WO2007064009A1

WO2007064009A1 - Light emitting element, light emitting device and electronic device

Info

Publication number: WO2007064009A1
Application number: PCT/JP2006/324142
Authority: WO
Inventors: Yuji Iwaki; Hisaso Ikeda; Junichiro Sakata; Satoshi Seo; Tomoya Aoyama; Takahiro Kawakami; Masahiko Hayakawa; Yumiko Fujiwara; Koichiro Kamata; Ryoji Nomura
Original assignee: Semiconductor Energy Laboratory Co., Ltd.
Priority date: 2005-11-30
Filing date: 2006-11-28
Publication date: 2007-06-07

Abstract

Provided are a light emitting element, a light emitting device and an electronic device, which use a compound material wherein charges are moved to the d orbital of a metal atom of a metal oxide from the p orbital of an atom in an organic compound. Since the compound material has a high conductivity, a drive voltage can be reduced even when the compound is used as a thick buffer layer. Therefore, power consumption of the light emitting element is reduced and generation of defects is suppressed.

Description

LIGHT EMITTING ELEMENT, LIGHT EMITTING DEVICE, AND ELECTRONIC DEVICE

[0 0 0 1]

The present invention relates to a current excitation type light emitting element. In addition, the present invention relates to a light-emitting device and an electronic device having a light-emitting element.

[Background]

[0 0 0 2]

In recent years, research and development of light-emitting elements using light-emitting organic compounds have been actively conducted. The basic structure of these light-emitting elements is such that a layer containing a light-emitting organic compound is sandwiched between a pair of electrodes. By applying a voltage to this element, electrons and holes are each injected from the pair of electrodes into the layer containing a light-emitting organic compound, and a current flows. Then, these carriers (electrons and holes) recombine, so that the luminescent organic compound forms an excited state, and emits light when the excited state returns to the ground state. Due to such a mechanism, such a light-emitting element is called a current-excitation light-emitting element.

[0 0 0 3]

Note that the types of excited states formed by organic compounds can be singlet excited states and triplet excited states. Light emission from singlet excited states is called fluorescence, and light emission from triplet excited states is called phosphorescence. ing.

[0 0 0 4]

Since such a light emitting element is formed of, for example, an organic thin film of about 0.1 im, it is a great advantage that it can be manufactured in a book-type lightweight. Also, since the time from carrier injection to light emission is about 1 / second or less, the response speed is very high. One of the features is that it is fast. These characteristics are considered suitable for flat panel display elements.

[0 0 0 5]

In addition, since these light-emitting elements are formed in a film shape, planar light emission can be easily obtained by forming a large-area element. This is a feature that is difficult to obtain with a point light source typified by an incandescent bulb or LED, or a line light source typified by a fluorescent lamp, and therefore has a high utility value as a surface light source that can be applied to lighting.

[0 0 0 6]

However, there is a reduction in power consumption as an issue for the practical application of light-emitting elements. There are two methods for reducing power consumption: improving current efficiency and reducing drive voltage. As a method for reducing the drive voltage, a method using a PIN structure has been reported (see Non-Patent Document 1).

[0 0 0 7]

PIN devices consist of a P-doped layer and an N-doped layer, and many researchers are searching for the best donor receptor and host.

[0 0 0 8]

Another issue for the practical application of light-emitting elements is short-circuiting between electrodes. The short between electrodes is caused by fine particles remaining on the substrate. Since the thickness of the thin film of the light emitting element is usually about 0.1 m, even a fine particle of about 0.1 m easily causes a short circuit between the electrodes. Since the light emitting element in which the short-circuit between the electrodes has occurred cannot emit light, these are recognized as saddle points. For example, when the light-emitting element is used as a flat panel display element, such a defect greatly reduces the commercial value of the display panel, resulting in an increase in panel cost.

[0 0 0 9]

One of the methods for preventing these inter-electrode shorts is to increase the thickness of the buffer layer. However, since many organic compounds have low conductivity, the power consumption of the light-emitting element increases by increasing the thickness.

[Non-Patent Document 1]

J an B irnstock, eta 1., Fu lly Or an ic PIN OLED s wi th H i gh Powe r E fficie nc y, L ifet ime, and Therma l Stability ", Eu roD isp 1 ay 2005, 195 (2005)

DISCLOSURE OF THE INVENTION

[Problems to be solved by the invention]

[0010]

Accordingly, the present invention provides a novel light-emitting element that can simultaneously reduce power consumption and suppress the occurrence of defects. We also provide light-emitting devices and electronic devices that can simultaneously reduce power consumption and suppress defects.

[Means for Solving the Problems]

[001 1]

As a result of intensive studies, the present inventors have found that the problem can be solved by using a composite of an organic compound and a metal oxide formed from an organic compound and a metal oxide.

[0012]

That is, one aspect of the present invention includes a complex using an organic compound and a metal oxide, and a charge is transferred from a ρ orbit of an atom in the organic compound to a d orbit of a metal atom of the metal oxide. It is a light emitting element characterized by the above.

[0013]

In the above structure, the metal atom is preferably a transition metal. Further, a metal belonging to Groups 4 to 8 in the element periodic table is preferable. Especially with molybdenum Preferably there is.

[0 0 1 4]

In the above structure, the organic compound is preferably an aromatic amine compound. When the organic compound is an aromatic amine compound, the charge is transferred from the p orbital of the nitrogen atom of the aromatic amine compound.

[0 0 1 5]

In the above structure, the organic compound is preferably an aromatic hydrocarbon. '

[0 0 1 6]

The present invention also includes a light emitting device having the above-described light emitting element.

[0 0 1 7]

Another aspect of the present invention includes a pixel including a composite including an organic compound and a metal oxide, and the number of increased pixel defects after driving at 85 for 60 hours is 0. 0 8 7% or less.

[0 0 1 8]

Another aspect of the present invention includes a pixel including a composite including an organic compound and a metal oxide, and the increase in pixel defects after driving for 60 hours at −40 is 0% of the total number of pixels. 0 8 7% or less of a light emitting device.

[0 0 1 9]

Another aspect of the present invention includes a pixel including a composite including an organic compound and a metal oxide. After driving for 85 hours for 4 hours and for 400 hours for 4 hours, driving for 60 hours The light emitting device is characterized in that the increase in the number of pixel defects is 0.087% or less of the total number of pixels. '

[0 0 2 0]

In addition, one aspect of the present invention includes a pixel having a complex using an organic compound and a metal oxide. The light emitting device is characterized in that the number of pixel defects after driving for 4 hours at 85: 4, driving for 4 hours at 1 and 40 hours is less than 3 per 1000 mm ^{2 of} display area. .

[0021]

In addition, one aspect of the present invention includes a layer including a complex using an organic compound and a metal oxide, and a layer including a complex including the organic compound and the metal oxide according to the emission color of each pixel. The light-emitting device is characterized in that the film thicknesses are different.

[0022]

Note that a light-emitting device in this specification includes an image display device, a light-emitting device, or a light source (including a lighting device). In addition, a module in which a connector, for example, FPC (Flexible Printed Circuit) or TAB (Tape Automated Bonding) tape or TC P (Tae Carrier Package) is attached to the light emitting element, All modules that have a printed wiring board on the end of TAB tape or TCP, or modules that have ICs (integrated circuits) directly mounted on the light-emitting elements using the COG (Ch i On G 1 ass) method are included in the light-emitting device. .

[0023]

In addition, an electronic device using the light-emitting element of the present invention for the display portion is also included in the category of the present invention. Therefore, an electronic apparatus of the present invention includes a display unit, and the display unit includes the above-described light emitting element and a control unit that controls light emission of the light emitting element.

【The invention's effect】

[0024]

Since the composite of the organic compound and the metal oxide used for the light-emitting element of the present invention has high conductivity, the driving voltage can be reduced even when used as a thick buffer layer. Thus, power consumption of the light emitting element can be reduced. [0 0 2 5]

In addition, the formation of defects can be suppressed by forming a thick buffer layer using a composite of an organic compound and a metal oxide.

[0 0 2 6]

Thus, a light-emitting element, a light-emitting device, and an electronic device in which power consumption is reduced and generation of defects is suppressed can be provided.

[Brief description of the drawings]

[0 0 2 7]

FIG. 1 illustrates a light-emitting element of the present invention.

FIG. 2 illustrates a light-emitting element of the present invention.

FIG. 3 illustrates a light-emitting element of the present invention.

FIG 4 illustrates a light-emitting element of the present invention.

FIG 5 illustrates a light-emitting element of the present invention.

FIG. 6 illustrates a light-emitting element of the present invention.

FIG. 7 illustrates a light-emitting device of the present invention.

FIG. 8 illustrates a light-emitting device of the present invention.

FIG. 9 illustrates an electronic device using the light-emitting device of the present invention.

FIG. 10 illustrates a light-emitting device of the present invention.

FIG. 1 illustrates a light-emitting element of the present invention.

[Fig. 1 2] A graph showing the voltage-current density characteristics of a film containing a composite of an organic compound and a metal oxide.

FIG. 13 shows an absorption spectrum of a film containing a composite of an organic compound and a metal oxide. FIG. 14 shows calculation results of a film containing a composite of an organic compound and a metal oxide.

FIG. 15 shows calculation results of a film containing a composite of an organic compound and a metal oxide. FIG 16 illustrates a light-emitting element of the present invention.

FIG. 17 is a graph showing voltage vs. current density characteristics of a light-emitting element in which the thickness of a layer containing a composite of an organic compound and a metal oxide is changed.

FIG. 18 illustrates a light-emitting element of the present invention. .

FIG. 19 is a graph showing voltage-luminance characteristics of the light-emitting element of the present invention.

FIG. 20 is a graph showing a change in normalized luminance time of the light-emitting element of the present invention.

FIG. 21 is a graph showing voltage-luminance characteristics of the light-emitting element of the present invention.

FIG. 22 shows a change in normalized luminance time of the light-emitting element of the present invention.

FIG. 23 illustrates a light-emitting element of the present invention.

FIG. 24 is a diagram showing the calculation results of atomic charges of N P B molecules.

FIG. 25 is a graph showing current density-luminance characteristics of a light-emitting element of the present invention.

FIG. 26 shows the luminance and current efficiency of the panel of the present invention.

FIG. 27 is a graph showing the film thickness dependence of a layer containing a composite of an organic compound and a metal oxide with increased point defects in the panel of the present invention.

FIG. 28 is a diagram showing an increased number of point defects in various environmental operation tests of the panel of the present invention. FIG. 29 is a diagram showing a cross-sectional TEM photograph of a point defect portion.

FIG. 30 is a diagram showing an ESR measurement result of a composite of an organic compound containing DNTPD and molybdenum oxide and a metal oxide.

FIG. 31 shows ESR measurement results of a DNTPD single film.

FIG. 32 is a diagram showing the ESR measurement results of a molybdenum oxide single film.

FIG. 33 shows a ¹ H-NMR chart of N, N′-bis (spiro-1,9′-bifluorene-1-yl) 1 N, N′-diphenylbenzidine.

Fig. 34 shows a DSC chart of N, N '-bis (9,9, 1 bifluorene-2-yl on spiro) — N, Ν' -diphenylbenzidine. BEST MODE FOR CARRYING OUT THE INVENTION

[0028]

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 it is easily understood by those skilled in the art that modes and details can be variously changed 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.

[0029]

(Embodiment 1)

In this embodiment mode, a composite of an organic compound and a metal oxide used for the light-emitting element of the present invention will be described. In this specification, the term “composite” means that not only two materials are mixed but also mixed at a molecular level so that charge can be transferred between the materials. .

[0030]

A composite of an organic compound and a metal oxide used for the light-emitting element of the present invention includes an organic compound and a metal oxide. As the organic compound, various compounds such as aromatic amine compounds, carbazol derivatives, aromatic hydrocarbons, and high molecular compounds (oligomers, dendrimers, polymers, etc.) can be used. The organic compound is preferably an organic compound having a high hole transporting property. Specifically, it is preferable to use a substance having a hole mobility of more than 10- ⁶ cm ² ZVs. However, other substances may be used as long as they have a property of transporting more holes than electrons. In the following, organic compounds that can be used in the complex of organic compound and metal oxide are specifically listed.

[0031]

For example, aromatic amine compounds include 4,4'-bis [N— (1_naphthyl) -N-phenylamino] biphenyl (abbreviation: NPB), 4, 4'-bis [N- (3 monomethylphenyl). ) 1 N-phenylamino] Biphenyl (abbreviation: TPD), 4, 4 ', 4 ', thoris (Ν, Ν-diphenylamino) 卜 phenylamine (abbreviation: TDA 略), 4, 4', 4 ', thoris [Ν- (3-methylphenyl) Ν-phenylamine] triphenylamine (abbreviation) : MTDATA), 4, 4'-bis [Ν-phenyl-Ν- (spirofluorene 2-yl)] biphenyl (abbreviation: BSPB).

[0032]

In addition, by using the organic compound shown below, a complex of an organic compound and a metal oxide having no absorption peak can be obtained in the wavelength region of 450 nm to 800 nm.

