JP2016185984A - Method for synthesizing material for light-emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for synthesizing a high-purity material for a light-emitting element, in order to provide a light-emitting element having a long lifetime.SOLUTION: The method for synthesizing a material for a light-emitting element has a specific feature that in synthesis of the material for the light-emitting element via an organic halide, the content rate of reaction byproducts contained in the material for the light-emitting element, or of halides of bromine, iodine and chlorine used as a raw material for synthesizing the material for the light-emitting element, identified by ultrahigh performance liquid chromatography time-of-flight mass spectrometry (UPLC/TOF-MS) before a sublimation purification treatment, is 3% or less.SELECTED DRAWING: None

Description

  One embodiment of the present invention relates to a method for synthesizing a high-purity organic compound.

The development of the organic chemistry field is remarkable, and organic compounds are currently used in various fields. Therefore, a wide variety of compounds suitable for the field have been synthesized. It can be said that various compounds can be synthesized along with the development of the synthesis method.

A coupling reaction is known as one method for synthesizing an organic compound. The development of this technique has made it possible to synthesize various new organic compounds. These are used in many organic syntheses because they are easy to react, have high yields, and can keep synthesis costs low.
An example of the coupling reaction is Suzuki-Miyaura coupling. This is a coupling reaction of an organic halide and an organic boron compound using a palladium catalyst or the like.

However, even in the case of organic compounds synthesized by such highly versatile reactions, if by-products or raw materials remain as impurities during synthesis, there are various device characteristics when used in devices as they are. Problems such as adverse effects may occur. That is, the purity of the organic compound used in the device may greatly affect the device characteristics.

This is considered to be more prominent in a light-emitting element formed by sandwiching a light-emitting organic compound between a pair of electrodes. That is, if the purity of the organic compound used for the light emitting element is low, it is considered that the driving voltage, the light emission efficiency, and the lifetime of the light emitting element are more greatly affected.

For this reason, a high-purity material is used for the organic compound used for the light-emitting element, and an ordinary purification method further subjected to sublimation purification is generally used. By sublimation purification, the residual solvent at the time of synthesis and a small amount of impurities can be separated (see, for example, Patent Document 1).

However, even if the above purification is performed, there may be a variation in purity and a variation in device characteristics even in a high-purity product. Therefore, development of a synthesis / purification method capable of further purification and development of a purity analysis method is desired.

JP 2011-216903 A

In the case of synthesizing an organic compound (light emitting element material) used for a light emitting element, if the organic compound contains a large amount of impurities, the characteristics of the light emitting element are greatly adversely affected. In particular, it is considered that if a small amount of an organic halide widely used as a raw material for synthesis is contained as an impurity, the driving voltage, luminous efficiency, and lifetime of the light emitting element are affected.

Therefore, in one embodiment of the present invention, a synthesis method is provided for increasing the purity of a final product in the synthesis of an organic compound (material for a light-emitting element) via an organic halide.

In the synthesis of a light emitting device material via an organic halide, if an organic halide is contained as an impurity in the light emitting device material, which is the target material before the sublimation purification treatment, the target product is halogenated during the sublimation purification treatment. It was found that a new halide was formed. In addition, since the produced | generated new halide is difficult to remove even if it performs repeatedly sublimation purification, it is necessary to reduce these impurities sufficiently before sublimation purification.

Therefore, in one embodiment of the present invention, before the sublimation purification treatment, the organic halide contained in the target light-emitting element material is removed as much as possible, and then the sublimation purification treatment is performed to generate a new halide. This is characterized in that the final product is highly purified.

Therefore, according to one embodiment of the present invention, ultrahigh performance liquid chromatograph time-of-flight mass spectrometry (UPLC / TO) is performed before sublimation purification treatment in the synthesis of a light-emitting element material via an organic halide.
F-MS), the content of reaction by-products and raw material bromine, iodine and chlorine halides contained in the target light-emitting device material is 3% or less, more preferably 2 %. The method for synthesizing a material for a light-emitting element, which is characterized by

In the above structure, in particular, the light-emitting element material is 4,4 ′, 4 ″-(benzene-1,
In the case of 3,5-triyl) tridibenzothiophene (abbreviation: DBT3P-II), the organic halide content before the sublimation purification treatment is 3% or less, more preferably 2% or less. It is a synthesis method.

In each of the above structures, the halide content of the light-emitting element material is 0.1% or less.

By using the method for synthesizing an organic compound for a light-emitting element which is one embodiment of the present invention, generation of a new halide can be reduced after sublimation purification in the synthesis of the organic compound for the light-emitting element, and thus light emission obtained The purity of the organic compound for the device can be increased. further,
To provide a light-emitting element with high emission efficiency and a long lifetime by forming a light-emitting element using a high-purity organic compound for a light-emitting element obtained by such a synthesis method, and a light-emitting device including the light-emitting element Can do.

The flowchart explaining a synthetic | combination method. The figure which shows the chromatogram of PDA of the sample 1. The figure which shows the chromatogram of PDA of the sample 2. The figure which shows the chromatogram of PDA of the sample 3. The figure which shows the mass spectrum data of the impurity 1. The figure which shows the mass spectrum data of the impurity 2. The figure which shows the mass spectrum data of the impurity 3. The figure which shows the mass spectrum data of the impurity 4. The figure which shows the NMR data of the sample 1. The figure which shows the chromatogram of PDA of the sample 4. The figure which shows the chromatogram of PDA of the sample 5. The figure which shows the chromatogram of PDA of the sample 6. The figure which shows the NMR data of the sample 4. The figure which shows the NMR data of the sample 5. The figure which shows the NMR data of the sample 6. The figure which shows the chromatogram of PDA of the sample 7. The figure which shows the chromatogram of PDA of the sample 8. The figure which shows the chromatogram of PDA of the sample 9. The figure which shows the chromatogram of PDA of the sample 10. The figure which shows the element structure of a light emitting element. FIG. 10 shows luminance-current efficiency characteristics of the light-emitting elements 1 and 2. FIG. 11 shows voltage-current characteristics of light-emitting elements 1 and 2; The figure which shows the luminance-chromaticity coordinate characteristic of the light emitting elements 1 and 2. FIG. The figure which shows the luminance-power efficiency characteristic of the light emitting elements 1 and 2. FIG. FIG. 6 shows emission spectra of the light-emitting elements 1 and 2; The figure which shows the reliability of the light emitting elements 1 and 2. FIG. FIG. 10 shows luminance-current efficiency characteristics of the light-emitting elements 3 and 4. FIG. 11 shows voltage-current characteristics of light-emitting elements 3 and 4; The figure which shows the luminance-chromaticity coordinate characteristic of the light emitting elements 3 and 4. FIG. FIG. 6 shows luminance-power efficiency characteristics of light-emitting elements 3 and 4. FIG. 6 shows emission spectra of the light-emitting elements 3 and 4; The figure which shows the reliability of the light emitting elements 3 and 4. FIG. 4A and 4B illustrate a structure of a light-emitting element. FIG. 6 illustrates a light-emitting device. 6A and 6B illustrate electronic devices. 6A and 6B illustrate electronic devices. The figure explaining a lighting fixture.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and various changes can be made in form and details without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below.

When synthesizing a material via a halogen substance, the content of the reaction by-product contained in the light emitting element material before the sublimation purification treatment and the halogen substance as a raw material for synthesizing the light emitting element material is 5%. It is less than 3% or less, more preferably 2% or less. If the reaction by-product or raw material halogen for synthesizing the light-emitting device material is contained before the sublimation purification treatment, the final target light-emitting device material halide is newly generated by sublimation purification. To do.

Since the newly produced halogenated compound of the light emitting device material is difficult to remove even after repeated sublimation purification treatments, it is preferably removed sufficiently before sublimation purification.

(Embodiment 1)
In this embodiment, a method for synthesizing a light-emitting element material via an organic halide which is one embodiment of the present invention will be described with reference to a flowchart shown in FIG.

  First, a material for a light emitting device is synthesized via an organic halide.

Next, the obtained material for light-emitting element (target product) is purified, and a purity test is performed by ultra high performance liquid chromatograph time-of-flight mass spectrometry (UPLC / TOF-MS). At this time, if the content of reaction by-products and raw material bromine, iodine and chlorine halides contained in the light-emitting element material (target product) is not 3% or less (preferably 2% or less), again Purify. However,
In order to prevent halogenation of the target light emitting device material during purification, a purification method performed at 350 ° C. or lower, preferably 300 ° C. or lower, more preferably 200 ° C. or lower is preferable. Examples of the purification method include column chromatography and recrystallization. The content is 3
If it is less than or equal to%, the sublimation purification treatment may be carried out as it is.

In this way, the content of reaction by-products and raw material bromine, iodine and chlorine halides contained in the light emitting device material (target product) before sublimation purification treatment is 3% or less (preferably 2% or less). Thus, the halide content of the light-emitting element material (target product) obtained after the sublimation purification treatment can be reduced to 0.1% or less.

Note that in one embodiment of the present invention, ultra-high performance liquid chromatograph flight is used for measuring the content of reaction by-products and raw material bromine, iodine, and chlorine halides contained in the light-emitting element material (target product). It is preferable to use time-type mass spectrometry (UPLC / TOF-MS).

In one embodiment of the present invention, the synthesis uses an organic halide as a raw material.
This method can be widely applied not only in the final reaction for synthesizing the target product but also when an organic halide is used in some step as an intermediate for synthesizing the target product. That is, it can be widely applied when there is a possibility of mixing organic halides.

Although it is ideal to completely react at these stages of synthesis, one of the raw materials usually tends to remain a little. Therefore, when reacting with a halide, it is preferable to add a coupling partner (such as a boron compound or an amine compound) excessively so as not to leave a halide. However, when an organic halide substituted with a plurality of halogens is used, if the coupling reaction does not proceed completely in all halogen groups,
The halogen group remains, which causes a problem. Therefore, one embodiment of the present invention is useful when the organic halide is an organic halide substituted with a plurality of halogens.

In particular, in the case of a reaction using orthodibromobenzene, 1,3,5-tribromobenzene, 2,2′-dibromobiphenyl, etc., the resulting substituents of the target product are close to each other sterically, making it difficult to react. In some cases, the group may not react completely. Moreover, the reaction may not proceed to the end even when the solubility of the raw materials and intermediates in the solvent is very poor. Easy to precipitate
Examples of the skeleton having poor solubility include a condensed aromatic ring skeleton and a condensed heteroaromatic skeleton having high planarity such as dibenzothiophene, dibenzofuran, triphenylene, and dibenzoquinoxaline. Both of these halides and target products having these as substituents have poor solubility. High-purity objectives are preferred, but these objectives and impurities are poorly soluble and difficult to purify. However, high purification costs a synthesis cost. Therefore, it is necessary to determine how much the purity of the organic halide, which is an impurity, needs to be increased before the next sublimation purification.

