KR100602050B1 - Organic semiconductor device, method and composition for producing the same - Google Patents

Abstract

Disclosed are an organic semiconductor device manufactured using a wet process, and a method of manufacturing the same. The method of manufacturing an organic semiconductor device may include forming an organic semiconductor layer by coating an organic compound solution composition including an organic solvent, an ionic salt, and an organic semiconductor compound on a substrate and removing the organic solvent; And performing heat-annealing and electro-annealing in parallel with the formed organic semiconductor layer. In addition, the organic semiconductor device is an anode; cathode; And a semiconductor layer interposed between the anode and the cathode and containing an ionic salt, wherein an anion number of the ionic salt is greater than a cation number of the ionic salt at an interface between the anode and the semiconductor layer. At the interface of the semiconductor layer, the number of cations of the ionic salt is larger than the number of anions of the ionic salt.

Organic Semiconductor Devices, Electroluminescence, Heat-Annealing, Electro-Annealing, Ionic Salts

Description

Organic semiconductor device, method for manufacturing the same, and composition for manufacturing same {Organic semiconductor device, method and composition for producing the same}             

1A is a diagram for explaining the structure of a conventional organic EL element.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1B is a view for explaining the structure of an organic EL device having a simple dispersed single thin film structure in which each component is uniformly dispersed.

2A is a diagram for explaining the structure of a single thin film structure EL element in the form of a graded cushion;

2B is a view for explaining the structure of an EL element including a thin film of a graded cushion form and a separate thin film;

3 is a view for explaining the structure of an organic semiconductor device according to an embodiment of the present invention.

Figure 4 is a photograph for comparing the light emitting surface of the organic EL device according to an embodiment of the present invention and the conventional organic EL device.

The present invention relates to an organic semiconductor device, a method for manufacturing the same, and a composition for manufacturing the same, and more particularly, to an organic semiconductor device manufactured using a wet process, a method for manufacturing the same, and a composition for manufacturing the same. will be.

In general, an organic semiconductor device is a device using electrical semiconductor properties related to the highest occupied molecular orbital (HOMO) level and the lowest unoccupied molecular orbital (LUMO) level, which is an electronic energy level of an organic material. Such as an organic transistor device. Specific examples of organic diode devices include organic light emitting diodes (Organic Light Emitting Diodes or organic electroluminescent diodes), and specific examples of organic transistor devices include organic field effect transistors (FETs), organic thin film transistors (TFTs), and organic SIT ( Static Induction Transistors, Organic Top Gate SITs, Organic Triodes, Organic Grid Transistors, Organic Thyristors, Organic Bipolar Transistors, and the like. Since these organic semiconductor devices have different electrical and optical properties depending on the thin film structure of the organic material layer formed on the substrate, the development of an efficient thin film structure is an important field of the organic semiconductor device manufacturing technology with the development of new organic material.

Hereinafter, the structure and operation of the organic semiconductor device will be described with reference to the organic electroluminescent device. An organic electroluminescent element, commonly referred to as "organic EL", is one of self-luminous display elements, and has a structure in which a thin film made of a luminescent organic compound is interposed between electrodes. The organic EL device using a low molecular weight or high molecular organic compound as a light emitting material has a simpler manufacturing method, a lower driving voltage, a large area and full color, compared to an EL device using an inorganic material as a light emitting material. There are many advantages, such as ease of display manufacturing. In such an organic EL device, an exciton is generated by injecting electrons and holes into the LUMO level and the HOMO level of the light-emitting organic compound and recombining them, thereby emitting light (fluorescence or phosphorescence) while the exciton loses activity. Done.

1A is a diagram for explaining the structure of a conventional organic EL element. As shown in Fig. 1A, a typical EL element has a multilayer stack structure in which the interlayer interface of the organic layer is clearly distinguished, and the representative multilayer stack structure EL layer 20 includes a hole transport layer 13, a light emitting layer 14, And an electron transport layer 15 (see Tang, C. et al. Appl. Phys. Lett. 1987, 51, 913-915), and if necessary, the hole injection layer 12 and / or the electron injection layer 16 It includes more. The EL layer 20 is interposed between the anode 11 and the cathode 17 formed on the substrate 10, and when a voltage is applied to the EL layer 20 from the electrodes 11 and 17, the light emitting layer ( In 14), recombination of charge carriers occurs to cause light emission. After forming the EL element in this manner, in order to prevent the EL element from being deteriorated by preventing the EL element from deteriorating, the substrate (EL panel) on which the EL element is formed is sealed (packed) with a sealing member or the like, and the lid member is covered and bonded. . Next, in order to connect the sealed EL element to an external signal terminal, a connector (FPC, TAB, etc.) can be attached to produce a passive or active matrix light emitting device. The EL element of such a laminated structure is employed in most of EL elements currently developed. For example, Tang or the like forms a multilayer structure by stacking a transparent electrode (anode) having a high work function, a hole transporting layer, an electron transporting light emitting region, and a metal electrode (cathode) having a low work function, thereby applying an applied voltage of 10 V or less. , An organic EL having low voltage operation and high luminous efficiency exhibiting a luminance of 1,000 cd / m 2 was realized. In the EL device, a tris (8-quinolinorate) aluminum complex (Alq) was used as a light emitting material, and Alq is known as an excellent light emitting material having high luminous efficiency and electron transporting performance. In addition, a device having a three-layer structure (Jpn. J. Appl Phys. 27 (1988) L269) having a light emitting region formed between the hole transporting layer and the electron transporting layer, a dye (dye: coumarin derivative, DCM1, etc.) in the light emitting region (Alq) A device (J. Appl Phys., 65 (1989) 3610) that controls the color of light emitted by doping fluorescent dyes and increases the intensity of light emitted has also been developed. In addition to the organic EL device using such a low molecular weight light emitting material, an EL device using a conjugated polymer such as poly (phenylene-vinylene) (PPV) as a light emitting material has been developed (Burroughes, JH Nature 1990, 347, 539-541), recent advances have been made in improving the stability, efficiency and durability of polymer EL devices.

The EL layer 20 described above can be formed in various ways. Examples of the proposed methods so far include dry process such as vacuum evaporation, sputtering, spin coating, cast method, and ink-jet method. Wet process such as method, dipping method, printing method, etc., other roll coating method, Langmuir-Blodgett method, ion play An ion plating method is also used. Drying methods such as vacuum deposition have been widely used to fabricate multilayer EL devices as shown in FIG. 1A using low molecular weight compounds that have good thermal stability and can be sublimated into thin films. The disadvantage is that this demanding, complex manufacturing process is expensive. In the wet method, a material for forming a hole transporting layer, an electron transporting layer, and / or a light emitting layer and a polymer binder are dissolved in a suitable solvent, coated on an electrode surface to form an organic layer, and then a counter electrode is formed by a vapor deposition method or the like. to be. Compared with the dry method, the wet method has the following advantages. (1) A dry method such as vapor deposition can be used to form a variety of materials that are difficult to form, and can be applied not only to low molecules but also to high molecular organic EL materials. (2) In the dry method, even a small amount of doping, which is difficult to control, can be easily realized. (3) Easy to large area. (4) The EL layer can be formed relatively easily, and the manufacturing cost of the device is low. (5) By using a plurality of light emitting materials, light emission from each light emitting molecule can be obtained simultaneously (for example, white light emission can be easily realized). (6) In the conventional laminated EL device, the polymer dispersed EL device is thermally stable because each material is dispersed in the polymer binder, whereas each layer is in an amorphous state.

Examples of forming a light emitting region by such a wet process include dispersing a pellin derivative or Alq as a light emitting molecule in polyvinylcarbazole (PVK), Alq and tetraphenylbendiazine as a light emitting molecule in polycarbonate. (Japanese Patent Application Laid-Open No. 3-790, Japanese Patent Laid-Open No. 3-171590, etc.) and the like are known, but in the device structure, since the light-emitting compound is uniformly dispersed throughout the light emitting region, holes and It is difficult to balance the injection and transport of electrons, and as a result, the probability of recombination is lowered, so that sufficient light emission efficiency is hard to be obtained. In addition, although the EL layer may be formed by combining the wet method and the dry method, if necessary, there are disadvantages in that the luminous efficiency of the manufactured EL element is not high enough or the operating voltage is high.

