KR100522702B1 - Iridium compound and organic electroluminescent display device using the same - Google Patents

Abstract

The present invention provides an iridium complex which is a blue phosphorescent light emitting material. The iridium complex is blue shifted toward the blue region than the conventional blue material (Firpic) to enable a deep blue light emission and excellent luminous efficiency. When using the compound to form an organic field device color purity can be improved and is useful as a low power consumption material.

Description

Iridium compound and organic electroluminescent display device using the same

The present invention relates to an iridium compound and an organic electroluminescent device using the same, and more particularly, to a blue phosphorescent compound for organic electroluminescence in the form of an organometallic compound including Ir metal and an organic electroluminescent device using the same.

A general organic organic electroluminescent device has an anode in which an anode is formed on a substrate, and a hole transport layer, a light emitting layer, an electron transport layer, and a cathode are sequentially formed on the anode. Here, the hole transport layer, the light emitting layer and the electron transport layer are organic thin films made of an organic compound.

 In the organic EL device having the structure as described above, the light emitting material is classified into a fluorescent material using excitons in the singlet state and a phosphorescent material using the triplet state according to the light emitting mechanism. Phosphorescent materials generally have an organic-inorganic compound structure containing heavy atoms, and the exciton in the triplet state, which was originally a forbidden transition, has a permissible transition property by the heavy atoms, thereby causing phosphorescence. Phosphorescent materials can use triplet excitons with 75% probability of production and can have much higher luminous efficiency than fluorescent materials using 25% singlet excitons.

As the light emitting material using triplet, various phosphorescent materials using iridium and platinum metal compounds have been published. As the blue light emitting material, Ir compounds based on (4,6-F2ppy) 2Irpic or fluorinated ppy ligand structures have been developed.However, in the case of (4,6-F2ppy) 2Irpic, the emission color is in the sky blue region, and especially the shoulder The peak (shoulder peak) is very large tends to show the disadvantage that the color purity y value increases. In addition, due to the absence of a host material suitable for the blue material, the problem is very low efficiency and lifespan compared to the red, green phosphorescent material, the development of high efficiency long-life blue phosphorescent material of deep blue light emission is very urgent situation.

Meanwhile, blue light emitting materials are disclosed in US Patent Publications 2003/080342, 2003/0059646, and 2003/0068526.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a blue phosphorescent compound capable of high color purity and low power consumption, and an organic EL device using the same.

In order to achieve the first technical problem, the present invention provides an iridium compound represented by the following formula (1).

[Formula 1]

Wherein R ₁ to R ₆ are each independently a hydrogen atom, a cyano group, a hydroxyl group, a thiol group, a halogen atom, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C1-C20 Alkoxy group, substituted or unsubstituted C2-C20 alkenyl group, substituted or unsubstituted C6-C30 aryl group, substituted or unsubstituted C6-C30 arylalkyl group, substituted or unsubstituted C6-C30 aryl jade Periodic, substituted or unsubstituted C2-C30 heteroaryl group, substituted or unsubstituted C2-C30 heteroarylalkyl group, substituted or unsubstituted C2-C30 heteroaryloxy group, substituted or unsubstituted C5-C20 Cycloalkyl groups, substituted or unsubstituted C2-C20 heterocycloalkyl groups, C1-C20 alkylthio groups, or -Si (R ') (R ") (R"'), wherein R 'and R' Is hydrogen or a C1-C20 alkyl group irrespective of each other , -N (R ') (R'') (wherein R' and R '' is a hydrogen or alkyl group of C1-C20 irrespective of each other) And R ₁ to Two or more selected from R ₄ are connected to each other to form an unsaturated or saturated hetero ring, X is a bidentate ligand and n is 2.

Another technical problem of the present invention is an organic electroluminescent device comprising an organic film provided between a pair of electrodes, wherein the organic film comprises an iridium compound as described above. .