For example, 4,4 ′, 4 ″-(benzene-1,3,5-triyl) tridibenzothiophene (abbreviation: DBT3P-II) is a simple synthesis method using 1,3,5-tribromobenzene and dibenzothiophene. Reacts with -4-boronic acid, but is an intermediate,
4,4 ′-(1-Bromobenzene-3,5-diyl) dibenzothiophene tends to precipitate and is difficult to further react with dibenzothiophene-4-boronic acid. In addition, reacting dibenzothiophene with all of the 1st, 3rd and 5th positions of benzene has steric hindrance,
Have difficulty. For this reason, some of the intermediate which is a halide tends to remain. The target DBT3P-II is also one of the materials that are very poor in solubility and difficult to purify.

In one embodiment of the present invention, a light-emitting element material (target object) obtained before sublimation purification treatment
Various known methods can be used as a method for purifying. However, the purification is preferably performed at 350 ° C. or lower so that the target light-emitting element material is not halogenated during purification. The purification method includes, for example, a column chromatography method, a recrystallization method, and the like, and may be performed by appropriately combining conditions.

In addition, as a sublimation purification treatment method in one embodiment of the present invention, various known methods can be used, but a train sublimation type is preferable because of its good resolution. At this time, it is preferable to flow an inert gas such as argon or nitrogen from the high vacuum or high temperature side in the system.

Therefore, a highly purified light-emitting element material can be obtained by using the synthesis method described above. Further, by using such a light emitting element material, a light emitting element having excellent element characteristics can be obtained.

Note that the structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

(Embodiment 2)
In this embodiment, a light-emitting element that can use the high-purity EL element material obtained by the synthesis method described in Embodiment 1 as one embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 33, the light-emitting element described in this embodiment includes a pair of electrodes (first electrode (anode)).
101 and the second electrode (cathode) 103), an EL layer 102 including a light emitting layer 113 is sandwiched between the EL layer 102, the hole (or hole) injection layer 111, Hole (or hole) transport layer 112, electron transport layer 114, electron injection layer 115, charge generation layer (
E) 116 and the like are formed.

By applying a voltage to such a light-emitting element, holes injected from the first electrode 101 side and electrons injected from the second electrode 103 side recombine in the light-emitting layer 113, The organometallic complex is brought into an excited state. Light is emitted when the organometallic complex in the excited state returns to the ground state. As described above, in one embodiment of the present invention, the organometallic complex functions as a light-emitting substance in a light-emitting element.

Note that the hole-injection layer 111 in the EL layer 102 includes a substance having a high hole-transport property and an acceptor substance, and holes are extracted by extraction of electrons from the substance having a high hole-transport property by the acceptor substance. (Hole) occurs. Accordingly, holes are injected from the hole injection layer 111 into the light emitting layer 113 through the hole transport layer 112.

The charge generation layer (E) 116 includes a substance having a high hole-transport property and an acceptor substance. Since electrons are extracted from the substance having a high hole-transport property by the acceptor substance, the extracted electrons are injected from the electron injection layer 115 having an electron-injection property into the light-emitting layer 113 through the electron-transport layer 114.

At this time, the purity of the material used is particularly important in the light emitting layer and the layer adjacent to the light emitting layer. A smaller amount of organic halide contained in these materials is preferred. By making the halide a detection limit, it can be expected that the reliability will be greatly improved.

  Specific examples for manufacturing the light-emitting element described in this embodiment will be described below.

For the first electrode (anode) 101 and the second electrode (cathode) 103, a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like can be used. Specifically, indium tin oxide (ITO), indium oxide-tin oxide containing silicon or silicon oxide, indium zinc oxide (Indium Zi).
nc Oxide), indium oxide containing tungsten oxide and zinc oxide, gold (A
u), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), titanium ( In addition to Ti, elements belonging to Group 1 or Group 2 of the periodic table of elements, that is, lithium (L
i) alkali metals such as cesium (Cs), magnesium (Mg), calcium (
Ca), alkaline earth metals such as strontium (Sr), and alloys containing them (Mg
Rare earth metals such as Ag, AlLi), europium (Eu), ytterbium (Yb), alloys containing these, and other graphene can be used. Note that the first electrode (anode) 101 and the second electrode (cathode) 103 can be formed by, for example, a sputtering method, an evaporation method (including a vacuum evaporation method), or the like.

As a substance having a high hole transporting property used for the hole injection layer 111, the hole transporting layer 112, and the charge generation layer (E) 116, for example, 4,4′-bis [N- (1-naphthyl) -N -Phenylamino] biphenyl (abbreviation: NPB or α-NPD) and N, N′-bis (3-methylphenyl) -N, N′-diphenyl- [1,1′-biphenyl] -4,4′-diamine (
Abbreviation: TPD), 4,4 ′, 4 ″ -tris (carbazol-9-yl) triphenylamine (abbreviation: TCTA), 4,4 ′, 4 ″ -tris (N, N-diphenylamino) tri Phenylamine (abbreviation: TDATA), 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (abbreviation: MTDATA), 4,4 ′
Aromatic aromatic compounds such as bis [N- (spiro-9,9′-bifluoren-2-yl) -N-phenylamino] biphenyl (abbreviation: BSPB), 3- [N- (9-phenylcarbazole-3) -Yl) -N-phenylamino] -9-phenylcarbazole (abbreviation: PC
zPCA1), 3,6-bis [N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole (abbreviation: PCzPCA2), 3- [N- (1-
Naphthyl) -N- (9-phenylcarbazol-3-yl) amino] -9-phenylcarbazole (abbreviation: PCzPCN1) and the like. In addition, 4,4′-di (N-carbazolyl) biphenyl (abbreviation: CBP), 1,3,5-tris [4- (N-carbazolyl)
Carbazole derivatives such as phenyl] benzene (abbreviation: TCPB), 9- [4- (10-phenyl-9-anthracenyl) phenyl] -9H-carbazole (abbreviation: CzPA), and the like can be used. The substances described here are mainly substances having a hole mobility of 10 ⁻⁶ cm ² / Vs or higher. Note that other than these substances, any substance that has a property of transporting more holes than electrons may be used.

Further, poly (N-vinylcarbazole) (abbreviation: PVK), poly (4-vinyltriphenylamine) (abbreviation: PVTPA), poly [N- (4- {N ′-[4- (4-diphenylamino)] Phenyl] phenyl-N′-phenylamino} phenyl) methacrylamide]
A polymer compound such as (abbreviation: PTPDMA) poly [N, N′-bis (4-butylphenyl) -N, N′-bis (phenyl) benzidine] (abbreviation: Poly-TPD) can also be used.

Examples of the acceptor substance used for the hole injection layer 111 and the charge generation layer (E) 116 include transition metal oxides and oxides of metals belonging to Groups 4 to 8 in the periodic table. . Specifically, molybdenum oxide is particularly preferable.

The light emitting layer 113 is a layer containing a light emitting substance. The light emitting layer 113 may be composed of only a light emitting substance or may be composed of a light emitting substance (guest material) dispersed in a host material.

As the light-emitting substance, N, N′-bis [4- (9H-carbazol-9-yl) phenyl] -N, N′-diphenylstilbene-4,4′-diamine (abbreviation: YGA2S), 4-
(9H-carbazol-9-yl) -4 ′-(10-phenyl-9-anthryl) triphenylamine (abbreviation: YGAPA), 4- (9H-carbazol-9-yl) -4 ′-(
9,10-diphenyl-2-anthryl) triphenylamine (abbreviation: 2YGAPPA)
, N, 9-diphenyl-N- [4- (10-phenyl-9-anthryl) phenyl] -9
H-carbazol-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), 4- (10-phenyl-9-anthryl) -4′- (9-phenyl-9H-carbazol-3-yl) triphenylamine (
Abbreviation: PCBAPA), N, N ″-(2-tert-butylanthracene-9,10-
Diyldi-4,1-phenylene) bis [N, N ′, N′-triphenyl-1,4-phenylenediamine] (abbreviation: DPABPA), N, 9-diphenyl-N- [4- (9,10-)
Diphenyl-2-anthryl) phenyl] -9H-carbazol-3-amine (abbreviation: 2)
PCAPPA), N- [4- (9,10-diphenyl-2-anthryl) phenyl] -N
, N ′, N′-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA),
N, N, N ′, N ′, N ″, N ″, N ′ ″, N ′ ″-octaphenyldibenzo [
g, p] chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), coumarin 3
0, N- (9,10-diphenyl-2-anthryl) -N, 9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCAPA), N- [9,10-bis (1,1′-biphenyl) -2-yl) -2-anthryl] -N, 9-diphenyl-9H-carbazole-3
-Amine (abbreviation: 2PCABPhA), N- (9,10-diphenyl-2-anthryl)
-N, N ', N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA)
N- [9,10-bis (1,1′-biphenyl-2-yl) -2-anthryl] -N,
N ′, N′-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA),
9,10-bis (1,1′-biphenyl-2-yl) -N- [4- (9H-carbazol-9-yl) phenyl] -N-phenylanthracen-2-amine (abbreviation: 2YGABP)
hA), N, N, 9-triphenylanthracen-9-amine (abbreviation: DPhAPhA)
Coumarin 545T, N, N′-diphenylquinacridone, (abbreviation: DPQd), rubrene, 5,12-bis (1,1′-biphenyl-4-yl) -6,11-diphenyltetracene (abbreviation: BPT), 2 -(2- {2- [4- (dimethylamino) phenyl] ethenyl}
-6-methyl-4H-pyran-4-ylidene) propanedinitrile (abbreviation: DCM1),
2- {2-Methyl-6- [2- (2,3,6,7-tetrahydro-1H, 5H-benzo [
ij] quinolinidin-9-yl) ethenyl] -4H-pyran-4-ylidene} propanedinitrile (abbreviation: DCM2), N, N, N ′, N′-tetrakis (4-methylphenyl) tetracene-5,11 -Diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,
N, N ′, N′-tetrakis (4-methylphenyl) acenaphtho [1,2-a] fluoranthene-3,10-diamine (abbreviation: p-mPhAFD), 2- {2-isopropyl-6
-[2- (1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H, 5H
-Benzo [ij] quinolizin-9-yl) ethenyl] -4H-pyran-4-ylidene} propanedinitrile (abbreviation: DCJTI), 2- {2-tert-butyl-6- [2- (1
, 1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H, 5H-benzo [i
j] quinolizin-9-yl) ethenyl] -4H-pyran-4-ylidene} propanedinitrile (abbreviation: DCJTB), 2- (2,6-bis {2- [4- (dimethylamino) phenyl] ethenyl} -4H-pyran-4-ylidene) propanedinitrile (abbreviation: BisDC)
M), 2- {2,6-bis [2- (8-methoxy-1,1,7,7-tetramethyl-2,
3,6,7-tetrahydro-1H, 5H-benzo [ij] quinolizin-9-yl) ethenyl] -4H-pyran-4-ylidene} propanedinitrile (abbreviation: BisDCJTM), and the like.

