JP2009530847A - Optoelectronic devices exhibiting improved efficiency - Google Patents

Abstract

In the present specification, an organic optoelectronic device comprising a cathode, an anode and a photoelectroactive organic material made of one or more zero-valent metals, wherein the cathode contacts one or more organic ammonium salts. An organic optoelectronic device is described. In some embodiments, the organic ammonium salt has the structural formula (I). In the formula, R ^{1 to} R ⁴ are each independently a C _{1 to} C ₂₀ aliphatic group, a C _{3 to} C ₂₀ alicyclic group or a C _{3 to} C ₂₀ aromatic group, and X ⁻ is a monovalent inorganic anion. , Selected from the group consisting of monovalent organic anions, polyvalent inorganic anions, polyvalent organic anions and mixtures thereof.
[Selection] Figure 1, Chemical formula 1

Description

  The present invention relates generally to the field of electro-optics, and more particularly to organic electro-optic devices and methods of manufacturing the same. More particularly, the present invention relates to organic electro-optic devices that operate with improved efficiency compared to currently known devices.

  One type of organic electro-optic device, or organic light-emitting diode (OLED), a device that converts electrical energy into light, has extensive research and development efforts due to its potential for use in applications such as flat panel displays and general lighting. It is the target of. Another type of organic electro-optic device, a photovoltaic device that is a device that converts light energy into electrical energy, is of similar interest. The usefulness and commercial appeal of currently available organic electro-optic devices (eg, OLEDs and photovoltaic devices) makes such devices (eg, light emitted per unit of electrical energy consumed in the case of OLEDs). It would be better if it could be operated with higher efficiency (by increasing the amount).

  Although impressive progress has been achieved in improving the efficiency of organic electro-optic devices, further improvements are needed to obtain devices that can be operated more economically.

  In one embodiment, the present invention provides (a) a cathode composed of one or more zero-valent metals, (b) an anode, and (c) an optoelectronic active organic material disposed between the cathode and the anode. An organic optoelectronic device comprising: the cathode being in contact with one or more organic ammonium salts.

  In another embodiment, the present invention provides (a) a cathode composed of one or more zero-valent metals, (b) an anode, and (c) an optoelectronically active organic disposed between the cathode and the anode. An organic optoelectronic device comprising a material, wherein the cathode is in contact with one or more organic ammonium salts having the following structural formula (I):

In the formula, R ^{1 to} R ⁴ are each independently a C _{1 to} C ₂₀ aliphatic group, a C _{3 to} C ₂₀ alicyclic group or a C _{3 to} C ₂₀ aromatic group, and X ⁻ is a monovalent inorganic anion. , Selected from the group consisting of monovalent organic anions, polyvalent inorganic anions, polyvalent organic anions and mixtures thereof.

  In another embodiment, the present invention provides: (a) a cathode composed of one or more zero-valent metals, (b) an anode, (c) an optoelectronic active organic material disposed between the cathode and the anode. And (d) an OLED device comprising one or more organic ammonium salts having the following structural formula (I), wherein the ammonium salt is disposed between a photoactive organic material and a cathode: Provided is an organic light emitting diode in which an ammonium salt is in contact with a cathode.

In the formula, R ^{1 to} R ⁴ are each independently a C _{1 to} C ₂₀ aliphatic group, a C _{3 to} C ₂₀ alicyclic group or a C _{3 to} C ₂₀ aromatic group, and X ⁻ is a monovalent inorganic anion. , Selected from the group consisting of monovalent organic anions, polyvalent inorganic anions, polyvalent organic anions and mixtures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS These and other features, aspects and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings, in which: In the accompanying drawings, like parts are designated by like numerals throughout.

  FIG. 1 is a schematic illustration of a first optoelectronic device structure including a cathode in contact with an organic ammonium salt in accordance with an embodiment of the present invention.

  FIG. 2 is a schematic diagram of a second optoelectronic device structure including an organic ammonium salt and a charge injection material layer in accordance with an embodiment of the present invention.

  FIG. 3 is a schematic diagram of a third optoelectronic device structure including a layer of an organic ammonium salt in accordance with an embodiment of the present invention.

  4 shows the efficiency versus current density plot for the OLED device of Comparative Example 1 (C. Ex. 1), which is a device comprising a light emitting polymer (LEP) as the photoelectroactive material and aluminum (Al) as the cathode. .

  FIG. 5 shows the IV behavior of the OLED device of Example 1 under forward and reverse bias.

  FIG. 6 is a graph plotting the efficiency of the OLED of Example 1 as a function of current density.

  FIG. 7 is a plot of current versus bias voltage for an exemplary embodiment of the invention measured under illumination and in the dark.

  A better understanding of the present invention can be obtained by reference to the following detailed description of the preferred embodiment of the invention and its examples. A number of terms are used throughout the specification and claims, which are defined to have the following meanings:

  Even in the singular form, it includes plural cases unless it is clear from the context.

  The term “optional” or “optionally” means that the event or situation described following the term may or may not occur, and such a description may be used when the event occurs. Includes cases that do not occur.

