interface between an anode and a

Support substrate, m is a natural number greater than or equal to 1 and dAnode a layer thickness of the anode. The carrier substrate used is preferably glass.

Preferably, a development of the invention provides that in the emission layer, a space region having a first concentration of the at least one phosphorescent emitter and a further space region with a second, different from the first concentration concentration of the at least one phosphorescent emitter are formed. In an advantageous embodiment of the invention can be provided that in the emission layer, a space area is formed, which is free of an admixture of the at least one phosphorescent emitter.

Furthermore, the invention provides an organic light-emitting component, in particular a phosphorescent organic light-emitting diode, having an anode and a cathode and an arrangement of organic layers therebetween, which comprises a hole transport layer, an emission layer and an electron transport layer, the emission layer having a sub-structuring with zones, which zones comprising at least one host material and zones comprising a mixing system with at least one phosphorescent emitter dye, wherein the zones consisting of the mixing system are spatially separated from each other by the zones consisting of the at least one host material. Such a device may also be referred to as a phosphorescent organic device.

Preferably, the triplet energies (Twin) of the at least one host material is greater than the triplet energy (T _Em m _er ) of the at least one phosphorescent emitter dye (Twm>

1 emitter) -

The mixing system may be formed by the at least one host material or by using one or more host materials different therefrom. Also, at least one additional host material may be added to the at least one host material. In contrast to the mixing system which contains one or more phosphorescent emitter dyes, the zones consisting of the at least one host material are free of emitter dyes and consist of one or more host materials. Host material ("matrix material", "host material") is generally the material that is used to transfer excitons from it to the emitter dye, a kind of donor material.

The emission layer can have layer-like zones of the mixed system of host material and emitter dye by a given sub-structuring, the sub-structuring consisting of sequential sequence of layer-like zones in the form of a vertical structuring of zones of pure host material and mixed system zones Host material and phosphorescent emitter light emitting emitter is formed.

The emission layer may, on the other hand, have layered zones of the mixed system of host material and emitter dye by a given sub-patterning, the sub-patterning being formed by sequential sequence of layered zones in the form of a lateral structuring of zones of pure host material and mixed system zones of host material and phosphorescent emitter dye emitting light , The emission layer can also consist of a vertical structuring and a lateral structuring of layer-like zones. Finally, in the emission layer, the zones of the mixing systems and / or the host materials may be formed as spherical or cubic bodies or as bodies of predetermined geometry. Both host material and emitter dye of different emission layers may be different.

The hole transport layers can be combined in one layer and / or the electron transport layers can be combined in one layer.

The zones of pure host material may be replaced by zones of another host material, the triplet energy of which is greater than the triplet energy of the emitter dye employed. The zones pure host material may be replaced by a plurality of materials by zones of a combination of materials, and their triplet energy TEmit Tic _o m _b greater than the triplet energy _te r of the emitter dye with Tκ _O mb> Temmer are for all materials. Also, different zones of pure host material may be replaced in any sequential order of zones of multiple materials. Different zones of the mixing system may contain different phosphorescent emitter dyes. The zones of a mixing system may contain a plurality of different host materials and / or a plurality of different emitter dyes.

The vertical patterning may be performed during a mixed vaporization of host material and emitter dye by an array of mechanically movable apertures in front of the emitter dye source which periodically interrupt the evaporation of the emitter dye. The lateral structuring can be generated during the mixed vaporization of host material and emitter dye by periodically introducing a shadow mask directly in front of the substrate. Such a mask is in its resolution by the Production limited (for example, laser beam cutting diffraction limit), so that centers produced in this way have an extension in the micrometer range. By quickly shifting the shadow mask in the x and / or y direction about the normal (z direction) of the mask itself, the effective openings of the mask can be drastically reduced. In this case, the displacement in both directions is preferably smaller than the diameter of the openings in the shadow mask. Since a combination of vertical and lateral structuring is possible, a sub-structuring in all directions can be achieved.

In the case of phosphorescent organic components, as described above, relatively high concentrations of the emitter material must be introduced into a host material. This is necessary to efficiently trap the electrically formed excitons on the emitter dye. The high concentration causes the excited triplet states of the emitter dye to efficiently diffuse on a lattice of unexcited emitter dyes. The diffusion is a Dexter process, typically with l-2nm interaction range (Dexter, Journ. Chem. Phys. 21 (1953) 836).

It is essential that the diffusion on the grating of the emitter dyes is effectively prevented. The diffusion is suppressed by the substructure of the emission layer, which restricts the excitons in their diffusion. The substructures are not needed to efficiently trap charges to increase, for example, recombination efficiency and thus absolute electroluminescent efficiency (Cheng et al., Jpn. J. Appl. Phys. 42 (2003) L376). Instead, it is attempted to confine the emitter dyes in zones spatially surrounded by a material whose triplet energy, similar to that of conventional blocking layers, is high relative to the triplet energy of the emitter dye. In this case, the effective concentration of the emitter dyes in these zones is not reduced in order to allow efficient energy transfer of the Wirtsexzitonen on the emitter. It is exploited that the process of diffusion is a random process without preferential direction, and further that each diffusion step to an adjacent molecule is not affected by the previous step. By the introduction of energetic barriers that prevent diffusion of the excited state in this direction, so the effective probability of diffusion in favor of the radiative recombination of excitons, ie Emission of light, reduced. Neighboring excitonic sub-layer structures are located further apart than the average Dexter-type interaction range, ie, at least about 1 to about 2 nm.

It is only relevant to the implementation of the sub-patterning that the triplet energy of the material surrounding the emitter dye zones is higher than that of the emitter-dye triplet energy in order to efficiently hold the dye-triplet excitons in the zones. At best, this structure may be prepared from a combination of pure, conventional host material and a mixed system of host material and emitter dye. The emission layer is patterned such that there are defined separated exciton sub-structures of the mixing system in an environment of the pure host material within the emission layer.

A development of the invention may provide that the zones are formed in a layer structure, wherein the layer structure comprises a sequential sequence of layer-like zones in the form of a vertical structuring of the zones consisting of the mixing system and the zones consisting of the at least one host material.

A preferred embodiment of the invention provides that the zones are formed in a layer structure, the layer structure comprising a sequential sequence of layer-like zones in the form of a lateral structuring of the zones consisting of the mixing system and the zones consisting of the at least one host material.

In an expedient embodiment of the invention can be provided that at least a portion of the zones are formed as a spherical or cubic body.

An advantageous embodiment of the invention provides that adjacent boundary surfaces of the zones consisting of the mixing system are at least at a distance in the nanometer range from each other, wherein the distance corresponds to a thickness of the zones consisting of the at least one host material. The distance is preferably at least two nanometers. Preferably, a development of the invention provides that the hole transport layer is p-doped and / or the electron transport layer is n-doped. Provided is an electrical doping.

In an advantageous embodiment of the invention it can be provided that the zones consisting of the at least one host material are replaced by zones of another host material, wherein its triplet energy (Twi _rt i) greater than the triplet energy (T _em m _er ) of the at least one phosphorescent emitter dye with Twirt9i> TEmmer.

A development of the invention can provide that zones consisting of the at least one host material are replaced by zones of a material combination of several materials, their triplet energies (Tκ _Omb ) being greater than the triplet energies (T _Em m _er ) of the at least one phosphorescent emitter dye are with Tκ _O mb> temm _e r for all materials.

A preferred development of the invention provides that zones consisting of the at least one host material are formed in sequential order with zones of several materials.

In an expedient embodiment of the invention can be provided that various phosphorescent emitter dyes are included in the mixing systems. The different emitter dyes differ by their respective emission spectrum.

An advantageous embodiment of the invention provides that several mixing systems are formed with different host materials. A mixing system is preferably formed from one or more host materials and one or more emitter dyes incorporated therein.

Preferably, a development of the invention provides that additional emission layers are formed with a fluorescence emission from singlet states. The additional

Emission layers are considered to be areas composed of one or more fluorescent

Emitter dyes or as areas consisting of a mixing system with one or formed a plurality of host material and one or more emitter fluorescent dyes.

In an advantageous embodiment of the invention, it may be provided that in the mixing systems, the concentration of the at least one phosphorescent emitter dye in the at least one host material is between 0.1 mol% and 50 mol%. 0.1 mol% ensures efficient transfer of the excitons from the host or matrix material to the emitter dye, and greater than 50 mol% significantly reduces the efficiency of aggregation emission.

A development of the invention may provide that a distance between the zones consisting of the at least one host material is between about 2 nm and about 20 nm. At a distance of about 2nm distance, the individual zones are sufficiently separated so that short-range energy transfer processes do not prevent the desired effect of localization. A distance of more than about 20nm leads to high voltages in the device. In addition, the transfer of host material to emitter dye becomes inefficient or no longer takes place.