Note that when the light-emitting element material obtained by the synthesis method of one embodiment of the present invention is a light-emitting substance, the light-emitting substance can be used in the same manner as the above-described materials.

In addition, as a substance (that is, a host material) used for bringing the light-emitting substance into a dispersed state, for example, 2,3-bis (4-diphenylaminophenyl) quinoxaline (abbreviation: TP)
AQn), a compound having an arylamine skeleton such as NPB, CBP, 4,4 ′,
Carbazole derivatives such as 4 ″ -tri (N-carbazolyl) triphenylamine (abbreviation: TCTA), bis [2- (2-hydroxyphenyl) pyridinato] zinc (abbreviation: Znp)
p ₂ ), bis [2- (2-hydroxyphenyl) benzoxazolate] zinc (abbreviation: Zn
(BOX) ₂ ), bis (2-methyl-8-quinolinolato) (4-phenylphenolato) aluminum (abbreviation: BAlq), tris (8-quinolinolato) aluminum (abbreviation: Al
Metal complexes such as q ₃ ) are preferred. A polymer compound such as PVK can also be used.

Note that in the case where the light-emitting element material obtained by the synthesis method which is one embodiment of the present invention is a host material, the light-emitting element material can be used in the same manner as the above materials.

The electron transport layer 114 is a layer containing a substance having a high electron transport property. The electron transport layer 114 includes
Alq ₃ , tris (4-methyl-8-quinolinolato) aluminum (abbreviation: Almq ₃ )
, Bis (10-hydroxybenzo [h] quinolinato) beryllium (abbreviation: BeBq _2),
Metal complexes such as BAlq, Zn (BOX) ₂ , and bis [2- (2-hydroxyphenyl) benzothiazolate] zinc (abbreviation: Zn (BTZ) ₂ ) can be used. Also, 2- (
4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis [5- (p-tert-butylphenyl) -1,
3,4-oxadiazol-2-yl] benzene (abbreviation: OXD-7), 3- (4-te
rt-butylphenyl) -4-phenyl-5- (4-biphenylyl) -1,2,4-triazole (abbreviation: TAZ), 3- (4-tert-butylphenyl) -4- (4-ethylphenyl) -5- (4-biphenylyl) -1,2,4-triazole (abbreviation: p-EtT)
AZ), bathophenanthroline (abbreviation: BPhen), bathocuproin (abbreviation: BCP)
), 4,4′-bis (5-methylbenzoxazol-2-yl) stilbene (abbreviation: B)
Heteroaromatic compounds such as zOs) can also be used. Further, poly (2,5-pyridine-diyl) (abbreviation: PPy), poly [(9,9-dihexylfluorene-2,7-diyl) -co- (pyridine-3,5-diyl)] (abbreviation: PF-Py), poly [(9,9-dioctylfluorene-2,7-diyl) -co- (2,2′-bipyridine-6,6′-diyl)] (abbreviation: PF-BPy) A high molecular compound can also be used. The substances mentioned here are mainly substances having an electron mobility of 10 ⁻⁶ cm ² / Vs or higher. Note that any substance other than the above substances may be used for the electron-transport layer 114 as long as it has a property of transporting more electrons than holes.

Further, the electron-transport layer 114 is not limited to a single layer, and two or more layers including the above substances may be stacked.

The electron injection layer 115 is a layer containing a substance having a high electron injection property. The electron injection layer 115 includes
Lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ₂ )
Alkali metals such as lithium oxide (LiOx), alkaline earth metals, or compounds thereof can be used. Alternatively, a rare earth metal compound such as erbium fluoride (ErF ₃ ) can be used. In addition, a substance constituting the electron transport layer 114 described above can be used.

Alternatively, a composite material obtained by mixing an organic compound and an electron donor (donor) may be used for the electron injection layer 115. Such a composite material is excellent in electron injecting property and electron transporting property because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material excellent in transporting the generated electrons. Specifically, for example, a substance (metal complex, heteroaromatic compound, or the like) constituting the electron transport layer 114 described above is used. Can be used. The electron donor may be any substance that exhibits an electron donating property to the organic compound. Specifically, alkali metals, alkaline earth metals, and rare earth metals are preferable, and lithium, cesium, magnesium, calcium, erbium, ytterbium, and the like can be given. Alkali metal oxides and alkaline earth metal oxides are preferable, and lithium oxide), calcium oxide, barium oxide, and the like can be given. A Lewis base such as magnesium oxide can also be used. Alternatively, an organic compound such as tetrathiafulvalene (abbreviation: TTF) can be used.

Note that the hole injection layer 111, the hole transport layer 112, the light emitting layer 113, and the electron transport layer 11 described above are used.
4. The electron injection layer 115 and the charge generation layer (E) 116 can be formed by a method such as a vapor deposition method (including a vacuum vapor deposition method), an ink jet method, or a coating method, respectively.

In the light-emitting element described above, current flows due to a potential difference generated between the first electrode 101 and the second electrode 103, and light is emitted by recombination of holes and electrons in the EL layer 102. Then, the emitted light is extracted outside through one or both of the first electrode 101 and the second electrode 103. Therefore, one or both of the first electrode 101 and the second electrode 103 is a light-transmitting electrode.

Since the light-emitting element described above is formed using a high-purity light-emitting element material synthesized by the synthesis method which is one embodiment of the present invention, a more efficient light-emitting element can be realized.

Note that the light-emitting element described in this embodiment is an example of a light-emitting element manufactured using a high-purity light-emitting element material synthesized by the synthesis method of one embodiment of the present invention. Note that the light-emitting element can also be applied to a light-emitting element having a structure including a plurality of EL layers with a charge generation layer interposed therebetween (so-called tandem light-emitting element). The light-emitting device including the light-emitting element includes a passive matrix light-emitting device and an active matrix light-emitting device, and a light-emitting element having a structure different from that described in another embodiment. A light emitting device having a microcavity structure provided can be manufactured, and these are all included in the present invention.

Note that there is no particular limitation on the structure of the TFT in the case of manufacturing the active matrix light-emitting device. For example, a staggered or inverted staggered TFT can be used as appropriate. T
The driving circuit formed on the FT substrate may be composed of N-type and P-type TFTs, or may be composed of only one of N-type TFTs and P-type TFTs. Further, the crystallinity of a semiconductor film used for the TFT is not particularly limited. For example, an amorphous semiconductor film, a crystalline semiconductor film, an oxide semiconductor film, or the like can be used.

Note that the structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

(Embodiment 3)
In this embodiment, a light-emitting device including a light-emitting element using a high-purity EL element material obtained by the synthesis method described in Embodiment 1 will be described.

The light-emitting device may be a passive matrix light-emitting device or an active matrix light-emitting device.

In this embodiment, an active matrix light-emitting device is described with reference to FIGS.

34A is a top view illustrating the light-emitting device, and FIG. 34B is a cross-sectional view taken along the chain line AA ′ in FIG. 34A. An active matrix light-emitting device according to this embodiment includes a pixel portion 502 provided over an element substrate 501, a driver circuit portion (source line driver circuit) 503, and a driver circuit portion (gate line driver circuit) 504 ( 504a and 504b). The pixel portion 502, the driver circuit portion 503, and the driver circuit portion 504 are sealed between the element substrate 501 and the sealing substrate 506 with a sealant 505.

Further, on the element substrate 501, external input terminals for transmitting signals (eg, a video signal, a clock signal, a start signal, or a reset signal) and a potential from the outside to the driver circuit portion 503 and the driver circuit portion 504 are provided. A lead wiring 507 for connection is provided. here,
An example in which an FPC (flexible printed circuit) 508 is provided as an external input terminal is shown. Although only the FPC is shown here, a printed wiring board (PWB) may be attached to the FPC. The light-emitting device in this specification includes not only a light-emitting device body but also a state in which an FPC or a PWB is attached thereto.

Next, a cross-sectional structure will be described with reference to FIG. A driver circuit portion and a pixel portion are formed over the element substrate 501, but here, the driver circuit portion 50 which is a source line driver circuit.
3 and the pixel portion 502 are shown.

The driver circuit portion 503 shows an example in which a CMOS circuit in which an n-channel TFT 509 and a p-channel TFT 510 are combined is formed. Note that the circuit forming the drive circuit section is
Various CMOS circuits, PMOS circuits, or NMOS circuits may be formed. In this embodiment mode, a driver integrated type in which a driver circuit is formed over a substrate is shown; however, this is not necessarily required, and the driver circuit can be formed outside the substrate.

The pixel portion 502 includes a plurality of pixels including a switching TFT 511 and a first electrode (anode) 513 electrically connected to a wiring (source electrode or drain electrode) of the current control TFT 512 and the current control TFT 512. It is formed by. The first electrode (anode) 5
An insulator 514 is formed so as to cover the end of 13. Here, it is formed by using a positive photosensitive acrylic resin.

In order to improve the covering property of the film formed to be stacked on the upper layer, it is preferable that a curved surface having a curvature be formed at the upper end portion or the lower end portion of the insulator 514. For example, in the case where a positive photosensitive acrylic resin is used as the material of the insulator 514, it is preferable that the upper end portion of the insulator 514 has a curved surface having a curvature radius (0.2 μm to 3 μm). The insulator 514 can be either a negative type that becomes insoluble in an etchant by photosensitive light or a positive type that becomes soluble in an etchant by light, and is not limited to an organic compound. For example, both silicon oxide and silicon oxynitride can be used.

