JP5123475B2 - Fluorescent structure, composite, light emitting device, and light emitting device assembly - Google Patents

Description

The present invention is, for example, the backlight power supply for an electronic display, relates phosphor structure Contact and composite suitably used for the light emitting device such as a fluorescent lamp, and more particularly, the light emitted from the light emitting element to the outside wavelength conversion composite fluorescent structures you and it is dispersed in a resin to be used for taking out, the light emitting device, a light emitting device assembly.

  A light emitting element made of a semiconductor material (hereinafter sometimes referred to as an LED chip) emits light of a bright color with a small size and high power efficiency. LED chips have excellent features such as long product life, strong on / off lighting repeatability, and low power consumption, so they are expected to be applied to backlight sources such as liquid crystals and lighting sources such as fluorescent lamps. Has been.

  In recent years, by forming a wavelength conversion unit containing three types of phosphors on an ultraviolet light emitting element (emission wavelength of 400 nm or less), a white light emitting device that covers a wide range of emission wavelengths and has improved color rendering is obtained. Attempts have been made. However, this method has a problem in that the fluorescent quantum yield of the phosphor is low, and particularly the red fluorescent quantum yield in the region of 600 to 750 nm is low. .

  Therefore, as a phosphor for obtaining a high fluorescence quantum yield at each wavelength, semiconductor ultrafine particles having an average particle diameter of 10 nm or less have been studied as a phosphor (for example, see Non-Patent Document 1). According to this method, if the average particle size of the phosphor composition is set to an appropriate value of about 10 nm, the semiconductor ultrafine particles can quickly absorb and emit light, so that a high fluorescence yield can be obtained. Since the energy level becomes discrete and the band gap energy of semiconductor nanoparticles changes according to the particle diameter of the phosphor, changing the particle diameter allows various emission from red (long wavelength) to blue (short wavelength) Indicates. For example, cadmium selenide that emits fluorescence having an emission wavelength of 700 to 800 nm emits red (long wavelength) to blue (short wavelength) light with a high fluorescence yield by changing the average particle diameter in the range of 2 nm to 10 nm. Therefore, it is expected that an efficient light-emitting device can be manufactured by using this method with high color rendering properties.

  However, when the semiconductor particles become smaller, there are the following two problems. As a first problem, when the particle diameter of the semiconductor particles is reduced to about 20 nm, the ratio of the surface area to the volume is high, and therefore the particle surface reacts with water and the fluorescence characteristics deteriorate. For this reason, in order to obtain a light emitting device that is stable for a long period of time, it is necessary to devise a technique that prevents the phosphor particles from being exposed to moisture. As a technique for solving this problem, there is a method in which a phosphor is sealed in a transparent resin having low moisture permeability and mounted in a light emitting device as a composite in which the phosphor is dispersed in a resin matrix. However, there is a problem in that the phosphor reacts with moisture in the process of mixing the phosphor with the resin and curing, thereby deteriorating the characteristics of the phosphor.

  As a method for producing such semiconductor ultrafine particles, for example, a hot soap method (see Patent Document 1) and a microreactor method (see Patent Document 2) have been reported. When these methods are used, semiconductor ultrafine particles having a particle diameter of 20 nm or less can be obtained.

  The second problem is the problem of aggregation. In general, since the aggregation of semiconductor particles becomes worse as the particle size becomes smaller, it becomes difficult to disperse the semiconductor particles in a single particle state in the resin matrix. When the diameter of the semiconductor ultrafine particles exceeds 20 nm, even if the semiconductor ultrafine particles form aggregates, the color of light generated by the aggregates is the same as the color of light generated by single particles. There is no need to worry about agglomeration. However, when the semiconductor ultrafine particles are aggregated, the aggregate emits fluorescence having a longer wavelength than when the particles are present alone. Therefore, when the number of aggregates is large, a light-emitting device that stably generates light of a certain wavelength is provided. It cannot be manufactured. Therefore, when manufacturing a light-emitting device including a composite containing semiconductor ultrafine particles having a particle diameter of 20 nm or less as a wavelength conversion part inside the resin, a technique for dispersing the semiconductor ultrafine particles as single particles in the resin is required.