In Formula 1, specific examples of X include acetylacetonate (acac), hexafluoroacetylacetonate (hfacac), and sali as shown in the following structural formula (for convenience, Ir is shown with a ligand). Salicylidene (sal), picolinate (pic), picolinate (pic), 8-hydroxyquinolinate (8-hydroxyquinolinate: hquin), α-amino acid L-proline (L-pro), dibenzoylmethane : dbm), tetramethyl-heptane dionate (tetrametylheptane dionate: tmd), 1- (2- hydroxyphenyl) pyrazol-rate (1- (2-hydoxyphenyl) pyrazolate: oppz) 3-isoquinoline carboxylate (3- isoquinolinecarboxylate: 3iq), 1,5-dimethyl-3-pyrazolecarboxylate (1,5-dimethyl-3-pyrazolecarboxylate: dm3PC), phenylpyrazole (ppz), quinolinecarboxylate (quino) It may be in the form of.

In Formula 1, R ₃ is an alkyl group of C1-C20, an alkoxy group of C1-C20 or -N (R ') (R'') (wherein R' and R '' are independently hydrogen or C1-C20 alkyl group).

The compound of Formula 1 according to the present invention may be used as a blue phosphorescent material for a full color organic electroluminescent device since it has a deeper blue light emitting property than conventionally proposed molecules as a blue light emitting phosphor containing Ir metal.

The above compound of Formula 1 is capable of dark blue light emission, by introducing an electron-withdrawing group F at positions 4 and 6 of the phenyl ring of the phenylpyridine ligand and at position 4 of the pyridine ring. in particular, by introducing an electron donating group, a methyl group (-CH _3), because the effect of increasing the band gap energy of the iridium compound. In addition, when the quantum efficiency of luminescence is compared, the compound of Formula 2 exhibits about 1.22 value when the quantum efficiency of Firpic is 1, so that the luminescence property is more excellent.

As a specific example of the iridium compound of Formula 1 according to the present invention, there are compounds represented by the following Formulas 2 to 16.

 [Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

 [Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

[Formula 16]

[Formula 17]

The synthesis method of the iridium compound represented by Formula 1 according to the present invention will be described in the case of a compound in which all of R ₁ , R ₂ , R ₄ , R ₅ , R ₆ are hydrogen, and R ₃ is a methyl group. However, this does not mean that the synthesis method is limited to these compounds.

A halogen compound (A) and 2,4-fluorophenylboronic acid are reacted in the presence of triphenylphosphine P (C ₆ H ₅ ) ₃ , palladium acetate, and K ₂ CO ₃ as in Scheme 1 below to give a compound (B) To prepare.

Scheme 1

Compound (B) thus obtained is reacted with iridium chloride as in Scheme 2 below to obtain an iridium dimer complex (C).

Scheme 2

As shown in Scheme 3, the iridium dimer complex (C) and the precursor compound XH necessary for introducing the bidentate ligand X of Formula 1 are each reacted to obtain a compound represented by Formula 1.

Scheme 3

Iridium compound represented by the formula (1) according to the present invention is excellent in blue light emission characteristics. The manufacturing method of the organic EL device employing the organic film using the compound will be described.

1 is a cross-sectional view showing the structure of a general organic EL device.

First, the anode 11 is formed by coating an anode electrode material on the substrate 10. Herein, a substrate used in a conventional organic EL device is used, and an organic substrate or a transparent plastic substrate having excellent transparency, surface smoothness, ease of handling, and waterproofness is preferable. In addition, transparent and conductive indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO ₂ ), and zinc oxide (ZnO) are used as the anode electrode material.

The hole injection layer material is vacuum-heat-deposited or spin-coated on the anode 11 to form a hole injection layer (HIL) 12. The hole injection layer material is not particularly limited and CuPc or Starburst type amines TCTA, m-MTDATA, and m-MTDAPB may be used as the hole injection layer.

A hole transport layer (HTL) 13 is formed by vacuum-heat deposition or spin coating a hole transport layer material on the hole injection layer. The hole transport layer material is not particularly limited, and N, N'-bis (3-methylphenyl) -N, N'-diphenyl- [1,1-biphenyl] -4,4'-diamine (TPD), N, N'-di (naphthalen-1-yl) -N, N'-diphenyl benzidine, N, N'-di (naphthalene-1-yl) -N, N'-diphenyl-benxidine: α-NPD) Etc. are used.