An EL layer 515 and a second electrode (cathode) 516 are stacked over the first electrode (anode) 513. The EL layer 515 is provided with at least a light-emitting layer, and the light-emitting layer contains the organometallic complex which is one embodiment of the present invention. In addition to the light-emitting layer, the EL layer 515 can be provided with a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a charge generation layer, and the like as appropriate.

Note that a light-emitting element 517 is formed with a stacked structure of a first electrode (anode) 513, an EL layer 515, and a second electrode (cathode) 516. First electrode (anode) 513, EL layer 515
As a material used for the second electrode (cathode) 516, the material described in Embodiment 1 can be used. Although not shown here, the second electrode (cathode) 516 is electrically connected to an FPC 508 which is an external input terminal.

In the cross-sectional view illustrated in FIG. 34B, only one light-emitting element 517 is illustrated; however, in the pixel portion 502, a plurality of light-emitting elements are arranged in a matrix. In the pixel portion 502, light-emitting elements that can emit three types of light (R, G, and B) can be selectively formed, so that a light-emitting device capable of full-color display can be formed. Alternatively, a light emitting device capable of full color display may be obtained by combining with a color filter.

Further, the sealing substrate 506 is bonded to the element substrate 501 with the sealant 505, whereby the light-emitting element 517 is provided in the space 518 surrounded by the element substrate 501, the sealing substrate 506, and the sealant 505. ing. Note that the space 518 includes a structure filled with a sealant 505 in addition to a case where the space 518 is filled with an inert gas (such as nitrogen or argon).

Note that an epoxy-based resin is preferably used for the sealant 505. Moreover, it is desirable that these materials are materials that do not transmit moisture and oxygen as much as possible. In addition, the sealing substrate 506
In addition to a glass substrate and a quartz substrate, FRP (Fiberglass-Rei)
For example, a plastic substrate made of nforced plastics), PVF (polyvinyl fluoride), polyester, acrylic, or the like can be used.

  As described above, an active matrix light-emitting device can be obtained.

Note that the structure described in this embodiment can be combined with any of the structures described in other embodiments as appropriate.

(Embodiment 4)
In this embodiment, examples of various electronic devices completed using a light-emitting device manufactured using an organometallic complex which is one embodiment of the present invention will be described with reference to FIGS.

As electronic devices to which the light-emitting device is applied, for example, a television set (also referred to as a television or a television receiver), a monitor for a computer, a digital camera, a digital video camera, a digital photo frame, a mobile phone (a mobile phone, a mobile phone) Also called a telephone device),
A large-sized game machine such as a portable game machine, a portable information terminal, a sound reproduction device, and a pachinko machine can be given. Specific examples of these electronic devices are shown in FIGS.

FIG. 35A illustrates an example of a television set. In the television device 7100, a display portion 7103 is incorporated in a housing 7101. Images can be displayed on the display portion 7103, and a light-emitting device can be used for the display portion 7103. Here, a structure in which the housing 7101 is supported by a stand 7105 is shown.

The television device 7100 can be operated with an operation switch included in the housing 7101 or a separate remote controller 7110. Channels and volume can be operated with an operation key 7109 provided in the remote controller 7110, and an image displayed on the display portion 7103 can be operated. The remote controller 7110 may be provided with a display portion 7107 for displaying information output from the remote controller 7110.

Note that the television device 7100 is provided with a receiver, a modem, and the like. A general television broadcast can be received by a receiver, and further connected to a wired or wireless communication network via a modem so that it can be transmitted in one direction (sender to receiver) or two-way (
It is also possible to perform information communication between a sender and a receiver, or between receivers).

FIG. 35B illustrates a computer, which includes a main body 7201, a housing 7202, a display portion 7203,
A keyboard 7204, an external connection port 7205, a pointing device 7206, and the like are included. Note that the computer is manufactured by using the light-emitting device for the display portion 7203.

FIG. 35C illustrates a portable game machine, which includes two housings, a housing 7301 and a housing 7302, which are connected with a joint portion 7303 so that the portable game machine can be opened or folded. A display portion 7304 is incorporated in the housing 7301 and a display portion 7305 is incorporated in the housing 7302. Also,
In addition, a portable game machine shown in FIG. 35C includes a speaker portion 7306 and a recording medium insertion portion 73.
07, LED lamp 7308, input means (operation key 7309, connection terminal 7310, sensor 7311 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, voice, Time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient,
Including a function of measuring vibration, smell, or infrared), a microphone 7312), and the like. Needless to say, the structure of the portable game machine is not limited to the above, and a light-emitting device may be used at least for one or both of the display portion 7304 and the display portion 7305, and other accessory facilities may be provided as appropriate. can do. The portable game machine shown in FIG. 35C has a function of reading a program or data recorded in a recording medium and displaying the program or data on the display unit, or performs wireless communication with another portable game machine to share information. It has a function. Note that FIG.
The functions of the portable game machine shown in (1) are not limited to this, and can have various functions.

FIG. 35D illustrates an example of a mobile phone. A mobile phone 7400 includes a housing 740.
1, an operation button 7403, an external connection port 7404,
A speaker 7405, a microphone 7406, and the like are provided. Note that the cellular phone 7400 is manufactured using the light-emitting device for the display portion 7402.

A cellular phone 7400 illustrated in FIG. 35D can touch the display portion 7402 with a finger or the like,
Information can be entered. In addition, operations such as making a call or creating a mail can be performed by touching the display portion 7402 with a finger or the like.

There are mainly three screen modes of the display portion 7402. The first mode is a display mode mainly for displaying an image. The first is a display mode mainly for displaying images, and the second is an input mode mainly for inputting information such as characters. The third is a display + input mode in which the display mode and the input mode are mixed.

For example, when making a call or creating a mail, the display portion 7402 may be set to a character input mode mainly for inputting characters, and an operation for inputting characters displayed on the screen may be performed. In this case, it is preferable to display a keyboard or number buttons on most of the screen of the display portion 7402.

Further, by providing a detection device having a sensor for detecting the inclination of a gyroscope, an acceleration sensor, or the like inside the mobile phone 7400, the orientation (vertical or horizontal) of the mobile phone 7400 is determined,
The screen display of the display portion 7402 can be automatically switched.

Further, the screen mode is switched by touching the display portion 7402 or operating the operation button 7403 of the housing 7401. Further, switching can be performed depending on the type of image displayed on the display portion 7402. For example, if the image signal to be displayed on the display unit is moving image data, the mode is switched to the display mode, and if it is text data, the mode is switched to the input mode.

Further, in the input mode, when a signal detected by the optical sensor of the display unit 7402 is detected and there is no input by a touch operation of the display unit 7402 for a certain period, the screen mode is switched from the input mode to the display mode. You may control.

The display portion 7402 can function as an image sensor. For example, the display unit 7
User authentication can be performed by touching 402 with a palm or a finger and imaging a palm print, fingerprint, or the like.
In addition, if a backlight that emits near-infrared light or a sensing light source that emits near-infrared light is used for the display portion, finger veins, palm veins, and the like can be imaged.

FIG. 36A and FIG. 36B illustrate a tablet terminal that can be folded. FIG. 36 (A
) Is an open state, and the tablet terminal includes a housing 9630, a display portion 9631a, a display portion 9631b, a display mode change switch 9034, a power switch 9035, a power saving mode change switch 9036, a fastener 9033, and an operation switch 9038. Have. Note that the tablet terminal is manufactured using the light-emitting device for one or both of the display portion 9631a and the display portion 9631b.

Part of the display portion 9631 a can be a touch panel region 9632 a and data can be input when a displayed operation key 9637 is touched. The display unit 96
In FIG. 31a, as an example, a configuration in which half of the area has a display-only function and a configuration in which the other half has a touch panel function is shown, but the configuration is not limited thereto. Display unit 96
All the regions 31a may have a touch panel function. For example, the display unit 9
The entire surface of 631a can be displayed as a keyboard button and used as a touch panel, and the display portion 9631b can be used as a display screen.

Further, in the display portion 9631b, as in the display portion 9631a, part of the display portion 9631b can be a touch panel region 9632b. Further, a keyboard button can be displayed on the display portion 9631b by touching a position where the keyboard display switching button 9539 on the touch panel is displayed with a finger or a stylus.

Touch input can be performed simultaneously on the touch panel region 9632a and the touch panel region 9632b.

A display mode switching switch 9034 can switch the display direction such as vertical display or horizontal display, and can select switching between monochrome display and color display. The power saving mode change-over switch 9036 can optimize the display brightness in accordance with the amount of external light in use detected by an optical sensor built in the tablet terminal. The tablet terminal may include not only an optical sensor but also other detection devices such as a gyroscope, an acceleration sensor, and other sensors that detect inclination.

FIG. 36A illustrates an example in which the display areas of the display portion 9631b and the display portion 9631a are the same; however, there is no particular limitation, and one size may differ from the other size, and the display quality may also be different. May be different. For example, one display panel may be capable of displaying images with higher definition than the other.

FIG. 36B illustrates a closed state, in which the tablet terminal includes a housing 9630, a solar cell 9
633, a charge / discharge control circuit 9634, a battery 9635, and a DCDC converter 9636. Note that in FIG. 36B, a battery 963 is illustrated as an example of the charge / discharge control circuit 9634.
5 shows a configuration having a DCDC converter 9636.

Note that since the tablet terminal can be folded in two, the housing 9630 can be closed when not in use. Therefore, since the display portion 9631a and the display portion 9631b can be protected,
It is possible to provide a tablet terminal with excellent durability and high reliability from the viewpoint of long-term use.

In addition, the tablet terminal shown in FIGS. 36 (A) and 36 (B) has a function for displaying various information (still images, moving images, text images, etc.), a calendar, a date, or a time. A function for displaying on the display unit, a touch input function for performing touch input operation or editing of information displayed on the display unit, a function for controlling processing by various software (programs), and the like can be provided.

Electric power can be supplied to the touch panel, the display unit, the video signal processing unit, or the like by the solar battery 9633 mounted on the surface of the tablet terminal. Note that the solar cell 9633 is preferable because it can efficiently charge the battery 9635 on one or two surfaces of the housing 9630. Note that as the battery 9635, when a lithium ion battery is used, there is an advantage that reduction in size can be achieved.