As used herein, the term “aromatic group” refers to an atomic arrangement having a valence of at least one comprising at least one aromatic group. The atomic arrangement of one or more valences containing one or more aromatic groups may contain heteroatoms such as nitrogen, sulfur, selenium, silicon and oxygen, or may be composed solely of carbon and hydrogen. Good. The term “aromatic group” as used herein is not particularly limited, but includes phenyl group, pyridyl group, furanyl group, thienyl group, naphthyl group, phenylene group and biphenyl group. As described above, the aromatic group contains one or more aromatic groups. The aromatic group is always a cyclic structure having “delocalized” electrons of 4n + 2 (where “n” is an integer of 1 or more), a phenyl group (n = 1), a thienyl group (n = 1), furanyl group (n = 1), naphthyl group (n = 2), azulenyl group (n = 2), anthracenyl group (n = 3) and the like. Aromatic groups can also include non-aromatic components. For example, a benzyl group is an aromatic group composed of a phenyl ring (aromatic atomic group) and a methylene group (non-aromatic component). Similarly, the tetrahydronaphthyl group is an aromatic group formed by condensing an aromatic group (C ₆ H ₃ ) with a non-aromatic component — (CH ₂ ) ₄ —. For convenience, the term “aromatic group” in this specification refers to an alkyl group, alkenyl group, alkynyl group, haloalkyl group, haloaromatic group, conjugated dienyl group, alcohol group, ether group, aldehyde group, ketone group, It is defined to include a wide range of functional groups such as carboxylic acid groups, acyl groups (for example, carboxylic acid derivatives such as esters and amides), amine groups and nitro groups. For example, the 4-methylphenyl radical is a C ₇ aromatic radical comprising a methyl group, the methyl group being a functional group which is an alkyl group. Similarly, the 2-nitrophenyl group is a C ₆ aromatic group containing a nitro group, and the nitro group is a functional group. Aromatic groups include 4-trifluoromethylphenyl, hexafluoroisopropylidenebis (4-phenyloxy) (ie —OPhC (CF ₃ ) ₂ PhO—), 4-chloromethylphenyl, 3-trifluorovinyl-2 A halogenated aromatic group such as thienyl, 3-trichloromethylphenyl (ie 3-CCl ₃ Ph—), 4- (3-bromopropyl) phenyl (ie 4-BrCH ₂ CH ₂ CH ₂ Ph—) Include. Still other examples of aromatic groups include 4-allyloxyphenoxy, 4-aminophenyl (ie, 4-H ₂ NPh—), 3-aminocarbonylphenyl (ie, NH ₂ COPh—), 4-benzoylphenyl. Dicyanomethylidenebis (4-phenyloxy) (ie —OPhC (CN) ₂ PhO—), 3-methylphenyl, methylenebis (4-phenyloxy) (ie —OPhCH ₂ PhO—), 2-ethylphenyl , phenylethenyl, 3-formyl-2-thienyl, 2-hexyl-5-furanyl, hexamethylene-1,6-bis (4-phenyloxy) _{(i.e., -OPh (CH 2) 6 PhO} -), 4 - hydroxymethylphenyl _{(i.e., 4-HOCH 2 Ph -)} , 4- mercaptomethylphenyl _{(i.e., 4-HSCH 2 Ph -)} , 4 Methylthiophenyl _{(i.e., 4-CH 3 SPh -)} , 3- methoxyphenyl, 2-methoxycarbonylphenyl oxy (e.g., methyl salicyl), 2-nitro-methylphenyl _{(i.e., 2-NO 2 CH 2 Ph} ), 3- Examples include trimethylsilylphenyl, 4-t-butyldimethylsilylphenyl, 4-vinylphenyl, vinylidenebis (phenyl), and the like. The term “C ₃ -C ₁₀ aromatic group” includes aromatic groups containing 3 to 10 carbon atoms. The aromatic group 1-imidazolyl (C ₃ H ₂ N ₂ —) represents a C ₃ aromatic group. Benzyl radical _(C 7 _{H 8} -) represents a _{C 7} aromatic radical.

As used herein, the term “alicyclic group” refers to a group having a valence of at least one comprising a cyclic but non-aromatic atomic arrangement. An “alicyclic group” as defined herein does not include an aromatic group. An “alicyclic group” can include one or more acyclic components. For example, a cyclohexylmethyl group (C ₆ H ₁₁ CH ₂ —) is an alicyclic group composed of a cyclohexyl ring (a cyclic but non-aromatic atomic arrangement) and a methylene group (acyclic component). The alicyclic group may contain heteroatoms such as nitrogen, sulfur, selenium, silicon and oxygen, or may consist solely of carbon and hydrogen. For convenience, the term “alicyclic group” in this specification refers to an alkyl group, an alkenyl group, an alkynyl group, a haloalkyl group, a conjugated dienyl group, an alcohol group, an ether group, an aldehyde group, a ketone group, a carboxylic acid group, Defined as containing a wide range of functional groups such as acyl groups (eg carboxylic acid derivatives such as esters and amides), amine groups, nitro groups and the like. For example, a 4-methylcyclopentyl group is a C ₆ alicyclic group containing a methyl group, and the methyl group is a functional group that is an alkyl group. Similarly, the 2-nitrocyclobutyl group is a C ₄ alicyclic group containing a nitro group, and the nitro group is a functional group. The alicyclic groups can contain one or more halogen atoms that can be the same or different. Halogen atoms include, for example, fluorine, chlorine, bromine and iodine. Alicyclic groups containing one or more halogen atoms include 2-trifluoromethylcyclohexyl, 4-bromodifluoromethylcyclooctyl, 2-chlorodifluoromethylcyclohexyl, hexafluoroisopropylidene-2,2-bis (cyclohexa-4 - yl) _{(i.e., -C 6 H 10 C (CF} 3) 2 C 6 H 10 -), 2- chloro-methylcyclohexyl, 3-difluoromethylene-cyclohexyl, 4-trichloromethyl-cyclohexyloxy, 4-bromo-dichloromethyl cyclohexylthio 2-bromoethylcyclopentyl, 2-bromopropylcyclohexyloxy (for example, CH ₃ CHBrCH ₂ C ₆ H ₁₀ O—) and the like. Still other examples of alicyclic groups include 4-allyloxycyclohexyl, 4-aminocyclohexyl (ie, H ₂ NC ₆ H ₁₀ —), 4-aminocarbonylcyclopentyl (ie, NH ₂ COC ₅ H ₈ —). , 4-acetyloxy-cyclohexyl, 2,2-dicyano isopropylidene bis (cyclohex-4-yloxy) _{(i.e., -OC 6 H 10 C (CN} ) 2 C 6 H 10 O -), 3- methylcyclohexyl, methylenebis ( cyclohex-4-yloxy) _{(i.e., -OC 6 H 10 CH 2 C} 6 H 10 O -), 1- ethyl-cyclobutyl, cyclopropyl ethenyl, 3-formyl-2-tetrahydrofuranyl, 2-hexyl-5- Tetrahydrofuranyl, hexamethylene-1,6-bis (cyclohex-4-yloxy) (i.e.,- _{OC 6 H 10 (CH 2)} 6 C 6 H 10 O -), 4- hydroxymethylcyclohexyl _{(i.e., 4-HOCH 2 C 6 H} 10 -), 4- mercaptomethyl cyclohexyl (i.e., 4-HSCH ₂ C ₆ H ₁₀ -), 4-methylthio-cyclohexyl _{(i.e., 4-CH 3 SC 6 H} 10 -), 4- methoxy-cyclohexyl, 2-methoxycarbonyl-cyclohexyloxy _{(2-CH 3 OCOC 6 H} 10 O -), 4- nitro methylcyclohexyl _{(i.e., NO 2 CH 2 C 6 H} 10 -), 3- trimethylsilyl cyclohexyl, 2-t-butyldimethylsilyl cyclopentyl, 4-trimethoxysilyl ethyl cyclohexyl _{(e.g., (CH 3 O) 3 SiCH} 2 CH 2 C ₆ H ₁₀ -), 4- vinyl cyclohexenyl, Biniri Nbisu (cyclohexyl), and the like. The term “C ₃ -C ₁₀ alicyclic group” includes alicyclic groups containing 3 to 10 carbon atoms. The alicyclic group 2-tetrahydrofuranyl (C ₄ H ₇ O—) represents a C ₄ alicyclic group. The cyclohexylmethyl group (C ₆ H ₁₁ CH ₂ —) represents a C ₇ alicyclic group.