0033

Aromatic amines contained in complexes of organic compounds and metal oxides that do not have an absorption peak in the wavelength range of 450 nm to 800 nm include N, N '-di (p-tolyl) -N, N' —Diphenyl—p-phenylenediamine (abbreviation: DTDPPA), 4, 4, 1bis [N— (4-diphenylaminophenyl) 1 N-phenylamino] biphenyl (abbreviation: DPAB), 4, 4 '—Bis (N— {4— [N— (3-Methylphenyl) 1 N-phenylamino] Phenyl} —N-phenylamino) Biphenyl (abbreviation: DNTPD), 1, 3, 5—Tris [ N- (4-diphenylaminophenyl) 1 N-phenylamino] benzene (abbreviation: DP A3 B), and the like can be given.

[0034]

Specific examples of force rubazole derivatives that can be used in composites of organic compounds and metal oxides include 3— [N- (9-phenylcarbazol-luyl 3-yl) -N-phenylamino. ] — 9-phenylcarbazol (abbreviation: PC z PCA 1), 3, 6_bis [N— (9-phenylcarbazole-3-yl) —N-phenylamino] 1-9 phenylcarbazole ( Abbreviations: PCz PCA2), 3— [N- (1-Naphtyl) -N- (9_phenylcarbazole—3-yl) amino] 1 9 1-phenylcarbazo (Abbreviation: PCz PCNl).

[0035]

In addition, 4, 4'-di (N—force rubazolyl) biphenyl (abbreviation: CBP), 1, 3, 5— 卜 lith [4_ (N-carbazolyl) phenyl] benzene (abbreviation: TCPB), 9-[ 4- (N-carbazolyl)] phenyl 10-phenylanthracene (abbreviation: C z PA), 2, 3, 5, 6-triphenyl-1,1,4-bis [4- (N-carbazolyl) phenyl] Benzene or the like can be used.

[0036]

Aromatic hydrocarbons that can be used in composites of organic compounds and metal oxides include, for example, 9, 10-di (naphthenylene-2-yl) — 2-tert-butylanthracene ( Abbreviations: t-BuDNA), 9, 10-di (naphtholene 1-yl) 1 2-tert-butylanthracene, 9, 10-bis (3,5-diphenylphenyl) anthracene (abbreviation: DPPA) , 9, 10-di (4-Ferphenyl) 1 2-tert-butylanthracene (abbreviation: t-BuDBA), 9, 10-di (naphthalene 2-yl) anthracene (abbreviation: DNA), 9 , 10-Diphenylanthracene (abbreviation: DPAn th), 2-tert-ptylanthracene (abbreviation: t- BuAnth), 9, 10-di (4-methylnaphthalene 1-yl) anthracene (abbreviation: DMNA), 2-tert-butyl-1,9-bis [2- (naphthalene-1-yl) phenyl] Nthracene, 9, 10-bis [2- (Naphthalene 1-yl) phenylene chloride] Anthracene, 2, 3, 6, 7-Tetramethyl-9, 10-di (Naphthalene-1-yl) Anthracene, 2, 3, 6, 7-Tetramethyl-9,10-di (Nafu Ren 1-yl) Anthracene, 9, 9 '—Bianthryl, 10, 10' —Diphenyl 9,9 '—Biantri J, 10 · , 10 '-di (2-phenylphenyl) 1,9,9' _Bianthryl, 10, 10, one bis [(2, 3, 4, 5, 6-Peneven phenyl) phenyl] 1,9,9 '-Bianthryl, Anthracene, tetracene, rubrene, pen Rylene, 2, 5, 8, 11-tetra (tert-butyl) perylene. In addition, Pen Yusen and Coronene can also be used. Thus, IX 10- ⁶ cm ² has a ZV s or hole mobility is more preferably an aromatic hydrocarbon which has 14 to 42 carbon atoms.

[0037]

Note that the aromatic hydrocarbon that can be used for the composite of the organic compound and the metal oxide may have a Biel skeleton. Examples of aromatic hydrocarbons having a vinyl group include 4, 4 'monobis (2, 2-diphenylvinyl) biphenyl (abbreviation: DPV B i), 9, 10-bis [4— (2 , 2-diphenylvinyl) phenyl] anthracene (abbreviation: DPVPA).

[0038]

Alternatively, a high molecular compound such as poly (N-vinylcarbazole) (abbreviation: PVK) or poly (4_vinyltriphenylamine) (abbreviation: PVTPA) can be used.

[0039]

Further, as the metal oxide used for the composite of the organic compound and the metal oxide, a transition metal oxide is preferable. In addition, an oxide of a metal belonging to Groups 4 to 8 in the periodic table is preferable. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide are preferable because of their high electron-accepting properties. Among these, molybdenum oxide is particularly preferable because it is stable in the air, has a low hygroscopic property, and is easy to handle.

[0040]

As a method for forming a complex of an organic compound and a metal oxide, any method may be used regardless of a wet method or a dry method. For example, a composite of an organic compound and a metal oxide can be manufactured by co-evaporating the organic compound and the metal oxide described above. In addition, a solution containing the above-described organic compound and metal alkoxide is applied and fired. Thus, a composite of an organic compound and a metal oxide can be produced. Note that when a composite of an organic compound and a metal oxide is formed by a co-evaporation method, molybdenum oxide is preferable from the viewpoint of a manufacturing process because molybdenum oxide is easily evaporated in a vacuum.

[0041]

In order to confirm that the composite of the organic compound and metal oxide used in the light-emitting element of the present invention exhibits high conductivity, resistivity was measured.

[0042]

A film containing a composite of organic compound and metal oxide was formed by co-evaporation of NPB and molybdenum oxide (VI), and the resistivity was measured. The thickness of the film containing the complex of organic compound and metal oxide is 200 nm, and the ratio of NPB and molybdenum oxide contained in the film containing the complex of organic compound and metal oxide is NPB: Molybdenum oxide was adjusted to be 1: 0.25. 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.

[0043]

The resistivity of the film containing a composite of an organic compound and a metal oxide using NPB and molybdenum oxide was 3 × 10 ⁵ Ω · cm. In other words, the resistivity of a film containing a composite of an organic compound and a metal oxide is very small compared to other organic layers. This feature makes it possible to increase the thickness of the device and prevent short-circuiting of the device. In addition, it is easy to obtain a film thickness that is suitable for optical design using Sengen.

[0044]

In addition, as a composite of an organic compound and a metal oxide, Device 1 was manufactured using a film containing a composite of an organic compound and a metal oxide in which NPB and molybdenum oxide were mixed. Was measured. Figure 12 shows the voltage-current density characteristics of element 1. For comparison, the IV characteristics of Comparative Element 2 using an NPB film and Comparative Element 3 using a molybdenum oxide film were also measured. [0045]

Element 1 was fabricated by the following method. An organic compound is formed by depositing indium oxide-tin oxide (ITO) on a glass substrate and co-depositing NPB and molybdenum oxide (VI) on the ITO. And a metal oxide composite film were formed. The film thickness of the layer containing the composite of the organic compound and the metal oxide is 200 nm, and the ratio of NPB and molybdenum oxide contained in the film containing the composite of the organic compound and the metal oxide is as follows: NPB: Molybdenum oxide was adjusted to 1: 0.375. Then, aluminum (A 1) was formed over the film containing the composite of the organic compound and the metal oxide, and device 1 was manufactured.

[0046]

In Comparative Element 2, an NPB film having a thickness of 200 nm was formed instead of the film containing the complex of the organic compound and metal oxide of Element 1.

[0047]

In Comparative Element 3, a molybdenum oxide film having a thickness of 7 Onm was formed instead of the film containing the complex of the organic compound and metal oxide of Element 1.

[0048]

The voltage-current density characteristics of element 1, comparative element 2, and comparative element 3 are shown in FIG. Comparing comparative element 2 using an NPB film and element 1 using a composite of an organic compound and a metal oxide, it can be seen that the resistance is extremely low by incorporating molybdenum oxide. 10111 eight (: 111 ² o'clock, the resistance became about 1/100.

[0049]

In addition, as can be seen from FIG. 12, a film containing a composite of an organic compound and a metal oxide can have an almost ohmic electrode contact.

[0050]

A film containing a composite of an organic compound and a metal oxide can be forward-biased and reverse-biased. It was found that the characteristics did not change. In addition, the film containing a composite of organic compound and metal oxide had a lower resistance than the NPB film as well as the molybdenum oxide film.

[0051]

FIG. 13 shows absorption spectra of a film containing a composite of an organic compound in which NPB and molybdenum oxide are mixed and a metal oxide, and an NPB film and a molybdenum oxide film.

[0052]

A film containing a composite using NPB and molybdenum oxide was manufactured by the following method. A film containing a composite of an organic compound and a metal oxide was formed by co-evaporation of NPB and molybdenum oxide (VI) on a stone substrate. The ratio of NPB and molybdenum oxide contained in the film containing the composite of the organic compound and the metal oxide was adjusted so that the weight ratio was NPB: molybdenum oxide = 1: 1.

[0053]

In Comparative Element 5, an N PB film was formed instead of a composite film of an organic compound and a metal oxide.

[0054]

In Comparative Element 6, a molybdenum oxide film was formed instead of a composite film of an organic compound and a metal oxide.

[0055]

As shown in Fig. 13, in the absorption spectrum of a complex of an organic compound composed of NPB and molybdenum oxide and a metal oxide, absorption is observed around 500 nm and around 1300 nm. These absorptions are not found in individual materials. This suggests that there is a charge transfer from NPB to molybdenum oxide. '

[0056]

Figure 30 shows the ESR spectrum of the complex of organic compound and metal oxide. [0057]

Aromatic amine compound 4, 4 'monobis (N-{4- [N- (3-methylphenyl) 1 N-phenylamino] phenyl} -N-phenylamino) by co-evaporation on a quartz substrate A layer containing biphenyl (abbreviation: DNTPD) and molybdenum oxide was formed to a thickness of 200 nm. At this time, co-evaporation was performed so that the ratio of DNTPD to molybdenum oxide was 1: 0.5 by weight. An ESR (electron spin on electron spin) measurement of the layer containing DNTPD and molybdenum oxide was performed. In ESR measurement, a strong magnetic field is applied to a sample with unpaired electrons, the energy level of unpaired electrons causes Zeman splitting, and the resonance absorption transition of microwaves, which is the energy difference between the levels, is measured. This is the measurement method used. In this ESR measurement, the presence of unpaired electrons and the spin state can be determined by measuring the frequency at which absorption occurs and the strength of the magnetic field. In addition, the electron spin concentration can be obtained from the absorption intensity. In this measurement, an electron spin resonance analyzer, J ES—TE200 (manufactured by JEOL), was used. Resonance frequency 9.3 GHz, modulation frequency 100 kHz, modulation width 0.63 mT, amplification factor 50, time constant 0.1 sec, microwave input 1 mW, sweep time 4 min, measurement temperature was room temperature. Note that manganese supported on magnesium oxide was used as a magnetic field calibration sample. Figure 30 shows the ESR measurement results. As comparative examples, ESR measurements were also performed on DNTPD single films (thickness 200 nm) and molybdenum oxide single films (thickness 200 nm). Figure 31 shows the ESR measurement results of the DNTPD single film, and Figure 32 shows the ESR measurement results of the molybdenum oxide single film.

[0058]

From Fig. 30 to Fig. 32, ESR signal was not detected in the DNTPD single film and molybdenum oxide single film, but ESR signal was detected in the layer containing DNTPD and molybdenum oxide. From this, it was found that the layer containing DNTPD and molybdenum oxide has unpaired electrons. In other words, including DNTPD and molybdenum oxide The layers were found to be in different electronic states from the DNTPD and molybdenum oxide single films. From FIG. 30, the g value of the layer containing DNTPD and molybdenum oxide is 2.0 0 25, which is very close to 2.0 0 2 3 which is the free electron g value. all right. On the other hand, the line width was found to be very narrow at 0.77 mT.

[0 0 5 9]

As can be seen from Fig. 30, an ESR signal is observed in the complex of organic compound and metal oxide. Therefore, these phenomena are evidence of the charge transfer. In other words, N P B and molybdenum oxide are considered to form a charge transfer complex. When the charge transfer complex is formed, the carrier concentration in the film increases and the resistance decreases. Therefore, it is considered that a composite of an organic compound and a metal oxide gives excellent conductivity.

[0 0 6 0]

Moreover, the fact that the current-voltage characteristics of the forward bias and reverse bias of the element 3 using a composite of an organic compound and a metal oxide are the same can be explained by the higher carrier density concentration. In the above device structure, the anode is different between I T O and A 1 in the forward and reverse directions. Since the work function of A 1 is smaller than that of I T O, no current flows in the reverse bias even though the current flows in the forward bias in the N P B film. However, in the case of a film containing a composite of an organic compound and a metal oxide, the carrier density concentration is high, so that carriers move between the anode and the film containing a composite of an organic compound and a metal oxide, and the anode Even when A 1 is selected, the injection barrier is reduced. Therefore, holes can be injected efficiently. That is, in the case of a film containing a composite of an organic compound and a metal oxide, since the work function dependence of the anode is small, various materials can be used as the anode. In other words, the electrode material can be selected without depending on the work function, and the range of options for the electrode material is expanded.