FIG. 36B illustrates the structure and operation of the charge and discharge control circuit 9634 illustrated in FIG.
C) will be described with reference to a block diagram. FIG. 36C illustrates a solar battery 9633, a battery 9
635, DCDC converter 9636, converter 9638, switches SW1 to SW3
, A display portion 9631, a battery 9635, a DCDC converter 963
6, the converter 9638 and the switches SW1 to SW3 are portions corresponding to the charge / discharge control circuit 9634 shown in FIG.

First, an example of operation in the case where power is generated by the solar battery 9633 using external light is described. The power generated by the solar battery is DC so that it becomes a voltage for charging the battery 9635.
The DC converter 9636 performs step-up or step-down. When power from the solar battery 9633 is used for the operation of the display portion 9631, the switch SW1 is turned on, and the converter 9638 performs step-up or step-down to a voltage necessary for the display portion 9631. In the case where display on the display portion 9631 is not performed, the battery 9635 may be charged by turning off SW1 and turning on SW2.

Note that the solar battery 9633 is shown as an example of the power generation unit, but is not particularly limited.
The battery 9635 may be charged by other power generation means such as a piezoelectric element (piezo element) or a thermoelectric conversion element (Peltier element). For example, it is good also as a structure performed combining a non-contact electric power transmission module which transmits / receives electric power by radio | wireless (non-contact), and another charging means.

Needless to say, the electronic device illustrated in FIG. 36 is not particularly limited as long as the display portion described in any of the above embodiments is included.

As described above, an electronic device can be obtained by using the light-emitting device which is one embodiment of the present invention. The application range of the light-emitting device is extremely wide and can be applied to electronic devices in various fields.

Note that the structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

(Embodiment 5)
In this embodiment, an example of a lighting device to which a light-emitting device including an organometallic complex which is one embodiment of the present invention is applied will be described with reference to FIGS.

FIG. 37 illustrates an example in which the light-emitting device is used as an indoor lighting device 8001. Note that since the light-emitting device can have a large area, a large-area lighting device can also be formed. In addition, by using a housing having a curved surface, the lighting device 8002 in which the light emitting region has a curved surface can be formed. A light-emitting element included in the light-emitting device described in this embodiment has a thin film shape, and the degree of freedom in designing a housing is high. Therefore, it is possible to form a lighting device with various designs. Further, a large lighting device 8003 may be provided on the wall surface of the room.

Further, by using the light-emitting device on the surface of the table, the lighting device 8004 having a function as a table can be obtained. Note that a lighting device having a function as furniture can be obtained by using a light-emitting device for part of other furniture.

As described above, various lighting devices to which the light-emitting device is applied can be obtained. Note that these lighting devices are included in one embodiment of the present invention.

The structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

In this example, 4,4 ′, 4 ″-(benzene-1,
3,5-triyl) tridibenzothiophene (abbreviation: DBT3P-II) was synthesized,
Sublimation purification was performed. By-product contained in each sample is analyzed by ultra high performance liquid chromatograph time-of-flight mass spectrometry (UPLC / TOF-MS) to determine whether impurities in the target product obtained by synthesis can be removed by sublimation purification. The identification and content of the product were analyzed.

  The samples used in this example are shown in Table 1 below.

That is, in this example, the above three samples were analyzed (sample 1: immediately after synthesis (before sublimation purification), sample 2: after sublimation purification of sample 1 (370 ° C.), sample 3: sublimation purification of sample 2 ( After 370 ° C.).

In the analysis, 1 mg of each sample was dissolved in 2 ml of chloroform and then diluted with the same amount of acetonitrile, and the resulting solution was used as a measurement sample.

The analyzer for ultra-high performance liquid chromatograph time-of-flight mass spectrometry (UPLC / TOF-MS) is Waters ACQUITY UPLC system and LCT-Premier.
TOF-MS was used.

The column is Waters ACQUITY UPLC BEH C8 (particle size 1.7).
(μm, 100 × 2.1 mm), and analysis was performed at 40 ° C. The moving bed was A: acetonitrile, B: 0.1% formic acid aqueous solution, and the gradient analysis was performed at a flow rate of 0.5 mL / min, holding A at 75% for 1 minute, and increasing at a constant rate up to 95% after 10 minutes. . Injection volume is 5 μL
It was.

As a condition of TOF-MS, measurement was performed in a positive ionization mode by an electrospray ionization method (ESI). MS scan range m / z 100-130
The analysis was performed at 0, an ionization voltage of 2500 V, an ion source temperature of 100 ° C., and a desolvation temperature of 200 ° C.

Chromatogram obtained by measurement (detector: PDA (Photodiode Arr
ay) (absorption wavelength: 210-500 nm)) is shown in FIGS. 2A and 2B.
) Shows the measurement result of sample 1 (immediately after synthesis (before sublimation purification)), and FIGS. 3 (A) and 3 (B) show the measurement result of sample 2 (after sublimation purification (370 ° C.) once). 4 (A) (B
) Shows the measurement results of sample 3 (after sublimation purification (370 ° C.) after completion of 2 times). 2, 3, and 4, (B) is an enlarged chromatogram of (A), the horizontal axis represents time (min), and the vertical axis represents intensity (arbitrary unit). Moreover, the content rate of the impurity contained in each sample was calculated | required by calculating a peak area from the chromatogram shown in FIG.2, FIG.3, FIG.4. At this time, since the peak detected within 1 minute was chloroform used to dissolve the material, it was excluded from the calculation of the peak area. In addition, a mass spectrum was calculated for each peak. The results are shown in Table 2.

That is, from sample 1 (immediately after synthesis (before sublimation purification)), DBT3P-II was 90.
1%, impurity 1 (m / z 442) is 0.1%, impurity 2 (m / z 522) is 5.2%
was detected. In addition, as other (including several types of impurities), the structure is not known, but 4.6% of all impurities were detected.

Note that a mass spectrum of the impurity 1 (m / z 442) is shown in FIG.
The mass spectrum of 22) is shown in FIG. The impurity 2 was found to be a bromine body from the mass spectrum shown in FIG. The structure inferred from the mass spectrum is shown below.

From sample 2 (after sublimation purification (370 ° C.) once), DBT3P-II was 95.3.
%, Impurity 1 (m / z 442) was detected at 0.1%, and impurity 2 (m / z 522) was detected at 0.5%. The impurity 1 (m / z 442) and the impurity 2 (m / z 522) are the same as the impurities detected from the sample 1.

Further, in sample 2, impurity 3 (m / z 704) was detected as two new peaks, and 3.6% in total, and impurity 4 (m / z 780) was detected at less than 0.1%. Also,
Others (including several types of impurities), the structure is not known, but the impurities are 0.5
%was detected.

The mass spectrum of impurity 3 (m / z 704) is shown in FIG.
The mass spectra are shown in FIG. The impurity 3 is a DBT3P-II bromine monosubstitution (monobromo) from the mass spectrum shown in FIG. 7, and the impurity 4 is a DBT3P-II bromine disubstitution (monobromine) from the mass spectrum shown in FIG. Dibromo form).

From sample 3 (after sublimation purification (370 ° C.) twice), DBT3P-II was 97.4.
%, Impurity 2 (m / z 522) was detected 0.2%. Impurity 2 (m / z 52
2) corresponds to the impurity 2 detected from the sample 1, the detection time, and the mass spectrum.
It can be inferred that they have the same structure.

Further, impurity 3 (m / z 704) detected in sample 2 was also detected in sample 3 together with 2.4%, and impurity 4 (m / z 780) was detected in less than 0.1%. Further, as other (including several types of impurities), the structure was not known, but the impurities detected in Sample 1 and Sample 2 were detected in less than 0.1% in total. However, impurity 1 (m / z 442) detected in sample 1 and sample 2 was the detection limit.

That is, in Sample 2, since 0.3% of impurity 2 and 3.6% of impurity 3 are detected, a total of 4.1% of halide is detected. In Sample 3, since 0.2% of impurity 2 and 2.4% of impurity 3 were detected, 2.6% of halides were detected in total. In other words, it was found that the halide was reduced by only 21% to 37% by sublimation purification. Impurity 3 is 3.6% in sample 2 and 2.4% in sample 3.
It was found that it decreased only 34%.

Furthermore, analysis by nuclear magnetic resonance (NMR) was performed on sample 1 (immediately after synthesis (before sublimation purification)). The obtained ¹ H NMR data is shown in FIG. FIG. 9B shows (A
) Is an enlarged chart. It was confirmed by NMR that impurities were contained in Sample 1 (immediately after synthesis (before sublimation purification)) from two peaks seen in the vicinity of 8 ppm surrounded by ◯ in FIG. 9B.

From the above results, it was found that the impurity 3 (m / z 704) and the impurity 4 (m / z 780) are newly generated impurities by sublimation purification performed after synthesis. Since these impurities are also detected in sample 3, which is a resublimation purified product of sample 2, impurities 3 (m / z 704) and impurity 4 (m / z 780) are difficult to remove by sublimation purification. I understood.

In this example, DBT3P-II was newly synthesized by the synthesis scheme A shown in Example 1. This sample contains impurity 2 (m / z 5) detected in sample 1 of Example 1.
22) Samples having different contents. Ultra high performance liquid chromatograph time-of-flight mass spectrometry (UPLC / TOF-MS) was used to determine whether impurities in this sample can be removed by sublimation purification.
) To analyze the identification and content of by-products contained in each sample.

  The samples used in this example are shown in Table 3 below.

That is, in this example, the above three samples were analyzed (sample 4: immediately after synthesis (before sublimation purification), sample 5: after sublimation purification of sample 4 (350 ° C.), sample 6: sublimation purification of sample 5 ( After 350 ° C.).

In addition, adjustment of measurement solution and ultra-high performance liquid chromatograph time-of-flight mass spectrometry (UPL
The measurement conditions in (C / TOF-MS) were the same as in Example 1.

Chromatogram obtained by measurement (detector: PDA (Photodiode Arr
ay) (absorption wavelength: 210-500 nm) is shown in FIGS. Note that FIG.
) (B) shows the measurement results of Sample 4 (immediately after synthesis (before sublimation purification)), and FIG.
(B) shows the measurement results of Sample 5 (after sublimation purification (350 ° C.) once finished), and FIG.
(A) and (B) show the measurement results of Sample 6 (after sublimation purification (350 ° C.) twice). 10, 11, and 12, (B) is an enlarged chromatogram of (A), the horizontal axis represents time (min), and the vertical axis represents intensity (arbitrary unit).