As one way to overcome this disadvantage, a method of doping an organic layer with an ionic salt formed of a cation and an anion may be considered. For example, a bias voltage is applied to a light emitting electrochemical cell doped with a salt such as LiCF ₃ SO _{3 to a} mixture of a polymer such as PPV and an ionic conductive material such as poly (ethylene-oxide) (PEO), It has been reported that electric annealing increases the luminescence intensity (Y. Yang and Q. Pei, J. Appl. Phys. Vol (81), page 3294, 1997). Similar phenomena have also been observed in ion-doped polymer ELs (DB Romero et al., Appl Phys. Lett. Vol (67) page 1659 1995, AG MacDiamid and F. Huang, Synth. Met. Vol (102) page 1026). , 1999), it has been reported that ions unintentionally introduced during synthesis play an important role in improving the properties of polymer EL (H. Aziz and G. Xu, J. Phys. Chem. B vol (101) page 4009, 1997). That is, when ions accumulate in the electrode region to form a space charge, the light emission efficiency is improved and the operation start voltage is reduced. This effect can be explained by the arrangement of ions by a kind of electric field. Specifically, when ions are present in the polymer thin film, the anions move to the anode and the cations move to the cathode in the electro-annealing process, and the ions are polarized, and the movement of the ions forms a space charge in the vicinity of the electrodes. When these space charges accumulate near the electrode, a large electric field is formed near the electrode, which reduces the energy barrier and facilitates the injection of charge carriers. Therefore, the probability of injecting holes and electrons is greatly increased, thereby increasing bipolar recombination and improving the efficiency of the device. In addition, a phenomenon in which the operation start voltage of the device decreases due to the change of the charge injection barrier at the interface between the electrode and the light emitting layer has also been reported in the case of dendrima EL (D. Ma et al., J. Phys. D, vol ( 35) page 520, 2002). In addition, when electro-annealing is performed by applying an electric field of 20 volts or more to the PVK single thin film structured light emitting layer doped with organic low molecular weight and ammonium salt (tetra-n-butylammonium tetrafluoroborate, Bu ₄ NBF ₄ ), PVK + BF ₄ ----> PVK + BF ⁴⁺ + e ^- Reports of reactions that facilitate charge injection (Y. Sakuratani, T. Watanabe, S. Miyata; Thin Solid Films V388 (2001) 256-259, Y. Sakuratani, M. Asai, M. Tokita, S. Miyata; Synthetic Metals V123 (2001) 207-210, S. Miyata, Y. Sakuratani, XT Tao; Optical Materials 21 (2002) 99-107). The maximum luminous intensity of the device fabricated by the light emitting device was about 1000 cd / m ² (at ~ 17 V), and sufficient light emitting brightness could not be obtained, and the electrical damage to the device was relatively high (> 20 V). This easily occurs and has a disadvantage in that the uniformity of the light emitting surface is inferior.

Accordingly, it is an object of the present invention to provide an organic semiconductor device comprising an organic EL device which solves the disadvantages of the organic semiconductor thin film produced by a conventional wet method, a method of manufacturing the same, and a composition for manufacturing the same.

Another object of the present invention is to provide an organic semiconductor device which is excellent in uniformity of light emitting surface, light emission luminance and light emission efficiency. Another object of the present invention is to provide an organic semiconductor device having a low operating voltage, excellent display image quality, and improved operation reliability. Still another object of the present invention is to provide an organic semiconductor device which is easy to manufacture and low in manufacturing cost.

In order to achieve the above object, the present invention comprises the steps of coating an organic compound solution composition comprising an organic solvent, an ionic salt and an organic semiconductor compound on a substrate and removing the organic solvent to form an organic semiconductor layer; And it provides a method for producing an organic semiconductor device comprising the step of performing heat-annealing and electro-annealing in parallel to the organic semiconductor layer formed and an organic semiconductor device manufactured by the method. The present invention also provides a composition for producing an organic semiconductor thin film comprising an organic solvent, an ionic salt and an organic semiconductor compound.

The invention also provides a positive electrode; cathode; And a semiconductor layer interposed between the anode and the cathode and containing an ionic salt, wherein an anion number of the ionic salt is greater than a cation number of the ionic salt at an interface between the anode and the semiconductor layer. The interface of the semiconductor layer provides a semiconductor device having a larger number of cations of the ionic salt than that of the ionic salt. The invention also provides a positive electrode; cathode; And a semiconductor layer interposed between the anode and the cathode, wherein an organic thin film including an ionic salt is formed on at least one of an interface between the anode and the semiconductor layer and an interface between the cathode and the semiconductor layer. Provided is a semiconductor device.

Here, the organic solvent may be composed of a single solvent. In addition, the organic compound solution includes two or more organic semiconductor compounds and two or more organic solvents having different volatility, and as the organic solvent is removed, the two or more organic semiconductor compounds have a concentration gradient along the stacking direction thereof. May be sequentially stacked.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In the accompanying drawings, members having the same and similar functions are given the same reference numerals as those given in the prior art.

When manufacturing an organic semiconductor device, the present invention firstly forms an organic layer doped with an ionic salt, and then emits light of an EL device manufactured by performing electro-anneal in parallel during a heat-annealing process. It is based on the discovery that the luminance can be improved and uniform and stable light emission characteristics can be obtained. Therefore, in the method of manufacturing an organic semiconductor device according to the present invention, an organic semiconductor layer is formed by a wet method using an organic compound solution containing an ionic salt, and heat-annealing and electro-annealing are performed on the formed organic semiconductor layer. It includes the process to perform. Existing EL thin film production methods, for example, Y. Sakuratani, T. Watanabe, S. Miyata; Thin Solid Films V388 (2001) 256-259, Y. Sakuratani, M. Asai, M. Tokita, S. Miyata; Synthetic Metals V123 (2001) 207-210, S. Miyata, Y. Sakuratani, X.T. Tao; Optical Materials 21 (2002) 99-107 et al. Disclose a method of doping an ammonium salt to an PVK polymer and subjecting it to electro-annealing, but any of the above reports doped an ionic salt as proposed in the present invention. And a method of treating heat-annealing and electro-annealing in parallel is not disclosed.

The manufacturing method of the organic semiconductor element which concerns on this invention is demonstrated with reference to the organic electroluminescent (EL) element which has the simplest structure among organic semiconductor elements. In the method of manufacturing an organic semiconductor device according to the present invention, as shown in FIG. 1B, not only a semiconductor device having a simple dispersed single thin film structure in which each component is uniformly dispersed, but also two or more organic substances constituting the organic semiconductor device are included. It can also be applied to a single thin film structure semiconductor device in the form of a graded junction that is sequentially stacked with a predetermined concentration gradient (see International Patent Publication WO 03/069959, Korean Patent Application No. 10-2003-8854) The contents of the patent document are all incorporated herein by reference. In addition, the method of the present invention can be applied to an EL element further comprising a separate layer in addition to the above layer, and the structures of these layers are as follows. In the following structure, " / " represents a separate layer having a clear interface with an adjacent layer, and layers connected by " ~ " represent a single thin film in the form of a graded junction in which the interface of each layer is unclear.