[0 0 6 1]

In order to elucidate the details of charge transfer in the complex of organic compound and metal oxide, we performed calculations using a supercomputer. As an initial model, three NPB molecules And two Mo class evenings composed of Mo ₅ 0 ₁₅ are used, and this is used as a T i gh t—B i nd i ng Qu ant t um Ch em ical Mo le cular Mo n d yn am ics C a 1 cu 1 Optimized by ation. The time for each step was 0.05 fs (femtosecond), and a total of 500,000 steps were calculated at a constant temperature and pressure. Figure 14 shows the optimized structure of a film containing a complex of organic compound and metal oxide. It can be seen that the NPB molecule and the molybdenum class are aggregated together. This is considered to contribute to smooth electron transfer.

[0062]

Similar calculations were performed for a single NPB molecule and a single cluster. Figure 15 shows the calculation results. Figure 15 shows the density of states of s-orbitals, p-orbitals, d-orbitals of molybdenum (Mo), and P-orbitals of oxygen (O).

[0063]

The electron acceptor level must be closest to the Fermi level and higher than the Fermi level. Figure 15 shows that molybdenum's s, p, d orbitals and oxygen P orbital satisfy this requirement. However, as shown in Fig. 15, it can be seen that the d-orbital of molybdenum has the highest density of states.

[0064]

We also calculated the atomic charge of NPB molecule. The semi-empirical molecular orbital calculation program MO PAC 2000 was used, and the atomic charge was calculated from the electrostatic potential of the molecular surface using EF PM5 PREC I SE ESP as a keyword. The results are shown in FIG. In the NPB molecule, the nitrogen atom was found to have the largest negative charge. Specifically, the two nitrogen atoms were found to have atomic charges of −0-6584 and −0.6323, respectively.

[0065] These results mean that the charge moves from the nitrogen atom of NPB to the d orbital of molybdenum. This means that the charge is moving from the p orbit of the atom in the organic compound to the d orbit of the metal atom of the metal oxide. As a result of this charge transfer, the number of carriers in the film containing a complex of an organic compound and a metal oxide is increased, and as a result, high conductivity is considered to be realized.

[0 0 6 6]

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

[0 0 6 7]

(Embodiment 2)

The light-emitting element of the present invention has a plurality of layers between a pair of electrodes. The plurality of layers are formed of a material or a carrier having a high carrier injection property so that a light emitting region is formed at a position away from the electrode, that is, a carrier (carrier) is recombined at a position away from the electrode. The layers are stacked by combining layers containing a substance having a high transportability.

[0 0 6 8]

One mode of the light-emitting element of the present invention will be described below with reference to FIG.

[0 0 6 9]

In this embodiment, the light-emitting element includes the first electrode 102, the first layer 103, the second layer 104, and the third layer stacked in order on the first electrode 102. The layer is composed of a layer 105, a fourth layer 106, and a second electrode 1007 provided thereon. In the present embodiment, the following description will be made on the assumption that the first electrode 102 functions as an anode and the second electrode 107 functions as a cathode.

[0 0 7 0]

The substrate 10 1 is used as a support for the light emitting element. As the substrate 101, for example, glass or plastic can be used. Note that other materials may be used as long as the light-emitting element functions as a support in the manufacturing process. [0071]

As the first electrode 102, various metals, alloys, electrically conductive compounds, and mixtures thereof can be used. For example, indium oxide-tin oxide (ITO), indium oxide-tin oxide containing silicon or silicon oxide, indium zinc oxide (I ZO: I nd i um Z inc) Xide), indium oxide containing tungsten oxide and zinc oxide (IW ZO), and the like. These conductive metal oxide films are usually formed by sputtering. For example, indium oxide-zinc oxide (I ZO) can be formed by a sputtering method using an evening get obtained by adding 1 to 20 wt% of zinc oxide to indium oxide. Indium oxide containing tungsten oxide and zinc oxide (I WZO) uses a target containing 0.5 to 5 wt% tungsten oxide and 0.1 to 1 wt% zinc oxide with respect to indium oxide. It can be formed by sputtering. In addition, gold (Au), platinum (P t), nickel (N i), tandasten (W), chromium (C r), molybdenum (1 ^ 0), iron (6), cobalt (Co), titanium (Ti), Copper (Cu), Palladium (Pd), Aluminum (Al), Aluminum-silicon (A1-Si), Aluminum-titanium (A1-Ti), Aluminum Mu-silicon- Copper (A l _S i—Cu) or a metal nitride (T i N) can be used. However, when the first electrode is used as the anode, the work function is large ( The work function is preferably 4.0 eV or more.

[0072]

Note that in the light-emitting element of the present invention, the first electrode 102 is not limited to a material having a high work function, and a material having a low work function can also be used.

[0073]

The first layer 103 is a buffer layer. That is, the layer includes the composite of the organic compound and the metal oxide described in Embodiment 1. [0074]

The second layer 104 is a layer containing a substance having a high hole-transport property. For example, 4, 4'-bis [N- (1-naphthyl) 1 N-phenylamino] biphenyl (abbreviation: NPB) and N, N'-bis (3-methylphenyl) 1 N, Ν '—Diphenyl— [1, 1, -biphenyl] —4, 4, azimin (abbreviation: TPD), 4, 4', 4 "—Tris (N, N-diphenylamino) Triphenylamine (abbreviation: TDATA ), 4, 4, 4 "— Tris [N— (3-Methylphenyl) 1 N-phenylamino] Triphenylamine (abbreviation: MTDATA) and other aromatic amines (ie, benzene ring-nitrogen And the like). The materials mentioned here are mainly 1 0— A substance having a hole mobility of s or more. However, any other substance may be used as long as it has a property of transporting more holes than electrons. In other words, various compounds such as aromatic amine compounds, strong rubazole derivatives, aromatic hydrocarbons, and high molecular compounds (oligomers, dendrimers, polymers, etc.) shown in Embodiment Mode 1 can be used. Note that the second layer 104 is not limited to a single layer, and may be a stack of two or more layers containing any of the above substances.

[0075]

The third layer 105 is a layer containing a substance having a high light-emitting property. Various materials can be used. For example, a highly luminescent substance, tris (8_ quinolinolato) aluminum (abbreviation: A 1 q), 9, 10 0-di (2-naphthyl) anthracene (abbreviation: DNA), 4, 4 '-bis [ N_ (1-Naphtyl) 1 N-Phenylamino] Biphenyl (abbreviation: NPB) and other materials with high carrier transport properties and good film quality (that is, difficult to crystallize) are freely combined. Specific examples of highly luminescent substances include N, N'-dimethylquinacridone (abbreviation: DMQd), N, N'-diphenylquinacridone (abbreviation: DPQd), and 3_ (2-benthothiazoyl). —Jetylaminocoumarin (abbreviation: Coumarin 6), 4— (Disanomethylene) — 2-Methyl-6 _ (p-Dimethyla) Minostyryl) 1 4H-pyran (abbreviation: DCM1), 4 1 (disyanomethylene) -2 —methyl 1 6— (julysine 1 4 1 ^ f lupinyl) —4H-pyran (abbreviation: DC M2), N, N— Singlet luminescent materials (fluorescent materials) such as dimethylquinacridone (abbreviation: DMQd), 9, 10-diphenylanthracene, 5,12-diphenyltetracene (abbreviation: DPT), coumarin 6, perylene, rubrene, and bis (2 — (2 '— Benzocheril) Pyridinato N, C ³ ') (Acetylasetonato) Iridium (abbreviation: I r (btp) ₂ (acac)) and other triplet light emitting materials (phosphorescent materials) Can be used. However, since A 1 Q and DNA are highly luminescent substances, these substances may be used alone and the third layer 105 may be used.

[0076]

The fourth layer 106 is a layer containing a substance having a high electron transporting property. For example, tris (8-quinolinolato) aluminum (abbreviation: A 1 q), tris (4-methyl-8_quinolinolato) aluminum (abbreviation: A 1 mq ₃ ), bis (1 0 —Hydroxybenzo [h] —quinolinato) Beryllium (abbreviation: BeBq ₂ ), Bis (2-methyl_8-quinolinolato) mono 4-phenylphenolatoaluminum (abbreviation: BA 1 Q), etc. And metal complexes having a nzoquinoline skeleton. In addition, bis [2- (2-hydroxyphenyl) monobenzoxazolate] zinc (abbreviation: Zn (BOX) ₂ ), bis [2- (2-hydroxyphenyl) monobenzothiazola 卜] zinc (abbreviation: Metal complexes having an oxazole-based or thiazole-based ligand such as Zn (BTZ) ₂ ) can also be used. In addition to metal complexes, 2- (4-biphenylyl) — 5— (4-tert-butylphenyl) — 1, 3, 4-oxazodiazole (abbreviation: PBD) and 1, 3-bis [5— (p— tert-butylphenyl) — 1, 3, 4— oxadiazo 2-ru benzene] (abbreviation: OXD— 7), 3— (4-tert-butylphenyl) 1 4- 1 phenyl Lou 5— (4 —biphenylyl) _ 1, 2, 4—triazole (abbreviation: TAZ), 3— (4— ter t-butylphenyl) _4— (4-ethylphenyl) —5— (4-biphenylyl) 1, 2, 4-triazole (abbreviation: p—E t TAZ), bathophenant mouth phosphorus (abbreviation: BPhen), Bathocuproine (abbreviation: BCP) can also be used. The substances mentioned here are Ru substance der having a predominantly 10- ⁶ cm ² ZV s or more electron mobility. Note that any substance other than the above substances may be used for the fourth layer 106 as long as it has a property of transporting more electrons than holes. The fourth layer 106 is not limited to a single layer, and may be a stack of two or more layers containing any of the above substances.

[0077]

As a material for forming the second electrode 107, a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like having a low work function (work function of 3.8 eV or less) can be used. Specific examples of such cathode materials include elements belonging to Group 1 or Group 2 of the Periodic Table of Elements, ie, alkali metals such as lithium (L i) and cesium (C s), and magnesium (Mg), calcium (Ca ), Alkaline earth metals such as strontium (Sr), and alloys containing these (Mg: Ag, A 1: Li). However, by providing a layer having a function of accelerating electron injection between the second electrode 107 and the light-emitting layer by stacking with the second electrode, regardless of the work function, Al, Ag, indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, indium oxide zinc oxide (I ΖΟ), indium oxide containing tandastene oxide and zinc oxide (IWZO) Various conductive materials such as the above can be used for the second electrode 107.

[0078]

Note that the layer that has the function of promoting electron injection is made of an alkali metal or an alkaline earth metal such as lithium fluoride (L i F), cesium fluoride (C s F), or calcium fluoride (CaF ₂ ). Compounds can be used. In addition, a layer made of a substance having an electron transporting property containing an alkali metal or an alkaline earth metal, for example For example, A 1 Q containing magnesium (Mg) can be used. [0 0 7 9]

Further, the formation method of the first layer 10 3, the second layer 1 0 4, the third layer 1 0 5, and the fourth layer 1 0 6 may be a method other than the above evaporation method. . For example, an ink jet method or a spin coat method may be used. In addition, each electrode or each layer may be formed using a different film formation method.

[0 0 8 0]

The light-emitting element of the present invention having the above structure is a layer containing a highly light-emitting substance in which current flows due to a potential difference generated between the first electrode 102 and the second electrode 107. In a certain third layer 10 5, holes and electrons recombine to emit light. That is, the light emitting region is formed in the third layer 105. However, it is not necessary for all of the third layers 105 to function as light emitting regions, for example, on the second layer 104 side or the fourth layer 106 side of the third layer 105. Only a light emitting region may be formed.

[0 0 8 1]

Light emission is extracted outside through one or both of the first electrode 102 and the second electrode 107. Accordingly, one or both of the first electrode 10 2 and the second electrode 10 7 are made of a light-transmitting substance. In the case where only the first electrode 10 2 is made of a light-transmitting substance, light emission is extracted from the substrate side through the first electrode 10 2 as shown in FIG. In addition, when only the second electrode 10 7 is made of a light-transmitting substance, as shown in FIG. 1 (b), light emission passes through the second electrode 10 7 and is opposite to the substrate. Taken from. When both the first electrode 1 0 2 and the second electrode 1 0 7 are made of a light-transmitting substance, as shown in FIG. 1 (c), light emission occurs in the first electrode 1 0 2 And through the second electrode 107 and taken out from the substrate side and both the substrate and the opposite side. [0 0 8 2]

Note that the structure of the layer provided between the first electrode 102 and the second electrode 107 is not limited to the above. In order to suppress quenching caused by the proximity of the light emitting region and the metal, a region where holes and electrons recombine is formed at a site away from the first electrode 102 and the second electrode 107. Any structure other than those described above may be used as long as the structure includes the layer including the composite material described in Embodiment 1.

[0 0 8 3]

In other words, there is no particular limitation on the layered structure of the layers, and a substance having a high electron transporting property or a substance having a high hole transporting property, a substance having a high electron injecting property, a substance having a high hole injecting property, a bipolar property (electron and positive A layer made of a substance having a high hole transporting property may be freely combined with a layer containing the composite material of the present invention. Further, a carrier recombination site may be controlled by providing a layer made of a silicon oxide film or the like over the first electrode 102.