A preferred embodiment of the invention provides that the zones consisting of the mixing system have a spatial extent of about 0.5 nm to about 100 nm. Smaller 0.5nm leads to a molecular size, which is technically hardly practicable.

In an expedient embodiment of the invention, it may be provided that the organic layers consist of small molecules vapor-deposited in a vacuum or partly of polymers.

An advantageous embodiment of the invention provides that the emission layer has a further sub-structuring, in which a mixed color light up to the white light-emitting combination of different emitter dyes, which have different basic emission spectra, is provided in different zones of a mixed area. Preferably, it is phosphorescent emitter dyes, but also fluorescent emitter dyes can be provided. Preferably, a further development of the invention provides that the triplet energies T _W i _rt of host materials are less than or equal to the triplet energies Te _m m _{er of} the emitter dyes.

For the generation of a coordinated color light emission up to the white light emission, an emission layer structure with at least one emission layer with a substructuring is formed. The at least one emission layer comprises a combination of different emitter materials with different base emission spectra in different zones of a mixing area, so that color-matched light or white light can be emitted. The different layers (zones) with different emission dyes, which in each case represent a mixed area, can also form an array of multiple emission layers. The further sub-structuring of the emission layer is superimposed with the zone structuring described above.

Energy transfer processes between different emitter dyes are suppressed for the generation of white light, since otherwise the energy is transferred by efficient transfer mechanisms to the most energetically favorable state, in particular the red emitter states, before a recombination occurs with the emission of photons. Accordingly, by means of the proposed device, both white light can be achieved by the emission of different zones with different emission spectrum and the reduction of the diffusion-based triplet triplet deletion. From the combinatorial possibility of arranging different emitter dyes spatially in the emission layer structure results in a simplified, modular variability in color matching to achieve light of a given spectrum, in particular white light.

The device having at least one emission layer for generating white light may have regions in which the triplet energy Twi _{rt of} the host material is less than or equal to the triplet energies T _E mm _e r of the emitter dye with Twin <Temmer or Twm ⁼ T _Em i _tter are. The component for emitting white light with at least one emission layer may additionally contain fluorescent emission layers, which in turn may be either pure layers of the emitter dye and / or a mixed system of host material and emitter dye. The light extraction efficiency of the device may be for the blue spectral range, the range between 400nm and 500nm in wavelength, and this optimization can be done by adjusting the layer thicknesses of the transport layers.

Such components are realized by means of a manufacturing method using different emitter dyes with different emission colors in a proposed emission layer structure for a coordinated color emission or a white light emission.

Also provided is a method for producing an organic component, in particular a phosphorescent organic light-emitting diode, in which an anode and a cathode and between them an arrangement of organic layers are formed which comprises a hole transport layer, an emission layer and an electron transport layer, wherein the emission layer is provided with a sub-layer. Structuring is formed with zones which zones comprises at least one host material and zones consisting of a mixed system of at least one phosphorescent emitter dye and the at least one host material, wherein the zones consisting of the mixing system spatially separated by the zones consisting of the at least one host material be formed. The method of manufacture may be extended or adapted accordingly in connection with the advantageous embodiments of the component.

Description of preferred embodiments of the invention

The invention is explained below with reference to embodiments with reference to figures of the drawing. Hereby show:

Fig. 1 is a schematic representation of a layer arrangement of an organic light-emitting component, Fig. 2 is a schematic representation of a layer arrangement of a further organic

3 is a schematic representation of a layer arrangement of another organic light-emitting component, 4 shows a graph for the quantum efficiency as a function of the brightness of a reference light-emitting diode according to the prior art and an organic light-emitting diode according to the invention,

5 shows a graphic representation of an electroluminescence spectrum of the organic light-emitting diode according to the invention,

6 is a graphical representation of an electric field distribution of the light emission of an organic light-emitting component having a plurality of emission layers with different emission wavelengths,

FIG. 7 is a graph showing a field distribution of light emission of two organic light emitting devices having different ones. FIG

Cathode material (aluminum and silver),

8 shows a graphic representation of an electric field distribution of light with a wavelength of 470 nm in an organic light-emitting component with layer thicknesses z and d optimized for this wavelength, which define distances of the emission zone from the cathode and an anode / glass substrate interface.

9 shows an electroluminescence spectrum.

10 shows a graph for the quantum efficiency as a function of the brightness of a reference light-emitting diode according to the prior art and a further organic light-emitting diode according to the invention, FIG. 11 shows a schematic representation of a layer sequence for a known OLED according to the prior art (I Ia ), an inventive OLED (I Ib) and an inventive OLED in a work function (eV) layer thickness diagram (Hc),

12 is a schematic representation of an emission layer in vertical layer sequence B A (12a), B C (12b), B C + D (12c) and B C D (12d), where A is a pure

Host material, B is a mixed system of host material and emitter dye, C is a host material other than A with the same physical specifications as A and D is another host material different from A with the same physical specifications as A. FIG. 13 is a schematic representation of an emission layer with A and B-components for a realization of a substructuring in all spatial directions in a perspective view (13a) and a side view (13b), FIG. 14 shows a photoluminescence spectrum of one 20 nm mixed-system layer TCTA: Ir (ppy) ₃ , wherein the broken-line quadratic curve for the reference emission layer is 9.6 mol% and the dashed-circle curve for the sub-layer structure emission layer is 11, FIG. 15 shows a plurality of photoluminescence decay curves for samples from the preliminary investigation according to FIG. 14, the dashed square curve for the reference emission layer being 9.6 mol% and the dashed curve for the sub-layer structure emission layer Fig. 16 is a current density-voltage characteristic of an OLED, wherein the dashed square curve for the reference emission layer is 9.6 mol% and the dashed-line curve is 11.4 mol% with the reference structure having larger TTA amounts for the sub-layer structure emission layer with 11, 4mol% apply and wherein for the sub-layer OLED a small additional barrier is to be noted, Fig. 17 Electroluminescence spectra of devices according to FIGS. 14 to 16, wherein the dashed square curve for the reference emission layer with 9.6 mol% and the dashed curve for the sub-layer structure emission layer with 11, 4 mol% apply, wherein also 18 shows a representation of the external quantum efficiency as a function of the current density for the components according to FIGS. 14 to 17, wherein the dashed quadratic curve for the reference emission layer is shown in FIG , 6mol% and the dashed curve for the sub-layer structure emission layer with ll, 4mol% apply, in addition Fit functions (solid lined and dashed) are shown, the. quantify the efficiency decrease at high brightness levels,

19 shows several organic materials which can be used in the components, FIG. 20 shows further organic materials which can be used in the components, FIG. 21 shows schematic representations of emission layer structures for an emission layer structure with the relative triplet energies of all used Materials using FΙr (pic), Ir (ppy) ₃ and Ir (MDQ) ₂ (acac) (21a), a

Emission layer structure with the relative triplet energies of all materials used when using FΙr (pic), Ir (ppy) ₃ and Ir (MDQ) ₂ (acac) (21b), an emission layer structure with the relative triplet energies of all used Materials using FIr (pic), Ir (ppy) ₃ and Ir (MDQ) ₂ (acac) (21c) and a schematic representation of the energy diagram of the associated device, an OLED (2Id),

FIG. 22 shows basic emission spectra of usable emitter dyes (here: FΙr (pic), Ir (ppy) ₃ and Ir (MDQ) ₂ (acac)) in an emission layer structure, FIG.

23 shows emission spectra of two OLEDs with emission layer structures according to FIG. 21a and FIG. 21b, the spectra of which is an additive composition from the basic emission spectra shown in FIG. 22, FIG.

FIG. 24 shows an emission spectrum of a third OLED according to FIG. 21 d with a third emission layer structure according to FIG. 21 c, which component of all

Base emitter colors, where the color coordinates of the emission are given according to CIE standard,

FIG. 25 shows the external quantum efficiency and the power efficiency of the third embodiment. FIG

FIG. 26 shows usable organic materials for the emission layer structures of components: 1. Iridium bis (4,6, -difluorophenyl-pyridinato-N, C2) FIG. 26 shows the emission layer structure according to FIG. 21c and FIG. -picolinate, abbreviated FΙr (pic), 2. iridium (III) bis (2-methyldibenzo [f, h] quinoxaline) (acetylacetonate), abbreviated Ir (MDQ) ₂ (acac), 3. N, N, N ' , N'-tetrakis (4-methoxyphenyl) benzidines, sbgek. MeO-TPD and4. fac-tris (2-phenylpyridine) iridium (Ir (ppy) ₃ ),

FIG. 27 utilizes organic materials for the emission layer structures of FIG

Components: 5. 4,4 ', 4 "-tris (N-carbazolyl) -triphenylamines (TCTA), 6. 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethanes (F4-). TCNQ), 7,4,7-diphenyl-1,10-phenanthroline (Bphen), 8. N, N'-di (naphthalen-2-yl) -N, N'-diphenylbenzidine (NPB) and

FIG. 28 usable organic material: 9,2,2'2 "(1, 3, 5-benzenetriyl) tris - (1-phenyl-1H-benzimidazole) (TPBi).