(1) Organic layer / cathode in which anode / hole injection, transport layer, light emitting layer, etc. are simply dispersed and mixed

(2) Anode / hole injection and transport layer ~ light emitting layer / cathode

(3) anode / light emitting layer ~ electron transport and injection layer / cathode

(4) Anode / hole injection and transport layer ~ light emitting layer ~ electron transport and injection layer / cathode

(5) Anode / hole injection layer / transport layer ~ light emitting layer ~ electron transport and injection layer / cathode

(6) Anode / hole injection and transport layer ~ light emitting layer ~ electron transport layer / electron injection layer / cathode

In the following description, organic semiconductor compounds generally refer to organic compounds having electrical and / or optical properties such as hole injection or transport, luminescence or fluorescence, electron transport or injection. FIG. 2A is a view for explaining the structure of a single thin film structure EL element in the form of a graded junction. As shown in FIG. 2A, the hole injection material 12 is illustrated in the single thin film structure EL element in the form of a graded junction. Two or more organic semiconductor compounds constituting the EL layer 20, such as the hole transport material 13, the light emitting material 14, the electron transport material 15, and the electron injection material 16, have a predetermined concentration gradient along the stacking direction. Laminated in order to have a (gradient), the EL layer 20 has a structure interposed between the anode and the cathode (11, 17). The single thin film structure EL device of the graded section is formed of a substrate having an anode 11 formed of a composite solution in which two or more organic semiconductor compounds having different solubility in the organic solvent are dissolved in two or more organic solvents having different volatility. After coating on the top of 10) to form an organic layer, by sequentially removing the organic solvent from the organic layer, it can be prepared by sequentially depositing the two or more organic compounds. In addition, FIG. 2B shows that the hole injection material 12, the hole transport material 13, the light emitting material 14, and the electron transport material 15 are formed in a single thin film having a graded section, and the electron injection layer 16 is formed. It is a figure which shows the structure of the organic electroluminescent element formed by dry methods, such as a wet method and a vacuum deposition.

The wet process organic compound solution used in the manufacture of the organic EL device according to the present invention comprises an organic semiconductor compound, for example, one or more organic light emitting compounds that emit red, green or blue light, wherein the EL device produced It is desirable to select the luminescent compound by optimizing the chromaticity (e.g., narrow lines of 460, 520 and 650 nm for blue, green and red, respectively) so that can represent a wide color range. Since there is no particular limitation on the light emitting compound that can be used in the present invention, it is commonly used in the manufacture of the organic EL device, a wide range of fluorescent materials or phosphorescent materials that emit light by electro-electron recombination. Can be used. Preferably, a low molecular weight or high molecular fluorescent material having luminescence may be used, and a low molecular weight material and a high molecular material may be mixed and used, and particularly, a cyanine dye, a merocyanine dye, a styryl dye, Pigments such as anthracene derivatives, polpyrin derivatives, phthalocyanine derivatives, coumarins, DCM, and Nile and laser dyes may also be used.

As a specific example of the organic compound that can be used in the present invention, as the hole injection and hole transport compound, a soluble phthalocyanine compound, TPD ((N, N'-diphenyl-N, N'-bis (3-methylphenyl) )-Aromatic diamine compounds such as [1,1'-biphenyl] -4,4'-diamine: triphenylamine derivatives), triphenylamine, MTDATA (4,4 ', 4 "- tris [3-methylphenyl (phenyl) amino] triphenylamine), quinacridone, bisstil anthracen derivatives, 5,10,15,20-tetraphenyl-21H, 23H-phosphorine, PVK ( polyvinyl carbazole), porphine compounds, α-NPD (N, N'-diphenyl-N, N'-bis (1-naphthylphenyl) -1,1'-biphenyl-4,4'-diamine), NPB (N, N'-Bis (naphthalen-1-yl) -N, N'-bis (phenyl) benzidine), Spiro-NPB, Spiro-TAD, polyaniline, PEDOT / PSS (Poly (3,4-oxyethyleneoxythiophene) / conductive polymers such as poly (styrene sulfonate)) may be exemplified, but are not limited thereto.

Examples of the electron injection and electron transport compound that can be used in the present invention include Alq3 and Zn complexes, ZnNBTZ, ZnBTZ, Zn (tOc-BTAZ), and distyrylbiphenyl derivatives, which are aluminum complexes formed by coordinating hydroxyquinoline three molecules to aluminum atoms. , Electron deficient compounds such as dilithium phthalocyanine, disodium phthalocyanine, magnesium porupin, 4,4,8,8-tetrakis (1H-pyrazol-1-yl) pyrazabol, 3- (2'-benzothiazole ) -7-diethylaminomarin, BND (2,5-bis (1-naphthyl) -1,3,4-oxadiazole), PBD (2- (4-tert-butylphenyl) -5- (4-biphenylyl ), 1,3,4-oxadiazole) and the like, but also vasoprophine BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), triazole derivatives [eg, 3, 4,5-Triphenyl- 1,2,4-triazole, 3- (biphenyl-4-yl) -4-phenyl-5-tert-butylphenyl-1,2,4-triazole, 3,5-bis (4- materials having a hole block function such as tert-butylphenyl) -4-phenyl- [1,2,4] triazole], but are not limited thereto. It is not.

As the organic light emitting compound, it is preferable to use a substance having an ionization potential smaller than that of the hole transport compound and an electron affinity larger than the electron transport compound. The light emitting low molecular weight organic compounds that can be used in the present invention include, but are not limited to, alumina quinone (Alq3, Tris (8-hydroxyquinolato) aluminum) or tris- (5- which emits light in the green region (520 nm) in the case of green light emitting materials. Tri- (5-chloro-8-hydroxy-quinolinato) -aluminium, tris (4-methyl-8-hydroxyquinoline) aluminum (Tris (4-methyl -8-hydroxyquinoline) aluminum), tris (5,7-dichloro-8-hydroxyquinolinato) aluminum (Tris (5,7-dichloro-8-hydroxyquinolinato) -aluminium), Gaq3 and other modified Alq3, BeBq2 ( Tris (1-phenyl-3-methyl-4- (2,2-dimethoxypropane-1-oil) -pyrazolin-5-one, such as 10-benzo [h] quinolinol -beryllium complex) ) Terbi 윰 (III) (Tris (1-phenyl-3-methyl-4- (2,2-dimethylpropan-1-oyl) -pyrazolin-5-one) terbium (III)) and the like can be used. Also typically, quinacridone, coumarin, coumarin 6, C545T (10- (2-Benzothiazolyl) -2,3,6,7-tetrahydro-1,1,7,7-tetramethyl- Luminous efficiency and durability by adding (doping) 1H, 5H, 11H- [1] benzopyrano [6,7,8-ij] quinolizin-11-one), Ir-complex at a concentration of several mol% You can also improve. Also typically, red light emitting compounds and dopants include Indigo, Nile Red, DCJTI (Propanedinitrile, [2- (2-propyl) -6- [2- (2,3,6,7). -tetrahydro-2,2,7,7-tetramethyl-1H, 5H-benzo [ij] quinolizin-9-yl) ethenyl] -4H-pyran], DCM2 (4- (Dicyanomethylene) -2-methyl-6- ( julolidin-4-yl-vinyl) -4H-pyran), DCM (4- (dicyanomethylene) -2-methyl-6- (p-dimethyl aminostyryl) -4H-pyran), DCJTB (Eastman Kodk Co.), Tris ( Hexafluoroacetylacetonate) mono (1,10-phenanthroline) erbium (III) (tris (hexafluoroacetylacetonate) mono (1,10-phenanthroline) erbium (III)), tris (benzoyltrifluoroacetonate) mono (1,10-phenanthroline) erbium (III) (Tris (benzoyltrifluoroacetonate) mono (1,10-phenanthroline) erbium (III)), bis (3- (2- (2-pyridyl) benzotenoyl) mono Acetylacetonate iridium III (Bis (3- (2- (2-pyridyl) benzothenoyl) mono-acetylacetonate iridium III) and Pt-complex, Rubrene, N, N'-dimethylkunacridone ( N, N'-Dimethylquinacridone), tris (di (4-bromobenzoyl) methane) mono (phenathroline) uropium (III) (Tris (di (4-bromobenzoyl) methane) mono (phenathroline) europium (III) ), Tris (dibenzoylmethane) mono (4,7-dimethylphenathroline) europium (III) (Tris (dibenzoylmethane) mono (4,7-dimethylphenathroline) europium (III)), tris (1,10-phenanthrol) Tri) (1,10-Phenanthrolene) ruthenium (II) chloride), 2,3,7,8,12,13,17,18-octaethyl-21H, 23H-phosphine platinum (II) (2,3,7,8,12,13,17,18-Octaethyl-21H, 23H-porphine platinum (II)), Ru (dpp) (Tris (4,7-diphenyl-1,10- phenanthroline) ruthenium (II) chloride) may be used. In addition, as the blue light-emitting compound, ZnPBO ((Bis [2- (2-benzoxazolyl) phenolato] Zinc (II)), Balq (Bis (2-methyl-8-quinolinolato) (para-phenyl -phenolato) aluminum), bis- (2-Methyl-8-quinolinolato) -4- (phenyl-phenolato) -aluminum (III) (Bis- (2-methyl-8-quinolinolato) -4- (phenyl-phenolato) -aluminium- ( III)), and metal complex compounds such as DPVBi (4,4'-bis (2,2'-biphenylvinyl) -1,1'-biphenyl) and oxiadia, which are styryl arylene derivatives, may be used. BczVBi (4,4'-Bis ((2-carbazole) vinylene) biphenyl) and lithium tetra (8-hydroxyquinolinato) boron as oxadiazole derivatives, bisstyryl anthracene derivatives, bisstyryl arylene derivatives Nonmetallic complexes such as Lithium tetra (8-hydroxyquinolinato) boron, Tetra (2-methyl-8-hydroxyquinolato) boron with lithium salt Compound, bis (3,5-difluoro-2- (2-pyridyl) phenyl- (2-carboxy) as phosphorescent monomolecule Ridyl) iridium III (bis (3,5-difluoro-2- (2-pyridyl) phenyl- (2-carboxypyridyl) iridium III), poly [(9,9-dihexyl) florene-2,7 as high molecule -Diyl] -alt-co- (9,9-di- (5-pentenyl) -florenyl-2,7-diyl)) (Poly [(9,9-dihexyl) fluoren-2,7-diyl] -alt-co- (9,9-di- (5-pentenyl) -fluorenyl-2,7-diyl))), and the blue light emitting dopant is phosphorescent monomolecular Ir (ppy) 3 (Tris). [2- (2-pyridinyl) phenyl-C, N] iridium (III); Tris (2-phenylpyridine) iridium (III)), bis (2- (2-hydroxyphenyl) -benz-1 as fluorescent monomolecule , 3-thiazolato) zinc complex (Bis (2- (2-hydroxyphenyl) -benz-1,3-thiazolato) zinc complex), perylene, coumarin 47 and the like can be used, but is not limited thereto. It is not. Since there is no particular limitation on the light emitting material of the organic EL device according to the present invention, a dendrima composed of the above-mentioned single molecule or low molecule may also be used.