Subsequently, an emission layer (EML) 14 is introduced on the hole transport layer, and the emission layer material is not particularly limited, and the compound of Formula 1 may be used alone or in combination with a conventional host material. As the host material, CBP (4,4'-Bis (carbazol-9-yl) -biphenyl or the like is used.

The light emitting layer forming method may vary depending on the light emitting layer material, for example, vacuum thermal co-deposition is used.

The content of the compound of Formula 1 used as the dopant is 0.1 to 20 parts by weight, particularly 0.5 to 12 parts by weight, based on 100 parts by weight of the light emitting layer forming material (ie, 100 parts by weight of the total weight of the compound of Formula 1 and the host as the dopant) It is desirable to disclaim. If the content of the dopant is less than 0.1 parts by weight, the effect of addition is insignificant, and if it exceeds 20 parts by weight, concentration phosphorescence or fluorescence, such as concentration quenching (quenching) is not preferable because it occurs.

An electron transport layer (ETL) 15 is formed on the light emitting layer by vacuum deposition or spin coating. It does not restrict | limit especially as an electron carrying layer material, Alq3 can be used. In the case of using the phosphorescent dopant in the light emitting layer, the hole blocking material is further vacuum-heat-deposited to form a hole blocking layer in order to prevent the triplet excitons or holes from diffusing into the electron transport layer. At this time, the hole blocking material is not particularly limited, but should have ionization potential higher than that of the light emitting compound while having electron transport ability, and typically, Balq and BCP are used. In addition, an electron injection layer (EIL) 16 may be selectively stacked on the electron transport layer, which does not particularly limit the material. As the electron injection layer forming material, materials such as LiF, NaCl, CsF, Li ₂ O, and BaO may be used. Then, the organic EL device is completed by forming a cathode 17 by vacuum-heat-depositing a metal for forming a cathode on the electron injection layer. The metal for forming the cathode may be lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lidium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver ( Mg-Ag) and the like are used. In addition, a transmissive cathode using ITO and IZO may be used to obtain a front light emitting device. In the organic electroluminescent device of the present invention, one or two intermediate layers may be further formed on the anode electrode, the hole injection layer, the hole transport layer, the light emitting layer, the hole blocking layer, the electron transport layer, the electron injection layer, and the cathode electrode as necessary. .

Hereinafter, a preferred embodiment of the present invention. However, the present invention is not limited to the following examples.

Palladium acetate, 2-bromo-4-methylpyridine, 2,4-difluorophenylboronicacid, 2-ethoxyethanol, (2,2 ', 6,6'-tetramethylheptanedionato-3,5) (tmd), picolinic acid used in the following synthesis examples Silver Aldrich was used, and methylene chloride, magnesium sulfate, ethyl acetate, methanol, hexane, dimethoxyethane (DME), and triphenylphosphine were used as such by Duksan Chemical. All new compounds were identified by 1H-NMR, 13C-NMR, UV and spectrofluorometers. 1H-NMR and 13C-NMR were recorded using Bruker AM-300 spectrometer, UV was used for BECKMAN DU-650, and spectrofluorometer was used for JASCO FP-7500. All chemical mobility is reported in ppm based on solvent

Synthesis Example 1 Preparation of Compound (B)

2-bromo-4-methylpyridine (1 mmol), 2,4-difluorophenylboronic acid (1.2 mmol), P (Ph) ₃ (0.1 mmol), palladium acetate (0.025 mmol), 2M K ₂ CO ₃ (5 ml) was added to DME (dimethoxyethane) and stirred with heating for about 18 hours while purging nitrogen. After confirming that the reaction of the reaction mixture was completed by TLC, the mixture was extracted using ethyl acetate, which was washed with water and NaCl. After removing the solvent by high vacuum distillation, the resultant was subjected to silica gel column chromatography using methylene chloride as an eluent to obtain a liquid substance, and then dried under a vacuum pump for about 3 hours to obtain a compound (B). (Yield: 80%)

Synthesis Example 2: Preparation of Iridium Dimer Complex (C)

Inject nitrogen gas into 2-ethoxyethanol (100 ml) at room temperature and stir for 30 minutes, add iridiumchloride hydrochloride hydrate (4 mmol) and compound (B) (10 mmol) under nitrogen for 12 hours. Heated and stirred.