1 shows a schematic representation of a layer arrangement of an organic light-emitting component.

There are formed two electrodes, anode 1 and cathode 2, between which an organic region having a hole transport layer 3 of an organic substance, optionally doped with an acceptor material, an electron block 7 of an organic substance, an organic light emitting region 4 having an emission layer EML 1, a hole block layer 6 of an organic substance and an electron transport layer 5 of an organic substance optionally doped with a donor material is arranged. The emission layer EML 1 comprises a fluorescent emitter which emits light predominantly in the blue or blue-green spectral region and to which one or more phosphorescent emitters predominantly emitting in the non-blue spectral region are / are mixed. In alternative embodiments, the electron block layer 7 and / or the hole block layer 6 are omitted.

The OLED operates as follows: Holes are injected through the anode 1 into the hole transport layer 3, pass through the hole transport layer 3, and reach the light emitting organic region 4, optionally through the electron block layer 7. Electrons are injected into the electron transport layer 5 through the cathode 2 , migrate through the electron transport layer 5 and reach, if necessary, through the hole block layer 6, the light-emitting organic region 4. In the light-emitting organic region 4 holes and electrons meet and recombine on the blue or blue-green fluorescent emitter molecules to excited states, so-called Excitons formed in triplet and singlet states. The singlet excitons partially recombine with the emission of blue fluorescent light; in some cases an energy transfer occurs after the Förster transfer mechanism to the phosphorescent emitters. The triplet excitons on the fluorescent blue or cyan emitter are predominantly transferred to the non-blue phosphorescent emitters, where they recombine with the emission of phosphorescent light.

FIG. 2 shows a schematic representation of a layer arrangement of a further organic light-emitting component e. For the same features, the same reference numerals as in Fig. 1 are used in Fig. 2.

The light-emitting organic region 4 consists of two emission layers EML 1 and EML 2. The additional emission layer EML 2 comprises one or more predominantly non-blue spectral emitting phosphorescent emitter (s). EML 1 is mainly holes conductive, EML 2 is predominantly electron conductive. Therefore, the main recombination zone is located in the region of the interface between EML 1 and EML 2. The term main recombination zone refers to a spatial area within the region of the organic layers between the anode and the cathode in which at least about 50% of the injected charge carriers recombine.

3 shows a schematic representation of a layer arrangement of another organic light-emitting component. For the same features, the same reference numerals as in Fig. 2 are used in Fig. 3. EML 1 is mainly electronically conductive, EML 2 is predominantly holes conductive. Therefore, the main recombination zone is located at the interface between EML 1 and EML 2.

In the following, embodiments for OLEDs will be described for further explanation of the invention. First, a reference OLED was prepared according to the prior art with the following layer arrangement:

1) anode: indium tin oxide (ITO)

2) P-doped hole transport layer: 60 nm N, N, N ', N'-tetrakis (4-methoxyphenyl) benzidine (MeO-TPD) doped with tetrafluoro-tetracyano-quinodimethanes (F4-TCNQ)

3) Hole-side intermediate layer: 10 nm 2,2 ', 7,7'-tetrakis- (N, N-diphenylamino) -9,9'-spirobifluorene (spiro-TAD)

4) Red emission layer: 20 nm N, N'-di (naphthalen-1-yl) -N, N'-diphenyl-benzidine (α-NPD) doped with iridium (III) bis (2-methyldibenzo [f, h] quinoxaline) (acetylacetonate) (ADS 076RE) (5% by weight)

5) Blue emission layer: 20 nm N, N'-di-1-naphthalenyl-N, N'-diphenyl- [1, 1 ': 4', 1 ": 4", 1 ^m -quaterphenyl] -4.4 "'diamines (4P-NPD)

6) Green emission layer: 10 nm l, 3,5-tris (N-phenylbenzimidazol-2-yl) benzene (TPBi) doped with fac tris (2-phenylpyridine) iridium (Ir (ppy) 3) (4% by weight) 7) Electron-side intermediate layer: 10 nm bathophenanthroline (BPhen)

8) N-doped electron transport layer: 30 nm BPhen doped with Cs

9) Cathode: 100 nm aluminum This OLED in the so-called pin embodiment shows, according to FIG. 4, a continuous decrease of the external quantum efficiency with increasing brightness. As already explained, this results from the strong accumulation of triplet excitons in the main recombination zone, which is located in the region of the interface between layer 5 (blue emission layer) and layer 6 (green emission layer), since layer 5 is predominantly holes conductive and layer 6 predominantly electron conductive is trained.

An exemplary embodiment of an inventive OLED provides the following layer structure: 1.1 Anode: indium tin oxide (ITO)

1.2 P-doped hole transport layer: 60 nm N, N, N ', N'-tetrakis (4-methoxyphenyl) benzidine (MeO-TPD) doped with tetrafiuoro-tetracyano-quinodimethane (F4-TCNQ)

1.3 Hole-side intermediate layer: 10 nm N, N'-di (naphthalen-1-yl) -N, N'-diphenylbenzidine (α-NPD)

1.4 Blue and red emitting layer: N, N'-di-1-naphthalenyl-N, N'-diphenyl- [I, I ': 4 ^I , I ": 4", R "-quaterphenyl] -4,4'"-diamine (4P-NPD) doped with iridium (III) bis (2-methyldibenzo [f, h] quinoxaline) (acetylacetonate) (ADS 076RE) (0.15% by weight) 1.5 Green emission layer: 10 nm l, 3.5 tris (N-phenylbenzimidazole-2-yl) benzene

(TPBi) doped with fac tris (2-phenylpyridine) iridium (Ir (ppy) 3) (1% by weight)

1.6 Electron-side Intermediate Layer: 10 nm Bathophenanthroline (BPhen)

1.7 N-doped electron transport layer: 30 nm BPhen doped with Cs 1.8 cathode: 100 nm aluminum

This OLED is a white OLED in so-called pin design, which shows a brightness of over 1000 cd / m ² at a voltage of 4.2 V. The Elektroluminszenzspektrum has shown in Figure 5 three peaks at 434 nm, 507 nm and 603 nm; the CIE 1931 color coordinates are x = 0.39 and y = 0.35. In particular, one can clearly see both the fluorescence of the 4P NPD (blue emission) and the phosphorescence of the ADS_076RE (red emission) from the mixed layer 4. The external quantum efficiency (see FIG. 4) is almost constant up to a brightness of about 1500 cd / m ² , while it has already dropped by a factor of about 2 in the reference component. In a direct comparison with the reference OLED according to the prior art, the external quantum efficiency of the inventive OLED from a brightness of about 500 cd / m ^{2 is} greater.

A further exemplary embodiment of an OLED according to the invention provides the following layer structure:

2.1 Anode: Indium Tin Oxide (ITO) 2.2 P-doped hole transport layer: 60 nm N, N, N ', N'-tetrakis (4-methoxyphenyl) benzidine (MeO-TPD) doped with tetrafluoro-tetracyano-quinodimethanes ( F4-TCNQ) 2.3 Hole side intermediate layer: 10 nm l, l-bis (4-methylphenyl) aminophenyl) cyclohexane (TAPC) 2.4 Blue and red emitting layer: N, N'-di-1-naphthalenyl-N, N '-diphenyl-

[l, r: 4 ', l ": 4", l " ^1- Quaterphenyl] -4,4'" - diamine (4P-NPD) doped with iridium (III) bis (2-methyldibenzo [f, h] quinoxaline ) (acetylacetonate) (ADS 076RE) (0.12 weight percent)

2.5 Green emission layer: 10 nm l, 3,5-tris (N-phenylbenzimidazol-2-yl) benzene (TPBi) doped with fac tris (2-phenylpyridine) iridium (Ir (ppy) 3) (0.8

By weight)

2.6 Electron-side intermediate layer: 10 nm TPBi

2.7 N-doped electron transport layer: 30 nm bathophenanthroline (BPhen) doped with Cs 2.8 cathode: 100 nm aluminum

Compared to the previous embodiment, other blocker materials are used. In addition, the percentages of the phosphorescent emitter are changed. Thus, a higher quantum efficiency can be achieved over the entire current density range than with the reference OLED.

The device according to the further embodiment is a white light emitting organic device in so-called pin-execution, which at a voltage of 3.7 V shows a brightness of over 1000 cd / m ² . In direct comparison with the reference OLED according to the prior art, the external quantum efficiency (see FIG. 10) over the entire measured brightness range of about 10 cd / m ² to about 10000 cd / m ^{2 is} significantly greater. In particular, it can be seen that the external quantum efficiency remains virtually constant up to a brightness of about 1500 cd / m ² , in contrast to the reference OLED, which shows a strong efficiency drop, starting even at low magnitudes of 10 cd / m ² .