  As a technique for solving the second problem, a method of dispersing and fixing semiconductor ultrafine particles as single particles in a polymethacrylate matrix has been reported (see Non-Patent Document 2). There has also been reported a method for obtaining a film in which semiconductor ultrafine particles are dispersed by dispersing semiconductor ultrafine particles in ethanol and mixing and applying it in a polyethylene oxide paint using alcohol as a solvent (see Patent Document 3).

  In addition, when a conventional micron-sized phosphor is used, in order to uniformly disperse the phosphor in the resin, for example, ethylene glycol, ethylene glycol ester, ethylene glycol diacetate, ethylene glycol isopropyl ether, ethylene glycol mono Ethylene glycol compounds such as ethyl ether, or ionic properties such as carboxylates, sulfates, sulfonates, phosphates, primary to tertiary amines, and quaternary amines A dispersant is used.

JP 2003-160336 A JP 2003-225900 A JP 2002-121548 A R. N. Bhargava, Phys. Rev. Lett. , 72, 416 (1994) Jinwork Lee et al, Adv. Mater. , 12, no. 15, 1102 (2000)

However, resins such as polymethacrylate and polyethylene oxide have low stability to light and heat, and if the light emitting device is used for a long time or when used for a high output light emitting device, the resin will change color, so it will be used for a long time. Alternatively, when used for a light-emitting device intended for use at a high output, there is a problem that the efficiency of the light-emitting device gradually decreases.
In addition, transparency is another characteristic required for the resin of the wavelength conversion part in which the semiconductor ultrafine particles are dispersed in the resin. Therefore, it is possible to stably disperse the semiconductor ultrafine particles as single particles in a resin that satisfies all three characteristics of light stability, heat resistance, and transparency. This is an important issue in manufacturing a light emitting device exhibiting white.
A silicone resin is an example of a resin that is effective for such problems and has high stability to light, heat resistance, and transparency.

  However, the semiconductor ultrafine particles obtained by coordinating to the surface of a compound mainly composed of an alkyl group such as trioctylphosphine oxide or alkylamine obtained by the method described in Patent Document 1 can be mixed with a silicone resin as it is. Due to the alienating action that occurs between the compound that is coordinated to and the silicone resin, the particles cannot be present alone in the resin to form aggregates. Therefore, even if it is used in the light emitting device as it is, the intended light emission cannot be obtained.

  That is, when semiconductor ultrafine particles having an average particle diameter of 20 nm or less are used, methods for effectively suppressing deterioration of fluorescence characteristics due to moisture and dispersing in a single particle state without aggregation in the silicone resin are still known. Absent.

Further, not only such ultrafine semiconductor particles, but also when using conventional micron-sized phosphors, there are the following problems when using conventional dispersants. Since the wavelength conversion part is exposed to light such as ultraviolet rays or heat emitted from the light emitting element, if a dispersant having a high molecular weight is used, these will decompose and the wavelength conversion part will turn brown. Cannot be used. Therefore, a phosphor having a low molecular weight is used as the phosphor dispersant used in the wavelength conversion section. However, in the case of a dispersant having a low molecular weight, when used for a long period of time, the dispersant vaporizes due to the heat generated by the light emitting element, and bubbles are formed in the wavelength conversion part, and the dispersant penetrates into the resin and permeates the surface. There are problems such as taking out. Therefore, the actual situation is that there is no dispersant that can be used for a long period of time in a high-power light-emitting device that is exposed to light and heat such as ultraviolet rays having a strong wavelength conversion layer.
For this reason, there is no known method for dispersing a conventional micron-sized phosphor in a state of single particles without aggregation in a silicone resin.

Therefore, in the present invention, a phosphor that can be used in a light-emitting device that is used for a long time at a high output, particularly a phosphor having an average particle diameter of 20 nm or less is mixed with a resin, and the phosphor is uniformly dispersed without aggregating It is an object to obtain a fluorescent structure capable of satisfying the requirements.
Furthermore, an object of the present invention is to provide a composite, a light-emitting device, and a light-emitting device assembly that are excellent in luminous efficiency using the fluorescent structure.

