EP1652410A1 - Use of a layer consisting of hydrophobic, linear or two-dimensional polycyclic aromatics as a barrier layer or an encapsulation and electric components constructed with a layer of this type and comprising organic polymers - Google Patents

Abstract

The invention relates to an electric component constructed with organic layers and comprising a layer consisting of a hydrophobic, linear or two-dimensional polycyclic aromatic with between 3 and 12 ring structures, including phthalocyanines containing metal or devoid of metal, which have -H and/or -F, alkyl groups, aryl groups and/or fluorinated hydrocarbons as residual groups, said layer being used as a barrier layer or an encapsulation. This permits in particular hybrid constructions consisting of SM layers and polymer layers to be obtained. In addition, a retroactive encapsulation of the component is no longer required.

Description

Use of a layer of hydrophobic, linear or two-dimensional polycyclic aromatics as a barrier layer or encapsulation and electrical components constructed with such a layer with organic polymers

Electrical components constructed from organic material are increasingly being investigated for their possible uses, since they offer advantages over the semiconductor components normally used. For example, it is known that certain organic materials can be excited to glow by an electrical voltage. Numerous structures of OLEDs (organic light emitting diodes) have therefore already become known. It has been found that the optically active layer is expediently composed of several layers, at least one layer specifically for hole formation (hole injection layer, HIL) or for hole conduction (hole transport layer, HTL) and another layer are trained in particular for electron release layer (EIL), for electron transport layer (ETL) or for light emission (emission layer, EML).

The known structure of such OLEDs provides a glass substrate on which a transparent anode made of a transparent conductive oxide

(TCO) is formed, for example from indium tin oxide (ITO). An HIL, for example, is successively applied to this arrangement, HTL, EML, ETL and EIL and finally a metallic cathode. With this construction, the light is emitted “downwards”, that is to say through the substrate. With regard to the choice of material, OLEDs of the known type are either made only from layers of different small molecules (SM-OLED, small molecule OLED) or from different polymers (PM- OLED), the small molecules are successively applied as thin layers on the substrate by vacuum sublimation, whereas polymers are processed from a solution (water or organic solvent), polymer layers offer particular advantages as HIL and HTL, since they show good hole transport properties Molecules which are suitable as HILs are, for example, anthracene, tetracene and pentacene (cf. EP 0 278 758 B1).

Since the layers of small organic molecules are easier to apply, while the layers of polymers offer advantages for hole conduction, attempts have been made to combine these layers. This is achieved with the conventional structure of an OLED if the polymer layers HIL and HTL relevant for the hole conduction are applied wet to the anode (made of ITO) and then dried and vacuum-degassed. Then the subsequent application of the small molecules by vacuum sublimation is possible without any problems.

In order to enable direct light emission, attempts are increasingly being made to implement an inverse structure of an OLED, in which the metallic cathode is thus applied to any substrate and then the electron-conducting layers are first built up before the hole-conducting layers are applied and finished with a transparent anode. A hybrid technique is not possible for this structure, since in the wet structure of the hole-conducting layers HTL and HIL, the small molecules of the electron-conducting layers by the solvent or dispersant from which the polymers for HTL and / or HIL are applied (e.g. water ), would be attacked and their electrical quality would become unusable, the metallic cathode is also sensitive to moisture and can be destroyed by contact with water.

It is also known that the layers of the OLEDs are highly susceptible to moisture, so that after the application of the second electrode, the OLEDs are encapsulated in such a way that only connections of the electrodes are accessible.

The susceptibility of organic materials to moisture is also a problem with other electrical components.

The distinction made above between “small molecules” and polymers is accepted and customary in the professional world. “Small molecules” are therefore organic molecules that do not form chains or networks through polymerization.

The present invention is therefore based on the object of eliminating or at least reducing the restrictions on the structure of electrical components made of organic substances due to moisture sensitivity and diffusion phenomena. This object is surprisingly achieved by using a layer of hydrophobic, linear or two-dimensional polycyclic aromatics with three to twelve ring structures, including metal-containing or metal-free phthalocyanines, which are residual groups - H and / or -F, alkyl groups, aryl groups and / or fluorinated hydrocarbons have, as a barrier layer in or as an encapsulation of electrical components constructed with organic layers.

The present invention is based on the knowledge that the layers mentioned, in particular and preferably made of pentacene, can not only be a functional layer in the construction of organic electrical components, but also unexpectedly has barrier properties which make it possible to counteract the corresponding layer as a barrier layer Use moisture to protect the underlying layers and the metallic cathode.

The layer used according to the invention is preferably made of a material from the group consisting of anthracene, phenanthrene, tetracene, chrysene, pentacene, hexacene, perylene, triphenylene, corones, m-naphthodianthracene, m-anthracenoditetracene, m-tetracenodipentacene, pyrene, benzopyrene, ovals, violanthrene and Derivatives of the aforementioned substances with residual groups -H and / or -F, alkyl groups, aryl groups and / or fluorinated hydrocarbons is formed.