Regardless of their individual design, an emission zone can be defined for the light-emitting organic devices with layer construction by means of a spatial distribution of the radiatively relaxing excitons, which depends on a charge carrier balance, exciton diffusion and the like. The emission zone thus forms a partial area within the emission layer of the component in which the predominant portion of the light is formed. Assuming that the emission zone extends over a broad range of the emission layer, the emission zone and emission layer can be treated approximately equally. A distance z between the cathode of the component and the emission zone then corresponds in the simplest case to the distance between the electrode and the center of the emission layer (see FIG. 6). This ensures at the same time that the wavelength range around λ _b i _au also optimally coupled to the optical field.

The description of an effective penetration depth ET is made by means of phase shift Φκ _{athode of} the light during the reflection. This shift depends on the cathode material (metal) and the wavelength and is calculated from the optical constants of the adjacent materials (see, for example, Dodabalapur et al., Journal of Applied Physics, 80, 6954 (1996)): ET = λ / 4 - | (Φ _K athode * λ / 4π) | with Φ Thode _Ka = arctan (2nok _m / ^(NO2 -N ² _m - k _m ^2)), where n is _0, n _mi k _m ... optical constants of the organic material and the metal material of the cathode. In one embodiment results in a cathode material Al, λbi _au ⁼ 470nm (wavelength in organic: λ _b i _au / n _o ⁼ 266 nm) and n _o (BPhen: Cs) = 1.76, n _m (AL) = 0.538, k _m (AL) = 4.81: ET = 266nm / 4 - 14.75nm = about 52nm. For 550 nm, about 64 nm results for Al and 55 nm for Ag (see FIG.

Microresonator effects occur in bottom emitting OLEDs primarily due to the refractive index difference between ITO and glass substrate. This is at fixed ITO Layer thickness given the cavity length by d _cav + duo. The resonance condition is approximately satisfied if: (2m + 1) π / 4 = Σ (di * 2π * n / λ) + | Φ _cathode / 2 |, (m = 1,2, ...). The condition ensures that a field maximum occurs at the boundary between ITO and glass substrate. In other words: 3/4, 5/4, 7/4 ... times the wavelength fit between ITO and glass and Al (+ effective penetration depth). The condition gives guideline values. Precise optimization is achieved by simulation using thin-film optics. In one embodiment, λreso = 470nm; di _TO = 90 nm, m _T o = 2; di = 45nm, ni = 1.76; d ML _E _s ⁼ 25nm, Π _EMLS = 2, n ₂ = 2, n _A, = 0.538, k _A1 = 4.81.

This results in a "first maximum": (m = 1) => d ₂ = lOnm => d = 45nm + 25nm + lOnm = about 80nm and a "second maximum": (m = 2) => d ₂ = 145nm => d = 45nm + 25nm + 145nm = about 215nm.

The proportion of fluorescent light to the light generated in the emission layer is determined by the concentration ratio of fluorescent and phosphorescent material in the

Emission layer set. The more fluorescent emitter is contained, the higher the proportion of fluorescent light in the total light emission. Experimentally, the

Fluorescence light can then be measured by an electroluminescence spectrum is recorded and the intensity of the fluorescence in the blue spectral emitter is determined.

In another embodiment, the following structure is formed: glass / ITO (90 nm) / MeO-TPD: F ₄ -TCNQ (60 nm, 4 mol%) / α-NPD (10 nm) / 4P NPD: Ir (MDQ ) ₂ (acac) (30 nm, 0.11 weight percent) / TPBi (10 nm) / BPhen: Cs (30 nm) / Al (100 nm). The emission layer consists of a solid layer (matrix material) of the blue-fluorescent emitter 4P-NPD, to which 0.11 percent by weight of the red-phosphorescent emitter Ir (MDQ) ₂ (acac) is admixed. The electroluminescence spectrum has about 50% of its intensity in the blue. This corresponds to an approximately 50% proportion of fluorescent light in the total light emission. Fig. 9 shows an electroluminescence spectrum for the above-described embodiment.

Depending on the application, it makes sense to strive for a compromise between high luminous efficacy and color purity. Therefore, it may be sufficient to over the attitude of the Layer thickness d ₂ only come in the vicinity of a satisfied for blue light resonance condition.

10 shows a graph for the quantum efficiency as a function of the brightness of a reference light-emitting diode according to the prior art and a further organic light-emitting diode according to the invention.

1 b shows a schematic illustration of a triplet state phosphorescent light emission device 1010, wherein the device 1010 comprises an injection hole anode 101, at least one hole injecting or hole transporting layer 102, 103 (hole transport layer), at least one emission layer 104, at least one electron injecting or electron transporting layer 105, 106 (electron transport layer) and an electron injection cathode 107, wherein the layers 102, 103, 104, 105, 106 are made of organic material.

According to the invention, the emission layer 1042 has a sub-structuring of zones 1014,

1016, 1018, 1020, 1022 of at least one mixing system 108 consisting of at least one host material 109 and at least one emitter dye 1011 and of zones 1015, 1017, 1019, 1021 of at least one host material 109, the zones 1014,

1016, 1018, 1020, 1022 of the mixing system 108 spatially from each other through the zones 1015,

1017, 1019, 1021 of the host material 109 are separated, wherein the triplet energies Twm of the host material 109 greater than the triplet energies TE _m i _{tter of} the emitter _dye 1011 with

Twirt> TEmitter are.

Adjacent interfaces 1012, 1013 of the zones 1014, 1016, 1018, 1020, 1022 of the mixing system 108 are spaced apart by a predetermined distance a with a minimum amount in the nanometer range. The minimum amount of the distance a may be two nanometers between the adjacent interfaces 1012, 1013 of the zones 1014, 1016, 1018, 1020, 1022 of the mixing system 108. In this case, the host material 109 as well as the emitter dye 101 1 of different emission layers 1042, 1043, 1044, 1045, 1046 may each be different. The emission layer 1042 has, by a given sub-patterning, layered zones 1014, 1016, 1018, 1020, 1022 of the mixed system 108 of host material 109 and emitter dye 101 1 and layered zones of the host material 109, the sub-patterning being by sequential succession of layered layers Zones in the form of a vertical structuring of zones 1015, 1017, 1019, 1021 pure host material of at least two nanometers thickness and mixing system zones 1014, 1016, 1018, 1020, 1022 formed of host material and phosphorescent light-emitting emitter dye.

In FIG. 12, with respect to the vertical structuring, a plurality of schematic embodiments of the emission layers 1042, 1043, 1044, 1045 are shown in vertical layer sequence, wherein in FIG. 12a the emission layer 1042 with alternating layers B and A, in FIG. 12b the emission layer 1043 with alternating layers B and C, in Fig. 12c the emission layer 1044 with alternating layers B and C + D and in Fig. 12d the emission layer 1045 with alternating layers B, C and D are shown and where A is pure host material, B is a mixed system of host material 109 and Emitter dye 101 1, C is a material other than A, with the physical specifications that apply to A, D is another material other than A, with the physical specifications that apply to A.

The hole transport layer 102 may be p-doped and / or the electron transport layer 106 may be n-doped. However, the hole transport layers 102, 103 may also be combined in one layer and / or the electron transport layers 105, 106 may be combined in one layer.

The zones 1015, 1017, 1019, 1021 pure host material 109 can be replaced 191 (not shown) through zones of another host material, wherein the triplet energy Twi _rt i ₉ i is greater than the triplet energy TEmitter the inserted emitter dye with Twirti9i>

TEmitter ISt.

The zones 1015, 1017, 1019, 1021 of the pure host material 109 can be replaced by zones of a material combination of a plurality of materials, their triplet energies Tκ _{omb being} greater than the triplet energies TEmmer of the emitter dye 1011 with Tκ _O mb ^> TEmitter for all materials , Different zones 1015, 1017, 1019, 1021 of pure host material may be replaced in any sequential order of zones of multiple materials. Different zones 1014, 1016, 1018, 1020, 1022 of the mixing system may contain various phosphorescent emitter dyes.

The zones of a mixing system may contain a plurality of different host materials and / or a plurality of different emitter dyes.

The device 1010 may include additional emission layers having fluorescence emission from singlet states, wherein the additional emission layers are pure zones or mixing systems. In mixed systems, the concentration of emitter dye in host material 109 may be between 0.1 mol% and 50 mol%. The distance of zones of pure host material may be between 2nm and 20nm. The zones of the mixed system of host material and emitter dye can have a spatial extent of 0.5 nm to 100 nm.

In the emission layer 1046, as shown in FIGS. 13a, 13b, the zones 1023, 1024, 1025 of the mixing systems 108 and / or the zones 1091 of the host materials may be formed as layers or as spherical or cubic bodies or as bodies of other predetermined geometry.