The fluorescent structure of the present invention has the following configuration.
(1) Fluorescence of any one of (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ C ₁₂ : Eu, La ₂ O ₂ S: Eu, and BaMgAl ₁₀ O ₁₇ : Eu, M n surface of the body, an amino group, comprises one single closed side chain functional group selected from the group consisting of mercapto group and a carboxyl group, a side chain used without the said functional group, free of silicon, methyl A fluorescent structure characterized by being coated with a compound having one type selected from the group consisting of a group, an ethyl group and a propyl group and having a silicon-oxygen repeating number of 5 to 500.

The composite of the present invention has the following configuration.
(2) composites the phosphor structure described under (1), characterized in that it dispersed in a resin matrix.
(3 ) The composite according to ( 2), wherein the resin matrix is a liquid resin .

The light emitting device of the present invention has the following configuration.
( 4 ) A light emitting element that is provided on the substrate and emits excitation light, and is located in front of the light emitting element, converts the wavelength of the excitation light, and emits output light having a wavelength different from that of the excitation light (2) or (3 emitting device characterized by comprising a composite according to).

The light emitting device assembly of the present invention is characterized by comprising a plurality pieces including a light-emitting device according to (4).

According to the above (1), the compound having 5 to 500 silicon-oxygen bonds acts as a phosphor dispersant for the composite resin, for example. Therefore, by covering the surface of the phosphor with the compound, it is possible to form a wavelength conversion unit in which the phosphor is uniformly dispersed in the resin, and thus a light emitting device without unevenness in light can be manufactured. .
Further, in a compound in which a silicon-oxygen bond is repeated for 5 to 500 , the bond at this portion is about 1.5 times as strong as the carbon-carbon bond, so that at least this portion is not easily decomposed by light such as ultraviolet rays or heat. Therefore, decomposition is less likely to occur than an organic compound dispersant whose main structure is a carbon-carbon bond. For this reason, by combining this fluorescent structure with a resin that is less deteriorated by ultraviolet rays or heat, the wavelength conversion unit is configured to turn brown into brown even when used in a high-output light-emitting device. It is possible to obtain a wavelength conversion unit in which the brightness does not decrease.
In addition, a compound having silicon-oxygen repeatedly has an effect in that the phosphor is protected from deterioration due to moisture from the water repellency of the compound.
Furthermore, the hydrophobicity of the compound can be improved by setting the number of silicon-oxygen repeats to 5 or more, and by setting it to 500 or less, the compound can be prevented from becoming unnecessarily large. Can be efficiently coordinated to the surface of the phosphor.

According to the composite ( 2 ), since the ultrafine particle structure, which is a fluorescent material having a high fluorescence yield, is dispersed in a resin matrix, a composite having a high fluorescence yield can be obtained .

According to the above ( 3 ), even when the composite is installed on the uneven structure, the composite can be made to follow the unevenness completely by filling the liquid resin into the uneven structure and then curing it. I can .

According to the light emitting device of ( 4 ), the wavelength of the light emitted from the light emitting element is converted by the composite, and the light different from the light emitted from the light emitting element is output, so that the color rendering property is high and the fluorescence quantum yield is low. A high light emitting device can be manufactured .

Since the light emitting device assembly of ( 5 ) includes a plurality of the light emitting devices, the light output can be made higher than when the light emitting device is used alone.

As shown in FIGS. 1A and 1B, the fluorescent structure according to the present invention will be described using the ultrafine particle structure 1 as an example. The ultrafine particle structure 1 has a structure in which the surface of a nanosized semiconductor ultrafine particle 3 is covered with a compound 5 having a structure in which a bond of silicon-oxygen is repeated for 5 to 500 , in particular, FIG. As shown in FIG. 2, it is desirable that the compound 5 is coordinated to the nanosized semiconductor ultrafine particles 3.

  Thus, by covering the surface of the nanosized semiconductor ultrafine particles 3 with the compound 5 having a structure in which two or more silicon-oxygen bonds are repeated and rich in hydrophobicity, the characteristics of the nanosized semiconductor ultrafine particles 3 with water are obtained. Deterioration can be prevented. Further, since this compound 5 has a very high affinity with the silicone resin, the ultrafine particle structure 1 can be easily dispersed in the silicone resin, and the bonding between the ultrafine particle structure 1 and the silicone resin can be achieved. Power can also be increased.