Moreover, the content rate of the impurity contained in each sample was calculated | required by calculating a peak area from the chromatogram shown in FIG.10, FIG.11, FIG.12. At this time, since the peak detected within 1 minute was chloroform used to dissolve the material, it was excluded from the calculation of the peak area. In addition, a mass spectrum was calculated for each peak. The results are shown in Table 4.

That is, from sample 4 (immediately after synthesis (before sublimation purification)), DBT3P-II was 96.
9% and 2% of impurities 2 (m / z 522) were detected. Impurity 2 (m / z 5
The structure derived from 22) is a bromine body from the detected mass spectrum, and is the same as that shown in Example 1. In addition, as other (including several types of impurities), 1.0% of impurities were detected.

From sample 5 (sublimation purification (350 ° C.) once completed), DBT3P-II is 99.
. 7%, others (including several types of impurities), the structure is unknown, but 0.3% of all impurities were detected. It was found that the impurity 2 (m / z 522) detected in the sample 4 was not detected and could be removed by sublimation purification.

Furthermore, from sample 6 (sublimation purification (350 ° C.) completed twice), DBT3P-II is 9
As for 9.8% and others (including several types of impurities), the structure is unknown, but 0.2% of impurities were detected.

Furthermore, sample 4 (immediately after synthesis (before sublimation purification)), sample 5 (after completion of sublimation purification (350 ° C.) once), and sample 6 (after completion of sublimation purification (350 ° C.) twice) used in this example.
Was analyzed by nuclear magnetic resonance (NMR). ¹ H NMR data of the obtained sample 4 (immediately after synthesis (before sublimation purification)) are shown in FIGS. 13A and 13B and sample 5 (sublimation purification (
350 ° C.) ¹ after completion once) H NMR data Figure 14 (A) (B), Sample 6 (Fig. ¹ H NMR data of the sublimation purification (350 ° C.) once after completion) 15 (A) (B ) Respectively. 13, 14, and 15, (B) is an enlarged chart of (A).

In addition, it was confirmed by NMR that impurities were contained in Sample 4 (immediately after synthesis (before sublimation purification)) from two peaks seen in the vicinity of 8 ppm surrounded by ○ in FIG. 13 (B). . Further, in Sample 5 (after completion of sublimation purification (350 ° C.) once) and Sample 6 (after completion of sublimation purification (350 ° C.) twice), these impurities observed in FIG. 13B are not confirmed. It was.

Based on the above results, impurity 2 (m / z 522) was used in this example before sublimation purification.
It was found that the bromine body represented by the formula (2) can be removed with high accuracy by keeping the bromine body at 2.1%, and the generation of new impurities as shown in Example 1 can be prevented.

In this example, the DBT detected after sublimation purification in DBT3P-II of Example 1 was used.
Impurity 3 (m / z 704) of bromine 1-substituted product (monobromo product) of 3P-II and Impurity 4 (m / z 780) of bromine 2-substituted product (dibromo product) are represented by impurity 2 (m / z 522)
In order to confirm whether it was generated by heating during sublimation purification due to the influence of the above, a heating test using a high vacuum differential type differential thermal balance (manufactured by Bruker AXS Co., Ltd., TG-DTA2410SA) was performed. The product after this heating test was analyzed by ultra high performance liquid chromatograph time-of-flight mass spectrometry (UPLC / TOF-MS) to analyze the content of materials and impurities before and after heating.

In addition, high vacuum differential type differential thermal balance (Bruker AXS Co., Ltd., TG-DT
A2410SA) was conducted for 5 hours at 370 ° C., atmospheric pressure and nitrogen stream. This temperature is a temperature at which DBT3P-II does not sublime under atmospheric pressure.

  The samples of DBT3P-II used in this example are shown in Table 5 below.

That is, in this example, the above four samples (sample 1: before heating test (with bromine)),
Sample 7: Sample 1 after the heating test of sample 1, sample 8: before the heating test (without bromine), sample 9: after the heating test of sample 8) was used. Sample 1 is the same sample as Sample 1 in Example 1 (immediately after synthesis (before sublimation purification)).

In the analysis, adjustment of the measurement solution and measurement conditions in ultra high performance liquid chromatograph time-of-flight mass spectrometry (UPLC / TOF-MS) were performed in the same manner as in Example 1.

Chromatogram obtained by measurement (detector: PDA (Photodiode Arr
ay) (absorption wavelength: 210-500 nm)) is shown in FIGS. Note that FIG.
) (B) shows the measurement results of Sample 7 (after the heating test of Sample 1), and FIG.
(B) shows the measurement results of Sample 8 (before the heating test (without bromine)), and FIG.
B) shows the measurement results of sample 9 (after the heating test of sample 8). In addition, for the measurement result of sample 1 (before the heating test (with bromine body)), the result shown in FIG. 2, 16, 17, and 18, (B) is (A).
The horizontal axis represents time (min), and the vertical axis represents intensity (arbitrary unit).

The content rate of impurities contained in each sample was determined by calculating the peak area from the chromatograms shown in FIGS. 2, 16, 17, and 18. At this time, since the peak detected within 1 minute is chloroform used to dissolve the material, it is excluded from the calculation of the peak area, and impurities of 6 to 10 minutes are not focused on in this example. The peak area was calculated limited to the range of 2 to 6 minutes. In addition, a mass spectrum was calculated for each peak.

  The results are shown in Table 6.

From sample 1 (before the heating test (with bromine)), DBT3P-II was 94.6%, impurity 1 (m / z 442) was less than 0.1%, and impurity 2 (m / z 522) was 5. 4% was detected. Note that the impurity 1 (m / z 442) and the impurity 2 (m / z 522) are the same as the impurities shown in Example 1.

In addition, from sample 7 (after the heating test of sample 1), DBT3P-II is 93.5%
Impurity 1 (m / z 442) was 1.7% and Impurity 2 (m / z 522) was 1.3%. Note that impurity 1 (m / z 442) and impurity 2 (m / z 522) are sample 1
Since the detection time and the mass spectrum correspond to the impurity 1 and the impurity 2 detected from 1 respectively, it can be assumed that they have the same structure. In addition, impurity 3 (m / z 704) is newly added after the heating test.
2 peaks, 3.5% in total, and impurity 4 (m / z 780) was detected at less than 0.1%. Similarly, impurity 3 (m / z 704) bromine monosubstituted product (monobromo compound), impurity 4
(M / z 780) is a bromine disubstituted product (dibromo product), which is the same as the impurity shown in Example 1.

From sample 8 (before the heating test (without bromine)), 99.9% or more of DBT3P-II was detected. Impurity 1 detected in Sample 1 and Sample 7 (m / z 442)
Impurity 2 (m / z 522), Impurity 3 (m / z 704), Impurity 4 (m / z 78)
0) was not detected.

From Sample 9 (after the heating test of Sample 8), 99.9% or more of DBT3P-II was detected. Impurity 1 detected in Sample 1 and Sample 7 (m / z 442)
Impurity 2 (m / z 522), Impurity 3 (m / z 704), Impurity 4 (m / z 78)
0) was not detected.

From the above results shown in Table 6, Sample 1 (before heating test (with bromine)) and Sample 7
If impurity 2 (m / z 522) is contained from (after the heating test of sample 1), bromine in impurity 2 (m / z 522) is removed by heating as shown below, and impurity 1 is newly added.
Impurity 3 (m / z 704), which is a bromine monosubstitution (monobromo form) of DBT3P-II, and impurity 4 is a bromine disubstitution (dibromo form) of DBT3P-II. It was suggested that (m / z 780) was generated. Moreover, from the sample 8 (before the heating test (no bromine body)) and the sample 9 (after the heating test of the sample 8), when the bromine body of the impurity 2 (m / z 522) is not included before heating, DBT3P-II after heating
It was found that no new bromine was formed.

In addition, according to this example, the halide of sample 3 in Example 1 did not decrease so much because the halogen of impurity 2 and impurity 3 was removed by heating and was again bonded to another compound in the sample. It turned out that it was because it was.

In this example, the test was performed at a different heating temperature from the heating test performed in Example 3. The test temperatures were 200 ° C. and 350 ° C., respectively.

In the sample subjected to the heating test at 200 ° C., impurity 2 (m / z 522) was detected, but impurity 3 (m / z 704) and impurity 4 (m / z 780) were not detected.
That is, it was found that DBT3P-II was difficult to be halogenated at 200 ° C.

In the sample subjected to the heating test at 350 ° C., impurity 2 (m / z 522) was also detected, but impurity 3 (m / z 704) was detected at 0.1%, and impurity 4 (m / z 780). Was not detected as a peak on the PDA chromatogram, but a similar mass spectrum was detected at the time corresponding to impurity 4 in Example 1. That is, DBT3P-II is 350
Although it was slightly halogenated at ° C, it was found that it was difficult to halogenate.

From the above results, the purification before sublimation purification of the target product using halide as a raw material was 35
0 ° C. or lower, preferably 300 ° C. or lower, more preferably 200 ° C. or lower.

In this example, in order to remove the bromine body of impurity 2 (m / z 522) detected in Sample 1 (immediately after synthesis (before sublimation purification)) in DBT3P-II of Example 1, 4-dibenzothiophene was removed. A coupling reaction was performed by adding boronic acid, and the content of impurities and impurities before and after the coupling were analyzed by ultra high performance liquid chromatography time-of-flight mass spectrometry (UPLC / TOF-MS).

In addition, impurity 2 (m / z 5) detected in sample 1 (immediately after synthesis (before sublimation purification))
Since the content of 22) was 5.2%, 4-dibenzothiopheneboronic acid was DBT.
An amount of 5 mol% was added to the amount of 3P-II to cause a coupling reaction. Reaction temperature,
The time was 80 ° C. for 7 hours.

  Table 7 shows samples of DBT3P-II used in this example.

That is, in this example, the sample in the case of the above two samples (sample 1: before the coupling reaction, sample 10: after the coupling reaction) was used. Sample 1 is the same sample as Sample 1 in Example 1 (immediately after synthesis (before sublimation purification)).

In the analysis, adjustment of the measurement solution and measurement conditions in ultra high performance liquid chromatograph time-of-flight mass spectrometry (UPLC / TOF-MS) were performed in the same manner as in Example 1.

Chromatogram obtained by measurement (detector: PDA (Photodiode Arr
ay) (absorption wavelength: 210-500 nm)) is shown in FIG. 19A and 19B.
Shows the measurement result of Sample 10 (after coupling reaction by adding 5 mol% of 4-dibenzothiopheneboronic acid to Sample 1). Sample 1 (before heating test (with bromine))
For the measurement results, refer to the results shown in FIG. In addition, FIG.
In FIG. 19, (B) is an enlarged chromatogram of (A), and the horizontal axis represents time (
min), and the vertical axis represents intensity (arbitrary unit).