As used herein, the term “aliphatic group” refers to an organic group having a valence of at least one consisting of a linear or branched atom array that is not cyclic. An aliphatic group is defined as containing one or more carbon atoms. The atomic arrangement forming the aliphatic group may contain heteroatoms such as nitrogen, sulfur, silicon, selenium and oxygen, or may be composed only of carbon and hydrogen. For convenience, the term “aliphatic group” as used herein refers to an alkyl group, alkenyl group, alkynyl group, haloalkyl group, conjugated dienyl group, as part of a “non-cyclic linear or branched atom array”, Defined as containing a wide range of functional groups such as alcohol groups, ether groups, aldehyde groups, ketone groups, carboxylic acid groups, acyl groups (eg carboxylic acid derivatives such as esters and amides), amine groups and nitro groups. . For example, a 4-methylpentyl group is a C ₆ aliphatic group containing a methyl group, and the methyl group is a functional group that is an alkyl group. Similarly, 4-nitrobutyl group is a C ₄ aliphatic radical comprising a nitro group, the nitro group being a functional group. Aliphatic groups can be haloalkyl groups containing one or more halogen atoms, which can be the same or different. Halogen atoms include, for example, fluorine, chlorine, bromine and iodine. Aliphatic groups containing one or more halogen atoms include alkyl halides trifluoromethyl, bromodifluoromethyl, chlorodifluoromethyl, hexafluoroisopropylidene, chloromethyl, difluorovinylidene, trichloromethyl, bromodichloromethyl, bromoethyl, 2-bromotrimethylene (eg, —CH ₂ CHBrCH ₂ —) and the like. Still other examples of aliphatic groups include allyl, aminocarbonyl (ie, —CONH ₂ ), carbonyl, 2,2-dicyanoisopropylidene (ie, —CH ₂ C (CN) ₂ CH ₂ —), methyl ( That is, —CH ₃ ), methylene (ie, —CH ₂ —), ethyl, ethylene, formyl (ie, —CHO), hexyl, hexamethylene, hydroxymethyl (ie, —CH ₂ OH), mercaptomethyl (ie, -CH ₂ SH), methylthio (i.e., -SCH _3), methylthiomethyl _(i.e., -CH 2 _SCH 3), methoxy, methoxycarbonyl _(i.e., CH 3 OCO-), nitromethyl _(i.e., -CH 2 _NO 2) , thiocarbonyl, trimethylsilyl _{(i.e., (CH 3) 3 Si -} ), t- butyldimethylsilyl, 3-trimethoxysilylpropyl Pro Le _{(i.e., (CH 3 O) 3 SiCH} 2 CH 2 CH 2 -), vinyl, vinylidene, and the like. As yet another _example, C 1 _{-C 10} aliphatic groups contain 10 or fewer carbon atoms in one or more. A methyl group (ie, CH ₃ —) is an example of a C ₁ aliphatic group. Decyl group _{(i.e., CH 3 (CH 2) 9} -) is an example of a _{C 10} aliphatic group.

  As described above, the present invention is an organic optoelectronic device comprising a cathode containing one or more zero-valent metals, an anode, and a photoelectroactive organic material disposed between the cathode and the anode. An organic optoelectronic device in which the cathode is in contact with one or more organic ammonium salts. In one embodiment, the cathode is in contact with one or more organic ammonium salts having the following structural formula (I):

In the formula, R ^{1 to} R ⁴ are each independently a C _{1 to} C ₂₀ aliphatic group, a C _{3 to} C ₂₀ alicyclic group or a C _{3 to} C ₂₀ aromatic group, and X ⁻ is a monovalent inorganic anion. , Selected from the group consisting of monovalent organic anions, polyvalent inorganic anions, polyvalent organic anions and mixtures thereof.

  In one embodiment, the cathode serves the purpose of injecting negative charge carriers (electrons) into the electroactive organic layer. In one embodiment, the cathode comprises K, Li, Na, Cs, Mg, Ca, Sr, Ba, Al, Ag, Au, In, Sn, Zn, Zr, Sc, Y, lanthanide series elements, and alloys thereof Or a metal such as a mixture thereof. Suitable alloy materials for forming the cathode layer are Ag-Mg, Al-Li, In-Mg, Al-Ca and Al-Au alloys. Layered non-alloy structures such as a thin layer of metal (eg calcium) or metal fluoride (eg LiF) coated with a thick layer of zero-valent metal (eg aluminum or silver) can also be used. . In one embodiment, the cathode comprises a zero valent metal. In one embodiment, the cathode is selected from the group consisting of aluminum, copper, zinc, silver, nickel, palladium, platinum, iridium, lithium, sodium, potassium, calcium, barium, strontium and mixtures of two or more of the foregoing. Made of zero-valent metal. The cathode can be deposited on the underlying component by physical vapor deposition, chemical vapor deposition, sputtering or similar techniques. In one embodiment, the cathode is transparent. The term “transparent” means that 50% or more, usually 80% or more, more usually 90% or more of light in the visible wavelength region is transmitted at an incident angle of 10 degrees or less. This means that a device or article described as “transparent” (eg, a transparent cathode) transmits at least 50% of visible light incident on the device or article at an incident angle of about 10 degrees or less. .