The viewpoint that the number of silicon-oxygen bonds (that is, the number of repeating units of silicon-oxygen, hereinafter the same) is 5 or more, particularly 7 or more in the compound 5 improves the hydrophobicity of the compound 5. Desirable from. On the other hand, when the number of silicon-oxygen bonds is 500 or less, the compound 5 can be prevented from becoming unnecessarily large, and the compound 5 is efficiently coordinated to the surface of the nano-sized semiconductor ultrafine particles 3. Can be made. In particular, from the viewpoint of coordinating more compounds 5 on the surface of the nano-sized semiconductor ultrafine particles 3, the number of silicon-oxygen bonds is preferably 300 or less, particularly 100 or less.
As shown in FIG. 2, the compound 5 is composed of a main chain 5a in which a silicon-oxygen bond is repeated for 5 to 500 and side chains 5b and 5c bonded to the main chain 5a. The side chain 5b has no functional group, and the side chain 5c has a functional group.

The side chain 5c, to facilitate coupling of the semiconductor ultrafine particles 3 and the compound 5, to improve the bonding strength between them, as shown in the following formula (a), an amino group, or selected mercapto and carboxyl groups It is desirable to have a functional group X.

Since these functional groups have a lone electron pair or π electron, they function as a nucleophile and strongly coordinate bond with the semiconductor ultrafine particle 3 or strongly coordinate with the semiconductor ultrafine particle 3 due to electric action of electric charge by polarization. Join. Therefore, the ultrafine particle structure 1 in which the compound 5 having these functional groups is coordinated to the semiconductor ultrafine particles 3 can stably maintain the coordinate bond for a long period of time. In particular, amino groups, mercapto groups, and carboxyl groups have a strong coordination bond strength with the semiconductor ultrafine particles 3, so that the ultrafine particle structure 1 that is stable for a longer period can be produced. In addition, the hydroxy group has a strong coordination bond to the oxide semiconductor. This is because an oxygen atom on the surface of the oxide semiconductor attracts hydrogen of a hydroxy group.
These functional groups may be directly bonded to the silicon atom of the main chain 5a, or may be bonded to the silicon atom through a side chain such as a methylene group or an ethylene group.

As shown in the following formula (b), the side chain 5b (indicated by Y in the formula) having no functional group among the side chains of the compound 5 does not contain silicon, and is a methyl group, an ethyl group, n- A propyl group or an iso-propyl group. Thereby, the light resistance and heat resistance of the ultrafine particle structure 1 can be improved.
Further, the side chain 5c having a functional group may be the functional group itself, or a part of the same group as the side chain 5b may be substituted with the functional group, and may be a methyl group or an ethyl group. In addition, a part of the propyl group or the like may be substituted with a functional group.

  This is because, when the side chain 5b has a functional group that absorbs ultraviolet light such as a phenyl group or a vinyl group, this portion absorbs light energy, so that not only the efficiency is lowered, but also this compound This is because it takes damage. Further, when the side chain 5b is composed of a hydrocarbon group and this hydrocarbon group is a long chain (9 or more carbon atoms), the heat resistance of the compound 5 is lower than that of a short chain.

As described above, by controlling the structure of the compound 5, the compound 5 can be firmly bonded to the semiconductor ultrafine particles 3, and the ultrafine particle structure having excellent water resistance, heat resistance, and light resistance. Body 1 is obtained.
The average particle size of the semiconductor ultrafine particles 3 used in the ultrafine particle structure 1 is preferably 0.5 to 20 nm in that the wavelength of fluorescence can be adjusted by the particle size. Thus, a light emitting device with high color rendering can be produced by adjusting the particle size of the semiconductor ultrafine particles.