The content of impurities contained in each sample was determined by calculating the peak area from the chromatograms shown in FIGS. At this time, since the peak detected within 1 minute is chloroform used to dissolve the material, it is excluded from the calculation of the peak area.
Since the minute impurity does not pay attention in this example, the peak area was calculated by limiting to the range of 2 to 6 minutes. In addition, a mass spectrum was calculated for each peak.

  The results are shown in Table 8.

That is, from sample 1 (before the coupling reaction), DBT3P-II is 94.6%.
Impurity 1 (m / z 442) is less than 0.1%, Impurity 2 (m / z 522) is 5.4%
was detected. Note that the impurity 1 (m / z 442) and the impurity 2 (m / z 522) are the same as the impurities shown in Example 1.

Further, from sample 10 (after the coupling reaction), DBT3P-II is 95.1%,
Impurity 1 (m / z 442) was detected as 2.5%, Impurity 2 (m / z 522) as 2.0%, and other (including several types of impurities), 0.4% of impurities were detected. The impurity 1 (m / z 442) and the impurity 2 (m / z 522) are the same as the impurities detected from the sample 1.

Therefore, as shown in Table 8, when a coupling reaction was performed by adding a sufficient amount of 4-dibenzothiopheneboronic acid from Sample 1 (before the coupling reaction) and Sample 10 (after the coupling reaction), Reaction with the bromine body of impurity 2 (m / z 522) leads to impurity 2
Although the content rate of (m / z 522) decreased, it turned out that it is difficult to make all react. In addition, as a result of sample 10 (after the coupling reaction), impurity 1 (m / z 442)
From the increase in the content of, it was suggested that the bromine body of impurity 2 (m / z 522) and 4-dibenzothiopheneboronic acid hardly react.

In this example, 4,4 ′, 4 ″-(benzene-1,3, in which halogen impurities were detected.
5-triyl) tridibenzothiophene (abbreviation: DBT3P-II) and a DBT3P-II (abbreviation) in which no halogen-based impurities were detected were respectively produced.
The result of having investigated the influence of the impurity with respect to a light emitting element is shown. DBT3 in which impurities are detected
As P-II (abbreviation), sample 2 analyzed in Example 1 was used, and as impurities were detected, DBT3P-II (abbreviation) was sample 6 analyzed in Example 2.
Were used as a hole injection layer, and the light emitting element 1 and the light emitting element 2 were produced. Light emitting element 1
The light-emitting element 2 will be described with reference to FIG. The chemical formula of the material used in this example is shown below. Note that the materials already shown are omitted.

  A method for manufacturing the light-emitting elements 1 and 2 of this example is described below.

(Light emitting element 1)
First, indium tin oxide containing silicon oxide (ITSO) was formed over a glass substrate 1100 by a sputtering method, so that a first electrode 1101 was formed. The film thickness is 110n.
m, and the electrode area was 2 mm × 2 mm. Here, the first electrode 1101 is an electrode functioning as an anode of the light-emitting element.

Next, as a pretreatment for forming a light-emitting element over the substrate 1100, the surface of the substrate was washed with water, baked at 200 ° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds.

Thereafter, the substrate is introduced into a vacuum vapor deposition apparatus whose internal pressure is reduced to about 10 ⁻⁴ Pa, vacuum baking is performed at 170 ° C. for 30 minutes in a heating chamber within the vacuum vapor deposition apparatus, and then the substrate 1100 is subjected to about 30 minutes. Allowed to cool.

Then, as the plane in which the first electrode 1101 was formed faced downward, and fixed to a substrate holder provided a substrate 1100 on which the first electrode 1101 was formed in the vacuum evaporation apparatus, ^10-4
After reducing the pressure to about Pa, 4,4 ′, 4 ″-(benzene-1,3) of Sample 2 analyzed in Example 1 was deposited on the first electrode 1101 by vapor deposition using resistance heating. , 5-triyl) tridibenzothiophene (abbreviation: DBT3P-II) and molybdenum oxide were co-evaporated to form a hole injection layer 1111. The film thickness was 50 nm, and DBT3P-II.
The weight ratio of molybdenum oxide was adjusted to be 4: 2 (= DBT3P-II: molybdenum oxide). Note that the co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

Next, 9-phenyl-3- [4- (10-phenyl-9-anthryl) phenyl] -9H-carbazole (abbreviation: PCzPA) is formed over the hole injection layer 1111 so as to have a thickness of 10 nm. A hole transport layer 1112 was formed.

Further, 9- [4- (10-phenyl-9-anthryl) phenyl] -9H-carbazole (abbreviation: CzPA) and N, N′-bis (3-methylphenyl) -N, N′-bis [3 -(9-Phenyl-9H-fluoren-9-yl) phenyl] -pyrene-1,6-diamine (abbreviation: 1,6 mM emFLPAPrn) was co-evaporated to form a light-emitting layer 1113 over the hole-transport layer 1112. Here, the mass ratio of CzPA and 1,6 mM emFLPAPrn was adjusted to 1: 0.05 (= CzPA: 1,6 mM emFLPAPrn). The thickness of the light emitting layer 1113 was set to 30 nm.

Next, after CzPA was formed to a thickness of 10 nm over the light-emitting layer 1113, bathophenanthroline (abbreviation: BPhen) was formed to a thickness of 15 nm to form the electron transport layer 1
114 was formed.

Further, lithium fluoride (LiF) was vapor-deposited with a thickness of 1 nm on the electron transport layer 1114 to form an electron injection layer 1115. Note that the hole injection layer 1111, the hole transport layer 1112, the light emitting layer 1113, the electron transport layer 1114, and the electron injection layer 1115 are collectively referred to as an EL layer 1102.

Lastly, as the second electrode 1103 functioning as a cathode, aluminum was deposited to a thickness of 200 nm, whereby the light-emitting element 1 of this example was manufactured.

(Light emitting element 2)
The hole injection layer 1111 of the light-emitting element 2 is the DBT3 of Sample 6 analyzed in Example 2.
It was formed by co-evaporation of P-II and molybdenum oxide. The film thickness is 50 nm and D
The ratio of BT3P-II to molybdenum oxide was adjusted to be 4: 2 (= DBT3P-II: molybdenum oxide) by weight. Except for the hole-injection layer 1111, the light-emitting element 1 was manufactured in the same manner.

  Note that, in the above-described vapor deposition process, the vapor deposition was all performed by a resistance heating method.

Table 9 shows element structures of the light-emitting elements 1 and 2 obtained as described above.

After performing the operation | work which sealed the light emitting elements 1 and 2 in the glove box of nitrogen atmosphere so that a light emitting element might not be exposed to air | atmosphere, the operating characteristic of the light emitting elements 1 and 2 was measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

FIG. 21 shows luminance-current efficiency characteristics of the light-emitting elements 1 and 2. In FIG. 21, the horizontal axis represents luminance (
cd / m ² ), and the vertical axis represents current efficiency (cd / A). Further, voltage-current characteristics are shown in FIG. In FIG. 22, the horizontal axis represents voltage (V) and the vertical axis represents current (mA). In addition, FIG. 23 shows luminance-chromaticity coordinate characteristics. In FIG. 23, the horizontal axis represents luminance (cd / m ² ), and the vertical axis represents chromaticity coordinates (x coordinate or y coordinate). In addition, FIG. 24 shows luminance-power efficiency characteristics. FIG.
, The horizontal axis represents luminance (cd / m ² ) and the vertical axis represents power efficiency (lm / W). Further, the voltage (V) and current density (mA) of the light-emitting elements 1 and 2 when the luminance is around 1000 cd / m ^2.
/ Cm ² ), CIE chromaticity coordinates (x, y), luminance (cd / m ² ), current efficiency (cd / A),
Table 10 shows the external quantum efficiency (%).

In addition, FIG. 25 shows an emission spectrum when a current of 1 mA is passed through the light-emitting elements 1 and 2.
In FIG. 25, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit). As shown in FIG. 25 and Table 10, the CIE chromaticity coordinate of the light-emitting element 1 when the luminance is around 1000 cd / m ² is (x, y) = (0.15, 0.20). CIE chromaticity coordinates are (x, y
) = (0.15, 0.20). From this result, it was found that both of the light-emitting elements 1 and 2 obtained blue light emission derived from 1,6 mM emFLPAPrn, which is the emission center substance.

The results of the light-emitting element 1 and the light-emitting element 2 illustrated in FIGS. 21 and 22 indicate that impurities contained in DBT3P-II (abbreviation) do not affect the voltage-current characteristics and the luminance-current efficiency characteristics. .

In addition, although DBT3P-II (sample 2) of the light emitting element 1 was degassed during vapor deposition,
There was no degassing in DBT3P-II (sample 6) of the light-emitting element 2.

Next, a reliability test of the light-emitting element 1 and the light-emitting element 2 was performed. The result of the reliability test is shown in FIG.
Shown in In FIG. 26, the vertical axis represents normalized luminance (%) when the initial luminance is 100%, and the horizontal axis represents element driving time (h). The reliability test is performed at room temperature and the initial luminance is 5000.
The light emitting element of this example was driven under the condition of cd / m ² and constant current density.

From FIG. 26, the luminance after 170 hours of the light-emitting element 1 was maintained at 56% of the initial luminance. In addition, the luminance after 170 hours of the light-emitting element 2 was maintained at 62% of the initial luminance. As a result of this reliability, the light-emitting element 1 manufactured using DBT3P-II (abbreviation) containing impurities has low reliability, and the light-emitting element manufactured using DBT3P-II (abbreviation) containing no impurities. 2 is
It turned out to be a highly reliable device.

From the above results, by setting the bromine contained in the sample 2 analyzed in Example 1 of the light emitting element 1 to the detection limit as in the sample 6 analyzed in Example 2 of the light emitting element 2, It was found that a highly reliable element can be manufactured.