The polymer organic compound that can be used as the light emitting compound of the organic EL device according to the present invention includes, but is not limited to, poly (p-phenylene) (poly (phenylene)) [eg, poly (2,5-dialkyl-1,4-phenylene). ), poly (p-phenylene)], Poly (phenylene- vinylene) [e.g. poly (1,4 phenylene vinylene), poly- (2,5-dialkoxy-1,4 phenylene vinylene ), poly (2,5-dialkyl-1,4 phenylene vinylene)], polyallylene, polyalkylthiophene, poly (fluorene) [e.g. poly (9,9-dialkyl fluorene)], Poly (thiophene) [eg, poly (3-alkylthiophene)], derivatives thereof, and the like. When the conductive polymer material is used as the light emitting material of the organic EL device according to the present invention, a random copolymer partially exhibiting the properties of the block copolymer, a random, block, or graft copolymer or polymer having any intermediate structure can be used. However, it is not limited to these.

In the organic EL device according to the present invention, the organic semiconductor compound may form a thin film together with a suitable conductive or insulating binder polymer, and may include a suitable dopant as necessary. The binder polymer may be PPV, PVK, PMMA, polyfluorine or the like, derivatives thereof, polycarbonate, polyester, polyallylate, butyral polymer, polyvinylacetal , Diallylphthalate polymer, acrylic polymer, methacrylic polymer, phenol polymer, epoxy polymer, silicone polymer, polysulfone polymer, urea ( urea) polymers and the like. Such predetermined polymers may be used alone, in a mixed or copolymer form, but are not limited thereto. In addition, in order to improve charge transport characteristics, an electron or a hole transport compound may be mixed. In addition, the binder polymer may be a polymer having alignment or liquid crystal properties as well as a polymer having no arrangement. When the binder polymer has liquid crystallinity, polarized EL light emission is possible, and thus a circular polarizer may be mounted outside the EL device to enhance contrast and light emission output. The amount of the organic compound and the binder polymer may vary depending on the purpose, component, thickness, etc. of the desired EL layer, and the amount of each component compound that can exhibit a desired function can be determined by experiment.

According to the present invention, the ionic salts contained in the organic compound solution and doped into the organic layer are typically LiClO ₄ , LiPF ₆ , LiBF ₄ , LiN (CF ₃ SO ₂ ) ₂ , and lithium trifluoromethane trisulfonate (lithium). Inorganic salts containing Li cations such as trifluoromethane sulfonate) and TEA-BF ₄ (tetraethylammonium tetrafluoroborate), Bu ₄ N-BF ₄ (tetra-n-butylammonium tetrafluoroborate), tetraalkyl, aryl or heteroaryl quarters Organic ammonium salts such as tetra-n-alkylammonium toluenesulfonate, tetra-n-alkylammonium tetrafluoroborate, tetra-n-alkyl ammonium tetraphenylborate, tetra-n-alkyl ammonium toluenesulfonate, tetraalkylammonium tetrafluoro borate, tetra-n-alkyl ammonium tetraphenylborate Salts, polymeric salts such as polystyrenesulfonate (PSS), and the like may be used alone or in combination of two or more. However, the salts are merely examples that can be used as the ionic salt of the present invention, and various salts composed of cations and anions can be used in the present invention. The amount of the ionic salt may vary depending on the use, component, thickness, etc. of the EL layer to be manufactured, but is preferably 0.02 to 30 parts by weight based on 100 parts by weight of the organic semiconductor compound and the binder polymer resin. If the amount is less than 0.02 part by weight, the effect of improving the luminous efficiency of the EL element and reducing the operation start voltage is insufficient. If the amount is more than 30 part by weight, the operation of the element is poor due to the excessive concentration of ions.

Typical solvents used in the preparation of the organic compound solution include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol and tert-butyl alcohol. (tert-butyl alcohol), dimethylformamide, dimethylacetamide, ketone, acetone, diacetone alcohol, keto-alcohol, dioxane, ether, polyethylene glycol, polypropylene glycol, polyalkylene glycol, ethylene glycol, propylene glycol, Butylene glycol, triethylene glycol, hexylene glycol, diethylene glycol, glycerol, ethylene glycol monomethyl ether, diethylene glycol methyl ether, triethylene glycol monomethyl ether, 2-pyrrolidone, toluene, xylene, chlorobenzene, Dichlorobenzene, chloroform, dichloromethane, dichloroethane, gammabutyllactone, butyl cellosolve, cyclohexane, NMP (N-methyl-2-pyrrolidone), cyclohexanone, THF (tetra Drofuran), carbon tetrachloride, tetrachloroethane, octylbenzene, dodecylbenzene, quinoline, trichlorobenzene, nitrobenzaldehyde, nitrobenzene, carbon disulfide, 2-heptanone, benzene, terpineol, butylcarbitol acetate, Ion-exchanged water (pure water), mixtures thereof and the like can be used. However, the above examples merely illustrate usable solvents, and the present invention is not limited thereto. In addition, in the present invention, by using a single solvent or by mixing two or more organic solvents having different volatility, an organic semiconductor layer having a concentration gradient may be formed using a difference in volatility and solubility of each solvent. . The viscosity of the organic compound solution can be adjusted to optimize the final thickness and luminescence intensity of the EL layer to be formed, by selection of a suitable solvent. The viscosity of a preferable solution is 5000cp or less, and the minimum of the said viscosity does not have a big meaning in this invention, For example, it is 100cp or more, More preferably, it is 1000cp or more. The concentration of the organic compound solution should usually be chosen to be a viscosity suitable for the wet process and is preferably 0.005 to 30% by weight, more preferably 0.01 to 10% by weight. If the viscosity and concentration are less than or above the above range, there is a concern that the film forming process by the wet process may not be efficiently performed.