  The anode is generally composed of a material having a bulk conductivity of 100 Siemens / centimeter or more as measured by a four-point probe technique. As the anode, indium tin oxide (ITO) is usually used. This is because ITO is substantially transparent to light transmission and thus facilitates light emitted from the electroactive organic layer to escape through the ITO anode layer without significant attenuation. . Other materials that can be used as the anode layer include tin oxide, indium oxide, zinc oxide, indium zinc oxide, zinc indium tin oxide, antimony oxide, and mixtures thereof. The cathode and anode are referred to as “conductive layers”.

  In manufacturing the device of the present invention, the conductive layer can be deposited on the underlying component by physical vapor deposition, chemical vapor deposition, sputtering or similar methods, or a combination of two or more of the techniques described above is used. You can also. The thickness of each conductive layer can vary independently, but is generally in the range of about 10 to about 500 nanometers. That is, in one embodiment, the thickness of the conductive layer is from about 10 to about 500 nanometers in one embodiment, from about 10 to about 200 nanometers in another embodiment, and from about 50 to about 200 nanometers in yet another embodiment. Within the range of meters. For example, a thin and substantially transparent metal layer having a thickness of less than about 50 nanometers can be used as a suitable conductive layer. Suitable exemplary metals include silver, copper, tungsten, nickel, cobalt, iron, selenium, germanium, gold, platinum, aluminum or a mixture of two or more of the foregoing, and alloys containing one or more of the above. There is. In one embodiment, the anode is disposed on a substantially transparent substrate (eg, a glass substrate or an organic polymer substrate).

  In one embodiment, the optoelectronic active material is arranged as a layer and serves as a transport medium for both holes and electrons in the optoelectronic device. In OLEDs, holes and electrons in an optoelectronic device combine to form an excited state species that emits electromagnetic radiation in the visible range. In some embodiments, reversing the electrical bias used to convert electrical energy into light energy in the OLED converts the OLED into a photovoltaic device that converts light energy into electrical energy. In photovoltaic devices, holes and electrons are generated by the combined effect of light incident on the optoelectronic active material and applied voltage bias. The holes and electrons thus generated then cause a current flow. Thus, the optoelectronic device of the present invention is characterized by its ability to convert electrical energy to light energy (OLED) and by its ability to convert light energy to electrical energy by reversing the voltage bias (photovoltaic). Electrical device (PV)). The optoelectronically active organic material is typically selected to exhibit electroluminescence within the desired wavelength range.

  As described above, the photoelectroactive material is typically disposed as a photoelectroactive layer in an optoelectronic device, the layer being disposed between the conductive layers of the device. The thickness of the optoelectronic active layer is typically in the exemplary range of about 10 to about 300 nanometers. The photoactive material used to form the photoactive layer is an organic material that can be a polymer, copolymer, polymer or mixture of copolymers, or a low molecular weight organic molecule having an unsaturated bond. Such materials generally have a delocalized π-electron system so that polymer chains or organic molecules can support positive and negative charge carriers with relatively high mobility. Suitable photoactive polymers are poly (n-vinylcarbazole) ("PVK", which emits violet to blue light in the wavelength range of about 380 to about 500 nanometers) and poly (n-vinylcarbazole) derivatives, Polyfluorene and poly (alkylfluorene) (eg, poly (9,9-dihexylfluorene) (emits light in the wavelength range of about 410 to about 550 nanometers), poly (dioctylfluorene) (436 nanometer peak) Electroluminescent (EL) emission wavelength) and poly {9,9-bis (3,6-dioxaheptyl) fluorene-2,7-diyl} (emitting light in the wavelength range of about 410 to about 550 nanometers) Polyfluorene derivatives such as poly (paraphenylene) ("PPP") and poly (2-decyloxy) -1,4-phenylene) (which emits light in the wavelength range of about 400 to about 550 nanometers) and derivatives thereof such as poly (2,5-diheptyl-1,4-phenylene), poly (p -Phenylene vinylene) ("PPV") and derivatives thereof such as dialkoxy-substituted PPV and cyano-substituted PPV, polythiophene and poly (3-alkylthiophene) and poly (4,4'-dialkyl-2,2'-bithiophene) ) And its derivatives such as poly (2,5-thienylene vinylene), poly (pyridine vinylene) and its derivatives, polyquinoxaline and its derivatives, and polyquinoline and its derivatives. Mixtures of these polymers and / or copolymers containing structural units common to two or more of the aforementioned polymers can also be used to tune the color of light emitted from organic optoelectronic devices (eg, OLEDs).

  Another class of suitable organic material that can be used as the photoelectroactive organic material is polysilane. Typically, polysilanes are linear silicon backbone polymers substituted with various alkyl and / or aryl groups. Polysilane is a quasi-one-dimensional material with delocalized σ conjugated electrons along the polymer backbone. Examples of suitable polysilanes include, but are not limited to, poly (di-n-butylsilane), poly (di-n-pentylsilane), poly (di-n-hexylsilane), poly (methylphenylsilane) and poly {Bis (p-butylphenyl) silane}. These polysilanes emit light of wavelengths generally in the range of about 320 to about 420 nanometers.

  In some embodiments, organic materials having a molecular weight of less than about 5000 grams / mole and containing one or more aromatic groups can also be applied as the luminescent photoelectroactive organic material. An example of such a material is 1,3,5-tris {n- (4-diphenylaminophenyl) phenylamino} benzene, which emits light in the wavelength range of about 380 to about 500 nanometers. The emissive organic layer may also include lower molecular weight organic molecules such as phenylanthracene, tetraarylethene, coumarin, rubrene, tetraphenylbutadiene, anthracene, perylene, coronene, derivatives thereof, or combinations of two or more of the foregoing. May also be included. These materials generally emit light having a maximum wavelength of about 520 nanometers. Yet another advantageous material is a low molecular weight metal-organic complex such as aluminum acetylacetonate, gallium acetylacetonate or indium acetylacetonate that emits light in the wavelength range of about 415 to about 457 nanometers. Scandium- (4-methoxy-picolylmethylketone) -bis (acetylacetonate) that emits light in the wavelength range of about 420 to about 433 nanometers can also be used. In some embodiments (eg, white light applications), useful luminescent organic materials are those that emit light in the blue-green wavelength range.