[0 0 8 4]

The light-emitting element shown in FIG. 2 includes a first layer 30 3 containing a substance having a high electron-transport property on a first electrode 30 2 functioning as a cathode, and a second layer 3 containing a substance having a high light-emitting property. (4) Third layer containing a substance having a high hole-transport property 3 0 5, fourth layer containing a composite of the organic compound and metal oxide described in Embodiment 1 3 0 6, functioning as an anode The second electrode 3 07 is laminated in order. Reference numeral 3 0 1 denotes a substrate.

[0 0 8 5]

In this embodiment mode, a light emitting element is manufactured over a substrate made of glass, plastic, or the like. By manufacturing a plurality of such light-emitting elements over one substrate, a passive light-emitting device can be manufactured. Further, for example, a thin film transistor (TFT) may be formed over a substrate made of glass, plastic, or the like, and a light emitting element may be formed over an electrode electrically connected to the TFT. Thereby, the light emitting element by TFT An active matrix light-emitting device that controls driving of the light-emitting diode can be manufactured. The TFT structure is not particularly limited. A Sugaga type TFT or a reverse Suga type TFT can be used. Also, the drive circuit formed on the TFT array substrate may be composed of N-type and P-type TFTs, or may be composed of only one of N-type and P-type. . Further, there is no particular limitation on the crystallinity of a semiconductor film used for TFT. An amorphous semiconductor film may be used, or a crystalline semiconductor film may be used.

[0 0 8 6]

A light-emitting element of the present invention includes a layer including the composite of the organic compound and metal oxide described in Embodiment 1. A layer including a composite of an organic compound and a metal oxide has high conductivity due to the intrinsic generation of carriers. Therefore, low-voltage driving of the light-emitting element can be realized.

[0 0 8 7]

In addition, since a layer including a composite of an organic compound and a metal oxide used in the light-emitting element of the present invention is formed thickly without increasing driving voltage or power consumption, the composite of an organic compound and a metal oxide is used. By adjusting the thickness of the layer to be included, optical design utilizing the microcavity effect and the interference effect can be performed. Therefore, a light-emitting element with high color purity and low display quality depending on the viewing angle can be manufactured.

[0 0 8 8]

In addition, since the layer including the composite of the organic compound and the metal oxide used for the light-emitting element of the present invention has a high carrier density, it can be in ohmic contact with the electrode. That is, the contact resistance with the electrode is small. Therefore, the electrode material can be selected without considering the work function and the like, and the options for the electrode material are expanded.

[0 0 8 9] In addition, by applying the present invention, even an organic compound that could not be used as a carrier injection layer in the past is mixed with a metal oxide to form a composite of an organic compound and a metal oxide, thereby injecting a highly injectable carrier. Available as a layer. In other words, the range of selection of organic compounds is expanded. For example, a material having a high glass transition point (T g) but low conductivity can be used for a light-emitting element, and an element having high heat resistance can be manufactured.

[0 0 9 0]

In addition, by increasing the thickness of the layer containing a composite of an organic compound and a metal oxide, a short circuit due to minute foreign matter or impact can be prevented, so that a highly reliable light-emitting element can be obtained. . For example, the film thickness between electrodes of a normal light emitting element is 100 nm to 1550 nm, whereas the film thickness between electrodes of a light emitting element using a layer containing a composite material is The thickness may be from 500 nm, preferably from 200 nm to 500 nm.

[0 0 9 1]

In addition, since the layer including the composite of the organic compound and the metal oxide used in the light-emitting element of the present invention can be formed by vacuum deposition, any layer containing the light-emitting substance is formed by vacuum deposition. The layers can also be formed in the same vacuum apparatus, and the light emitting elements can be formed consistently in the vacuum. Therefore, it is possible to prevent the adhesion of minute foreign matters in the manufacturing process and improve the yield.

[0 0 9 2]

In addition, since the layer including the composite of the organic compound and the metal oxide used in the light-emitting element of the present invention includes the organic compound and the metal oxide, the stress generated between the electrode and the layer including the light-emitting substance. Can be relaxed.

[0 0 9 3]

[0 0 9 4]

(Embodiment 3) In this embodiment, a light-emitting element having a structure different from the structure shown in Embodiment 2 will be described with reference to FIGS. In the structure described in this embodiment, a layer including a composite of an organic compound and a metal oxide can be provided so as to be in contact with an electrode functioning as a cathode.

[0 0 9 5]

FIG. 5 (a) shows an example of the structure of the light emitting element of the present invention. A structure in which a first layer 4 1 1, a second layer 4 1 2, and a third layer 4 1 3 are stacked between a first electrode 4 0 1 and a second electrode 4 0 2; It has become. In this embodiment, the case where the first electrode 40 01 functions as an anode and the second electrode 40 2 functions as a cathode will be described.

[0 0 9 6]

The same structure as that in Embodiment Mode 2 can be applied to the first electrode 4 01 and the second electrode 40 2. In addition, the first layer 4 1 1 is a layer containing a substance having a high light-emitting property. The second layer 4 1 2 is a layer containing one compound selected from electron donating substances and a compound having a high electron transporting property, and the third layer 4 1 3 is described in Embodiment 1. The layer includes a composite of an organic compound and a metal oxide. The electron donating substance contained in the second layer 4 1 2 is preferably alkali metal or alkaline earth metal and oxides or salts thereof. Specific examples include lithium, cesium, calcium, lithium oxide, calcium oxide, barium oxide, and cesium carbonate.

[0 0 9 7]

With such a configuration, as shown in FIG. 5 (a), when a voltage is applied, electrons are exchanged near the interface between the second layer 4 1 2 and the third layer 4 1 3. The second layer 4 1 2 transports electrons to the first layer 4 1 1, while the third layer 4 1 3 transports holes to the second electrode 4 0 Transport to 2. That is, the second layer 4 1 2 and the third layer 4 1 3 together serve as a carrier generation layer. The third layer 4 1 3 has a function of transporting holes to the second electrode 40 2. Yeah.

[0098]

The third layer 413 exhibits extremely high hole injection property and hole transport property. Therefore, the driving voltage of the light emitting element can be reduced. In addition, when the third layer 413 is thickened, an increase in driving voltage can be suppressed.

[0099]

In addition, even if the thickness of the third layer 413 is increased, an increase in driving voltage can be suppressed, so the thickness of the third layer 413 can be set freely, and light emission from the first layer 41 1 can be prevented. The extraction efficiency can be improved. In addition, the film thickness of the third layer 413 can be set so that the color purity of light emission from the first layer 41 1 is improved.

[0100]

Further, taking FIG. 5A as an example, when the second electrode 402 is formed by sputtering, damage to the first layer 41 1 in which a light-emitting substance is present can be reduced. .

[0101]

Note that the light-emitting element of this embodiment also has various variations by changing materials of the first electrode 40.1 and the second electrode 402. The schematic diagram is shown in Fig. 5 (b), Fig. 5 (c) and Fig. 6. In FIG. 5 (b), FIG. 5 (c) and FIG. 6, the reference numerals in FIG. Reference numeral 400 denotes a substrate carrying the light emitting element of the present invention.

[0102]

FIG. 5 shows an example in which the first layer 411, the second layer 412, and the third layer 413 are configured in this order from the substrate 400 side. 'At this time, the first electrode 401 is made light transmissive and the second electrode 402 is made light-shielding (particularly reflective) so that light is emitted from the substrate 400 side as shown in Fig. 5 (a). It becomes. In addition, the first electrode 401 has a light shielding property (particularly By making the second electrode 402 light transmissive, light is emitted from the opposite side of the substrate 400 as shown in FIG. 5 (b). Furthermore, by making both the first electrode 401 and the second electrode 402 light transmissive, light is emitted to both the substrate 400 side and the opposite side of the substrate 400 as shown in FIG. 5 (c). The structure which performs is also attained.

[0103]

FIG. 6 shows an example in which the third layer 413, the second layer 412, and the first layer 411 are configured in this order from the substrate 400 side. At this time, the first electrode 401 is made light-shielding (particularly reflective) and the second electrode 402 is made light-transmissive so that light can be extracted from the substrate 400 side as shown in FIG. 6 (a). Become. In addition, by making the first electrode 401 light-transmissive and the second electrode 402 light-shielding (especially reflective), light can be extracted from the opposite side of the substrate 400 as shown in FIG. 6 (b). Become. Furthermore, by making both the first electrode 401 and the second electrode 402 light transmissive, light is emitted to both the substrate 400 side and the opposite side of the substrate 400 as shown in FIG. 6 (c). The structure which performs is also attained.

[0104]

Note that in the case of manufacturing the light-emitting element in this embodiment mode, various methods can be used regardless of a wet method or a dry method.

[0105]

In addition, as shown in FIG. 5, after the first electrode 401 is formed, the first layer 411, the second layer 412, and the third layer 413 are sequentially stacked to form the second electrode 402. Alternatively, as shown in FIG. 6, after the second electrode 402 is formed, the third layer 413, the second layer 412, and the first layer 411 are sequentially stacked to form the first electrode 401. May be formed.

[0106]

[0107]

(Embodiment 4) In this embodiment, a light-emitting element having a structure different from the structures shown in Embodiments 2 and 3 will be described with reference to FIGS. In the structure described in this embodiment, a layer including a composite of an organic compound and a metal oxide can be provided so as to be in contact with two electrodes of the light-emitting element.

[0108]

FIG. 3 (a) shows an example of the structure of the light emitting element of the present invention. A first layer 211, a second layer 212, a third layer 213, and a fourth layer 214 are stacked between the first electrode 201 and the second electrode 202. . In this embodiment, the case where the first electrode 201 functions as an anode and the second electrode 202 functions as a cathode is described.

[0109]

The first electrode 201 and the second electrode 202 can have the same structure as that in Embodiment 2. In addition, the first layer 211 is a layer including a complex of the organic compound and the metal oxide described in Embodiment 1, and the second layer 212 is a layer including a substance having a high light-emitting property. The third layer 213 is a layer containing an electron-donating substance and a compound having a high electron-transport property, and the fourth layer 214 is a layer containing a composite of the organic compound and metal oxide described in Embodiment 1. is there. The electron donating substance contained in the third layer 213 is preferably an alkali metal or alkaline earth metal and oxides or salts thereof. Specific examples include lithium, cesium, calcium, lithium oxide, calcium oxide, barium oxide, cesium carbonate, and the like.

[01 10]

With such a configuration, as shown in FIG. 3 (a), when a voltage is applied, electrons are exchanged near the interface between the third layer 213 and the fourth layer 214. At the same time as the third layer 213 transports electrons to the second layer 212, the fourth layer 214 transports holes to the second electrode 202. That is, the third layer 213 And the fourth layer 2 1 4 together serve as a carrier generation layer. Further, it can be said that the fourth layer 2 14 has a function of transporting holes to the second electrode 20 2. It is also possible to obtain an evening light emitting element by stacking the second layer and the third layer again between the fourth layer 2 14 and the second electrode 20 2. It is.

[0 1 1 1]

In addition, the first layer 2 11 1 and the fourth layer 2 1 4 exhibit extremely high hole injection properties and hole transport properties. Therefore, the driving voltage of the light emitting element can be reduced.

In addition, when the first layer 2 11 1 or the fourth layer 2 14 is thickened, an increase in driving voltage can be suppressed.

[0 1 1 2]

In addition, even if the first layer 2 1 1 and the fourth layer 2 1 4 are made thicker, an increase in the driving voltage of the light emitting element can be suppressed, so the first layer 2 1 1 and the fourth layer The film thickness of the layer 2 14 can be set freely, and the light extraction efficiency from the second layer 2 1 2 can be improved. In addition, the film thicknesses of the first layer 2 11 1 and the fourth layer 2 14 can be set so that the color purity of light emitted from the second layer 2 1 2 is improved.

[0 1 1 3]

In addition, the light emitting element of this embodiment can make the anode side and the cathode side of the second layer responsible for the light emitting function very thick, and can effectively prevent a short circuit of the light emitting element. Taking Fig. 3 (a) as an example, when the second electrode 20 2 is formed by sputtering, damage to the second layer 2 1 2 containing the light-emitting substance is caused. It can also be reduced. Furthermore, since the first layer 2 11 1 and the fourth layer 2 14 are made of the same material, a layer made of the same material can be provided on both sides of the layer responsible for the light emitting function. There is also an effect of suppressing stress strain.

[0 1 1 4]

Note that also in the light-emitting element of this embodiment mode, the first electrode 2 0 1 and the second electrode 2 0 By changing the 2 materials, it has various variations. The schematic diagram is shown in Fig. 3 (b), Fig. 3 (c) and Fig. 4. In FIG. 3 (b), FIG. 3 (c) and FIG. 4, the reference numerals in FIG. 3 (a) are cited. Reference numeral 200 denotes a substrate carrying the light emitting element of the present invention.

[01 15]

FIG. 3 shows an example in which the first layer 21 1, the second layer 212, the third layer 213, and the fourth layer 214 are configured in this order from the substrate 200 side. At this time, the first electrode 201 is made light-transmitting, and the second electrode 202 is made light-shielding (particularly reflective) so that light is emitted from the substrate 200 side as shown in FIG. Become. Further, by making the first electrode 201 light-shielding (particularly reflective) and the second electrode 202 light-transmissive, light is emitted from the opposite side of the substrate 200 as shown in FIG. It becomes composition. Furthermore, by making both the first electrode 20 1 and the second electrode 202 light transmissive, light is emitted to both the substrate 200 side and the opposite side of the substrate 200 as shown in FIG. The structure which performs is also attained.