The zones formed as layers can consist of vacuum-deposited small molecules or partially of polymers. In the method of manufacturing devices containing at least one phosphorescent light emitting emission layer, the emission layer 1042, 1043, 1044, 1045; 1046 by a targeted sub-structuring of zones 1014, 1016, 1018, 1020, 1022; 1023, 1024, 1025 of at least one mixing system 108 of at least one host material 109 and at least one emitter dye 1011 and zones 1015, 1017, 1019, 1021; 1091 of a host material 109, wherein the zones 1014, 1016, 1018, 1020, 1022 of the mixing system 108 are spatially defined by zones 1015, 1017, 1019, 1021; 1091 of the host material are positioned apart 109 whose triplet energy greater than that of the emitter Twm dye 1011 T _emitter (Twin> T _Em i _tter), wherein the sub-structure by sequential sequence of zones in the form of a vertical structuring of layers 1015, 1017, 1019, 1021 of the host material 109 of at least two nanometers thickness and mixed layers 1014, 1016, 1018, 1020, 1022 of host material 109 and emitter phosphorescent emitter 1011 or by a predetermined distributed arrangement of zones 1023, 1024, 1025 in the form of bodies of at least one mixing system 108 in at least one zone 1091 of a surrounding host material 109 or vice versa.

The vertical patterning may be performed during a mixed vaporization of host material 109 and emitter dye 1011 by an array of mechanically movable apertures in front of the emitter dye source which periodically interrupt the vaporization of emitter dye 1011.

The sub-patterning may also be achieved by means of a lateral structuring (not shown) during a mixed evaporation of host material 109 and emitter dye 1011 by periodically introducing shadow masks between substrate and evaporation sources. A combination of vertical and lateral structuring is also possible, so that a sub-structuring in all spatial directions can be achieved.

In particular, a sub-structuring of the emission layer is proposed. The formation of the remaining layer sequence can be known from those known from the prior art

Structures are based. Both blocker layers 103, 105 must be higher in energy

Have triplet levels as the emitter dye. Hole and electron transport layer 102,

106 may optionally be p- or n-doped. In the case of doping of the transport layers, the block layers 103, 105 are obligatory in order to avoid exciton quenching at the interfaces. Conventional, electrically undoped OLEDs can have a reduced number of layers depending on the design. Here, for example, functions of the layers 102 and

103 and 105 and 106 are combined in one material.

The preparation of the individual organic layers can be done by thermal evaporation, molecular beam epitaxy, spin-on from solutions and by deposition from the gas phase. The mixing system is generally subject to the following conditions: a) The triplet energy Twin of the host material 109, 191 should be greater than or equal to the triplet energy Te _m m _{er of} the emitter dye 1011, and b) The absorption spectrum of the emitter dye 1011 should be strongly with overlap the emission spectrum of the host material 109, 191, so that an efficient exciton energy transfer can take place.

The requirement that the triplet energy Tw of the host material 109, 191 be greater than the triplet energy T _{E of} the emitter dye 1011 means to capture the triplet excitons efficiently on the emitter dye 1011, ie, to prevent their diffusion to host states.

Other conditions for the sub-layer structures are: i) The zones of the mixing system 108 should be as thin as possible to minimize diffusion in the individual zones. ii) The pure layers of the host material 109 should be as thin as possible to both inhibit fluorescence thereof and avoid side electrical effects such as higher operating voltages through thick additional intrinsic layers in the emission layer 1042. iii) The pure layers with the host material 109 must be at least so thick that dextransfer processes between the substructures 1042 is not possible (> 1-2nm).

In a specific embodiment, the following materials are used in the OLED 10 corresponding to FIG. 1 lb, the chemical names of the materials being illustrated in FIGS. 19, 20:

101 transparent ITO (indium tin oxide) on a glass substrate (90 nm) as an anode

102 MeO-TPD electrically doped with F ₄ -TCNQ, 4mol% (35nm)

103 NPB (lOnm)

104 TCTA: Ir (ppy) ₃ ((a reference structure 1041 20nm) and (as a sub-layer structure 20nm 1042))

105 TPBi (lOnm)

106 BPhen electrically doped with cesium (Cs) (55nm)

107 reflective aluminum layer (1 OOnrn) as a cathode. The sub-layer structure 1042 corresponds exactly to the structure explained below in the preliminary investigation. As preliminary investigations photoluminescence investigations of the TCTA: Ir (ppy) ₃ emission layer (reference structure 1041 and sub-layer structure 1042) are carried out. In each case, 20 nm of emission layer are vapor-deposited on quartz glass substrates. The reference structure 1041 is a mixed system layer of TCTA: Ir (ppy) ₃ with a concentration of about 10 mol%. The sub-layer structure has the following sequence, in which case A layer = TCTA (host material) and the layer B = TCTA: (ppy) corresponds Ir ₃ (mixed system of a host material and emitter dye): B (2 nm) [/ A (2nm ) / B (lnm)] ₆ , with a total thickness of 20nm, which exactly corresponds to the emission zone thickness of the reference structure 1041.

FIG. 14 shows the photoluminescence (PL) spectra of both structure layers 1041, 1042. Both show strong emission of the Ir (ppy) ₃ triplet state with a maximum at around 510nm. For the sub-layer structure 1042, it is seen that the fluorescence of TCTA, the host material, is increased. This is to be expected in the case of optical excitation, since almost all excitons are formed in the singlet state of TCTA, so that a fraction is directly emitted, instead of contributing to the transfer of energy.

The two structural layers 1041, 1042 were time-resolved, i. excited with a short laser pulse and measured the decay behavior of the emission. The corresponding decay curves are shown in FIG. A purely exponential decay occurs when the triplet triplet deletion TTA is negligible, i. the excited species only relax directly. The curvature to be observed at the beginning of the decay is a measure of the bimolecular recombination, in this case the triplet triplet deletion TTA (compare Reineke et al., Phys. Rev. B 75 (2007) 125328).

In a comparison of the sub-layer structure 1042 with the reference structure 1041, the sub-layer structure 1042 has a significantly reduced contribution of the triplet triplet deletion TTA. The effect is even more pronounced if the active volume, ie the volume in which Ir (ppy) _{3 is} located, is smaller by approximately 2/3 than in the reference structure 1041, ie the effective exciton density in the sub-layer structure 1042 is larger by a factor of three. As also shown in Figure 11c, the energetic positions of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) or work function (WF) in the case of metals are shown in the following list (Reineke et al., Phys Rev. B 75 (2007) 125328 and Kundu et al., Adv. Funct. Mat. 13 (2003) 445):

101 ITO / WF = -4.6eV

102 MeO-TPD: _F4-TCNQ / HOMO = -5.IeV / LUMO = -1.9eV

103 NPB / HOMO = -5.4eV / LUMO = -2.3eV

104 Host material: TCTA / HOMO = -5.9eV / LUMO = -2.7eV; Emitter dye: Ir (ppy) ₃ / HOMO = -5.4eV / LUMO = -2.4eV

105 TPBi / HOMO = -6.2eV / LUMO = -2.7eV

106 BPhen: Cs / HOMO = -6.4eV / LUMO = -3.OeV

107 Al / WF = -4.3eV.

In Fig. 16, the current density-voltage characteristics of both structures 1041, 1042 can be seen. At low voltages, a slightly higher current flows in the reference structure 1041 at the same voltage. The reason for this is the additional pure TCTA layers, which impede the possible transport of charge carriers on the emitter molecule. Taken together, however, it is noteworthy that the current density-voltage curves are nearly identical, ie that no differences are to be seen in the range of ordinary brightnesses (0.1 to 100 mA / cm ² ), so that the performance efficiency by the sub-layer structure 1042 is not decisive being affected.

FIG. 17 shows the electroluminescence (EL) spectra of both structure layers 1041, 1042. Likewise, for both structure gates 1041, 1042, there is no fluorescence from the host material, TCTA, as shown in Figure 14. This proves that the energy transfer in both structures 1041, 1042 is very efficient and thus high efficiency of Ir (ppy) ₃ emission is to be expected. The fact that no TCTA fluorescence is observed in contrast to the photoluminescence spectra is due to the strong difference in exciton generation in the case of electron luminescence. Statistically, already 75% of the excitons are formed in the triplet state, both on TCTA and Ir (ppy) ₃ , whereas in photoluminescence experiments, as mentioned above, almost only singlet excitons are generated on TCTA. FIG. 18 contains the external quantum efficiency EQE of both OLEDs 101, 1010 as a function of the current density j with EQE = f (j). Both curves fall to high current densities, which also means high brightness. Both OLEDs 101, 1010 have comparable efficiencies at low magnitudes between 14% and 16%. The slightly lower efficiency of the sub-layer structure 1042 is statistical in nature, and the photoluminescence measurement at the same excitation density as shown in Fig. 14 for preliminary examination shows that both OLEDs 101, 1010 achieve equal intensities. The course of the external quantum efficiency of both OLEDs 101, 1010 shows that the sub-layer structure 1042 has a reduced efficiency drop at high current densities. At current densities of 20-30mA / cm ² , the efficiencies of both OLEDs 101, 1010 are approximately equal to 12% EQE.