  Other photoactive organic materials that emit light in the visible wavelength range and that can be used in the techniques of the present invention are described in US Pat. Mitschke and P.M. Bauerle, “The Electroluminescence of Organic Materials”, J. Am. Mater. Chem. , Vol. 10, pp. 1471-1507 (2000), the disclosure of which is incorporated herein by reference, organometallics of 8-hydroxyquinoline such as tris (8-quinolinolato) aluminum and other materials. It is a complex. Additional exemplary organic materials that can be used in the photoactive layers of the present invention include Akcelrud, “Electroluminescent Polymers”, Progress in Polymer Science, Vol. 28 (2003), pp. 875-962, the disclosure of which is incorporated herein by reference. The optoelectronically active organic materials used in the present invention are structural or structural units known in the art to be active or expected to exhibit other functions that enhance device performance (eg, hole Transport materials, electron transport, charge transport and charge confinement, etc.) can include polymeric materials having structures that include various combinations with structures known or potentially expected to perform.

  In one embodiment, the organic optoelectronic device provided by the present invention comprises a plurality of layers comprising an optoelectronic active organic material, said layers comprising the same or different optoelectronic active organic materials. In one embodiment, the present invention provides an organic optoelectronic device that includes a plurality of electroactive layers, each including an optoelectronic active organic material. In this case, the layer is formed by sequentially depositing another layer containing the photoelectron active organic material on one layer containing the photoelectron active organic material. In one embodiment, each layer comprises a dissimilar photoactive organic material that emits light in different wavelength ranges. In another embodiment of the invention, each layer comprises a mixture of two or more photoactive organic materials. In one embodiment, the organic optoelectronic device is an OLED comprising a plurality of electroactive layers, each of the layers comprising a dissimilar luminescent organic material, each of the dissimilar luminescent organic materials being in a different wavelength range. Release.

  In various embodiments of the present invention, the cathode is in contact with an organic ammonium salt, which in some embodiments is an organic ammonium salt having the following structural formula (I):

In the formula, R ^{1 to} R ⁴ are each independently a C _{1 to} C ₂₀ aliphatic group, a C _{3 to} C ₂₀ alicyclic group or a C _{3 to} C ₂₀ aromatic group, and X ⁻ is a monovalent inorganic anion. , Selected from the group consisting of monovalent organic anions, polyvalent inorganic anions, polyvalent organic anions and mixtures thereof.

In one embodiment, R ¹ , R ² , R ³ and R ⁴ in the ammonium salt represented by Structural Formula (I) are the same or different and each has 1 to 20 carbon atoms. Represents a hydrocarbon group. In this case, R ¹ , R ² , R ³ and R ⁴ are each independently selected from the group consisting of aliphatic and aromatic hydrocarbon groups. For example, R ¹ , R ² , R ³ and R ⁴ are methyl, ethyl, n-propyl, isopropyl, allyl, n-butyl, sec-butyl, tert-butyl, 2-butenyl, 1-pentyl, 2-pentyl. 3-pentyl, 2-methyl-1-butyl, isopentyl, tert-pentyl, 3-methyl-2-butyl, neopentyl, n-hexyl, 4-methyl-2-pentyl, cyclopentyl, cyclohexyl, 1-heptyl, 3 -Heptyl, 1-octyl, 2-octyl, 2-ethyl-1-hexyl, 1,1-dimethyl-3,3-dimethylbutyl (common name: tert-octyl), nonyl, decyl, phenyl, 4-toluyl, It can be benzyl, 1-phenylethyl and 2-phenylethyl. In one embodiment, R ¹ , R ² , R ³ and R ⁴ are aliphatic hydrocarbon groups having 1 to 12 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, tert-butyl, tert-pentyl and 1,1-dimethyl-3,3-dimethylbutyl.

In another embodiment, R ¹ , R ² , R ³ and R ⁴ can form a cyclic structure containing one or more heteroatoms. For example, if both R ¹ and R ² are bonded to the same nitrogen atom and both R ¹ and R ² represent an aliphatic group, then R ¹ and R ² together are cyclic containing one or more heteroatoms A structure can be formed.

Structure anionic species X of I ^- is a monovalent inorganic anions, monovalent organic anions, polyvalent inorganic anions, selected from polyvalent organic anions, and mixtures thereof. Examples of monovalent inorganic anions include chloride ions, bromide ions, fluoride ions, methanesulfonate ions, hydrogen sulfate ions, and bicarbonate ions. The polyvalent inorganic anion includes carbonate ion, sulfate ion, sulfite ion and the like. The monovalent organic anion includes methanesulfonate ion, acetate ion, alkoxide ion, acetylacetonate ion, and the like. The multivalent organic anions, malonate ion, succinate ion, ethylene sulfonate ion _{^{(i.e., - O 3 SCH 2 CH 2}} SO 3 -) and the like.

  A wide variety of organic ammonium salts can be used as the constituent material of the organic optoelectronic device of the present invention. Organic ammonium salts that can be used include ammonium salts having the following structural formula (I), which are illustrated in Table 1. (The dashed line (------) indicates the point of attachment of the group.) For those skilled in the art, structural formula (I) does not exemplify all suitable organic ammonium salts that can be used in the present invention. Will be understood. For example, the imidazolium salts 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide and 1-ethyl-3-methylimidazolium hexafluorophosphate are in the class defined by structural formula (I). Although it is outside, it can still be used as an organic ammonium salt in the practice of the present invention. Moreover, as will be readily appreciated by those skilled in the art, mixtures of organic ammonium salts can be advantageously used in the practice of the present invention. One skilled in the art will further appreciate that the performance characteristics of the organic optoelectronic devices of the present invention can be adjusted by changing the structure and / or physical properties of the organic ammonium salt used. In one embodiment, the organic ammonium salt is an ammonium salt that is an ionic liquid. In another embodiment, a mixture comprising two or more organic ammonium salts is used. The organic ammonium salt used may be used in essentially pure form or may be used as a mixture comprising the organic ammonium salt and one or more adjuvants. Suitable adjuvants include solvents, oils, waxes and the like.