After confirming that the reaction of the reaction mixture was completed by TLC, about half of the solvent was removed by high vacuum distillation. Water was added to the resultant, filtered and washed with ether and hexane. It dried about 3 hours under a vacuum pump, and obtained the iridium dimer complex (C). (Yield 70%).

1 H-NMR (300 MHz, DMSO-d ₆ ), ppm: 9.61 (d, 2H, J 6.0 Hz), 9.36 (d, 2H, J 5.8 Hz), 8.10 (d, 4H, J 18.0 Hz), 7.52 ( d, 2H, J 5.0 Hz), 7.41 (d, 2H, J 6.6 Hz), 6.81 (q, 4H,, J 39.4 Hz), 5.75 (d, 2H, J 7.5 Hz), 5.13 (d, 2H, J 7.6 Hz), 2.66 (s, 6H), 2.61 (s, 6H). Anal. Found: C 45.57, H 2.56, N 4.37. Calcd: C 45.32, H 2.54, N 4.40.

Synthesis Example 3 Preparation of Compound of Formula 2

After stirring for 30 minutes while injecting nitrogen into 2-ethoxyethanol (30 ml) at room temperature, iridium dimer complex (C) (1 mmol) and picolinic acid (5 mmol) were added thereto, followed by 2N as a base. K ₂ CO ₃ (10 ml) was added. The reaction mixture was stirred for 48 hours while heating in a nitrogen gas atmosphere, and then TLC confirmed the completion of the reaction.

The reaction product was removed by about half of the solvent by high vacuum distillation, and then solidified by addition of H ₂ O and filtered. After filtering as described above, a flash column was carried out under methylene chloride / methanol conditions to remove the solvent by high vacuum distillation, followed by drying under a vacuum pump for 3 hours to obtain a compound of Chemical Formula 2. (Yield 50%). The NMR spectrum of this compound is as shown in FIG.

 Scheme 4

Synthesis Example 4 Synthesis of Compound of Formula 3

After stirring for 30 minutes while injecting nitrogen into 2-ethoxyethanol (30 ml) at room temperature, iridium dimer complex (C) (1 mmol) and oppzH (5 mmol) were added thereto, and 2N K ₂ CO ₃ (10 ml) was used as a base. ) Was added. The reaction mixture was stirred with heating for 48 hours under a nitrogen gas atmosphere, and then TLC confirmed that the reaction of the reaction mixture was completed.

The reaction mixture was distilled under high vacuum to remove about 1/2 of the solvent and solidified by addition of H ₂ O. After filtering the resultant, using a methylene chloride / methanol to perform a flash column, the solvent was removed by high vacuum distillation under reduced pressure and dried for 3 hours under a vacuum pump to obtain a compound of formula (3). (Yield 50%).

Scheme 5

Synthesis Example 5 Preparation of Chemical Formula 4

After stirring for 30 minutes while injecting nitrogen into 2-ethoxyethanol (30 ml) at room temperature, iridium dimer complex (C) (1 mmol) and tmdH (5 mmol) were added thereto, and 2N K ₂ CO ₃ (10 ml) was used as a base. ) Was added.

The reaction mixture was stirred with heating for 48 hours under a nitrogen gas atmosphere, and then TLC confirmed that the reaction of the reaction mixture was completed.

The reaction mixture was distilled under high vacuum to remove about 1/2 of the solvent and solidified by addition of H ₂ O. After filtering the resultant, using a methylene chloride / methanol to perform a flash column, the solvent was removed by high vacuum distillation and dried for 3 hours under a vacuum pump to obtain a compound of formula (4). (Yield 50%).

¹ H NMR (300 MHz, DMSO-d ₆ ), ppm: 8.11 (d), 8.04 (s), 7.30 (d), 6.56 (m), 5.67 (d), 5.54 (s), 0.889 (s).

Scheme 6

Synthesis Example 6 Preparation of Compound of Formula 9

After stirring for 30 minutes while injecting nitrogen into glycerol (100 mL) at room temperature. Formula B (1 mmol) and ppzH (5 mmol) were added, and 2N K ₂ CO ₃ (10 ml) was added as a base.