Furthermore, the average particle diameter of the semiconductor ultrafine particles 1 is preferably 1 nm or more, particularly 2 nm or more from the viewpoint of preventing aggregation. Further, it is desirable that the thickness is 10 nm or less, particularly 5 nm or less from the viewpoint of obtaining a high fluorescence yield.
As a method of obtaining the semiconductor ultrafine particles 3 having an average particle diameter of 0.5 to 20 nm, for example, reverse micelles are formed with trioctylphosphine oxide, and the metal element and the chalcogen element are heated at a temperature of about 300 ° C. in the micelles. The method of making it react is mentioned.
The particle diameter can be measured using a method in which the particle diameter of the cadmium selenide semiconductor ultrafine particles 3 is measured in Examples described later.

Moreover, it is preferable that the semiconductor ultrafine particles 3 have a photoluminescence function in that a light emitting device having a small size and high color rendering properties can be manufactured.
The semiconductor ultrafine particles 3 are (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ C ₁₂ : Eu, La ₂ O ₂ S: Eu, and BaMgAl ₁₀ O ₁₇ : Any one of the phosphors of Eu and Mn is preferable. Since such a phosphor (semiconductor ultrafine particle 3) has high fluorescence quantum efficiency, an ultrafine particle structure 1 having high fluorescence quantum efficiency can be produced.

  The semiconductor ultrafine particle 3 preferably has a core-shell structure in that an ultrafine particle structure 1 with high fluorescence quantum efficiency can be obtained. The reason why the quantum quantum efficiency is increased by adopting the core-shell structure is that the composition of the semiconductor of the shell forms an energy barrier by using a material whose forbidden bandwidth (band gap) is larger than that of the core. It is presumed that this is due to a mechanism that suppresses the influence of an undesirable surface level or the like due to the influence or a crystal lattice defect on the crystal surface. Examples of the composition suitably used for the shell include III-V group compound semiconductors such as BN, BAs, GaN and GaP, II-VI group compound semiconductors such as ZnO and ZnS, and periodic table Group 2 elements such as MgS and MgSe. And compounds of Group 16 elements of the periodic table are preferably used.

Since the ultrafine particle structure 1 described above is dispersed in a resin matrix 7 as shown in FIG. 3 to form a composite 9, the effect of blocking the ultrafine particle structure 1 from moisture is further enhanced. The characteristic deterioration due to moisture of the semiconductor ultrafine particles 3 can be effectively prevented. Moreover, since the ultrafine particle structure 1 can be handled from a powder state to a liquid or solid state, the handleability and storage stability are significantly improved.
The resin matrix 7 constituting the composite 9 is obtained, for example, by mixing a photocurable resin, a resin matrix containing a thermosetting resin, and the ultrafine particle structure 1 in a liquid state. From the viewpoint of handling, it is desirable to cure to an arbitrary shape by heat or light.

Needless to say, when the resin matrix 7 is cured by heat energy, the composite 9 can be cured by inexpensive equipment such as a dryer or a heater block.
Moreover, it is preferable that the resin matrix 7 is hardened | cured with light energy at the point which can obtain the light-emitting device with high adhesiveness of the composite 9 and a light emitting element. If the resin matrix 7 is of a type that is cured by light energy, the liquid uncured composite 9 can be placed on the light emitting element, and then the liquid uncured composite 9 can be cured by light. According to this method, unlike the case where the thermosetting type composite 9 is used, the composite 9 can be cured without causing destruction of the light emitting element due to heat for curing. Therefore, since the light emitting element and the liquid uncured composite 9 can be brought into direct contact, the light emitting device 11 having high adhesion between the composite 9 and the light emitting element can be obtained.
When a silicone resin is used as the resin matrix 7, the composite 9 is excellent in translucency and excellent in heat resistance, light resistance, and particularly water resistance.

  The silicone resin will be described in detail. The silicone resin is composed of a main chain whose main part has a form of repeating silicon-oxygen and a side chain bonded to the silicon atom. is there. When the side chain is a group that absorbs ultraviolet light such as a phenyl group or vinyl group, light absorption occurs in the silicone resin. For this reason, it is preferable that the side chain of the silicone resin used for the composite 9 is a linear or cyclic saturated hydrocarbon group. However, when this linear or cyclic saturated hydrocarbon group has more than 7 carbon atoms, its heat resistance is lowered, so the side chain is a linear or branched alkyl group having 1 to 7 carbon atoms, carbon number Is preferably at least one of 3 to 8 cycloalkyl groups, specifically, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, n- It is preferably composed of any one of a pentyl group, an iso-pentyl group, an n-hexyl group, an iso-hexyl group, a cyclohexyl group, or a combination of two or more thereof. For the same reason, the side chain 5b of the compound 5 is a straight chain or branched alkyl group having 1 to 7 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, or a straight chain having 1 to 7 carbon atoms. Alternatively, it is preferably at least one selected from a branched alkoxy group or a cycloalkyloxy group having 3 to 8 carbon atoms.