In one embodiment, the organic ammonium salt is trihexyl tetradecyl ammonium bis (trifluoromethylsulfonyl) amide, trihexyl (tetradecyl) ammonium hexafluorophosphate, trihexyl (tetradecyl) ammonium dicyanamide, methyl triisobutyl ammonium tosylate, tetradecyl Trihexylammonium decanoate, tetradecyltrihexylammonium bis (2,4,4-trimethylpentyl) phosphinate, tetradecyltrihexylammonium bromide, tetrahexylammonium tetrafluoroborate, 1-ethyl-3-methylimidazolium bis ( Trifluoromethylsulfonyl) imide, 1-ethyl-3-methylimidazolium hexafluorophosphate and It is selected from the group consisting of these.

  1 to 3 show an embodiment of the present invention. FIG. 1 illustrates an exemplary optoelectronic device having an organic ammonium salt dispersed in an optoelectronic active organic material that emits light under the action of a voltage bias applied between a cathode 10 and an anode 14. The combination of ammonium salt and optoelectronically active organic material is shown in FIG. The organic ammonium salt is in contact with the anode by being dispersed in the photoelectron active organic material, and no intervening layer exists between the cathode and the photoelectron active organic material. FIG. 2 shows another embodiment of the present invention which is an optoelectronic device comprising a cathode 10 in contact with a layer 12 comprising a mixture of ammonium salts having structural formula (I) dispersed in a photoelectroactive organic material. . The optoelectronic device shown in FIG. 2 also includes an anode 14 and a charge injection layer 16. FIG. 3 shows yet another embodiment of the present invention in which the cathode 10 is in direct contact with a layer 18 of an ionic liquid comprising an ammonium salt having the structural formula (I). The layer 18 of ionic liquid serves as an intervening layer between the layer 20 containing the photoactive organic material, which in one embodiment is a mixture of two or more electroactive polymers. The organic optoelectronic device of FIG. 3 can be operated as an OLED by applying a voltage bias between the cathode 10 and the anode 14. The organic optoelectronic device of FIG. 3 is a photovoltaic (PV) device by applying a reverse voltage bias between the cathode 10 and the anode 14 (relative to the voltage bias used when operating the optoelectronic device as an OLED). It can be operated.

  In addition to the layer containing the optoelectronic material, one or more layers disposed between the conductive layers can also be present in the organic optoelectronic device provided by the present invention. Such layers are sometimes referred to as “intervening layers” because they are typically located between a layer containing an optoelectronic material and one or more conductive layers. For example, FIG. 3 includes an intervening layer 16 between the anode 14 and the layer 12 containing the photoelectroactive organic material. Various intervening layers can be included in the optoelectronic device to further increase the efficiency of the exemplary optoelectronic device. For example, the intervening layer can serve to improve the injection and / or transport of positive charges (“holes”) into the optoelectronic device. The thickness of each of these layers is typically kept below 500 nanometers, usually below 100 nanometers. Exemplary materials for these intervening layers include, in some embodiments, organic molecules of low to medium molecular weight (eg, less than about 2000 grams / mole molecular weight), polystyrene sulfonic acid (to name a few examples) Doped poly (3,4-ethylenedioxythiophene) ("PEDOT: PSS") and polyaniline. These can be applied during the manufacture of the device by conventional methods such as spray coating, dipping, physical vapor deposition or chemical vapor deposition and other methods. In one embodiment of the present invention, a positive injection between the anode layer and the active organic material layer to obtain a higher injection current under a given forward bias and / or to obtain a higher maximum current before device failure. A hole injection enhancement layer can be introduced. In this way, the hole injection enhancement layer facilitates the injection of holes from the anode. Exemplary materials for the hole injection enhancement layer are arylene systems such as those disclosed in US Pat. No. 5,998,803, the disclosure of which is incorporated herein by reference. A compound. Specific examples include 3,4,9,10-perylenetetracarboxylic dianhydride and bis (1,2,5-thiadiazolo) -p-quinobis (1,3-dithiol).

  In one embodiment, the exemplary device includes an intervening layer that is a hole transport layer. In one embodiment, the hole transport layer is disposed between the hole injection enhancement layer and the layer comprising the photoactive organic material. The hole transport layer transports holes and blocks electron transport, so that holes and electrons can be substantially optimally combined in the active organic material layer. Exemplary materials for the hole transport layer include triarylamine, triaryldiamine, tetraphenyldiamine, aromatic tertiary amine, hydrazone derivative, carbazole derivative, triazole derivative, imidazole derivative, to name a few examples. There are oxadiazole derivatives having amino groups and polythiophenes.

  In other embodiments, the intervening layer includes an “electron injection and transport enhancement layer” as an additional layer, which is typically disposed between the electron donating material and the photoelectroactive organic material layer. Typical materials used as electron injection and transport enhancement layers include organometallic complexes such as tris (8-quinolinolato) aluminum, oxadiazole derivatives, perylene derivatives, pyridine derivatives, pyrimidine derivatives, quinoline derivatives, quinoxaline derivatives. , Diphenylquinone derivatives and nitro-substituted fluorene derivatives.

  In one embodiment, the optoelectronically active material can also be mixed with a polymeric material that can serve as a matrix polymer. In general, any known polymeric material can be used.

  In one embodiment, the layer comprising the photoelectroactive material further comprises a fluorescent dye or a phosphorescent dye. In one embodiment, the present invention provides an organic optoelectronic device that is an organic light emitting diode (OLED), wherein the OLED includes a photoluminescent ("PL") layer. In one embodiment, the photoluminescent layer is a fluorescent layer that includes one or more fluorescent materials. In another embodiment of the present invention, the photoluminescent layer is a phosphorescent layer comprising one or more phosphorescent materials. In one embodiment, the optoelectronic device provided by the present invention includes both a fluorescent layer and a phosphorescent layer. Suitable photoluminescent materials for use in such layers are, for example, those disclosed in US Pat. No. 6,847,162.

  The optoelectronic device provided by the present invention generally comprises a cathode, an anode, an intervening layer, and an optoelectronic active organic material layer that are in contact with an organic ammonium salt comprising one or more zero-valent metals and having the structural formula (I) Is included. In one embodiment, at least one of the cathode and the anode is transparent. In another embodiment, all layers present in the optoelectronic device are transparent as defined herein. In one embodiment, an optoelectronic device provided by the present invention includes a transparent electrode that exhibits a light transmission of about 90% or more in one embodiment and 95% or more in another embodiment. In one embodiment, the present invention provides an optoelectronic device that is a photovoltaic (“PV”) cell that exhibits efficient electron transport across the interface between a transparent electrode and an adjacent active organic material.