In this example, 4,4 ′, 4 ″-(benzene-1,3,5-triyl) tridibenzothiophene (abbreviation: DBT3P-II) in which impurities were detected and DBT3P-II in which no impurities were detected. The results of examining the influence of impurities on the light-emitting elements are shown in Table 1. As for DBT3P-II (abbreviation) in which impurities were detected, analysis was conducted in Example 1. DBT3 in which impurities were not detected using sample 2
As P-II (abbreviation), the light-emitting element 3 and the light-emitting element 4 were manufactured using the sample 6 analyzed in Example 2 as a hole injection layer and a hole transport layer, respectively. The light-emitting element 3 and the light-emitting element 4 will be described with reference to FIG. Since the material used in this example is the same as that in Example 6, the structural formula of the material is omitted.

  A method for manufacturing the light-emitting elements 3 and 4 of this example will be described below.

(Light emitting element 3)
First, an ITSO film was formed over a glass substrate 1100 by a sputtering method, so that a first electrode 1101 functioning as an anode was formed. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

Next, as a pretreatment for forming a light-emitting element over the substrate 1100, the surface of the substrate was washed with water, baked at 200 ° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds.

Thereafter, the substrate is introduced into a vacuum vapor deposition apparatus whose internal pressure is reduced to about 10 ⁻⁴ Pa, vacuum baking is performed at 170 ° C. for 30 minutes in a heating chamber within the vacuum vapor deposition apparatus, and then the substrate 1100 is subjected to about 30 minutes. Allowed to cool.

Then, as the plane in which the first electrode 1101 was formed faced downward, and fixed to a substrate holder provided a substrate 1100 on which the first electrode 1101 was formed in the vacuum evaporation apparatus, ^10-4
After reducing the pressure to about Pa, the sample 2 DBT3P-II analyzed in Example 1 and molybdenum oxide were co-deposited on the first electrode 1101 by an evaporation method using resistance heating. A hole injection layer 1111 was formed. The film thickness was 50 nm, and the weight ratio of DBT3P-II and molybdenum oxide was adjusted to 4: 2 (= DBT3P-II: molybdenum oxide).

Next, DBT 3 of Sample 2 analyzed again in Example 1 on the hole injection layer 1111.
P-II was formed to a thickness of 10 nm to form a hole transport layer 1112.

Further, CzPA and 1,6 mM emFLPAPrn were co-evaporated to form a hole transport layer 111.
A light emitting layer 1113 was formed on the substrate 2. Where CzPA and 1,6 mM emFLPAPr
The mass ratio of n was adjusted to be 1: 0.05 (= CzPA: 1,6 mM emFLPAPrn). The thickness of the light emitting layer 1113 was set to 30 nm.

Next, after CzPA was formed to a thickness of 10 nm over the light-emitting layer 1113, bathophenanthroline (abbreviation: BPhen) was formed to a thickness of 15 nm to form the electron transport layer 1
114 was formed.

Further, lithium fluoride (LiF) was vapor-deposited with a thickness of 1 nm on the electron transport layer 1114 to form an electron injection layer 1115.

Lastly, as the second electrode 1103 functioning as a cathode, aluminum was deposited to a thickness of 200 nm, whereby the light-emitting element 3 of this example was manufactured.

(Light emitting element 4)
The hole injection layer 1111 of the light-emitting element 4 is the DBT3 of sample 6 analyzed in Example 2.
It was formed by co-evaporation of P-II and molybdenum oxide. The film thickness is 50 nm and D
The ratio of BT3P-II to molybdenum oxide was adjusted to be 4: 2 (= DBT3P-II: molybdenum oxide) by weight.

Next, DBT3 of sample 6 analyzed again in Example 2 on the hole injection layer 1111.
P-II was formed to a thickness of 10 nm to form a hole transport layer 1112.

Except for the hole-injection layer 1111 and the hole-transport layer 1112, the light-emitting element 3 was manufactured.

  Note that, in the above-described vapor deposition process, the vapor deposition was all performed by a resistance heating method.

Table 11 shows element structures of the light-emitting elements 3 and 4 obtained as described above.

After performing the operation | work which sealed the light emitting elements 3 and 4 so that a light emitting element might not be exposed to air | atmosphere in the glove box of nitrogen atmosphere, the operating characteristic of the light emitting elements 3 and 4 was measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

FIG. 27 shows luminance-current efficiency characteristics of the light-emitting elements 3 and 4. In FIG. 27, the horizontal axis represents luminance (
cd / m ² ), and the vertical axis represents current efficiency (cd / A). The voltage-current characteristics are shown in FIG. In FIG. 28, the horizontal axis represents voltage (V) and the vertical axis represents current (mA). In addition, FIG. 29 shows luminance-chromaticity coordinate characteristics. In FIG. 29, the horizontal axis represents luminance (cd / m ² ), and the vertical axis represents chromaticity coordinates (x coordinate or y coordinate). Further, FIG. 30 shows luminance-power efficiency characteristics. FIG.
, The horizontal axis represents luminance (cd / m ² ) and the vertical axis represents power efficiency (lm / W). Further, the voltage (V) and current density (mA) of the light-emitting elements 3 and 4 when the luminance is around 1000 cd / m ^2.
/ Cm ² ), CIE chromaticity coordinates (x, y), luminance (cd / m ² ), current efficiency (cd / A),
Table 12 shows the external quantum efficiency (%).

In addition, FIG. 31 shows an emission spectrum obtained when a current of 1 mA was passed through the light-emitting elements 3 and 4.
In FIG. 31, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity (arbitrary unit). As shown in FIG. 31 and Table 12, the CIE chromaticity coordinates of the light-emitting element 3 when the luminance is around 1000 cd / m ² are (x, y) = (0.15, 0.22). CIE chromaticity coordinates are (x, y
) = (0.15, 0.21). From this result, it was found that both of the light-emitting elements 3 and 4 obtained blue light emission derived from 1,6 mM emFLPAPrn, which is the emission center substance.

From the results of the light-emitting element 3 and the light-emitting element 4 illustrated in FIGS. 27 and 28, it was found that impurities contained in DBT3P-II (abbreviation) do not affect the voltage-current characteristics and the luminance-current efficiency characteristics. .

In addition, although DBT3P-II (sample 2) of the light emitting element 3 was degassed during vapor deposition,
There was no degassing in DBT3P-II (sample 6) of the light-emitting element 4.

Next, a reliability test of the light-emitting element 3 and the light-emitting element 4 was performed. The result of the reliability test is shown in FIG.
Shown in In FIG. 32, the vertical axis represents normalized luminance (%) when the initial luminance is 100%, and the horizontal axis represents element driving time (h). The reliability test is performed at room temperature and the initial luminance is 5000.
The light emitting element of this example was driven under the condition of cd / m ² and constant current density.

From FIG. 32, it was 2 hours that the light emitting element 3 maintained 50% of the initial luminance, and 170 hours that the light emitting element 4 maintained 65% of the initial luminance. As a result of this reliability, the light-emitting element 3 manufactured using DBT3P-II (abbreviation) containing impurities has low reliability, and the light-emitting element manufactured using DBT3P-II (abbreviation) containing no impurities. 4 was found to be a highly reliable element.

From the above results, by setting the bromine contained in the sample 2 analyzed in Example 1 of the light emitting element 3 to the detection limit as in the sample 6 analyzed in Example 2 of the light emitting element 4, It was found that a highly reliable element can be manufactured.

In particular, it has been found that the reliability can be greatly improved by setting the halide as the detection limit in the layer adjacent to the light emitting layer.

(Reference Example 1)
In this reference example, 4,4 ′, 4 ″-(benzene-1,3,5-triyl) tridibenzothiophene (abbreviation: DBT3P-II) represented by the following structural formula used in Examples 1 to 7 above. A synthesis example of is shown.

[Synthesis Method of 4,4 ′, 4 ″-(Benzene-1,3,5-triyl) tridibenzothiophene (abbreviation: DBT3P-II)]

100 g (0.44 mol) of 4-dibenzothiopheneboronic acid and 46 g (0.15
mol) of 1,3,5-tribromobenzene and 3.03 g (10 mmol) of tris (
2-methylphenyl) phosphine, 449 g (20 mmol) of palladium (II) acetate
3.10 g (22.4 mmol) of potassium carbonate was added to a 2000 mL three-necked flask.

To this mixture, 500 mL of toluene, 200 mL of ethanol, and 273 mL of pure water were added and stirred. The mixture was degassed and refluxed at 110 ° C. for 12 hours. After allowing to cool to room temperature, the liquid in the reaction vessel is separated into an organic layer and a water tank with a separatory funnel, and the organic layer is washed twice with water and once with saturated brine, dried by adding magnesium sulfate. And then filtered. The filtrate was concentrated to obtain 9.98 g of a solid.

Sublimation purification of 6.99 g of the obtained DBT3P-II solid was performed by a train sublimation method. Sublimation purification is performed under the conditions of a pressure of 2.3 Pa and an argon flow rate of 10 mL / min.
T3P-II was heated at 370 ° C. After sublimation purification, the solid of DBT3P-II was 5.5.
Obtained 7 g, 79.7% recovery.

In addition, 2.99 g of DBT3P-II solid that had been subjected to sublimation purification was subjected to a second sublimation purification by a train sublimation method. Sublimation purification is performed at a pressure of 2.0 Pa and an argon flow rate of 10
DBT3P-II was heated at 350 ° C. under the conditions of mL / min. Sublimation purified DB
2.12 g of T3P-II solid was obtained with a recovery rate of 70.8%.

  The synthesis scheme of the above step is shown in (a-1) below.

DESCRIPTION OF SYMBOLS 1100 Substrate 1101 1st electrode 1102 EL layer 1103 2nd electrode 1111 Hole injection layer 1112 Hole transport layer 1113 Light emitting layer 1114 Electron transport layer 1115 Electron injection layer

Claims (3)

Synthesize materials for light emitting devices via organic halides,
After purifying the light-emitting element material until the content of the reaction by-product contained in the light-emitting element material and the halide content of the raw material for synthesizing the light-emitting element material is 3% or less, By performing sublimation purification treatment on a light emitting device material, the content of the halide of the light emitting device material produced by the sublimation purification treatment is 0.1% or less. Synthesis method.   2. The light emitting device according to claim 1, wherein the content of the halide in the raw material for synthesizing the reaction by-product and the light emitting device material contained in the light emitting device material is 3% or less. A method for synthesizing a material for a light-emitting element, wherein the material is purified at 350 ° C. or lower.   3. The luminescence according to claim 1, wherein ultrahigh performance liquid chromatograph time-of-flight mass spectrometry (UPLC / TOF-MS) is used for measuring the content of the reaction by-product and the halide of the raw material. A method for synthesizing element materials.