[01 16]

FIG. 4 shows an example in which the fourth layer 214, the third layer 213, the second layer 212, and the first layer 211 are formed in this order from the substrate 200 side. At this time, the first electrode 201 is made light-shielding (particularly reflective), and the second electrode 202 is made light-transmissive so that light is extracted from the substrate 200 side as shown in FIG. . Further, by making the first electrode 201 light-transmissive and the second electrode 202 light-shielding (particularly reflective), the light can be extracted from the opposite side of the substrate 200 as shown in FIG. 4 (b). Become. Furthermore, by making both the first electrode 20 1 and the second electrode 202 light transmissive, light is emitted to both the substrate 200 side and the opposite side of the substrate 200 as shown in FIG. 4 (c). The structure which performs is also attained.

[01 17]

Note that as shown in FIG. 23, the first layer 71 1 includes one compound selected from an electron-donating substance and a compound having a high electron-transport property, and the second layer 712 has a light-emitting property. material The third layer 713 is a layer containing a composite of the organic compound and metal oxide shown in Embodiment 1 and the fourth layer 714 is selected from among electron donating substances. It is also possible to employ a structure containing the above compound and a compound having a high electron transporting property.

[01 18]

[01 19]

Further, as shown in FIG. 3, after the first electrode 201 is formed, the first layer 211, the second layer 212, the third layer 213, and the fourth layer 214 are sequentially stacked, As shown in FIG. 4, after forming the second electrode 202, the fourth layer 214, the third layer 213, the second layer 212, and the first layer 202 are formed. The layer 211 may be sequentially stacked to form the first electrode.

[0120]

[0121]

(Embodiment 5)

In this embodiment, a light-emitting element having a structure which is different from the structures described in Embodiments 2 to 4 will be described. The structure described in this embodiment is a structure in which the composite material of the present invention is applied as a charge generation layer of a light-emitting element having a structure in which a plurality of light-emitting units are stacked.

[0122]

In this embodiment, a light-emitting element having a structure in which a plurality of light-emitting units are stacked (hereinafter referred to as a stacked element) will be described. In other words, the light-emitting element has a plurality of light-emitting units between the first electrode and the second electrode. Figure 11 shows a stacked element in which two light emitting units are stacked. [0 1 2 3]

In FIG. 11, a first light emitting unit 51 1 1 and a second light emitting unit 51 2 are stacked between a first electrode 5 01 and a second electrode 5 02. A charge generation layer 5 13 is formed between the first light emitting unit 5 1 1 and the second light emitting unit 5 1 2.

[0 1 2 4]

Various materials can be used for the first electrode 5 0 1 and the second electrode 5 0 2.

[0 1 2 5]

The first light-emitting unit 5 111 and the second light-emitting unit 51 12 can each have various configurations.

[0 1 2 6]

The charge generation layer 5 1 3 contains the composite of the organic compound and metal oxide described in Embodiment 1. Since a composite of an organic compound and a metal oxide is excellent in carrier injecting property and carrier transporting property, low voltage driving and low current driving can be realized.

[0 1 2 7]

Note that the charge generation layer 5 13 may be formed by combining a composite of an organic compound and a metal oxide with another material. For example, as shown in Embodiment Mode 3, a layer including a composite of an organic compound and a metal oxide, one compound selected from electron donating substances, and a compound having a high electron transporting property are included. You may form combining a layer. Alternatively, a layer including a composite of an organic compound and a metal oxide may be combined with a transparent conductive film.

[0 1 2 8]

In this embodiment mode, a light-emitting element having two light-emitting units has been described. Similarly, a light-emitting element in which three or more light-emitting units are stacked has the same structure as that of the organic compound described in Embodiment Mode 1. Metal oxide composites can be applied. For example, three The light emitting element in which the light emitting units are stacked is stacked in the order of the first light emitting unit, the first charge generating layer, the second light emitting unit, the second charge generating layer, and the third light emitting unit. The composite of the compound and the metal oxide may be contained in any one of the charge generation layers, or may be contained in all the charge generation layers.

[0129]

[0130]

(Embodiment 6)

In this embodiment mode, an optical design of a light-emitting element will be described.

[0131]

In the light-emitting elements described in any of Embodiments 2 to 5, the thickness of at least one of the layers excluding the first electrode and the second electrode is different for each light-emitting element that emits each emission color. Thus, the light extraction efficiency for each emission color can be increased.

[0132]

For example, as shown in FIG. 10, a light-emitting element that emits red color (R), green color (G), and blue color (B) includes a first electrode 1101, which is a reflective electrode, and a light-transmitting element. Second electrode 1102 having the same properties, and the first layer 1 1 1 1 R, 1 1 11 G, 1 1 1 1 B, the second layer 1 1 12 R, 1 1 12G, 1 1 12 B, third layer 1 1 13 R, 1 1 13 G, 1 1 13 B, fourth layer 1 1 14 R, 1 1 14 G, 1 1 14 B Then, the first layer 1 1 1 1 R, 1 1 1 1 G, and 1 1 1 1 B are made different for each emission color.

[0133]

Note that in the light-emitting element shown in FIG. 10, when a voltage is applied so that the potential of the first electrode 1101 is higher than the potential of the second electrode 1102, the first layer 1 1 1 1 to the second electrode Holes are injected into layers 1 1 12. Electrons are exchanged near the interface between the third layer 1 1 13 and the fourth layer 1 1 14 to generate electrons and holes, and the third layer 1 1 13 Is transported to the second layer 1 1 1 2, while the fourth layer 1 1 14 transports holes to the second electrode 1 1 02. Holes and electrons recombine in the second layer 1 1 12 to bring the luminescent material into an excited state. The excited luminescent material emits light when returning to the ground state.

[0 1 34]

As shown in Fig. 10, when the first layer 1 1 1 1 R, 1 1 1 1 G, 1 1 1 1 B is differentiated for each luminescent color and directly recognized through the second electrode It is possible to prevent the light extraction efficiency from being lowered due to the difference in the optical path between the case where the light is reflected by the first electrode and recognized through the second electrode.

[01 35]

Specifically, when light is incident on the first electrode, a phase inversion occurs in the reflected light, resulting in a light interference effect. As a result, the optical distance between the light emitting region and the reflecting electrode, that is, the refractive index X distance is (2m-1) Z4 times the emission wavelength (m is an arbitrary positive integer), that is, m = l 4, 3 / 4, 5/4-· When doubled, the external extraction efficiency of light emission increases. On the other hand, m / 2 times (m is an arbitrary positive integer) That is, when m = lZ2, 1, 3/2 ··· times, the external extraction efficiency of light emission becomes low.

[01 36]

Therefore, in the light emitting device of the present invention, the optical distance between the light emitting region and the reflective electrode, that is, the refractive index X distance is (2m−1) Z4 times the emission wavelength (m is an arbitrary positive integer). Further, the thickness of any one of the first layer to the fourth layer is made different for each light emitting element.

[01 37]

In particular, in the first to fourth layers, the thickness of the layer between the layer where the electrons and holes are recombined and the reflective electrode may be different (the layer where the electrons and holes are recombined). Therefore, the thickness of the light-transmitting electrode may be different from that of the light-transmitting electrode, and the thickness of both of the electrodes may be different. [0 1 3 8]

In order to change the thickness of any of the first to fourth layers, it is necessary to increase the thickness of the layers. The light-emitting element of the present invention is characterized in that a layer including the composite of the organic compound and the metal oxide described in Embodiment 1 is used for the layer to be thickened.

[0 1 3 9]

In general, when the thickness of the light emitting element layer is increased, the driving voltage increases, which is not preferable. However, when the composite of the organic compound and metal oxide described in Embodiment 1 is used for the layer to be thickened, the driving voltage can be lowered and the increase in driving voltage due to the thickening can be suppressed. it can.

[0 1 4 0]

In FIG. 10, the optical distance between the light emitting region of the red light emitting element (R) and the reflective electrode is 14 times the emission wavelength, and the light emitting region of the green light emitting element (G) and the reflective electrode The optical distance was 3 Z 4 times the emission wavelength, and the optical distance between the light emitting region of the blue light emitting element (B) and the reflective electrode was 5 Z 4 times the emission wavelength. Note that the present invention is not limited to this value, and the value of m can be set appropriately. Further, as shown in FIG. 10, the value of m which is (2 m−1) / 4 times the emission wavelength may be different for each light emitting element. .

[0 1 4 1]

In addition, by increasing the thickness of any of the first to fourth layers, it is possible to prevent the first electrode and the second electrode from being short-circuited and to increase the yield, which is very preferable. .

[0 1 4 2]

As described above, in the light-emitting element of the present invention, the film thickness of at least the first layer to the fourth layer can be made different for each emission color. At this time, it is preferable that the thickness of the layer between the layer where the electrons and holes are recombined and the reflective electrode be different for each emission color. For the layer that needs to be thicker, the composite of the organic compound and metal oxide shown in Embodiment Mode 1 It is preferable to use a layer containing, because the driving voltage is not increased.

[0143]

Note that although this embodiment mode has been described using the light-emitting element having the structure described in Embodiment Mode 4, it can be combined with any other embodiment mode as appropriate.

[0144]

(Embodiment 7)

In this embodiment mode, a light-emitting device having the light-emitting element of the present invention will be described.

[0145]

In this embodiment mode, a light-emitting device having the light-emitting element of the present invention in a pixel portion will be described with reference to FIG. 7A is a top view illustrating the light-emitting device, and FIG. 7B is a cross-sectional view taken along lines A—A ′ and B—B ′ in FIG. 7A. Reference numeral 601 indicated by a dotted line denotes a drive circuit portion (source side drive circuit), 602 denotes a pixel portion, and 603 denotes a drive circuit portion (gate side drive circuit). Reference numeral 604 denotes a sealing substrate, reference numeral 605 denotes a sealing material, and an inner side surrounded by the sealing material 605 is a space 607.

[0146]

Note that the routing wiring 608 is a wiring for transmitting a signal input to the source side driving circuit 601 and the gate side driving circuit 603, and from the FPC (flexible printed circuit) 609 serving as an external input terminal, Receives clock signal, start signal, reset signal, etc. 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 the light-emitting device body but also a state in which an FPC or PWB is attached thereto.

[0147]

Next, the cross-sectional structure is described with reference to FIG. A drive circuit portion and a pixel portion are formed on the element substrate 610. Here, the source side driver, which is a drive circuit portion, is formed. A moving circuit 601 and one pixel in the pixel portion 602 are shown.

[0148]

Note that the source side driver circuit 601 is a CMOS circuit in which an n-channel TFT 623 and a p-channel TFT 624 are combined. The TFT forming the driving circuit may be formed of various CMOS circuits, PMOS circuits, or NMOS circuits. In this embodiment mode, a driver integrated type in which a driver circuit is formed over a substrate is shown. However, this is not always necessary, and the driver circuit can be formed outside the substrate.

[0149]

The pixel portion 602 is formed by a plurality of pixels including a switching TFT 611, a current control TFT 612, and a first electrode 613 electrically connected to the drain thereof. Note that an insulator 614 is formed so as to cover an end portion of the first electrode 613. Here, it is formed by using a positive type photosensitive acrylic resin film.

[0150]

In order to improve the covering property, a curved surface having a curvature is formed at the upper end portion or the lower end portion of the insulator 614. For example, in the case where positive photosensitive acrylic is used as the material of the insulator 614, it is preferable that only the upper end portion of the insulator 614 has a curved surface having a curvature radius (0.2 / m to 3 wm). As the insulator 614, either a negative type that becomes insoluble in an etchant by light irradiation or a positive type that becomes soluble in an etchant by light irradiation can be used.

[0151]

A layer 616 containing a light-emitting substance and a second electrode 617 are formed over the first electrode 613, respectively. Here, as a material used for the first electrode 613 functioning as an anode, various metals, alloys, electrically conductive compounds, and mixtures thereof, metals, compounds, and alloys can be used. When using the first electrode as the anode Among them, it is preferable that the material is formed with a large work function (work function 4. O eV or more). For example, indium tin oxide containing silicon, zinc oxide zinc oxide, titanium nitride film, chromium film, tungsten film, Zn film, Pt film, etc., as well as titanium nitride and aluminum as main components A three-layer structure of a titanium nitride film, a titanium nitride film, a film containing aluminum as a main component, and a titanium nitride film can be used. Note that, when a laminated structure is used, resistance as a wiring is low, a good ohmic contact can be obtained, and a function as an anode can be obtained.

[0152]

The layer 616 containing a light-emitting substance is formed by various methods such as an evaporation method using an evaporation mask, an ink-jet method, and a spin coating method. The layer 616 containing a light-emitting substance has a layer containing a composite of an organic compound and a metal oxide described in Embodiment 1. Further, another material constituting the light-emitting substance-containing layer 616 may be a low molecular weight material, a molecular weight material (including an oligomer or a dendrimer), or a high molecular weight material. In addition, as a material used for the layer containing a light-emitting substance, not only an organic compound but also an inorganic compound may be used.