  In another embodiment, the present invention encompasses a method of operating an optoelectronic device. Such methods include applying an electric field or light energy to the optoelectronic device to convert between electrical energy and light energy. In yet another embodiment, the optoelectronic devices can be organic photovoltaic devices, photodetectors, display devices and organic light emitting devices. A display device is exemplified by a device used for visual sign transmission. In one embodiment, such a device can be operated in a direct current mode. Alternatively, such a device can be operated in an alternating mode.

General procedure:
In the following examples, poly (3,4-ethylenedioxythiophene (PEDOT: PSS) doped with polystyrene sulfonate was purchased from Bayer Corporation under the trade name Baytron® P. Green light emitting polymer (LEP). Was commercially obtained from the Dow Chemical Company under the trade name Lumation® 1304. The device was manufactured as follows: Pre-patterned ITO coated glass used as the anode substrate was UV-ozone for 10 minutes. A layer of {poly (3,4-ethylenedioxythiophene) / polystyrene sulfonate} (PEDOT: PSS) polymer (60 nm) was then deposited on the ITO by spin coating and the assembly was placed in air. And baked for about 1 hour at 180 ° C. The light emitting layer was composed of a mixture of the light emitting polymer Lumation 1304 and an ammonium salt ionic liquid, and in Comparative Example 1, no ammonium salt ionic liquid was included in the light emitting layer. The emissive layer was formed by spin coating a solution of LEP and ammonium salt ionic liquid onto the PEDOT: PSS layer, followed by argon (moisture and oxygen were nominally less than 1 ppm and less than 10 ppm, respectively). The sample was then transferred into a glove box filled with a glass substrate, and then a 110 nm Al cathode layer was thermally deposited on the light-emitting layer.After metallization, optics obtained from Norland products, Inc. (Cranberry, NJ 08512, USA) Cover glass sealed with adhesive NORLAND 68 . Active area encapsulating devices using was about 0.2 cm ^2.

Comparative Example 1
OLEDs were prepared as described in the general procedure. The OLED was exactly the same as the OLEDs of Examples 1 and 2 except that no ammonium salt was included in the light emitting layer.

The performance of the OLEDs of Examples 1 and 2 and the OLED of Comparative Example 1 was evaluated by measuring the current-voltage-luminance (IV-L) characteristics of each OLED. Luminance was measured (in candela / square meter (cd / m ² )) using a photodiode calibrated with a luminance meter (Minolta LS-110). For each device, from its IVL data, efficiency (measured in candela / ampere (cd / A) units) as a function of current density (measured in milliamps per square centimeter (mA / cm ² )). A plotted graph was obtained. 4 shows the efficiency versus current density plot for the OLED device of Comparative Example 1 (C. Ex. 1), which is a device comprising a light emitting polymer (LEP) as the photoelectroactive material and aluminum (Al) as the cathode. .

Example 1 (Ex. 1)
An exemplary OLED was fabricated as described in the general procedure. The ammonium salt used was the ionic liquid trihexyl tetradecyl ammonium tetrafluoroborate {CH ₃ (CH ₂ ) ₅ } ₄ N (BF ₄ ) (CAS # 15553-50-1) obtained from Sigma-Aldrich. It was. A solution of LEP and ionic liquid was prepared by mixing 2 ml of a 1.0 wt% tetrahydrofuran solution of LEP and 0.20 ml of a 0.5% tetrahydrofuran solution of trihexyltetradecyl ammonium tetrafluoroborate.

  Considering FIGS. 5 and 6, this is evidenced by a highly asymmetric IV curve (FIG. 5) (ie, current under forward bias is more than five orders of magnitude greater than current under reverse bias). Thus, it can be clearly seen that an OLED containing an ammonium salt ionic liquid functions as an organic light emitting diode. In the IV measurement shown in FIG. 5, the bias voltage was changed from -10 volts to 10 volts in steps of 0.2V. FIG. 6 showing the efficiency vs. current density plot shows that the efficiency of the exemplary OLED of Example 1 is superior to the efficiency observed in Comparative Example 1 (compare FIGS. 4 and 6). .

Example 2
Similar to Example 1, an exemplary organic optoelectronic device that can be used as both an OLED and a photovoltaic device (eg, a photodetector) was fabricated. The ammonium salt used was the ionic liquid trihexyl tetradecyl ammonium tetrafluoroborate. FIG. 7 shows the IV characteristics of the device of Example 2 under UV illumination and in the dark. When this device was operated as a photovoltaic device, a handheld long wavelength ultraviolet lamp having an intensity of about 3 mW / cm ² at 364 nm was used as the illumination light source. The device was illuminated through a transparent ITO electrode.

As can be seen from FIG. 7, the exemplary device exhibits a short circuit current (Isc) of about 2 × 10 ⁻⁶ amps (corresponding to about 1 × 10 ⁻⁵ mA / cm ² ), which is 2.05V More than three orders of magnitude higher than the current measured in the dark at an open circuit voltage of. The observed optical response clearly shows that the exemplary device can be used as a photovoltaic device. In FIG. 7, current is plotted against applied voltage bias under illumination and in the dark. In FIG. 7, “Isc” (“short-circuit current”) refers to current at zero voltage bias measured under illumination, and “Voc” (“open-circuit voltage”) corresponds to when the current reaches a minimum value. Voltage.

  The above-described embodiments are merely illustrative of the present invention and serve only to illustrate some of the features of the present invention. The following claims are intended to claim the invention in the broadest possible scope and the examples presented herein illustrate embodiments selected from a multitude of all possible embodiments. . Accordingly, the applicant intends that the scope of the claims should not be limited by the choice of examples used to illustrate features of the invention. As used in the claims, the term “comprising” and grammatical variations thereof logically mean terms with different ranges (eg, but not limited to, “consisting essentially of” and “consisting of” ) Is included and included. Where required ranges are presented, these ranges include all sub-ranges within that range. Changes within these ranges should be expected to occur to those skilled in the art and, if not already in public use, these changes are included in the claims, if possible. Should be understood. It is also anticipated that advances in science and technology will allow equivalents and substitutions not currently envisaged due to language inaccuracies, and these modifications are included in the claims if possible. Should be understood.