  By using at least two kinds of semiconductor ultrafine particles having different compositions, it becomes easy to combine a plurality of fluorescent lights having different wavelengths, and a light emitting device having high color rendering properties can be obtained. For example, by combining cadmium selenide and zinc sulfide, it is possible to simultaneously emit red and blue light within the composite with the same particle diameter. For this reason, the composite 9 of high color rendering property can be obtained by preparing the ultrafine particle structure 1 having several kinds of compositions manufactured with a particle diameter that is easy to make on a manufacturing apparatus.

  The composite 9 preferably has a refractive index of 1.7 or more in that the light whose wavelength is converted inside the composite 9 can be efficiently emitted to the atmosphere. The light emitted from the light emitting element is guided to the composite 9 in which the ultrafine particle structure 1 and the silicone resin 13 are mixed. Here, the wavelength of the light is converted and then emitted to the atmosphere. At this time, when the refractive index of the composite 9 is smaller than 1.7, the light is reflected at the interface between the composite 9 and the atmosphere and is not easily released into the atmosphere. The refractive index was measured by molding a composite into a film having a thickness of 1 mm and using a refractive index measuring machine 2010 prism coupler made by Ipros.

The composite 9 preferably emits fluorescence having at least two or more intensity peaks in the visible light wavelength range, and particularly in the visible light wavelength range, in that a white light emitting device having high color rendering properties can be obtained. It is preferable to emit fluorescence having three or more intensity peaks. In this way, white light with high color rendering can be obtained.
As shown in FIG. 4, the light emitting device 11 of the present invention can convert the light emitted from the light emitting element 13 as the light source by using the composite 9 to output the light different from the light emitted from the light emitting element. is important.

The light emitting device 11 of the present invention includes, for example, a wiring board 17 provided with electrodes 15 for supplying power to the light emitting element 13 from the outside, a light emitting element 13 mounted on the wiring board 17, and a light emitting element of the wiring board 17. It is comprised from the frame 19 provided in the 13th side, and the composite 9 formed so that the light emitting element 13 might be covered.
On the wiring board 17, for example, the light emitting element 13 that emits ultraviolet light having a wavelength of 395 nm is connected to the electrode 9 through a metal brazing material. When power is supplied to the electrode 9, the light emitting element 13 emits ultraviolet light, and this light is supplied into the composite 9. Ultraviolet rays are converted into light having a visible wavelength by the ultrafine particle structure 1 inside the composite 9, and the converted light is emitted from the composite 9 to the outside of the light emitting device 11.

Moreover, it is preferable to comprise the light-emitting device 11 so that output light may emit light having a wide spectrum of 400 to 900 nm in terms of enhancing color rendering. As this method, there is a method in which the composite 9 contains the ultrafine particle structure 1 having a wide particle size distribution in addition to the composite 9 containing the ultrafine particle structure having a plurality of average particle sizes.
Moreover, it is preferable to make the band gap energy of at least a part of the semiconductor ultrafine particles 3 smaller than the energy emitted from the light emitting element 13 in terms of making the light emitting device 11 with good light emission efficiency. When all the band gap energies of the semiconductor ultrafine particles 3 are higher than the energy emitted from the light emitting element 13, the semiconductor ultrafine particles 3 cannot absorb the light energy emitted from the light emitting elements, and the efficiency of the light emitting device is significantly reduced. .

  The light-emitting device assembly 11 of the present invention includes a plurality of the light-emitting devices 11 described above, and can produce a white light-emitting device assembly having high power efficiency and long color rendering properties.