[0153]

Further, a material used for the second electrode 617 formed on the layer 616 containing a light-emitting substance and functioning as a cathode includes a metal, an alloy, an electrically conductive compound having a low work function (work function of 3.8 eV or less). , And mixtures thereof can be used. Specific examples of such cathode materials include elements belonging to Group 1 or Group 2 of the Periodic Table of Elements, that is, alkali metals such as lithium (L i) and cesium (C s), and magnesium (Mg), Examples thereof include alkaline earth metals such as calcium (Ca) and strontium (Sr), and alloys containing these (Mg: Ag, A1: Li). Note that in the case where light generated in the layer 616 containing a light-emitting substance passes through the second electrode 617, the second electrode 617 includes a thin metal film, a transparent conductive film (indium oxide-acid Stacking with tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, zinc oxide indium oxide (I ζο), indium oxide containing tungsten oxide and zinc oxide (IWZO), etc.) It is also possible to use it.

[0154]

Further, the sealing substrate 604 is bonded to the element substrate 610 with the sealing material 605, whereby the light emitting element 618 is provided in the space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. It has become. Note that the space 607 is filled with a filler, and may be filled with a sealant 605 in addition to being filled with an inert gas (such as nitrogen or argon).

[0155]

Note that an epoxy resin is preferably used for the sealing material 605. In addition, it is desirable that these materials are materials that do not transmit moisture and oxygen as much as possible. In addition to glass substrates and quartz substrates, the plastic substrate made of FRP (Fiberglass-Reinforced Plastics), PVF (Polyvinyl fluoride), Mylar, polyester or acrylic is used as the material for the sealing substrate 604. Can be used.

[0156]

As described above, a light-emitting device having the light-emitting element of the present invention can be obtained.

[0157]

The light-emitting device of the present invention includes a layer including the composite of the organic compound and metal oxide described in Embodiment 1. A layer including a composite of an organic compound and a metal oxide has high conductivity due to the intrinsic generation of carriers. Therefore, low-voltage driving of the light-emitting element can be realized. Thus, power consumption of the light-emitting device can be reduced.

[0158]

In addition, the layer containing the composite of the organic compound and the metal oxide used in the light-emitting device of the present invention is thick. Optical design using the micro-cavity effect and interference effect by adjusting the film thickness of the layer containing the composite of organic compound and metal oxide. It can be performed. Therefore, a light-emitting device with good display quality with high color purity and small change in color depending on the viewing angle can be manufactured.

[0 1 5 9]

In addition, by increasing the thickness of a layer containing a composite of an organic compound and a metal oxide, a short circuit due to minute foreign matter or impact can be prevented, so that a highly reliable light-emitting device can be obtained. .

[0 1 6 0]

As described above, in this embodiment, an active light-emitting device that controls driving of a light-emitting element with a transistor has been described. In addition to this, a light-emitting element is driven without particularly providing a driving element such as a transistor. FIG. 8 is a perspective view of a passive light emitting device manufactured by applying the present invention. In FIG. 8, on a substrate 9 51, a layer 9 5 5 containing a light emitting substance is provided between an electrode 9 5 2 and an electrode 9 5 6. The end of the electrode 9 52 is covered with an insulating layer 9 53. A partition wall layer 9 5 4 is provided on the insulating layer 9 5 3. The side wall of the partition wall layer 95 4 has an inclination such that the distance between one side wall and the other side wall becomes narrower as it approaches the substrate surface. In other words, the cross section in the short side direction of the partition wall layer 954 is trapezoidal, and the bottom side (the side facing the insulating layer 953 in the same direction as the surface direction of the insulating layer 953) is the upper side. (The side facing the same direction as the surface of the insulating layer 953, and the side not contacting the insulating layer 953) is shorter. In this manner, by providing the partition layer 954, it is possible to prevent a light emitting element from being defective due to static electricity or the like. A passive light emitting device can also be driven with low power consumption by including the light emitting element of the present invention that operates at a low driving voltage. [0161]

(Embodiment 8)

In this embodiment, electronic devices of the present invention including the light-emitting device described in Embodiment 7 as part thereof will be described. An electronic device of the present invention includes a layer including the composite of the organic compound and metal oxide described in Embodiment 1, and includes a display portion with low power consumption. In addition, by increasing the thickness of the layer containing the composite of the organic compound and metal oxide described in Embodiment 1, a highly reliable display portion in which short-circuiting due to minute foreign matters or external impacts is suppressed is suppressed. It is also possible to provide electronic devices having

[0162]

As an electronic device manufactured using the light emitting device of the present invention, a video camera, a digital camera, a goggle type display, a navigation system, a sound reproduction device (car audio, audio component, etc.), a computer, a game device, a portable information terminal ( Play back recorded media such as mobile computers, mobile phones, portable game machines or electronic books, and image playback devices equipped with recording media (specifically, Digital Versatile Disc (D VD)). And a device equipped with a display device capable of displaying the image). Specific examples of these electronic devices are shown in FIG.

FIG. 9B illustrates a television device according to the present invention, which includes a housing 9101, a support base 9102, a display portion 9103, a speaker portion 9104, a video input terminal 9105, and the like. In this television set, display portion 9103 is formed by arranging light-emitting elements similar to those described in Embodiments 2 to 6 in a matrix. The light-emitting element is characterized by high luminous efficiency and low driving voltage. It is also possible to prevent short-circuiting due to minute foreign matter or external impacts. Since the display portion 9103 including the light-emitting elements has similar features, this television set has no deterioration in image quality and has low power consumption. With such a feature, the deterioration compensation function and the power supply circuit can be greatly reduced or reduced in the television device. 1 and support base 9 1 0 2 can be reduced in size and weight. Since the television set according to the present invention has low power consumption, high image quality, and small size and light weight, it can provide a product suitable for the living environment.

[0 1 6 3]

FIG. 9 (B) shows a computer according to the present invention, including a main body 9 2 0 1, a housing 9 2 0 2, a display portion 9 2 0 3, a keyboard 9 2 0 4, an external connection port 9 2 0 5, and a pointing mouse Including 9 2 0 6 etc. In this computer, the display portion 9203 is formed by arranging light-emitting elements similar to those described in Embodiments 2 to 6 in a matrix. The light-emitting element has a feature of high luminous efficiency and low driving voltage. It is also possible to prevent a short circuit due to a minute foreign matter or an external impact. Since the display portion 9203 formed using the light-emitting elements has similar characteristics, image quality is not deteriorated in this combination and power consumption is reduced. With these features, deterioration compensation functions and power supply circuits can be greatly reduced or reduced in computers, so the main unit 9 2 0 1 and the housing 9 2 0 2 can be reduced in size and weight. is there. Since the computer according to the present invention achieves low power consumption, high image quality, and a small size and light weight, a product suitable for the environment can be provided. In addition, it is possible to carry around, and it is possible to provide a combu evening that has a display portion that is resistant to external shocks when carrying around.

[0 1 6 4]

FIG. 9 (C) shows a mobile phone according to the present invention. Main body 9 4 0 1, housing 9 4 0 2, display 9 4 0 3, audio input 9 4 0 4, audio output 9 4 0 5 , Including operation keys 9 4 0 6, external connection ports 9 4 0 7, antennas 9 4 0 8, etc. In this cellular phone, display portion 943 is configured by arranging light-emitting elements similar to those described in Embodiments 2 to 6 in a matrix. The light-emitting element has a feature of high luminous efficiency and low driving voltage. In addition, short-circuit due to minute foreign matter or external impact is prevented. It is also possible to do. Since the display portion 943 composed of the light-emitting elements has similar characteristics, this mobile phone has no deterioration in image quality and has low power consumption. Because of these features, deterioration compensation functions and power supply circuits can be greatly reduced or reduced in mobile phones, so the main body 9 4 0 1 and the housing 9 4 0 2 can be made smaller and lighter. Is possible. Since the mobile phone according to the present invention has low power consumption, high image quality, and small size and light weight, a product suitable for carrying can be provided. In addition, a product having a display portion that is resistant to impact when being carried can be provided.

[0 1 6 5]

FIG. 9 (D) shows a camera according to the present invention, including a main body 9 5 0 1, a display unit 9 5 0 2, a housing 9 5 0 3, an external connection port 9 5 0 4, a remote control receiving unit 9 5 0 5, Image receiving unit 9 5 0 6, battery 9 5 0 7, audio input unit 9 5 0 8, operation keys 9 5 0 9, eyepiece 9 5 10, etc. In this camera, the display unit 952 is configured by arranging light-emitting elements similar to those described in Embodiments 2 to 6 in a matrix. The light-emitting element has characteristics such as high luminous efficiency, low driving voltage, and prevention of short-circuit due to minute foreign matter or external impact. Since the display portion 9520 composed of the light-emitting elements has the same characteristics, this camera has no deterioration in image quality, and 'low power consumption' is achieved. With such a feature, the deterioration compensation function can greatly reduce or reduce the power supply circuit in the camera, so that the main body 9 5 0 1 can be reduced in size and weight. In the camera according to the present invention, low power consumption, high image quality, and reduction in size and weight are achieved; therefore, a product suitable for carrying can be provided. In addition, a product having a display portion that is resistant to impact when carried can be provided.

[0 1 6 6]

As described above, the applicable range of the light-emitting device of the present invention is so wide that the light-emitting device can be applied to electronic devices in various fields. By using the light-emitting device of the present invention, it is possible to provide an electronic device having a display portion with low power consumption and high reliability. It becomes.

[Example 1]

[0167]

The composite of the organic compound and the metal oxide used for the light-emitting element of the present invention can suppress an increase in driving voltage even when the film thickness is increased. Figure 16 shows the structure of a light-emitting element using a composite of an organic compound and a metal oxide.

[0168]

First, indium oxide-tin oxide containing silicon oxide was formed over a glass substrate 2101 by a sputtering method, whereby the first electrode 2102 was formed. The film thickness was 1 10 nm and the electrode area was 2 mm x 2 mm.

[0169]

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Then evacuating the vacuum apparatus was evacuated to about 10- ⁴ P a, on the first electrode 2102 by co-evaporation of NPB and molybdenum oxide (VI), a composite of an organic compound and a metal oxide A layer 2103 containing a body was formed. The film thickness of the layer containing the complex of organic compound and metal oxide was changed to 60 nm, 90 nm, 120 nm, and 150 nm. The ratio of NPB and molybdenum oxide (VI) contained in the layer containing the composite of organic compound and metal oxide was adjusted so that molybdenum oxide (VI) was 10% by volume. The co-evaporation method is an evaporation method in which evaporation is simultaneously performed from a plurality of evaporation sources in one processing chamber.

[0170]

Next, NPB was formed to a thickness of 10 nm by a vapor deposition method using resistance heating, whereby a hole transport layer 2104 was formed.

[0171]

Furthermore, by co-evaporating A 1 q and coumarin 6, A light emitting layer 2 105 having a thickness of 40 nm was formed. Here, the weight ratio between A 1 Q and coumarin 6 was adjusted to be 1: 0.0. 0 1 (== A 1 Q: coumarin 6). As a result, Coumarin 6 is dispersed in the layer composed of A 1 Q.

[0172]

Thereafter, A 1 Q was deposited on the light-emitting layer 2 105 to have a thickness of 30 nm by using a resistance heating vapor deposition method to form an electron transport layer 2106.

[0173]

Further, an electron injection layer 2107 was formed on the electron transport layer 2106 by a vapor deposition method using resistance heating so as to have a thickness of 1 nm.

[0174]

Finally, a second electrode 2108 is formed by depositing aluminum to a thickness of 200 nm on the electron injection layer 2107 using a resistance heating vapor deposition method, and the light-emitting element of the present invention is manufactured. did.

[0175]

FIG. 17 shows voltage-current density characteristics of the light-emitting element of the present invention. FIG. 25 shows current density-luminance characteristics of the light-emitting element of the present invention. When a composite of an organic compound and a metal oxide and a light emitting layer are directly joined, molybdenum oxide becomes a quencher and the light emission efficiency decreases. Therefore, NPB was introduced between the layer containing the complex of organic compound and metal oxide and the light emitting layer. As shown in FIGS. 17 and 25, in the light emitting device of the present invention, the driving voltage and the current efficiency were not substantially changed even when the thickness of the layer containing the composite of the organic compound and the metal oxide was changed. Specifically, the driving voltage at 1000 c dZm ² is 5.5 V when the layer containing the composite of the organic compound and the metal oxide is 50 nm, but 5.5 V even at 150 ηm. Met. This is because the resistivity of a layer containing a composite of an organic compound and a metal oxide is very small compared to other organic layers. This feature makes it possible to increase the thickness of the device and prevent short-circuiting of the device. Also, optical design using interference etc. It is easy to obtain a film thickness that is suitable for processing.

[Example 2]

[0176]

A light-emitting element of the present invention will be described with reference to FIG.

[0177]

First, indium oxide-tin oxide containing silicon oxide was formed over a glass substrate 2201 by a sputtering method, whereby a first electrode 2202 was formed. The film thickness was 110 nm and the electrode area was 2 mm x 2 mm.