  While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. Therefore, it is to be understood that the claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

1 is a schematic illustration of a first optoelectronic device structure including a cathode in contact with an organic ammonium salt in accordance with an embodiment of the present invention. 2 is a schematic illustration of a second optoelectronic device structure including an organic ammonium salt and a charge injection material layer in accordance with an embodiment of the present invention. 3 is a schematic illustration of a third optoelectronic device structure including a layer of organic ammonium salt in accordance with an embodiment of the present invention. FIG. 2 shows efficiency vs. current density plot for an OLED device of Comparative Example 1 (C. Ex. 1), which is a device comprising a light emitting polymer (LEP) as a photoelectroactive material and aluminum (Al) as a cathode. Figure 2 shows the IV behavior of the OLED device of Example 1 under forward and reverse bias. 2 is a graph plotting the efficiency of the OLED of Example 1 as a function of current density. 2 is a plot of current versus bias voltage for an exemplary embodiment of the invention measured under illumination and in the dark.

Explanation of symbols

10 Cathode 12 Mixture of Ammonium Salt and Photoelectroactive Organic Material 14 Anode

Claims (26)

An organic optoelectronic device comprising a cathode composed of one or more zero-valent metals, an anode, and a photoelectroactive organic material disposed between the cathode and the anode, wherein the cathode comprises one or more An organic optoelectronic device in contact with an organic ammonium salt. The device of claim 1, wherein the ammonium salt has the following structural formula (I):
(Wherein R ^{1 to} R ⁴ are each independently a C _{1 to} C ₂₀ aliphatic group, a C _{3 to} C ₂₀ alicyclic group or a C _{3 to} C ₂₀ aromatic group, and X ⁻ is a monovalent inorganic group) Selected from the group consisting of ions, monovalent organic anions, polyvalent inorganic anions, polyvalent organic anions, and mixtures thereof.) The device of claim 1, wherein the photoactive organic material is in contact with the organic ammonium salt. The device of claim 1, wherein the device is an organic light emitting diode. The device of claim 1 which is an organic photovoltaic device. The device of claim 1, wherein the device is operable in a direct current mode. The device of claim 1, wherein the device is operable in an alternating mode. The zero-valent metal is selected from the group consisting of aluminum, copper, zinc, silver, nickel, palladium, platinum, iridium, lithium, sodium, potassium, calcium, strontium and mixtures of two or more of the foregoing. Item 1. The device according to Item 1. The device of claim 1, wherein the zero valent metal comprises aluminum. The device of claim 1, wherein the cathode is transparent. 2. The anode is made of one or more materials selected from the group consisting of indium tin oxide, tin oxide, indium oxide, zinc oxide, indium zinc oxide, zinc indium tin oxide, antimony oxide, and mixtures thereof. The device described. The photoactive organic material is poly (n-vinylcarbazole), poly (n-vinylcarbazole) derivative, polyfluorene, polyfluorene derivative, poly (paraphenylene), poly (paraphenylene) derivative, poly (p The device of claim 1, comprising one or more materials selected from the group consisting of: -phenylene vinylene), poly (p-phenylene vinylene) derivatives, polythiophene, polythiophene derivatives, and mixtures thereof. The ammonium salt is trihexyl tetradecyl ammonium bis (trifluoromethylsulfonyl) amide, trihexyl (tetradecyl) ammonium hexafluorophosphate, trihexyl (tetradecyl) ammonium dicyanamide, methyl triisobutyl ammonium tosylate, tetradecyl trihexyl ammonium decano , Tetradecyltrihexylammonium bis (2,4,4-trimethylpentyl) phosphinate, tetradecyltrihexylammonium bromide, tetrahexylammonium tetrafluoroborate, 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) Imido, 1-ethyl-3-methylimidazolium hexafluorophosphate and mixtures thereof? Made is selected from the group, according to claim 1, wherein the device. The device of claim 2, wherein the one or more organic ammonium salts having the structural formula (I) consist essentially of tetrahexylammonium tetrafluoroborate. The device of claim 1, wherein the ammonium salt is an ionic liquid. The device of claim 1, wherein one or more organic ammonium salts are disposed on the surface of the cathode. The device of claim 1, wherein the one or more organic ammonium salts are disposed in the photoactive organic material. The device of claim 1, further comprising an intervening layer. The device of claim 18, wherein the intervening layer is selected from the group consisting of a hole injection layer, an electron blocking layer, a hole blocking layer, and an electron injection layer. The device of claim 1, wherein the one or more organic ammonium salts are disposed in one or more intervening layers. A cathode composed of one or more zero-valent metals, an anode, a photoelectron-active organic material disposed between the cathode and the anode, and one or more organic ammonium salts having the following structural formula (I): An organic light emitting diode comprising: the ammonium salt disposed between a photoelectroactive organic material and a cathode, wherein the ammonium salt is in contact with the cathode.
(Wherein R ^{1 to} R ⁴ are each independently a C _{1 to} C ₂₀ aliphatic group, a C _{3 to} C ₂₀ alicyclic group or a C _{3 to} C ₂₀ aromatic group, and X ⁻ is a monovalent inorganic group) Selected from the group consisting of ions, monovalent organic anions, polyvalent inorganic anions, polyvalent organic anions, and mixtures thereof.) 24. The device of claim 21, wherein the one or more organic ammonium salts are disposed in the photoactive organic material. The device of claim 21 further comprising an intervening layer. 24. The device of claim 23, wherein the intervening layer is one or more selected from the group consisting of a hole injection layer, an electron block layer, a hole block layer, and an electron injection layer. 24. The device of claim 23, wherein the one or more organic ammonium salts are disposed in one or more intervening layers. An organic light-emitting diode device comprising: a cathode made of a zero-valent metal; an anode made of indium tin oxide; a photoelectron-active polyfluorene disposed between the cathode and the anode; and one or more organic ammonium salts. An organic light emitting diode device, wherein the ammonium salt is disposed between a photoelectroactive organic material and a cathode, and the ammonium salt is in contact with the cathode.