As a method of forming the organic layer using the organic compound solution, it is preferable to use a wet method such as a spin-coating method, a casting method, an ink jet method, a deposition method, a printing method, or the like. When the organic layer is formed on the electrode (anode or cathode) using the wet method, the organic layer is likely to be deteriorated by moisture and oxygen in the atmosphere. Therefore, in order to remove moisture and oxygen, an organic layer is formed using the organic compound solution in a wet film forming apparatus disposed in a clean booth filled with a less reactive gas such as rare gas such as argon, helium, nitrogen, or an inert gas. It is desirable to. Thereafter, the organic layer is heat-treated to completely remove the solvent contained in the organic layer sequentially to form the EL layer 20. Therefore, the solvent used is preferably evaporated at a temperature lower than the glass transition temperature (Tg) of the organic compound or polymer used in the organic layer. The organic layer may also be formed of a polymeric precursor, and then heated to convert the precursor into a polymeric compound as an EL material. In addition, when the organic layer includes a red, green, and blue light emitting compound, the forming of the organic semiconductor layer by removing the organic solvent is preferably performed separately for each of the organic layers including the red, green, and blue light emitting compounds. Do. It is preferable that the film thickness of the formed EL layer 20 is 10-1000 nm. If the film thickness is less than 10 nm, there is a possibility of shorting when a voltage is applied, and if it exceeds 1000 nm, a high applied voltage It is necessary, and there exists a possibility that luminous efficiency may fall.

After the EL layer 20 is formed in this manner, the cathode 17 (or the anode 11) is formed on the EL layer 20. Typically, the anode 11 (or anode) is preferably made of a material having a large work function, for example, silver, nickel, gold, platinum, palladium, selenium, or rhenium. , Iridium, alloys thereof, tin oxide, indium-tin-oxide (ITO), indium-zinc-oxide (IZO), copper iodide Or the like. In addition, conductive polymers such as polyaniline, poly (3-methythiophene), polyphenylenesulfide, polypyrrole, PEDOT / PSS, etc. may be used as the anode 11 material. have. On the other hand, the cathode 17 (or the cathode) is preferably made of a material having a small work function, for example, aluminum (Al), magnesium (Mg), lithium (Li), cesium (Cs), barium (Ba ), Potassium (K), beryllium (Be), calcium (Ca), mixtures thereof, and the like, specifically MgAg electrodes (Mg: Ag = 10: 1), MgAgAl electrodes, LiAl electrodes, LiFAl electrodes, Or a stacked electrode such as Li / Al or LiF / Al. In addition, as in a conventional organic EL device, a protection electrode (not shown) for protecting the cathode 17 from external moisture or the like may be further formed, and the protection electrode may be formed of aluminum (Al) or silver (Ag). It may be formed of a material that contains. The cathode 17 may be formed by a deposition method or a sputtering method. If dilithium phthalocyanine, disodium phthalocyanine, magnesium porupin, 4,4,8,8-tetrakis (1H-pyrazol-1-yl) pyrazabol, etc. are used as the electron injection compound (16), Since the cathode 17 can be formed only by a large and stable metal, the oxidation reaction of the cathode 17 can be suppressed and the lifespan characteristics of the EL element can be improved. As the board | substrate 10 used for the organic electroluminescent element which concerns on this invention, the board | substrate normally used for manufacture of organic electroluminescent element can be used widely. For example, the substrate 10 may be a transparent substrate made of glass such as Corning 1737, a polymer film such as polyester polycarbonate, polymethyl methacrylate (PMMA), polyethylene terephthalate, or silicon, gallium arsenide ( inorganic semiconductor substrates such as gallium arsenide), but the present invention is not limited thereto. The positive electrode 11 and the negative electrode 17 may be formed in a stripe shape orthogonal to each other, and by applying a voltage in a forward direction to the selected positive electrode 11 and the negative electrode 17, the intersections of the positive electrodes 11 and 17 may be formed. Voltage is applied to the light emitting area to emit light. In FIG. 2A, the substrate 10 / anode 11 / EL layer 20 / cathode 17 are sequentially stacked from the bottom, but need not be stacked in this order, and the substrate / first electrode / It may be laminated in the order of the EL layer / second electrode or the substrate / second electrode / EL layer / first electrode. In addition, when only the electrode 11 on the substrate 10 side, that is, the anode 11 is transparent, and the cathode 17 is opaque, the substrate 10 also needs to be a transparent substrate in order to extract light emission to the outside. In addition, in order to protect the EL element on which the cathode 17 is formed from oxygen and moisture, if necessary, a sealing member such as glass, ceramic, plastic, or metal is used to seal the EL element in an inert gas atmosphere, or to heat or ultraviolet rays. The said EL element can be sealed using cured resin. In addition, it is effective to put a hygroscopic material inside the sealed hermetic space, and a representative example of such hygroscopic material is barium oxide.

As described above, after the cathode 17 is formed on the EL layer 20 including the ionic salt, a heat-annealing process is performed by heating using a Celsius temperature controller or the like. The heat-annealing temperature is preferably 35 to 200 degrees Celsius, and more preferably set to approximately the same vitrification temperature of the compound constituting the organic EL layer 20. The heat-annealing time may vary depending on the heating temperature, but is usually within 10 seconds to 5 minutes. If the heat-annealing temperature and time is less than the range, there is a problem that the device is not sufficiently heated to obtain a heat-annealing effect, and if the heat-annealing temperature and time is exceeded, the device may be damaged due to excessive heating of the device. have. Thus, a predetermined bias voltage is applied to the EL layer 20 to be heat-annealed, for example, from the anode 11 and the cathode 17, and the electro-annealing treatment is performed in parallel. The electro-annealing treatment voltage is preferably 3 to 20 volts, and the electro-annealing treatment time may vary depending on the intensity of the applied voltage, but preferably 1 second to 5 minutes. If the electro-annealing voltage and time are less than the above range, there is a fear that the ions of the ionic salt may not move sufficiently toward the electrode. There is a risk of causing electrical deterioration. After the electro-annealing treatment is performed in this manner, the EL element is cooled to room temperature, or after the EL element is cooled to room temperature, the electro-annealing is finished. When heat-annealing and electro-annealing are performed in this manner, the ion distribution of the salt is limited to the interface between the EL layer 20 and the electrodes 11 and 17. That is, ions are uniformly accumulated in the regions of the electrodes 11 and 17 over the entire emission region, thereby forming a uniform space charge, and forming an electric field in the vicinity of the electrodes 11 and 17. This electric field reduces the energy barrier to facilitate the injection of charge carriers, thereby increasing the probability of hole and electron injection from the electrodes 11 and 17 to the EL layer 20, thus resulting in bipolar recombination. ) Increases, improving the luminous efficiency of the EL element and reducing the operation start voltage. The bias voltage used in the step of electro-annealing may have various forms such as direct current, alternating current, and pulse as long as ions are accumulated in the electrode to form a uniform space charge. It is not limited to.