[0178]

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Then evacuating the vacuum apparatus, pressure was reduced to about 10_ ⁴ P a, on the first electrode 2202, 4, 4 '- bi scan [N- phenyl - N- (spiro-fluorene - 2-I le) A layer 2203 containing a composite of an organic compound and a metal oxide was formed by co-evaporation of biphenyl (abbreviation: BS PB), molybdenum oxide (VI), and rubrene. The thickness of the layer containing the composite of organic compound and metal oxide was 12 Onm. The ratio of BSPB, molybdenum oxide (VI), and rubrene contained in the layer containing the composite of organic compound and metal oxide is BSPB: molybdenum oxide: rubrene = 2: 0. 75: 0.04 It was adjusted so that The co-evaporation method is a vapor deposition method in which vapor deposition is performed simultaneously from a plurality of evaporation sources in one processing chamber.

[0179]

Next, NPB was formed to a thickness of 10 nm by vapor deposition using resistance heating to form a hole transport layer 2204.

[0180]

Furthermore, A 1 q and coumarin 6 are co-evaporated to form a hole transport layer 2204 A light emitting layer 2205 having a thickness of 37.5 nm was formed. Here, the weight ratio between A 1 Q and coumarin 6 was adjusted to be 1: 0.01 (= A 1 Q: coumarin 6). As a result, Coumarin 6 is dispersed in the layer composed of A 1 Q.

[0181]

Thereafter, A 1 Q was deposited on the light emitting layer 2205 to have a thickness of 37.5 nm by using a resistance heating vapor deposition method, whereby an electron transport layer 2206 was formed.

[0182]

Further, an electron injection layer 2207 was formed on the electron transport layer 2206 by a vapor deposition method using resistance heating so as to have a thickness of 1 nm.

[0183]

Finally, a second electrode 2208 is formed by depositing aluminum on the electron injection layer 2207 so as to have a film thickness of 200 nm by using a resistance heating vapor deposition method. Produced.

[0184]

(Comparative Example 1)

First, indium oxide-tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 1 1 O nm, and the electrode area was 2 mm x 2 mm.

[0185]

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. After that, BSPB was deposited on the first electrode to a thickness of 5 O nm by vapor deposition using resistance heating.

[0186]

Then, a 10 nm NPB film is formed on BSPB by vapor deposition using resistance heating. Formed with thickness.

[0187]

Furthermore, by co-evaporating A 1 q and coumarin 6, A light emitting layer having a thickness of 37.5 nm was formed on 8. Here, the weight ratio between A 1 q and coumarin 6 was adjusted to be 1: 0.01 (= A 1 Q: coumarin 6). As a result, Coumarin 6 is dispersed in the layer composed of A 1 Q.

[0188]

Subsequently, A 1 Q was deposited on the light-emitting layer to a thickness of 37.5 nm using a resistance heating vapor deposition method to form an electron transport layer.

[0189]

Furthermore, an electron injection layer was formed by depositing calcium fluoride to a thickness of 1 nm on the electron transport layer by vapor deposition using resistance heating.

[0190]

Finally, by using a resistance heating vapor deposition method, aluminum is deposited on the electron injection layer to a thickness of 200 nm, thereby forming a second electrode, thereby producing comparative light emitting element 1. did.

[0191]

FIG. 19 shows voltage-luminance characteristics of the light-emitting element 1 and the comparative light-emitting element 1. The comparative light-emitting element 1 is not practical because the driving voltage of the light-emitting element becomes very high, but the light-emitting element 1 of the present invention using a layer containing a composite of an organic compound and a metal oxide is It can be seen that the drive voltage has been reduced. In other words, the voltage is lowered by mixing BSPB with molybdenum oxide to form a composite of an organic compound and a metal oxide.

[0192]

FIG. 20 shows the results of a constant current driving test of the light-emitting element 1 and the comparative light-emitting element 1 at an initial luminance of 3000 cdZm ² . Light-emitting element 1 is longer than comparative light-emitting element 1. It can be seen that the service life is improved and the reliability is improved.

[0193]

From the above results, it was found that the driving voltage can be reduced by using a composite of an organic compound and a metal oxide for a light emitting element. It was also found that reliability was improved.

[0194]

In other words, mixing with molybdenum oxide to form a composite of an organic compound and a metal oxide not only makes it possible to use a variety of anodes, but also widens the choice of organic compounds. For example, a material having a high glass transition point (Tg) but low conductivity, such as BSPB, can be used for a light emitting element, and an element having high heat resistance can be manufactured. [Example 3]

[0195]

[0196]

First, indium oxide-tin oxide containing silicon oxide was formed over a glass substrate 2201 by a sputtering method, whereby a first electrode 2202 was formed. The film thickness was 1 10 nm and the electrode area was 2 mm x 2 mm.

[0197]

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Then evacuating the vacuum apparatus was evacuated to about 10- ⁴ P a, on the first electrode 2202 by co-evaporation of t- BuDN A and molybdenum oxide (VI), an organic compound and metal oxide A layer 2203 containing a composite of objects is formed. The film thickness of the layer containing the complex of organic compound and metal oxide was 12 Onm. The ratio of t-BuDNA to molybdenum oxide (VI) contained in the layer containing the complex of organic compound and metal oxide is t-Bu DNA: acid by weight ratio. Molybdenum fluoride was adjusted to be 1: 0.5. The co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

[0198]

Next, NPB was formed to a thickness of 10 nm by a vapor deposition method using resistance heating, whereby a hole transport layer 2204 was formed.

[0199]

Further, A 1 q and coumarin 6 were co-evaporated to form a light emitting layer 2205 having a thickness of 37.5 nm on the hole transport layer 2 204. Here, the weight ratio between A I q and coumarin 6 was adjusted to be 1: 0. 0 1 (= A 1 Q: coumarin 6). As a result, Coumarin 6 is dispersed in the layer composed of A 1 Q.

[0200]

Thereafter, A 1 Q was deposited on the light emitting layer 2 205 to a thickness of 37.5 nm by using a resistance heating vapor deposition method to form an electron transport layer 2206.

[0201]

Further, an electron injection layer 2207 was formed on the electron transport layer 2206 by a vapor deposition method using resistance heating so as to have a thickness of 1 nm. ·

[0202]

Finally, a second electrode 2208 is formed by depositing aluminum on the electron injection layer 2207 so as to have a film thickness of 200 nm using a resistance heating vapor deposition method, and the light-emitting element 2 of the present invention is formed. Produced.

[0203]

(Comparative Example 2)

First, indium tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 1 l Onm, and the electrode area was 2 mm x 2 mm. [0204]

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, t-BuDNA was deposited on the first electrode to a thickness of 50 nm by vapor deposition using resistance heating.

[0205]

Then, by an evaporation method using resistance heating, t-on BuDNA, NPB was deposited to a film thickness of 10 eta _m.

[0206]

In addition, A 1 q and coumarin 6 were co-evaporated to form a 37.5 nm light-emitting layer on NPB. Here, the weight ratio between A 1 q and coumarin 6 was adjusted to be 1: 0.01 (2 Al Q: coumarin 6). As a result, Coumarin 6 is dispersed in the layer composed of A 1 Q.

[0207]

Then, using an evaporation method using resistance heating, A 1 q was deposited on the light emitting layer to a thickness of 37.5 nm to form an electron transport layer.

[0208]

[0209]

Finally, using a vapor deposition method using resistance heating, a comparative light-emitting element 2 was fabricated by forming a second electrode by depositing aluminum on the electron injection layer to a thickness of 200 nm. did. '

[0210]

FIG. 21 shows voltage-luminance characteristics of the light-emitting element 2 and the comparative light-emitting element 2. Comparative luminescent element The element 2 is not practical because the driving voltage of the light emitting element becomes very high, but the driving voltage of the light emitting element 2 of the present invention using a layer containing a composite of an organic compound and a metal oxide is low. It can be seen that it has been reduced. In other words, t-BuDN A is mixed with molybdenum oxide to form a composite of an organic compound and a metal oxide, thereby reducing the voltage.

[021 1]

In addition, FIG. 22 shows the results of a constant current driving test of the light-emitting element 2 and the comparative light-emitting element 2 at an initial luminance of 3000 cdZm ² . It can be seen that the light-emitting element 2 has a longer life than the comparative light-emitting element 2 and has improved reliability.

[0212]

[0213]

In other words, mixing with molybdenum oxide to form a composite of an organic compound and a metal oxide not only makes it possible to use a variety of anodes, but also widens the choice of organic compounds. For example, a material with a high glass transition point (Tg) but low conductivity, such as t-BuDNA, can be used for a light emitting device, and a device with high heat resistance can be manufactured.

[Example 4]

[0214]

In this example, a light-emitting element of the present invention will be described with reference to FIG.

[0215]

First, indium oxide-tin oxide containing silicon oxide was formed over a glass substrate 2201 by a sputtering method, so that a first electrode 2202 was formed. The film thickness was 110 nm, and the electrode area was 2 mm x 2 mm. [0216]

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Then evacuating the vacuum apparatus was evacuated to about 10- ⁴ P a, on the first electrode 2202 by co-evaporation of rubrene and NPB and molybdenum oxide (VI), organic compound and metal oxide A layer 2203 containing the composite of was formed. The thickness of the layer containing the composite of the organic compound and the metal oxide was 12 Onm. The weight ratio of NPB, molybdenum oxide (VI), and rubrene contained in the layer containing the composite of organic compound and metal oxide is NPB: molybdenum oxide: rubrene = 1: 0. 25: 0.02. It adjusted so that it might become. The co-evaporation method is an evaporation method in which evaporation is performed simultaneously from a plurality of evaporation sources in one processing chamber.

[0217]

[0218]

Further, a light emitting layer 2205 having a thickness of 37.5 nm was formed on the hole transport layer 2204 by co-evaporation of Al q and coumarin 6. Here, the weight ratio between A 1 Q and coumarin 6 was adjusted to be 1: 0.01 (= A 1 Q: coumarin 6). As a result, Coumarin 6 is dispersed in the layer composed of A 1 Q.

[0219]

[0220]

Further, on the electron transport layer 2206, a film of calcium fluoride having a thickness of 1 nm was formed by a vapor deposition method using resistance heating to form an electron injection layer 2207.

[022 1] Finally, a second electrode 2208 is formed by depositing aluminum to a thickness of 200 nm on the electron injection layer 2207 using a resistance heating vapor deposition method, and the light-emitting element 3 of the present invention is formed. Produced.

[0222]

(Comparative Example 3)

First, indium oxide-tin oxide containing silicon oxide was formed over a glass substrate by a sputtering method to form a first electrode. The film thickness was 1 1 Onm, and the electrode area was 2 mm x 2 mm.

[0223]

Next, the substrate on which the first electrode was formed was fixed to a substrate holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode was formed was downward. Thereafter, copper phthalocyanine (abbreviation: CuPc) was deposited on the first electrode to a thickness of 20 nm by a vapor deposition method using resistance heating.

[0224]

After that, NPB was formed with a film thickness of 40 nm on CuPc by vapor deposition using resistance heating.

[0225]

Further, A 1 q and coumarin 6 were co-evaporated to form a light emitting layer having a thickness of 37.5 nm on NPB. Here, the weight ratio between A 1 Q and coumarin 6 was adjusted to be 1: 0.01 (= A 1 Q: coumarin 6). As a result, Coumarin 6 is dispersed in the layer composed of A 1 q.

[0226]

After that, using an evaporation method by resistance heating, Alq was deposited on the light emitting layer so as to have a film thickness of 37.5 nm to form an electron transport layer.

[0227] Furthermore, an electron injection layer was formed by depositing calcium fluoride to a thickness of 1 nm on the electron transport layer by vapor deposition using resistance heating.

[0 2 2 8]

Finally, by using a resistance heating vapor deposition method, a second electrode is formed by depositing aluminum on the electron injection layer so as to have a thickness of 20 O nm. Was made.

[0 2 2 9]

The voltage-luminance characteristics of the light-emitting element 3 and the comparative light-emitting element 3 are shown in FIG. The light-emitting element 3 using a layer containing a composite of an organic compound and a metal oxide has a driving voltage lower than that of the comparative light-emitting element 3.

[0 2 3 0]

From the above results, it was found that the driving voltage can be reduced by using a composite of an organic compound and a metal oxide for a light emitting element.

[Example 5]

[0 2 3 1]

In this example, a light-emitting device using a composite of an organic compound and a metal oxide will be described.

[0 2 3 2]

Table 1 shows the basic specifications of the active matrix display fabricated in this example, and Table 2 shows the element structure. The display used in this example is capable of color display by RGB color separation, but in order to eliminate the occurrence of point defects due to the effect of color separation, vapor deposition is performed on the entire surface in a single green color. Yes. Table 2 also shows the structure of a comparative display using copper phthalocyanine (CuPc) instead of a complex of organic compound and metal oxide.

[0 2 3 3] 【table 1】

Built-in temperature & deterioration correction function

[0 2 3 4]

[Table 2]

[0 2 3 5]

Figure 26 shows the luminance and current efficiency when the thickness of the layer containing a composite of an organic compound and metal oxide using NPB and molybdenum oxide is changed. The light extraction efficiency is affected by the thickness of the layer containing the complex of organic compound and metal oxide. The brightness changes periodically. However, when the thickness of the layer containing the composite of the organic compound and metal oxide is increased from 30 nm to 150 nm, the reduction in luminance can be suppressed to about 10%.