  Below, the manufacturing method of the ultrafine particle structure of this invention is demonstrated in detail. The ultrafine particle structure 1 shown in FIG. 1 can be manufactured by mixing the semiconductor ultrafine particles 3 and a compound 5 that repeats two or more silicon-oxygen bonds capable of coordination bonding, and stirring while heating. it can. The semiconductor ultrafine particle 3 can be produced by a hot soap method or a microreactor method using a compound mainly composed of an alkyl group and having a functional group as a solvent. For example, trioctylphosphine oxide or dodecylamine can be used as the compound mainly composed of the alkyl group. As the compound in which two or more silicon-oxygen bonds capable of coordination bonding are repeated, those described above can be used. The semiconductor ultrafine particle 3 and the compound 5 are mixed and stirred while heating to exchange trioctylphosphine oxide or dodecylamine which has been coordinated and bonded to the surface of the semiconductor ultrafine particle 3 with the compound 5, and the semiconductor ultrafine particle 3 The ultrafine particle structure 1 can be obtained by coordination bonding of the compound 5 to the surface. At this time, heating may be performed as necessary. If the compound 5 can be coordinated to the surface of the semiconductor ultrafine particles 3 at room temperature, the heating may not be performed.

  The liquid uncured composite 9 can be produced by mixing the ultrafine particle structure 1 with an uncured resin or a resin plasticized with a solvent. For example, a silicone resin or an epoxy resin can be used as the uncured resin. These resins may be of a type in which two liquids are mixed and cured, or a type that is cured in one liquid. Even if the fine particle structure 1 is kneaded, the ultrafine particle structure 1 may be kneaded in either one of the liquids. Moreover, as a resin given plasticity with a solvent, for example, an acrylic resin can be used.

  The cured composite 9 can be obtained by forming the uncured composite 9 into a film shape or pouring it into a predetermined mold and solidifying it. As a method of curing the resin, there is a method of using heat energy or light energy, and a method of volatilizing the solvent.

  The light emitting device 11 of the present invention can be obtained by installing the composite 9 on the light emitting element 13 mounted on the wiring board 17. As a method of installing the composite 9 on the light emitting element 13, it is possible to install the cured composite 9 on the light emitting element 13, and after setting the liquid uncured composite 9 on the light emitting element 13, curing is performed. It is also possible to install them.

  The light emitting device assembly of the present invention can be obtained by arranging a plurality of light emitting devices 11 on a substrate. In this case, electrodes can be formed in advance on the substrate, and the light emitting device 11 can be obtained by connecting with a metal brazing material. For example, a printed circuit board can be used as the substrate, and solder can be used as the metal brazing agent.

In the above description, the ultrafine particle structure using the nanosized semiconductor ultrafine particles 3, the composite 9, and the light emitting element 13 have been described. However, instead of the nanosized semiconductor ultrafine particles 3, a micron size phosphor ( For example, the present invention can be similarly applied to the case of using a phosphor having an average particle size of 0.1 μm or more. The micron-sized phosphor is the same as the semiconductor ultrafine particle 3 except for the particle diameter, but has the following characteristics. In the case of the nano-sized semiconductor ultrafine particles 3, it is possible to manufacture a light emitting device with high color rendering properties by using several types having different particle sizes. In the case of a phosphor of micron size, the light emission wavelength does not change depending on the particle size of the phosphor, and it is not necessary to finely manage the particle size, so that a light emitting device can be easily manufactured.
It is also possible to use the nano-sized semiconductor ultrafine particles 3 and the micron-sized phosphor together.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited only to a following example.