The sub-layer structure 1042 is only mentioned and illustrated in this specific exemplary embodiment as representative of the other substructures 1043, 1044, 1045, 1046.

In the publication Reineke et al., Phys. Rev. B 75 (2007) 125328, a model calculation is described which makes it possible to model this efficiency decrease as a function of the current density. Here are the important parameters for the OLEDs 101, 1010, which determine the quantum efficiency decline: a) triplet lifetime τ, b) TTA rate constant krr _, c) triplet carrier extinction rate constant kp and d) thickness of the exciton recombination zone w ,

The model equation is based on the following rate equation, which describes the time evolution of the exciton density of excited emitter dyes:

- rζrprp Yl / C n Vl H dt τ 2 e ew

In OLED continuous operation dn / dt = O, so that the following stationary equation is found for the above rate equation:

with the following parameters: j - current density, e - elementary charge, EQE - external quantum efficiency, C - constant describing material properties and 1 - unitless parameter characterizing transport properties in organic solids. The latter equation thus describes the external quantum efficiency η (j) as a function of the current density in functional dependence of the abovementioned parameters (krr, kp _, τ and w). With the help of the model calculation, influences of different parameters, as listed below for krr, can be evaluated.

The triplet lifetime τ is determined to be 1.64 μs and recorded. For the TTA rate constant krr and triplet carrier extinction rate constant kp, values are taken and recorded that were measured on other comparable TCTA: Ir (ppy) ₃ -based OLEDs 101 (Reineke et al., Phys. Rev. B 75 (2007 125328). The thickness of the recombination zone was used for fitting. The result is the solid fit straight line from FIG. 18.

To model the course of the sub-layer structure 1042, starting from the solid curve in Fig. 18, only the rate constant for the triplet triplet deletion TTA is changed, and halved as shown in Fig. 18. A good agreement with the experimental data regarding the dashed curve in Fig. 18 can be found. For a better comparison, the model calculation for the sub-layer structure 1042 is again plotted with the parameters of the reference structure 1041 (black-dotted). Here it becomes clear that the model calculation overestimates the decline in efficiency. In the model calculation, the thickness of the recombination zone w is kept constant, which makes sense from the following consideration. It has been shown that the reference structure 1041 has a recombination zone of about 5 nm (Reineke et al., Phys. Rev. B 75 (2007) 125328). The sub-layer structure has a maximum of 8nm due to its composition Emission zone available because the excitons are trapped in the mixed layer parts. Furthermore, as mentioned in the above structure, NPB is used as an electron blocker which, due to its low triplet level with a maximum wavelength of about 540 nm, deletes the Ir (ppy) ₃ localized at 510 nm, ie the excitons are applied to the non-radiative NPB triplet level (Goushi et al., Journ. Appl. Phys. 95 (2004) 7798). For the sub-layer OLED 1010, therefore, a significantly lower output efficiency at low brightnesses should be expected. It can be concluded that the recombination zone thickness of the sub-layer structure 1042 is smaller than the nominal 8 nm, thus comparable to the reference structure 1041.

If a current density j _{c is} defined as the current density at which the efficiency equals half the value of those at low magnitudes, in which extinguishing mechanisms are irrelevant, the model calculation can be used to make quantitative statements about the differences. In comparison with the reference structure 1041, the current density j _c can be almost doubled from 140mA / cm ² to 270mA / cm ² for the sub-structure 1042.

The invention describes a way to reduce the efficiency decrease by a targeted modification of the sub-structure of the emission zone, i. the layer in which the charge carriers are converted into light.

In FIG. 21, emission layer structures 2020, 2030, 2040 of components 2070 for phosphorescent light emission from triplet states are shown.

According to the invention, at least one emission layer 209, 2010 is present in an emission layer structure 2020, 2030 or 2040 for producing a matched colored light emission 2053, 2054 or white light emission 2055, at least one of the emission layers 209, 2010 being present or at least one

Emission layer 209, 2010 is present with a sub-structuring, in which the

Combination of different emitter materials, with different base emission spectra, is provided in different zones of the mixing area.

Here, FIGS. 21a and 21b show a first emission layer structure 2020 and a second emission layer structure 2030, each with a composition for simple, modular color matching by the sub-structuring and FIG. 21 c shows a third emission layer structure 2040 and FIG. 21 c shows a component 2070 which is embodied concretely on the basis of the emitter layer structure 2040 and emits white light.

In the emission layer structures 2020, 2030, 2040, the following materials are used, the chemical names of which are given in FIGS. 26, 27, 28. The various emission zones of the emission layer structures 2020, 2030, 2040 are shown in FIGS. 21a, 21b, 21c. The schematically illustrated, associated layer structure of the complete OLED 2070, which is shown in FIG. 2 Id, is constructed as follows, wherein the reference numeral 2060 denotes transparent ITO (indium tin oxide) on a glass substrate (90 nm) as an anode,

2061 MeO-TPD electrically doped with F ₄ -TCNQ, 4mol% (60nm),

2062 NPB (lOnm),

2040 entire emission layer structure,

2063 TPBi (lOnm), 2064 BPhen electrically doped with cesium (Cs) (40nm),

2065, a reflective aluminum layer (100 nm) as a cathode, wherein the respective layer thicknesses in nanometers - nm - are indicated represent.

Instead of the emission layer structure 2040 for a white light emission, the emission layer structures 2020, 2030 can be used for producing a coordinated color emission.

FIG. 21 schematically illustrates the emission layer structures 2020, 2030, 2040 for the associated components 2070-OLED. These are each a combination of two sequentially used host materials 207, 208, wherein the host material 207 is TCTA and the host material 208 TPBi, whose structural formula and structure are given in FIGS. 27 and 28. In the mixing zones 201, 202, 203, 204, 205, 206, the emitter dyes are each incorporated in the respective host material 207, 208 at about ten percent by weight. The individual layers 201, 202, 203, 204, 205, 206 of the mixing zones are thick, the zones of pure host material 207, 208 have a thickness of 2 nm, so that in each case the entire emission layer structures 2020, 2030 are about 20 nm and the emission layer Structure 2040 are about 17nm thick, wherein the emission layer structures 2020, 2030, 2040 are composed of two single emission layers 209, 2010 each 10nm (or 7nm in the case of 2040), where the individual emission layers 209, 2010 are defined by the choice of host materials 207 and 208. In this case, the triplet energy of the host material 208 TPBi is smaller than that of the emitter dye FΙr (pic) in the mixed zone layer 204 in Fig. 21. Accordingly, the nature of the blue dyes also requires host materials with ever higher triplet energies, which has the consequence the band gap of the transport levels (difference HOMO-LUMO) also gets bigger. Such host materials often have the disadvantage that thus the injection of charge carriers in such a material is significantly heavier, which drives the operating voltage soaring. A compromise is achieved by providing a worse energy conversion efficiency for the blue color due to the higher triplet energy of the blue dye compared to the host material for the emission layer structure, to keep the operating voltage low and thus ensure high power efficiencies.

Figure 22 shows three basic electroluminescence spectra 2050, 2051, 2052 of the emitter dyes as can be measured in monochrome emission layer structures. The monochrome emission layer structures have the base colors whose additive combination reaches the tuned emission spectrum 2053, 2054, in particular the white light emission 2055.

FIG. 23 shows the composite electroluminescence spectra 2053, 2054 of the emission layer structures 2020, 2030 according to FIGS. 21a and 21b. In both associated emission spectra 2053, 2054, a composition of the base spectra 2050, 2051 and 2050, 2052 from FIG. 22 is present. Noteworthy is the difference of the spectral distribution of the emission layer structures 2020, 2030 according to FIG. 21 a and FIG. 21 b, taking into account the similarity of both structures 2020, 2030. Compared to the emission layer structure 2020 in FIG. 21 a, in the emission layer structure 2030 according to Fig. 21b, only a lnm thick mixed layer zone containing the green emitter Ir (ppy) ₃ in TPBi, by a combination of lnm Ir (MDQ) ₂ (acac) in TPBi replaced. The emission, in the case of FIG. 21 a, green-heavy, changes strongly to a blue-red combination in the emission layer structure 2030 according to FIG. 21 b. The comparison of the emission layer structures 2020, 2030 in FIGS. 21a and 21b shows how easily the color matching in an associated OLED can be adjusted if the emitter dyes can be varied in spatially separated zones. FIG. 24 shows the electroluminescence spectrum 2055 of the emission layer structure 2040 of a schematically illustrated OLED 2070. All spectra 2050, 2051, 2052 of the base emitter dyes illustrated in FIG. 22 contribute to the spectrum 2055. The CIE coordinates in the CIE color space are (0.42, 0.47), which are close to the white point (0.445.0.405).