On the other hand, as described above, the organic EL device in which the ion distribution of the salt is defined at the interface 11 and 17 of the EL layer 20 and the electrode includes an organic thin film including an ionic salt on at least one surface of the EL layer 20. It can also be prepared by forming a. That is, as shown in Fig. 3, when the organic thin films 30 and 32 to which the ionic salt is added are formed between the EL layer 20 and the electrodes 11 and 17, thermal and electric-air as described above. Simultaneous processing of nining can be obtained. As the organic thin films 30 and 32 including the ionic salt, a conductive polymer doped with an ionic salt or an insulating polymer may be used. In particular, the conductive polymer doped with an ionic salt may be used as an anode of an EL device. It is more preferable as it can. Specific examples of the conductive polymer may include polyaniline, poly (3-methylthiophene), polyphenylene sulfide, polypyrrole, PEDOT / PSS, and the like, and include ionic salts included in the organic thin films 30 and 32. The same ionic salts used for preparing the organic compound solution can be used. The organic thin films 30 and 32 may be formed by a conventional film forming process such as a wet method or a dry method. When forming the organic thin films 30 and 32 to which the ionic salts are added, the content of the ionic salts is It is preferable that it is 0.02-30 weight% with respect to the organic thin films 30 and 32. If the content of the ionic salt is less than 0.02% by weight, the effect of improving the luminous efficiency of the EL device and reducing the operation starting voltage is insufficient. If the content of the ionic salt exceeds 30% by weight, the operation of the device is poor due to the excessive concentration of ions. . The method has a disadvantage in that the organic thin films 30 and 32 must be further formed, but the heat-annealing and electro-annealing steps can be omitted. The thickness of the organic thin films 30 and 32 is preferably 10 to 1000 nm, more preferably about 100 nm, and more preferably if the thickness of the organic thin films 30 and 32 is less than or above the range. There is a fear that the effect of improving the luminous efficiency and reducing the operation start voltage will be insufficient.

Since the method of manufacturing the organic semiconductor device according to the present invention does not require an expensive device such as a vacuum evaporator for organic thin film deposition, the entire manufacturing process is simple and the manufacturing cost of the organic semiconductor device can be reduced. The organic EL device fabricated according to the present invention has a maximum emission luminance of about 10000 cd / m ² (at 17 V) and a low bias applied voltage in the electro-annealing step, so that the device is subjected to electro-annealing. Damage can be prevented and the uniformity of the light emitting surface can be improved. In the method of manufacturing an organic semiconductor device according to the present invention, in order to form an organic light emitting device by further dropping and penetrating a light emitting molecule, a doping material or a charge transporting material into a polymer thin film or a polymer thin film in which a charge transporting material is dispersed (TR Hebner and JC Sturma, Applied Phisics Letters Vol 73, Num 13, p1775, or Korean Patent Application No. 10-2001-7006372), further adds an ionic salt to the polymer thin film or the dropping ink, heat-annealing and electro-er It may also be carried out by performing the niling step in parallel.

The present invention provides a semiconductor device manufactured by the above-described manufacturing method and a light emitting device including the same. Accordingly, the semiconductor device according to the present invention includes a semiconductor layer, preferably an organic semiconductor layer, which is interposed between an anode, a cathode, and the anode and the cathode, and contains an ionic salt, and at the interface between the anode and the semiconductor layer The number of anions of the ionic salt is larger than the number of cations of the ionic salt, and the number of cations of the ionic salt is larger than the number of anions of the ionic salt at the interface between the cathode and the semiconductor layer. In addition, the semiconductor device according to the present invention includes an anode, a cathode, and a semiconductor layer interposed between the anode and the cathode, wherein at least one of the interface between the anode and the semiconductor layer and the interface between the cathode and the semiconductor layer is ionized. An organic thin film containing a salt is formed. Here, the semiconductor element refers to a single or multiple elements made of an inorganic or organic semiconductor material and having a switching function, and include all of the various semiconductor elements as described above in the related art, including an organic EL element. In addition, the light emitting device refers to an image display device using a semiconductor element such as an organic EL element, without being limited to an anisotropic conductive film, FPC (flexible printed circuit), TAB (tape automated bonding) tape, Or a module obtained by attaching a connector such as a tape carrier package (TCP) to a semiconductor device, a module having a printed wiring board provided at an end of the TAB tape or TCP, and an integrated circuit (IC) having a chip on glass (COG). Modules and the like mounted directly on the semiconductor elements by the method are included in the light emitting device.

In the accompanying drawings and the present specification, the present invention has been described with reference to only one pixel element, but a plurality of pixels having the same structure may be arranged in a matrix form, and a plurality of light emitting semiconductor elements having different colors are arranged so that the color display EL An element can also be formed. In addition, the present invention is a system in which a white light-emitting EL element and a color filter are combined, a system in which a blue or blue-green light-emitting EL element is combined with a fluorescent material (CCM), a transparent electrode is used as a cathode, and R, G, The present invention can be applied to black and white display elements in which a white light emitting EL layer is formed, as well as color display elements in which EL elements corresponding to B are stacked. Since the organic semiconductor element according to the present invention can have a passive or active matrix electrode structure, the present invention can be applied not only to a passive matrix EL light emitting device but also to an active matrix EL light emitting device using a thin film transistor as a switching element. As the switching element, not only a thin film transistor but also another switching element such as a two-terminal element such as MIM may be used. The semiconductor device may be driven in various ways such as passive driving, static image driving, segment display driving, and the like. The switching element per pixel is not limited to one, and a plurality of pixels may be provided in one pixel. It may be provided with a switching element.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The following examples are provided to aid the understanding of the present invention, and the present invention is not limited to the following examples.

Example 1 Fabrication of Single Thin Film Structure EL Device in Graded Cushion Form Containing Organic Salt

A glass substrate (0.7 mm) coated with indium-tin-oxide (ITO) with a resistance of 15 Ω was sequentially sonicated in a commercially available detergent and washed with deionized water. PVK (poly-N-vinylcarbazole) 6.5 mg as charge carrier binder polymer, α-NPD 6.5 mg as hole transport compound, 6.5 mg Alq3 as green luminescent and electron injection compound, 0.2 mg C545T as green luminescent dopant and organic salt Organic matter containing 0.5 mg of Bu ₄ N-BF _{4 as} chloroform (boiling point: 62 degrees Celsius): dichloroethane (dichloroethane, ClCH ₂ CH ₂ Cl, boiling point: 82 degrees Celsius) 1: 3 (mass ratio ) Dissolved in 6.0 g of a mixed solution to prepare an organic compound solution, which was filtered through a 0.2 μm Teflon filter, and then spin coated onto the ITO-coated glass substrate for 1 minute at a spin speed of 1000 rpm. The coated organic layer was heat-treated at 80 degrees Celsius for 30 minutes to completely evaporate the organic solvent, thereby forming a single thin film EL layer of α-NPD to Alq3 (hole injection, transport layer to light emitting layer) having a thickness of 50 to 70 nm and a graded section. It was. An Al: Li cathode was deposited to a thickness of 200 nm on the formed EL layer by a vacuum deposition method, and sealed in a dry glove box to protect the EL element from the surrounding environment. The vacuum degree of the vacuum deposition process was 5 × 10 ⁻⁶ torr, the deposition rate was 1 nm / sec, and the emission area of the manufactured organic EL device was 1 × 3 mm ² . Heat-annealing the EL element at a temperature of 80 degrees Celsius for 3 minutes, applying a bias voltage of 9V to the anode and cathode of the EL element for about 30 seconds and performing electro-annealing in parallel, then cooling to room temperature The final EL device was produced. As shown in Table 1, the EL light emission start voltage V _onset of the EL device was about 3.5V, and the current and the light emission luminance of the device at a voltage of 10V were 8.5 mA and about 3200 cd / m 2, respectively. Emitted green light (530 nm) stably and uniformly over a long period of time.