[0 2 3 6]

Figure 27 shows the film thickness dependence of the layer containing a complex of organic compounds and metal oxides with increased point defects. The panel used for the measurement was driven at room temperature for 1 hour and then temperature cycled. When the film thickness of the layer containing the composite of organic compound and metal oxide was 40 nm, an increase of nearly 20 point defects per panel was observed after 60 hours of temperature cycling. However, by increasing the film thickness of the layer containing the composite of organic compound and metal oxide to 75 nm or more, the number of point defects was reduced to about 2 or less even after the same temperature cycle operation. . The display area of the panel used for the measurement in Fig. 27 is 36 mm x 48 mm, and the aperture ratio is 39%. Therefore, increase the number of point defects per display area 3 6 mx 4 8 mm x 0.39 = 6 7 3.9 2 mm ² to 2 or less (3 or less per 100 mm ² ). I was able to. Therefore, the increased dark spot suppression effect is fully demonstrated and the light extraction efficiency is relatively good. The film thickness of the layer containing a complex of organic compound and metal oxide is 1550 nm. The standard condition for the layer containing the composite of organic compound and metal oxide in the test was adopted.

[0 2 3 7]

Figure 28 shows the number of increased point defects in various environmental operation tests. Table 3 shows the conditions for each operation test.

[0 2 3 8]

[Table 3]

Environmental operation test conditions ''

High temperature operation 8 5 to 6 60 hours

Low temperature operation 4 0 to 6 60 hours 4 hours at 85, 4 hours at 40 (1 cycle 8 hours) Temperature cycle operation

Repeat for 660 hours

[0239]

Without thickening with a layer containing a complex of organic compound and metal oxide, tens to hundreds of increased saddle points occur 60 hours after the start of the test in low temperature operation or temperature cycle operation is doing. This panel has a monitor element through which a constant current flows, in addition to the pixel part specified in Table 1. The drive voltage of the light-emitting element in the pixel unit reflects the voltage of the monitor element, and it is corrected so that the brightness is constant over time and changes over time (Hiroyuki Miyak eeta 1 ., SID '05 Digestof Technological Papers, Vol. X XXVI, p 240-243). Therefore, it is thought that defects were promoted during high-temperature operation than during high-temperature operation because a higher voltage was applied between the cathode and anode. Furthermore, during the temperature cycle, the stress between the cathode and the anode is thought to be promoted due to the stress concentration in the weak coverage of the layer containing the luminescent material with respect to the minute particles due to the temperature change. However, in the case of a display in which a layer containing a light emitting material is thickened by a layer containing a composite of an organic compound and a metal oxide, the increased dark spot is 2 per panel even in these severe environmental operation tests. It is greatly reduced to less than about one. The panel used in this embodiment is a QVGA panel with 240 XRGBX 320 = 230 400 pixels. Therefore, the number of incremental points for 230400 pixels can be 2 or less (0.087% or less).

[0240]

Figure 29 shows a cross-sectional TEM photograph of a typical fine particle part that is the cause of point defects. It can be seen that it is difficult to obtain good coverage when a thin hole injection layer such as Cu Pc is used. Since the film thickness of the light-emitting element is very small, if good coverage cannot be obtained, it can easily lead to a short circuit between the electrodes. Special When spherical particles such as (a) and (b) are present, the lower side of the particle has an inversely tapered shape, so it is relatively good by increasing the film thickness using a composite of organic compound and metal oxide. Coverage can be obtained.

[0241]

In other words, when an active matrix display is manufactured using a layer containing a composite of an organic compound and a metal oxide exhibiting high conductivity, the layer containing a light-emitting substance can be made thick without greatly degrading the characteristics. I was able to confirm. In addition, increasing the thickness of the layer containing a composite of an organic compound and a metal oxide was effective in suppressing point defects caused by fine particles. In particular, it has been found that it exhibits a significant suppression effect against the increasing type of point defects that are likely to occur in harsh environments such as temperature cycle operation stress.

[Example 6]

[0242]

A 6.5_in c h, WQVG A active matrix panel was fabricated using a layer containing a composite of an organic compound and a metal oxide. An NTSC ratio of 83% could be obtained by adjusting the thickness of the organic layer and the layer containing the composite of organic compound and metal oxide. In addition, this panel had very few dark spots due to a short circuit between the electrodes. · [Example 7]

[0243]

Below, synthesis of N, N '—bis (spiro-9, 9' —bifluorene-2-yl) represented by the structural formula (1) — N, N, —diphenylbenzidine (abbreviation: BSPB) A method will be described.

[0244]

[Chemical 1]

[0245]

[step 1]

First, the synthesis method of 2-promospiro_9,9'-bifluorene is explained. 2-Promospiro 9, 9 '— Bifluorene synthesis scheme (j– 1) is shown below.

[0246]

[Chemical 2]

[0247]

Magnesium (1.26 g, 0.052 mo 1) was placed in a 10 OmL three-necked flask, and the system was evacuated and heated and stirred for 30 minutes to activate. After cooling to room temperature, place the system under a nitrogen stream, add 5 mL of jetyl ether and a few drops of dibromoethane, and add 2-bromobiphenyl 1 1.65 g (0. 05 0 mo 1) dissolved in 15 mL of jet ether. After dripping slowly, the solution was refluxed for 3 hours after the completion of the dripping to obtain a darinier reagent. 2-Bromofluoreno> 1 1.7 g (0.045 mol) and jetyl ether 4 OmL were placed in a 20 OmL three-necked flask. The synthesized Grignard reagent was slowly added dropwise to the reaction solution, refluxed for 2 hours after completion of the addition, and further stirred at room temperature for about 12 hours. After completion of the reaction, the reaction solution was washed twice with a saturated aqueous solution of ammonium chloride, the aqueous layer was extracted twice with ethyl acetate, and the organic layer was washed with saturated brine. After drying with magnesium sulfate, suction filtration and concentration were carried out to obtain 18.76 g of solid 9- (2-biphenylyl) 1-2-promo 9 monofluorenol in a yield of 90%.

[0248]

Next, in a 3OmL flask of 20 OmL, the synthesized 9-one (2-biphenylyl) —2— Bromo-9-fluorenol (18.76 g, 0.045 mo 1) and glacial acetic acid (100 mL) were added, and a few drops of concentrated hydrochloric acid were added, followed by refluxing for 2 hours. After completion of the reaction, the precipitate was collected by suction filtration, and washed with a saturated aqueous sodium hydrogen carbonate solution and water. The resulting brown solid 10.24 _§ a pale brown powdered solid was recrystallized with ethanol to obtain 57% yield. Proton nuclear magnetic resonance (NMR) confirmed that this light brown powdery solid was 2-bromo-spiro 9,9'-bifluorene.

[0249]

The ¹ H-NMR of this compound is shown below. — NMR (300MHz, CDC 1 ₃ ) (5 = 7. 86— 7. 79 (m, 3H), 7.70 (d, 1 H, J = 8.4 Hz), 7. 47-7. 50 (m , 1 H), 7. 41—7.34 (m, 3H), 7.12 (t, 3 H, J-7.7 Hz), 6. 85 (d, 1 H, J = 2.1 Hz) 6.74—6.70 (m, 3H).

[0250]

[Step 2]

Next, a method for synthesizing N, N, -bis (spiro 9,9, 1 bifluorene 1 2-yl) 1 N, N '-diphenyl pendidine (abbreviation: BSPB) is described. The synthesis scheme of BSPB (j-12) is shown below.

[0251]

[Chemical 3]

[0252]

In a 10-OmL three-necked flask, 1.00, 0'-diphenylbenzidine was 1.00 g 0. 003 Omo 1), and 2-bromo-spiro-9,9'-bifluorene synthesized in step 1 was 2.49 g (0. 1), bis (dibenzylideneacetone) nodium (0) 17 Omg (0.3 Ommo 1), tert-butoxy sodium 1.08 g (0. 01 lmo 1) After under nitrogen flow, 20 mL of dehydrated toluene and 10 wt% hexane solution of tri (tert-butyl) phosphine 0.6 m L was added, and the mixture was stirred at 8 O: for 6 hours. After completion of the reaction, the reaction solution was cooled to room temperature, water was added, and the precipitated solid was collected by suction filtration and washed with dichloromethane. The resulting white solid was purified by alumina column chromatography (Kuroguchi Form) and recrystallized from dichloromethane to obtain 2.66 g of a white powdery solid in a yield of 93%.

[0253]

When the obtained white powdered solid was analyzed by proton nuclear magnetic resonance (H-NMR), the following results were obtained, and N, N ′ bis (s) represented by the structural formula (1) was obtained. It was confirmed that the substance was N, N'-diphenylbenzidine (abbreviation: BSPB). The NMR chart is shown in Fig. 33. iH— NMR (300 MHz, DMSO— d ₆ ) 6 = 7. 93— 7. 89 (m, 8H), 7. 39-7. 33 (m, 1 OH), 7. 19— 7. 14 (m, 8H), 7.09-6.96 (m, 6H), 6.89— 6.84 (m, 8H), 6.69 (d, 4H, J = 7.5Hz), 6.54 (d , 2H, J = 7.8Hz), 6.25 (d, 2H, J = 2.4Hz)

[0254]

When 4.74 g of the obtained compound was purified by sublimation for 24 hours under the conditions of 14 Pa, 350: 3.49 g could be recovered and the recovery rate was 74%.

[0255]

In addition, regarding the glass transition temperature, crystallization temperature, and melting point of the obtained compound, a differential scanning calorimetric analyzer (DSC: Differenci Al Sc n i n CA n ri cal me try, manufactured by Perkin Elmer, model number: Py ris 1 DSC). The DSC measurement was performed according to the following procedure. First, the sample (the obtained compound) was heated to 450 ° C. at a temperature increase rate of 40 / min, and then the sample was cooled to a glass state at a temperature increase rate of 40 minutes. And the sample in the glass state Was heated at a rate of temperature increase of 1 O tZ, and the measurement results shown in Fig. 34 were obtained. In Fig. 34, the horizontal axis represents temperature () and the vertical axis represents heat flow (upward is endothermic) (mW). From the measurement results, it was found that the obtained compound had a glass transition temperature of 1 72 ° C. and a crystallization temperature of 2 68 t :. Also, from the intersection of the tangent at 3 1 2 and the tangent at 3 2: ~ 3 2 8, it was found that the melting point was 3 2 3 and ~ 3 2 4. That is, the BSPB synthesized as in this example has a glass transition temperature of 1550 ° C. or higher, preferably 1 6 Ot: up to 30 0 0, and a melting point of 1 80 0 up to 4 0 0 It can be seen that it is in the range of ° C.

[0 2 5 6]

Thus, the obtained compound has a high glass transition temperature of 1 7 2 and has good heat resistance. Further, in FIG. 34, the peak representing crystallization of the obtained compound is broad, and it was found that the obtained compound is a substance that is difficult to crystallize.

[Industrial applicability]

[0 2 5 7]

As described above, the composite of an organic compound and a metal oxide according to the present invention is useful for simultaneously reducing power consumption and suppressing the occurrence of defects. A light emitting element and a light emitting device using the light emitting element Suitable for use in electronic equipment.

Claims

The scope of the claims

[Claim 1]

A light-emitting element comprising a composite of an organic compound and a metal oxide, wherein charge is transferred from a P orbit of an atom in the organic compound to a d orbit of a metal atom of the metal oxide.

[Claim 2]

The light-emitting element according to claim 1, wherein the metal atom is a transition metal.

[Claim 3]

2. The light-emitting element according to claim 1, wherein the metal atom is molybdenum.

[Claim 4]

2. The light-emitting element according to claim 1, wherein the organic compound is an aromatic amine compound.

[Claim 5]

5. The light-emitting element according to claim 4, wherein electric charges are transferred from the!) Orbit of the nitrogen atom of the aromatic amine compound.

[Claim 6]

2. The light emitting element according to claim 1, wherein the organic compound is an aromatic hydrocarbon.

[Claim 7]

A light-emitting device comprising the light-emitting element according to claim 1.

[Claim 8]

It has a plurality of pixels having a composite using an organic compound and a metal oxide,

A light emitting device characterized in that the increased number of pixel defects after driving for 60 hours is 0.087% or less of the total number of pixels.

[Claim 9] Having multiple pixels with composites using organic compounds and metal oxides, the number of pixel defects after driving for 85 hours at 60 hours is less than 0.087% of the total number of pixels. There is a light emitting device.

[Claim 1 0]

Having a plurality of pixels having a composite using an organic compound and a metal oxide,

— A light emitting device characterized in that the number of increased pixel defects after driving for 60 hours at 40 ° C. is 0.087% or less of the total number of pixels.

[Claim 1 1]

It is characterized by the fact that the number of pixel defects after driving for 8 hours at 85 and for 4 hours at _40 and driving for 60 hours is 0.087% or less of the total number of pixels. Light emitting device to be used.

[Claim 1 2]

It has a pixel having a complex using an organic compound and a metal oxide,

8 5 4 hours driving, _ 4 0 Repeat 4 hours driving, characterized in that the increase in the number of picture element defects after driving 6 0 hour, the display area 1 is 0 0 0 mm ² 3 per below A light emitting device.

[Claim 1 3]

A layer including a composite using an organic compound and a metal oxide;

A light-emitting device characterized in that the film thickness of a layer including the composite using the organic compound and the metal oxide differs depending on the emission color of each pixel.

[Claim 1 4]

An electronic apparatus comprising the light emitting device according to any one of claims 8 to 13.