After refluxing under heating in a nitrogen gas atmosphere for 48 hours, the completion state of the reaction mixture was confirmed by TLC. The reaction product was distilled under high vacuum to remove about 1/2 of the solvent and solidified by addition of hexane. Subsequently, the solid was filtered and then subjected to a flash column under methylene chloride / methanol conditions to remove the solvent by high vacuum distillation. The resultant was dried under a vacuum pump for 3 hours to obtain a compound of formula 9. (Yield 50%)

Scheme 7

Synthesis Example 7 Preparation of Compound of Formula 10

Compound of Formula 10 was obtained by the same method as in Synthesis Example 6, using the compound obtained in Synthesis Example 1 using 2-bromo-4-dimethylaminepyridine instead of 2-bromo-4-methylpyridine.

Synthesis Example 8 Preparation of Compound of Formula 11

Compound of Formula 11 was obtained by the same method as Synthesis Example 6, using the compound obtained in Synthesis Example 1 using 2-bromo-4-methoxypyridine instead of 2-bromo-4-methylpyridine.

Synthesis Example 9 Preparation of Compound of Formula 12

Synthetic Example 1 was used in the same manner as in Synthesis Example 6 with the compound obtained by using 2-bromopyridine instead of 2-bromo-4-methylpyridine to obtain a compound of Formula 12.

Synthesis Example 10 Preparation of Compound of Formula 15

Compound of Formula 15 was obtained by the same method as Synthesis Example 3 with the compound obtained using Synthesis Example 1 using 2-bromo-4-methoxypyridine instead of 2-bromo-4-methylpyridine.

Synthesis Example 11 Preparation of Compound of Formula 16

Compound of Formula 15 was obtained by the same method as Synthesis Example 3 with the compound obtained in Synthesis Example 1 using 2-bromo-4-dimethylaminepyridine instead of 2-bromo-4-methylpyridine.

Synthesis Example 12 Preparation of Compound of Formula 6

Synthesis Example 1 was synthesized with the compound obtained by using 2-bromo-4-dimethylaminepyridine instead of 2-bromo-4-methylpyridine in Synthesis Example 4 to obtain a compound of Formula 6.

Synthesis Example 13 Preparation of Compound of Formula 7

Synthesis Example 1 was synthesized using the compound obtained using 2-bromo-4-methoxypyridine instead of 2-bromo-4-methylpyridine in Synthesis Example 4 to obtain the compound of Formula 7.

Synthesis Example 14 Preparation of Compound of Formula 8

Synthesis Example 1 was synthesized using the compound obtained by using 2-bromopyridine instead of 2-bromo-4-methylpyridine in Synthesis Example 4 to obtain a compound of Formula 8.

In the iridium compounds represented by Chemical Formulas 2, 3, and 4, PL spectra in methylene chloride solvent were examined and shown in FIGS. 2 to 4, respectively. Referring to this, it was found that these compounds emit blue light near 450 nm.

In the compound represented by the formula (2), the quantum efficiency was investigated.

As a result, the quantum efficiency of the compound represented by the formula (2) was 1.22, respectively.

Example 1

Corning's 10 Ω / cm 2 ITO substrate was used as an anode, and an IDE406 (Idemitsu Corp.) was vacuum deposited on the substrate to form a hole injection layer having a thickness of 600 mm 3. Subsequently, the IDE320 (Idemitsu Co., Ltd.) was vacuum deposited to a thickness of 300 kPa on the hole injection layer to form a hole transport layer. The light emitting layer was formed by spin-coating 12 parts by weight of the compound of Formula 2 and 88 parts by weight of CBP on the hole transport layer.

Thereafter, BAlq was vacuum-deposited on the emission layer to form a 50-mm thick HBL layer. Thereafter, Alq3 was vacuum deposited on the emission layer to form an electron transport layer having a thickness of 200 kHz. An organic electroluminescent device was completed by forming a cathode by vacuum evaporation of LiF 10kV and Al 3000kV sequentially on the electron transport layer.

In the organic EL device manufactured according to Example 1, luminance, efficiency, driving voltage, and color purity characteristics were investigated. As a result, it was confirmed that the organic EL device of Example 1 was excellent in brightness, efficiency, driving voltage, and color purity characteristics.