Alternatively, the layer of a metal-containing phthalocyanine of the formula with M = Cu, Zn, Fe, Mn, Co, Ni, V ⁼ 0, TrO and each R is an -H and / or -F and / or an alkyl group and / or an aryl group and / or a fluorinated one Can be hydrocarbon.

Alternatively, the layer of a metal-free phthalocyanine

formula

with M = Cu, Zn, Fe, ^' Mn, Co, Ni, V ⁼ 0, TrO and each R is an -H and / or -F and / or an alkyl group and / or an aryl group and / or a can be fluorinated hydrocarbon. In all cases it is preferred if the number of ring structures of the aromatic is between 5 and 10, preferably between 4 and 10, preferably between 5 and 8.

Due to the illustrated use of the layer explained in more detail as a barrier layer or encapsulation, organic electrical components can be constructed in which the layer both fulfills an electrical function and is constructed as a barrier layer or as an in-situ encapsulation.

Accordingly, according to the invention, an organic light-emitting diode with a substrate, a first electrode applied to the substrate, at least one electron-injecting and transporting zone, at least one hole-injecting and transporting zone and a second electrode is characterized in that the hole-injecting and transporting zone is a layer of linear or two-dimensionally linked polycyclic aromatics with 3 to 12 ring structures, including metal-containing or metal-free phthalocyanines which have -H and / or -F, alkyl groups, aryl groups and / or fluorinated hydrocarbons as residual groups, this layer being designed as an encapsulation layer.

According to the invention, not only is a functional layer formed with the layer mentioned, but also an in-situ encapsulation is carried out. For this purpose, the layer structure is designed so that the layer covers all moisture-sensitive layers that have been built up beforehand.

The invention further enables an organic light-emitting diode with a substrate, a cathode applied to the substrate, at least one electron-injecting and transporting zone, at least a hole-injecting and transporting zone and a translucent anode, the electron-injecting and transporting zone being built up with small molecules and attached to it a layer of linearly or two-dimensionally linked polycyclic aromatics with 3 to 12 ring structures, including metal-containing or metal-free phthalocyanines, which act as residual groups -H and / or -F, alkyl groups, aryl groups and / or fluorinated hydrocarbons connected to the anode.

The present invention therefore also enables an organic light-emitting diode (OLED) constructed in a hybrid structure, in which the radiation is “upward”, that is to say away from the substrate side. Accordingly, the invention enables an optimized structure of an upward-radiating OLED because the said layer acts as an effective barrier layer which prevents the diffusion of water into the layers below it. Accordingly, an aqueous polymer film, for example made of PDOT: PSS, can preferably be applied to the said layer as an additional hole-injecting layer towards the anode to reduce the required operating voltage of the OLED.

Examples of substances from which the layer serving as a barrier layer or encapsulation according to the invention can be formed are: anthracene

phenanthrene

tetracenes

chrysene

pentacene

Hexaceπe

30 perylenes

Triphenyiene

coronenes

m-Naphthodianthracene

30 m-Anthracenoditetracene

m ^: tetracenodipentacene

pyrene

benzopyrene Ovalene

ne

and / or alkyl, aryl, and / or fluorinated hydrocarbons

Phthalocyaπϊπe

metalliferous

M = Cu, Zn, Fe, Mn, Co, Ni, V = O, Tϊ = O

metal-free

R = H and / or F and / or alkyl, aryl, and / or fluorinated r \ ι πci iw Döci oiunc; For the sake of clarity, it should be pointed out that all of the enumerated molecules of this layer, even if they contain up to 12 ring structures, are “small molecules” in the sense of this invention, since there is no polymerization.

The invention will be explained in more detail below on the basis of exemplary embodiments shown in the drawing. Show it:

FIG. 1 shows a schematic structure of an “upward” emitting OLED with an HIL layer as the encapsulation layer, all layers being constructed as SM layers.

Figure 2 shows a schematic structure of an OLED with a hybrid structure of SM layers and a polymer layer.

The OLEDs shown in FIGS. 1 and 2 emit upwards. They consist of a substrate 1 on which a metal layer as cathode 2 is applied. A suitable metal layer is magnesium or an alloy of LiF / Al.

An electron-injecting layer EIL adjoins the cathode 2 and provides free electrons in a known manner. These recombine with holes from the other layers explained in more detail below in an emission layer EML, in which electroluminescence is produced by the recombination, that is to say light is emitted.

There may be several hole-conducting layers HTLs above the emission layer EML. These are covered by a jicant layer HIL 1, which can be formed from pentacene in the illustrated embodiment. This layer is used as an encapsulation layer in that it is formed in the real construction in such a way that it covers the other layers below. The HIL 1 is followed by a transparent anode 3, which preferably consists of indium tin oxide. The layers EIL, EML, HTL and HIL 1 are formed in a known manner as thin layers and emit light when a sufficient voltage relative to the cathode 2 is applied to the anode 3. The upward emission is illustrated in Figure 1 by an arrow.

The use of the HIL 1 layer as an encapsulation layer eliminates the need to subsequently (ex-situ) encapsulate the OLED. The OLED according to the invention according to FIG. 1 is therefore encapsulated in situ, so that subsequent encapsulation can be carried out in a much simpler manner due to the reduced requirements with regard to its permeability to water vapor.