[Comparative Example 1] Fabrication of reference EL device containing no ionic salt

A reference EL device was fabricated in substantially the same manner as in Example 1 except that the organic salt was not doped, and the manufactured reference EL device was 1.3 mA and about luminescent brightness, respectively, and the current flowing through the device at a voltage of 10V. 38 cd / m 2. Therefore, the EL element of Example 1 exhibits 84 times enhanced emission luminance at a voltage of 10V, compared to the reference EL element of Comparative Example 1.

Comparative Example 2 Fabrication of EL Devices Without Heat-Annealing

An EL device was manufactured in the same manner as in Example 1, except that only electro-annealing was performed at a voltage of 20 V at room temperature, instead of performing heat-annealing and electro-annealing in parallel. As shown in Table 1, the EL light emission start voltage V _onset of the manufactured EL device was about 3.5V, and the current and the light emission luminance of the device at a voltage of 10V were 4.4 mA and about 1000 cd / m 2, respectively. (520 nm) was emitted at a relatively high emission luminance, but the uniformity of the emission surface was not good. 4 is a photograph showing a light emitting surface of the organic EL device manufactured according to Example 1 and Comparative Example 2. The left is a light-emitting surface of the conventional organic EL device shown in Fig. 4 (area: 3 x 3 mm ²⁾ the emission surface (the area of the organic EL device according to the invention, this is shown, the right side of Fig. 4: 3 x 3 mm ² ) Is shown. It can be seen from FIG. 4 that the conventional organic EL device has a nonuniform emission surface and low emission luminance as compared with the organic EL device of the present invention.

Example 2 Fabrication of Single Thin Film Structure EL Device of Graded Section Type Containing Inorganic Salt

An EL device was manufactured in the same manner as in Example 1, except that LiF inorganic salt was used instead of Bu ₄ N-BF ₄ organic salt. As shown in Table 1, the EL emission start voltage V _onset of the EL element was about 5 V, and the current and the emission intensity flowing through the element at a voltage of 10 V were 7.4 mA and about 114 cd / m 2, respectively. It emits green light (520 nm) stably and uniformly over a long time. Therefore, the EL element exhibits a three times enhanced emission luminance at a voltage of 10 V, compared with the reference EL element of Comparative Example 1.

Example 3 Fabrication of Simple Dispersed Single Thin Film Structure EL Device Containing Organic Salt

An EL device was manufactured in the same manner as in Example 1, except that a chloroform single solvent was used instead of the chloroform and dichloroethane mixed solution. As shown in Table 1, the EL emission start voltage V _onset of the EL element was about 5 V, and the current and the emission intensity flowing through the element at a voltage of 10 V were 2.5 mA and about 260 cd / m 2, respectively. It emits green light stably and uniformly over a long time. Therefore, the EL element exhibits a luminescence brightness enhanced 6.8 times at a voltage of 10 V, compared to the reference EL element of Comparative Example 1.

Example 4 Fabrication of Simple Dispersed Single Thin Film Structure EL Device Containing Organic Salt

An EL device was manufactured in the same manner as in Example 1, except that a dichloroethane single solvent was used instead of the chloroform and dichloroethane mixed solution. As shown in Table 1, the EL light emission start voltage (V _onset ) of the EL device was about 5V, and the current and the light emission intensity flowing through the device at a voltage of 10V were 12 mA and about 45 cd / m 2, respectively. Was released. Therefore, the EL device showed a luminescence brightness increased 1.2 times at a voltage of 10V, compared to the reference EL device of Comparative Example 1, but the uniformity was relatively low, indicating that solvent selection was important.

Example 5 Fabrication of EL Device Using PMMA Polymer Binder

An EL device was manufactured in the same manner as in Example 1, except that PMMA was used instead of the PVK polymer. As shown in Table 1, the EL light emission starting voltage (V _onset ) of the EL device was about 4 V, and the current and the light emission intensity flowing through the device at a voltage of 10 V were 1.6 mA and about 500 cd / m 2, respectively. It emits green light stably and uniformly over a long time. Therefore, the EL element exhibits a light emission luminance enhanced by 13 times at a voltage of 10 V, compared to the reference EL element of Comparative Example 1.

Example 6 Fabrication of EL Device Using PPV Polymer Binder

An EL device was manufactured in the same manner as in Example 1, except that PPV was used instead of the PVK polymer. As shown in Table 1, the EL emission start voltage V _onset of the EL element was about 4 V, and the current and the emission luminance of the element at a voltage of 10 V were 2.7 mA and about 307 cd / m 2, respectively. It emits green light stably and uniformly over a long time. Therefore, the EL element exhibits 8 times enhanced emission luminance at a voltage of 10 V, compared to the reference EL element of Comparative Example 1.

Example 7 Fabrication of EL Devices Using PVK and PMMA Mixed Polymer Binders

An EL device was manufactured in the same manner as in Example 1, except that a binder was used as a polymer based on a weight ratio of PVK: PMMA = 3: 1 instead of a PVK polymer. As shown in Table 1, the EL light emission starting voltage (V _onset ) of the EL device was about 4V, and the current flowing through the device and the light emission luminance at the voltage of 10V were 1.96 mA and about 760 cd / m 2, respectively. It emits green light stably and uniformly over a long time. Therefore, the EL element exhibits 20 times enhanced light emission luminance at a voltage of 10 V, compared to the reference EL element of Comparative Example 1.

Example 8 Fabrication of EL Device Using PVK and PPV Mixed Polymer Binder

An EL device was manufactured in the same manner as in Example 1, except that a polymer binder mixed in a weight ratio of PVK: PPV = 3: 1 was used instead of the PVK polymer. As shown in Table 1, the EL light emission starting voltage (V _onset ) of the EL device was about 4V, and the current flowing through the device and the light emission luminance at the voltage of 10V were 2.4 mA and about 693 cd / m 2, respectively. It emits green light stably and uniformly over a long time. Thus, the EL element exhibits an emission luminance enhanced by 18 times at a voltage of 10 V, compared to the reference EL element of Comparative Example 1.

Example 9 Fabrication of Red EL Device

An EL device was manufactured in the same manner as in Example 1, except that DCJTB was used instead of C545T as the light emitting dopant. As shown in Table 1, the EL light emission start voltage (V _onset ) of the EL device was about 4V, and the current flowing through the device and the light emission luminance at the voltage of 10V were 3.6 mA and about 213 cd / m 2, respectively. It emitted red light (585 nm) stably and uniformly over a long time.

Example 10 Fabrication of Blue EL Device

An EL device was manufactured in the same manner as in Example 1, except that DPVBi and TBT which were commercially available instead of Alq3 and C545T were used. As shown in Table 1, the EL light emission start voltage V _onset of the EL device was about 4V, and the current and the light emission luminance of the device at a voltage of 10V were 3.5 mA and about 66 cd / m 2, respectively. It emitted blue light (490 nm) stably and uniformly over a long time.

Example 11 Fabrication of EL Device Containing Al Cathode

An EL device was manufactured in the same manner as in Example 1, except that Al was used instead of Al: Li. As shown in Table 1, the EL light emission starting voltage (V _onset ) of the EL device was about 5V, and the current flowing through the device and the light emission luminance at the voltage of 10V were 2.3 mA and about 892 cd / m 2, respectively. It emits green light (540 nm) stably and uniformly over a long time. Therefore, the EL element exhibits 23 times enhanced light emission luminance at a voltage of 10 V, compared to the reference EL element of Comparative Example 1.

Example 12 Fabrication of EL Device with Organic Thin Film Containing Ionic Salt

Before forming a single thin film EL layer, a solution of a conductive polymer PEDOT aqueous solution (2.7 wt% aqueous solution, Aldrich) containing water (1 wt. After spin coating for 60 seconds at a rotational speed of 2000 rpm, heat treatment was performed at 150 degrees Celsius for 2 hours to form a 100 nm thick PEDOT / PSS thin film, except that Bu ₄ N-BF ₄ organic salt was not used. Manufactured EL devices in the same manner as in Example 1. As shown in Table 1, the EL light emission start voltage (V _onset ) of the EL device was about 4V, and the current flowing through the device and the light emission luminance at the voltage of 10V were 2.8 mA and about 886 cd / m 2, respectively. It emits green light stably and uniformly over a long time.