As described above, the present invention provides an iridium complex which is a blue phosphorescent light emitting material. The iridium complex is blue shifted toward the blue region than the conventional blue material (Firpic) to enable a deep blue light emission and excellent luminous efficiency. When using the compound to form an organic field device color purity can be improved and is useful as a low power consumption material.

1 is a view schematically showing the structure of an organic EL device of the present invention,

2 is a diagram showing a photoluminescence (PL) spectrum in a methylene chloride solvent in the iridium compound represented by Chemical Formula 2 of the present invention.

3 is a diagram showing a PL spectrum in a methylene chloride solvent in the iridium compound represented by Chemical Formula 3 of the present invention,

4 is a diagram showing a PL spectrum in a methylene chloride solvent in the iridium compound represented by Chemical Formula 4 of the present invention,

FIG. 5 shows a nuclear magnetic resonance (NMR) spectrum of an iridium compound represented by Chemical Formula 2 of the present invention.

<Brief description of the major symbols in the drawings>

10... Substrate 11.. Anode

12... Hole injection layer 13... Hall transport layer

14... Luminous layer 15... Electron transport layer

16... Electron injection layer 17. Cathode

Claims (6)

Iridium compound represented by the formula (1): [Formula 1] Wherein R ₁ to R ₆ are each independently a hydrogen atom, a cyano group, a hydroxyl group, a thiol group, a halogen atom, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C1-C20 Alkoxy group, substituted or unsubstituted C2-C20 alkenyl group, substituted or unsubstituted C6-C30 aryl group, substituted or unsubstituted C6-C30 arylalkyl group, substituted or unsubstituted C6-C30 aryl jade Periodic, substituted or unsubstituted C2-C30 heteroaryl group, substituted or unsubstituted C2-C30 heteroarylalkyl group, substituted or unsubstituted C2-C30 heteroaryloxy group, substituted or unsubstituted C5-C20 Cycloalkyl groups, substituted or unsubstituted C2-C20 heterocycloalkyl groups, C1-C20 alkylthio groups, or -Si (R ') (R ") (R"'), wherein R 'and R' Is hydrogen or a C1-C20 alkyl group irrespective of each other , -N (R ') (R'') (wherein R' and R '' is a hydrogen or alkyl group of C1-C20 irrespective of each other) And R ₁ to Two or more selected from R ₄ are connected to each other to form an unsaturated or saturated hetero ring, X is a bidentate ligand and n is 2. The method of claim 1, wherein X is acetylacetonate (acac), hexafluoroacetylacetonate (hexafluoroacetylacetonate (hfacac), salicylidene (sal), picolinate (picolinate: pic), 8- hydroxy-quinolinyl carbonate (8-hydroxyquinolinate: hquin), α-amino acid L- proline (L-pro), dibenzyl methane (dibenzoylmethane: dbm), tetramethyl-heptane dionate (tetrametylheptane dionate: tmd), 1- ( 2-hydroxyphenyl) pyrazolate (1- (2-hydoxyphenyl) pyrazolate: oppz) 3-isoquinolinecarboxylate (3iq), 1,5-dimethyl-3-pyrazolecarboxylate ( Iridium compound, characterized in that it is selected from 1,5-dimethyl-3-pyrazolecarboxylate (dm3PC), phenylpyrazole (ppz), quinolinecarboxylate (quin) . The compound of claim 1, wherein R ₃ is a C1-C20 alkyl group , a C1-C20 alkoxy group, or -N (R ') (R''), wherein R' and R '' are independent of each other. Hydrogen or an alkyl group of C1-C20). The iridium compound according to claim 1, wherein the compound is selected from compounds represented by the following Chemical Formulas 2 to 16. [Formula 2] [Formula 3] [Formula 4] [Formula 5] [Formula 6]  [Formula 7] [Formula 8] [Formula 9] [Formula 10] [Formula 11] [Formula 12]  [Formula 13] [Formula 14] [Formula 15] [Formula 16] [Formula 17] In an organic electroluminescent element comprising an organic film provided between a pair of electrodes, An organic electroluminescent element, wherein the organic film contains the iridium compound of any one of claims 1 to 4. The organic electroluminescent device according to claim 5, wherein the organic film is a light emitting layer.