In summary, the inventive method for producing a device 2070 for phosphorescent light emission from triplet states according to patent application 10 2007 033 209.4-33 is performed with a proposed emission layer structure 2020, 2030 or 2040, wherein using different emitter dyes with different emission colors a coordinated color emission 2053, 2054 or a white light emission 2055 is realized.

Both a white light emission 2055 can be achieved by the emission of different zones with different emission spectrum 2050, 2051, 2052 as well as the reduction of the diffusion-based triplet triplet deletion.

The combinatorial spatial arrangement of different emitter dyes spatially in emission layer structure 2020, 2030, 2040 can provide modular variability in color matching to produce light of a given spectrum, particularly white light.

Fig. 25 shows the external quantum efficiency and the power efficiency of the emission layer structure 2030 of an OLED as a function of the brightness. At illumination relevant magnitudes of 1000 cd / m ² , the emission layer structure 2040 achieves an external quantum efficiency (circular connection curve) of 12.5% and a power efficiency (black square connection curve) of 29.6 InVW, measured in the forward direction assuming a Lambertian radiation characteristic. The power efficiency decrease from 100 to 1000 cd / m ² here is 89%. In comparison with the above-mentioned document D'Andrade, Adv. Mat. 16, 2004, p. 624, both the absolute value of the power efficiency at 1000 cd / m ^{2 is} higher, ie by a factor of three, and the efficiency decrease at high brightnesses significantly reduced. The features of the invention disclosed in the foregoing description, the claims and the figures may be of importance both individually and in any combination for the realization of the invention in its various embodiments.

LIST OF REFERENCE NUMBERS

1 anode

2 cathode 3 hole transport layer

4 light emitting area

5 electron transport layer

6 hole block layer

7 electron block layer 101 highly conductive anode

102 hole transport layer

103 electron and exciton block layer

104 emission layer

1041 Standard emission zone 1042 Emission layer with excitonic substructures 1043, 1044, 1045, 1046 Emission layer

105 hole and exciton block layer

106 electron transport layer

107 highly conductive cathode 108 mixing system

109 host material

191 other host material

1091 zone

1010 device 10101 device according to the prior art

1011 emitter dye

1012 first interface

1013 second interface

1014, 1015, 1016, 1017, 1018, 1019, 1020, 1021, 1022, 1023, 1024, 1025 Zone 201 Mhschicht with TCTA and Ir (MDQ) 2 (acac)

202 mixed layer with TCTA and Ir (ρpy) 3

203 mixed layer with TCTA and FΙr (pic)

204 mixed layer with TPBi and FIr (pic) 205 mixed layer with TPBi and Ir (ppy) 3

206 mixed layer with TPBi and Ir (MDQ) 2 (acac)

207 first host material TCTA

208 second host material TPBi 209 first single emission layer

210 second single emission layer

2020 first entire emission layer structure

2030 second entire emission layer structure

2040 third entire emission layer structure 2050 first base spectrum

2051 second basic spectrum

2052 third basic spectrum

2053 first composite color spectrum

2054 second composite color spectrum 2055 white light spectrum

2060 anode

2061 hole transport layer

2062 electron blocker layer

2063 hole blocker layer 2064 electron transport layer

2065 cathode

2070 component

Claims

claims

1. Light-emitting component, in particular organic light-emitting diode, having an electrode and a counter electrode and an organic region arranged between the electrode and the counterelectrode organic region having an organic light emitting area, which at least one emission layer (EML 1) and which when creating a electrical voltage to the electrode and the counter electrode light in several color ranges in the visible spectral region emitting, optionally up to white light, wherein: - the emission layer (EML 1) at least one predominantly in the blue or blue-green spectral light emitting fluorescent emitter and at least one predominantly in the non-blue spectral region contains light-emitting, phosphorescent emitter,

in the emission layer (EML 1) for the at least one fluorescent emitter, a triplet energy for an energy level of a triplet state is greater than or equal to approximately (within 0, IeV) a triplet energy for an energy level of a triplet state of the at least one phosphorescent emitter, and

- The light-emitting organic region at least a 5% proportion of the generated light in the visible spectral range as fluorescent light of singlet states of the at least one fluorescent emitter in the emission layer

(EML 1) is made.

2. Light-emitting component according to claim 1, characterized in that the emission layer (EML1) consists of a solid layer of the matrix material used as at least one fluorescent emitter, in which the at least one phosphorescent emitter is embedded.

3. Light-emitting component according to claim 1, characterized in that the emission layer (EML1) consists of an organic material into which the at least one fluorescent emitter with a concentration between 0.1 and

50 mol% and the at least one phosphorescent emitter are incorporated.

4. Light-emitting component according to one of claims 1 to 3, characterized in that the organic light-emitting region has an at least 10% proportion of the generated light in the visible spectral range as fluorescent light of Singulettzuständen the at least one fluorescent emitter in the E- emission layer (EML 1) is made.

5. Light-emitting component according to one of claims 1 to 3, characterized in that the organic light-emitting region at least a 15% proportion of the generated light in the visible spectral range as fluorescent light of singlet states of the at least one fluorescent emitter in the E missionsschicht ( EML 1) is formed.

6. Light-emitting component according to claim 1, characterized in that the organic light-emitting region contains at least 20% of the generated light in the visible spectral range as fluorescent light of singlet states of the at least one fluorescent emitter in the emission layer ( EML 1) is formed.

7. The light-emitting component according to claim 1, characterized in that the organic light-emitting region contains at least 25% of the generated light in the visible spectral range as the fluorescent light of singlet states of the at least one fluorescent emitter in the mission layer (EML 1) is formed.

8. Light-emitting component according to one of claims 1 to 7, characterized in that the organic light emitting region comprises a further emission layer (EML 2) with at least one predominantly in the non-blue spectral light emitting phosphorescent emitters.

9. Light-emitting component according to claim 8, characterized in that the emission layer (EML 1) and the further emission layer (EML 2) are formed adjacent to one another.

10. Light-emitting component according to claim 8 or 9, characterized in that the emission layer (EML 1) and the further emission layer (EML 2) are formed transporting holes and that a distance between one of the electrode formed as a cathode surface facing the emission layer (EML 1) and one of the emission layer (EML 1) facing surface of the cathode is smaller than a distance between a cathode-facing surface of the further emission layer (EML 2) and one of the further emission layer (EML 2) facing surface of the cathode.

11. Light-emitting component according to claim 8 or 9, characterized in that the emission layer (EML 1) and the further emission layer (EML 2) are formed transporting electrons and that a distance between one of the counter electrode formed as an anode surface of the emission layer (EML 1) and one of the emission layer (EML 1) facing surface of

Anode is smaller than a distance between one of the anode-facing surface of the further emission layer (EML 2) and one of the further emission layer (EML 2) facing surface of the anode.

12. Light-emitting component according to claim 8 or 9, characterized in that the emission layer (EML 1) is formed transporting electrons and the further emission layer (EML 2) is formed transporting holes and that a distance between one of the electrode formed as a cathode surface the emission layer (EML 1) and a surface of the cathode facing the emission layer (EML 1) are smaller than a distance between a surface of the further emission layer (EML 2) facing the cathode and a surface facing the further emission layer (EML 2) the cathode is.

13. A light-emitting component according to claim 8 or 9, characterized in that the emission layer (EML 1) is designed to transport holes and the further emission layer (EML 2) is formed transporting electrons and that a distance between one of the counter electrode formed as an anode facing surface of the emission layer (EML 1) and one of the emission layer (EML 1) facing surface of the anode smaller than a distance between an anode of the surface facing the further emission layer (EML 2) and one of the other

Emission layer (EML 2) facing surface of the anode.

14. Light-emitting component according to one of claims 1 to 10, characterized in that a hole block layer is arranged between the emission layer (EML 1) and the cathode, wherein the hole block layer carries electrons. and an organic material of the hole block layer has a HOMO level which is at least about 0.3 eV lower than a HOMO level of the fluorescent emitter in the emission layer (EML 1).

15. A light-emitting device according to any one of claims 1 to 9 or 11, characterized in that between the emission layer (EML 1) and the anode, an electron block layer is arranged, wherein the electron block layer is hole transporting and an organic material of the electron block layer a LUMO level which is at least about 0.3 eV higher than a LUMO level of the fluorescent emitter in the emission layer (EML 1).

16. Light-emitting component according to claim 14 or 15, characterized in that a minimum energy of singlet excitons and of triplet excitons in the hole block layer or in the electron block layer is greater than a minimum energy of singlet exciters and of triplet excitons in the emission layer (EML 1). ,

17. Light-emitting component according to one of the preceding claims, characterized in that the emission layer (EML 1) and / or the further emission layer (EML 2) are formed in multiple layers.