Thin film form Vonset (V) Luminance Luminance (cd / ㎡) Current (mA) Example 1 Graded cushion type 3.5 3200 8.5 Comparative Example 1 Graded cushion type - 38 1.3 Comparative Example 2 Graded cushion type 3.5 1000 4.4 Example 2 Graded cushion type 5.0 114 7.4 Example 3 Simple distributed 5.0 260 2.5 Example 4 Simple distributed 5.0 45 12 Example 5 Graded cushion type 4.0 500 1.6 Example 6 Graded cushion type 4.0 307 2.7 Example 7 Graded cushion type 4.0 760 2.0 Example 8 Graded cushion type 4.0 693 2.4 Example 9 Graded cushion type 4.0 213 3.6 Example 10 Graded cushion type 4.0 66 3.5 Example 11 Graded cushion type 5.0 892 2.3 Example 12 Graded cushion type 4.0 886 2.8

From Examples 1 and 2, when the heat-annealing and electro-annealing steps are simultaneously performed on the PVK dispersed graded junction organic thin film to which the ionic salt is added, the luminescence brightness of the EL element is increased. It is possible to improve and to reduce the driving voltage, and it can be seen from Examples 3 and 4 that the same effect can be obtained even in the organic EL device having a simple dispersion structure. The same effect is also obtained when the type of the polymer binder (Examples 5 to 8) and the emission color (Examples 9 and 10) are changed, or when a cathode material having a high work function is used (Example 11) due to a large work function. Can be obtained. Such an effect can also be achieved by separately forming an organic thin film containing an ionic salt adjacent to the EL layer (Example 12).

As described above, the organic semiconductor device according to the present invention not only has excellent uniformity, light emission brightness and light emission efficiency of the light emitting surface, but also has low operating voltage, excellent display image quality, and high reliability of operation. . Moreover, according to the manufacturing method of the organic semiconductor element which concerns on this invention, an organic semiconductor element can be manufactured simply and inexpensively. In addition, the organic semiconductor thin film according to the present invention is excellent in voltage-emitting intensity and applied voltage-current characteristics, and is a non-linear current of a typical diode device applied to an electrical switch device. Because of its characteristics, it can be applied not only to the production of organic EL devices but also to the production of various organic semiconductor devices including organic diode devices. The organic semiconductor device, in particular, the organic EL device according to the present invention is not limited to various display devices, televisions, digital cameras, computers, notebook computers, mobile computers, portable playback devices equipped with recording media, screens, billboards, billboards, and goggles. It can be applied to a display device, an automobile display device, a video camera, a printer display device, a telecommunication device, a phone display device, a mobile phone, and the like. While the invention has been described above with reference to certain preferred embodiments, it will be understood that various modifications and changes can be made within the spirit and scope of the invention.

Claims (38)

Coating an organic compound solution including an organic solvent, an ionic salt, and an organic semiconductor compound on a substrate, and then removing the organic solvent to form an organic semiconductor layer; And A method of manufacturing an organic semiconductor device comprising the step of performing heat-annealing and electro-annealing in parallel to the formed organic semiconductor layer. delete The method of claim 1, wherein the organic compound solution comprises two or more organic semiconductor compounds and two or more organic solvents different in volatility. Claim 4 was abandoned when the registration fee was paid. The method of claim 3, wherein the two or more organic semiconductor compounds are sequentially stacked to have a concentration gradient along the stacking direction as the organic solvent is removed. delete delete The method of claim 1, wherein the heat-annealing temperature is 35 degrees Celsius to 200 degrees Celsius. The method of claim 1, wherein the bias voltage of the electro-annealing process is 3 to 20 volts. The method of claim 1, wherein the ionic salt is any one selected from the group consisting of inorganic salts, organic salts, polymer salts, and mixtures thereof. Claim 10 was abandoned upon payment of a setup registration fee. The inorganic salt of claim 9, wherein the inorganic salt is any one selected from the group consisting of LiClO ₄ , LiPF ₆ , LiBF ₄ , LiN (CF ₃ SO ₂ ) ₂ , lithium trifluoromethane trisulfonate, and mixtures thereof. The manufacturing method of phosphorus organic semiconductor element. Claim 11 was abandoned upon payment of a setup registration fee. The method of claim 9, wherein the organic salt is any one selected from tetra alkyl, aryl, and heteroaryl quaternary ammonium salts. Claim 12 was abandoned upon payment of a registration fee. The method of claim 9, wherein the polymer salt is polystyrenesulfonate. delete The method of claim 1, wherein the organic semiconductor compound has at least one compound selected from the group consisting of a hole injection compound, a hole transport compound, a light emitting compound, an electron transport compound, and an electron injection compound. . The method of claim 1, wherein the organic compound solution further comprises at least one of a binder polymer and a dopant. delete delete delete delete Claim 20 was abandoned upon payment of a registration fee. The method of claim 1, wherein the organic semiconductor compound includes red, green, and blue light emitting compounds, and the forming of the organic semiconductor layer by removing the organic solvent is performed separately for the red, green, and blue light emitting compounds. The manufacturing method of the organic semiconductor element. Claim 21 was abandoned upon payment of a registration fee. The method of claim 1, wherein the organic compound solution is applied to the substrate by any one of a wet method selected from the group consisting of spin-coating method, cast method, inkjet method, deposition method, and printing method Method of manufacturing a semiconductor device. An organic semiconductor thin film composition comprising an organic solvent, an ionic salt and an organic semiconductor compound. The composition of claim 22, wherein the composition comprises at least two organic semiconductor compounds and at least two organic solvents having different volatility. The composition of claim 22, wherein the composition further comprises at least one of a binder polymer and a dopant . The composition of claim 22, wherein the concentration of the composition is 0.005 to 30% by weight. The composition of claim 22, wherein the composition has a viscosity of 100 cps to 5000 cps. Claim 27 was abandoned upon payment of a registration fee. An organic semiconductor device manufactured by the method according to claim 1. anode; cathode; And a semiconductor layer interposed between the anode and the cathode and containing an ionic salt. And anion number of the ionic salt is greater than the cation number of the ionic salt at the interface between the anode and the semiconductor layer, and a cation number of the ionic salt is more than the anion number of the ionic salt at the interface between the cathode and the semiconductor layer. delete The semiconductor device according to claim 28, wherein the semiconductor layer is formed by uniformly dispersing two or more organic compounds. 29. The semiconductor device according to claim 28, wherein the semiconductor layer is sequentially stacked such that two or more organic compounds have a concentration gradient along their stacking direction. The semiconductor device according to claim 28, wherein the semiconductor layer has a thickness of 10 to 1000 nm. Claim 33 was abandoned upon payment of a registration fee. 29. The semiconductor device of claim 28, wherein the anode and cathode have a passive or active matrix electrode structure. delete anode; cathode; And a semiconductor layer interposed between the anode and the cathode. An organic thin film including an ionic salt is formed on at least one of the interface between the anode and the semiconductor layer and the interface between the cathode and the semiconductor layer. 36. The semiconductor device of claim 35, wherein the organic thin film is made of a conductive polymer doped with an ionic salt, or an insulating polymer. Claim 37 was abandoned upon payment of a registration fee. 37. The group of claim 36, wherein the conductive polymer is comprised of polyaniline, poly (3-methylthiophene), polyphenylenesulphide, polypyrrole, and poly (3,4-oxyethyleneoxythiophene) / poly (styrenesulfonate) The semiconductor device is any one selected from. 36. The semiconductor device according to claim 35, wherein the content of the ionic salt is 0.02 to 30 wt% based on the total organic thin film, and the thickness of the organic thin film is 10 to 1000 nm.

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