The structure of the OLED shown in FIG. 2 is basically the same, the layers EIL, EML, HTL and HIL 1 all consisting of small molecules (as SM layers). Between the layer HIL 1 used according to the invention as a barrier layer and the A node 3, a layer HIL 2 is also applied, which is designed as a polymer layer, for example PDOT. This polymer layer HIL 2 is applied wet, but does not damage the underlying moisture-sensitive layers HTL, EML and EIL because of the barrier layer effect of HIL 1. The layer HIL 2 enables the working voltage between the anode 3 and the cathode 2 to be reduced or increases the efficiency of the emission, which also takes place upward in the exemplary embodiment according to FIG. 2.

Since the polymer layer HIL 2 is not sensitive to moisture, the layer HIL 1 can also be formed as an encapsulation layer in this exemplary embodiment, that is to say cover the layers HTL, EML and EIL underneath.

Claims

Expectations 1 . Use of a layer (HIL 1) made of a hydrophobic, linear or two-dimensional polycyclic aromatic with 3 to 12 ring structures, including metal-containing or metal-free phthalocyanines, which have -H and / or -F, alkyl groups, aryl groups and / or fluorinated hydrocarbons as residual groups , as a barrier layer in or as an encapsulation of electrical components constructed with organic layers. 2. Use according to claim 1, wherein the layer of a material selected from the group consisting of anthracene, phenanthrene, tetracene, chrysene, pentacene, hexacene, perylene, triphenylene, coronene, m-Naphthodianthracen, m-Anthracenoditetracen, m-Tetracenodipentacen, _pyrene. Benzopyrene, ovals, violanthrene and derivatives of the aforementioned substances, with residual groups -H and / or -F, alkyl groups, aryl groups and / or fluorinated hydrocarbons. Use according to claim 1, wherein the layer of a metal-containing phthalocyanine of the formula with M = Cu, Zn, Fe, Mn, Co, Ni, V ⁼ 0, TrO and each R is an -H and / or -F and / or an alkyl group and / or an aryl group and / or a fluorinated hydrocarbon can. Use according to claim 1, wherein the layer consists of a metal-free phthalocyanine of the formula with M = Cu, Zn, Fe, Mn, Co, Ni, V ⁼ 0, TrO and each R is an -H and / or -F and / or an alkyl group and / or an aryl group and / or a fluorinated hydrocarbon can. Organic light-emitting diode with a substrate (1), a first electrode (2) applied to the substrate (1), at least one electron-injecting and transporting zone (EIL), at least one hole-injecting and transporting zone (HTL, HIL) and a second electrode (3 ), characterized in that the hole-injecting and transporting zone includes a layer (HIL 1) of linearly or two-dimensionally linked polycyclic aromatics with 3 to 12 ring structures. borrowed metal-containing or metal-free phthalocyanines which have residual groups -H and / or -F, alkyl groups, aryl groups and / or fluorinated hydrocarbons, this layer (HIL 1) being designed as an encapsulation layer. 6. Organic light-emitting diode with a substrate (1), a on the substrate (1), a cathode (2) applied to the substrate (1), at least one electron-injecting and transporting zone (EIL), at least one hole-injecting and transporting zone (HTL, HIL) and a translucent anode (3), characterized in that the electron-injecting and transporting zone (EIL) is built up with small molecules and that there is a layer of linearly or two-dimensionally linked polycyclic aromatics with 3 to 12 ring structures , including metal-containing or metal-free phthalocyanines, which as residual groups -H and / or -F, alkyl groups, aryl groups and / or fluorinated hydrocarbons adjoins the anode (3). 7. Organic light-emitting diode according to claim 5 or 6, in which the material of the layer from the group anthracene, phenanthrene, tetracene, chrysene, pentacene, hexacene, perylene, triphenylene, corones, m-naphthodianthracene, m-anthracenoditetracene, m-tetracenodipentacene, pyrene , Benzopyrene ,. Ovals, violanthrene and derivatives of the aforementioned substances with residual groups -H and / or -F, alkyl groups, aryl groups and / or fluorinated hydrocarbons are formed. Organic light emitting diode according to claim 5 or 6, wherein the layer of a metal-containing phthalocyanine of the formula with M = Cu, Zn, Fe, Mn, Co, Ni, V ⁼ 0, Ti ^β O and each R represents an -H and / or -F and / or an alkyl group and / or an aryl group and / or a fluorinated one Can be hydrocarbon. Organic light emitting diode according to claim 5 or 6, wherein the layer of a metal-free phthalocyanine of the formula with M = Cu, Zn, Fe, Mn, Co, Ni, V ⁼ 0, TrO and each R is an -H and / or -F and / or an alkyl group and / or an aryl group and / or a fluorinated hydrocarbon can. 10. Organic light-emitting diode according to one of claims 5 to 9, characterized in that between the layer (HIL 1) and the second electrode (3) an applied from aqueous solution, hole-injecting and transporting polymer layer (HIL 2) is applied.