18. Light-emitting component according to one of the preceding claims, characterized in that the emission layer (EML 1) has a thickness between about 10 nm and about 100 nm.

19. Light-emitting component according to one of the preceding claims, characterized in that the organic light-emitting region is formed emitting white light, wherein the at least one phosphorescent emitter in the E- emission layer (EML 1) and / or in the further emission layer (EML 2nd ) is an emitter emitting light in the red, orange, yellow or green spectral range.

20. Light-emitting component according to one of the preceding claims, characterized in that between the organic light-emitting region and the electrode and / or between the organic light emitting region and the counter electrode, a respective doped organic layer is formed.

21. A light-emitting component according to claim 20, characterized in that the respective doped organic layer is p-doped with an acceptor material or n-doped with a donor material layer.

22. Light-emitting component according to one of the preceding claims, characterized in that the at least one fluorescent emitter in the emissi- onsschicht (EML 1) is a metal-organic compound or a complex compound with a metal having an atomic number less than 40.

23. Light-emitting component according to one of claims 1 to 21, characterized in that the at least one fluorescent emitter in the emission layer (EML 1) has an electron-withdrawing substituent from one of the following

Classes includes:

- Halogens such as fluorine, chlorine, bromine or iodine;

- CN;

halogenated or cyano-substituted alkanes or alkenes, in particular trifluoromethyl, pentafluoroethyl, cyanovinyl, dicyanovinyl, tricyanovinyl;

- halogenated or cyano-substituted aryl radicals, in particular pentafluorophenyl; and

Boryl radicals, in particular dialkylboryl, dialkylboryl having substituents on the alkyl groups, diarylboryl or diarylboryl having substituents on the aryl groups.

24. Light-emitting component according to one of claims 1 to 21, characterized in that the at least one fluorescent emitter in the emission layer (EML 1) comprises an electron-donating substituent of one of the following classes:

- alkyl radicals such as methyl, ethyl, tert-butyl, isopropyl; - alkoxy radicals;

- aryl radicals with or without substituents on the aryl, in particular tolyl and mesithyl; and

- amino groups in particular NH 2, dialkylamine, diarylamine and diarlyamine having substituents on the aryl.

25. Light-emitting component according to one of claims 1 to 21, characterized in that the fluorescent at least one emitter in the emission layer (EML 1) comprises a functional group having an electron acceptor property from one of the following classes: - oxadiazole

- triazole

- benzothiadiazoles

- Benzimidazoles and N-aryl-benzimidazoles

- bipyridine - cyanovinyl

- Quinoline

- triarylboryl

- Silol units, in particular derivative groups of silacyclopentadiene

- Cyclooctatetraene - Chinoids Structures and ketones, incl. Quinoid thiophene derivatives

- pyrazolines

- Pentaaryl cyclopentadiene

- benzothiadiazoles

- oligo-para-phenyl with electron-withdrawing substituents, and - fluorenes and spiro-bifluorenes with electron-withdrawing substituents.

26. Light-emitting component according to one of claims 1 to 21, characterized in that the fluorescent at least one emitter in the emission layer (EML 1) comprises a functional group having an electron donor property from one of the following classes:

- triarylamines

- Oligo-para-phenyl or oligo-meta-phenyl

- carbazole

- fluorene or spiro-bifluorenes - phenylene-vinylene units

- Naphtals

- Anthracene

- Perylene

- pyrene and - thiophene.

27. Light-emitting component according to one of the preceding claims, characterized in that the following features are formed:

the electrode is formed as an optically reflecting electrode, between the emission zone (EML 1) and the optically reflecting electrode a charge carrier transport layer having a layer thickness d 1 is arranged, and

- For the layer thickness dl = (λ _b i _au / 4) -ET, where ET is the penetration depth of electromagnetic waves in the optically reflective electrode and λ _b i _au a wavelength in the blue spectral range from 380nm to 500nm.

28. Light-emitting component according to one of the preceding claims, characterized in that the organic region is formed with a layer thickness dOB, for which applies: dOB = dOBl + dOB2-d anode, where dOBl = (2 * n + 1) * 0.25 * λ _b i _au and dOB2 = m * 0.5 * λbiaιi and where dOBl is a distance of the emission layer from a cathode, n integer n is greater than or equal to zero, dOB2 is a distance of the emission layer from an interface between an anode and a carrier substrate, m is a natural one Number is greater than or equal to 1 and the anode is a layer thickness of the anode.

29. Light-emitting component according to one of the preceding claims, characterized in that in the emission layer (EML 1) a spatial region having a first concentration of the at least one phosphorescent emitter and another spatial region having a second, different from the first concentration concentration of the at least one phosphorescent emitter are formed.

30. Light-emitting component according to one of the preceding claims, characterized in that in the emission layer (EML 1) a space region is formed which is free of an admixture of the at least one phosphorescent emitter.

31. Organic light-emitting component, in particular a phosphorescent organic light-emitting diode, having an anode and a cathode and an arrangement of organic layers therebetween, which comprises a hole transport layer, an emission layer and an electron transport layer, wherein the emission layer comprises a sub-layer Structuring with zones comprising zones comprising at least one host material and zones comprising a mixing system with at least one phosphorescent emitter dye, wherein the zones consisting of the mixing system are spatially separated from each other by the zones consisting of the at least one host material.

32. Component according to claim 31, characterized in that the zones are formed in a layer structure, wherein the layer structure comprises a sequential sequence of layer-like zones in the form of a vertical structuring of the zones consisting of the mixing system and the zones consisting of the at least one host material.

33. Component according to claim 31 or 32, characterized in that the zones are formed in a layer structure, wherein the layer structure is a sequential sequence of layered zones in the form of a lateral structuring of the zones consisting of the mixing system and the zones consisting of the at least includes a host material.

34. Component according to at least one of claims 31 to 33, characterized in that at least a part of the zones are formed as a spherical or cubic body.

35. Component according to claim 31, characterized in that adjacent boundary surfaces of the zones consisting of the mixing system are at least at a distance in the nanometer range from each other, wherein the distance corresponds to a thickness of the zones consisting of the at least one host material ,

36. Component according to claim 31, characterized in that the hole transport layer is p-doped and / or the electron transport layer is n-doped.

37. Component according to at least one of claims 31 to 36, characterized in that the zones consisting of the at least one host material are replaced by zones of another host material, the triplet energy (Twi _rt i) greater than the triplet energy (TEmitter) of the at least one phosphorescent emitter dye with T _W. _r t91> T _Emltter.

38. Component according to claim 31, characterized in that zones (1015, 1017, 1019, 1021) consisting of the at least one

Host material are replaced by zones of a material combination of several materials, wherein the triplet energies (Tκomb) are greater than the triplet energies (TEmitter) of the at least one phosphorescent emitter dye with Tκ _om b> TEmitter for all materials.

39. Component according to claim 31, characterized in that zones (1015, 1017, 1019, 1021) consisting of the at least one host material are formed in sequential order with zones of several materials.

40. Component according to at least one of claims 31 to 39, characterized in that various phosphorescent emitter dyes are contained in the mixing systems.

41. Component according to at least one of claims 31 to 40, characterized in that a plurality of mixing systems are formed with different host materials.

42. Component according to claim 31, characterized in that additional emission layers with a fluorescence emission

Singlet states are formed.

43. Component according to claim 31, characterized in that in the mixing system the concentration of the at least one phosphorescent emitter dye in the at least one host material is between

0.1mol% and 50mol%.

44. Component according to claim 31, characterized in that a distance between the zones consisting of the at least one host material is between approximately 2 nm and approximately 20 nm.

45. Component according to at least one of claims 31 to 44, characterized in that the zones consisting of the mixing system have a spatial extent of about 0.5 nm to about 100 nm.

46. Component according to claim 31, characterized in that the organic layers consist of vacuum-deposited small molecules or partially of polymers.

47. Component according to at least one of the claims 31 to 46, characterized in that the emission layer has a further sub-structuring, in which a mixed color light up to the white light emitting combination of different emitter dyes having different basic emission spectra, in different zones of a Mixed region (201, 202, 203, 204, 205, 206) is provided.

48. Component according to claim 47, characterized in that the triplet energies Twin of host materials are smaller than or equal to the triplet energies TEmitter of the emitter dyes.

49. A method for producing an organic component, in particular a phosphorescent organic light-emitting diode, in which an anode and a cathode and in between an arrangement of organic layers are formed, which comprises a hole transport layer, an emission layer and an electron transport layer, wherein the emission layer is provided with a sub-layer. Structuring is formed with zones which zones comprises at least one host material and zones consisting of a mixed system of at least one phosphorescent emitter dye and the at least one host material, wherein the zones consisting of the mixing system spatially separated by the zones consisting of the at least one host material be formed.