First, three types of phosphors that emit blue, red, and green fluorescence were prepared. Compound 5 having silicon-oxygen repeatedly on the surface of these phosphors, having an amino group as a functional group, and a side group without a functional group being a methyl group (repetition number of silicon-oxygen: 70, molecular weight: about 5000, functional The number of groups: 1 group / molecule) was bonded. The phosphors used were (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu (blue) with a particle size of 5.5 μm, La ₂ O ₂ S: Eu (red) with a particle size of 6.3 μm. BaMgAl ₁₀ O ₁₇ : Eu, Mn (green) having a particle diameter of 5.8 μm. In the treatment method, 99 g of toluene was added to 1 g of compound 5 and stirred well, and 10 g of a phosphor (mixing ratio was blue: red: green = 2: 1: 1) was immersed in the mixture. The mixture was stirred at ° C. for 2 hours, filtered through filter paper, and then vacuum dried to remove toluene.
This was mixed with 100 g of a main component of a two-component thermosetting silicone resin (condensation curing type, curing condition at room temperature for 24 hours, viscosity of 5.2 Pa · s) with a stirring deaerator, and then 0.1 g of curing agent for this silicone resin. And further mixed with a stirring devolatilizer to obtain an uncured composite. This was poured onto a glass plate so as to have a thickness of 2 mm, degassed by vacuuming, and then heat-cured at 80 ° C. for 2 hours and peeled off from the glass plate. In this way, a cured silicone resin composite containing three kinds of phosphors of blue, red and green was obtained. This was cut into a circle with a diameter of 2 mm and placed on an InGaN light emitting device (6.5 mW at a current of 20 mA) that emits light with a size of 0.35 mm × 0.35 mm and a peak emission wavelength of 395 nm. The luminescence intensity was measured.

[Comparative Example 1]
A silicone resin composite was obtained in the same manner as in Example 1 except that polyoxyethylene alkyl ether was used instead of compound 5. That is, 1 g of polyoxyethylene alkyl ether was added to 99 g of ethanol and stirred well. The three kinds of blue, red and green phosphors were immersed in this, stirred at 60 ° C. for 2 hours, and filtered. Then, it was vacuum dried to remove ethanol. This was mixed with a main component of a two-component thermosetting silicone resin with a stirring defoamer, and then a silicone resin curing agent was added and further mixed with a stirring deaerator to obtain an uncured composite. This is poured onto a glass plate to a thickness of 2 mm, vacuumed and degassed, then heated and cured at 80 ° C. for 2 hours, peeled off from the glass plate, and blue, red, and green phosphors. A cured silicone resin composite containing was obtained. The emission intensity of this composite was measured in the same manner as in Example 1.

[Comparative Example 2]
A silicone resin composite was obtained in the same manner as in Example 1 except that ethylene glycol isopropyl ether was used instead of compound 5. That is, 1 g of ethylene glycol isopropyl ether was added to 99 g of ethanol and stirred well. The three types of blue, red, and green phosphors were immersed in the mixture, stirred at 60 ° C. for 2 hours, and then filtered and vacuumed. Dry to remove ethanol. This was mixed with a main component of a two-component thermosetting silicone resin with a stirring defoamer, and then a silicone resin curing agent was added and further mixed with a stirring deaerator to obtain an uncured composite. This is poured onto a glass plate to a thickness of 2 mm, vacuumed and degassed, then heated and cured at 80 ° C. for 2 hours, peeled off from the glass plate, and blue, red, and green phosphors. A cured silicone resin composite containing was obtained. The emission intensity of this composite was measured in the same manner as in Example 1.
The measurement results of the fluorescence intensity are shown in Table 1. Sample number 1 is a sample in which compound 5 is bound to the phosphor surface. In this sample, the emission intensity was 0 hour and the emission efficiency was 20 Lm / W, but the fluorescence intensity was maintained as high as 20 Lm / W even at 500 hours. On the other hand, in sample No. 3 of the comparative example, the fluorescence intensity was 20 Lm / W, which was the same as that in sample No. 1 at 0 hour, but decreased to 5 Lm / W after 500 hours. When the composite at this time was confirmed, the portion near the light emitting element inside the composite was discolored to yellow. Further, in the sample number 2 of the comparative example, the fluorescence intensity was 20 Lm / W which was not different from that in the case of the sample number 1 at 0 hours, but decreased to 15 after 500 hours. When the composite at this time was confirmed, the composite was cloudy, and when the inside was monitored, bubbles were generated in a portion close to the light emitting element.

First, a method for producing CdSe ultrafine particles, which are semiconductor ultrafine particles, will be described. 7.9 g (0.1 M) of Se powder manufactured by Kanto Chemical Co., Inc. is dissolved in 250 g of trioctylphosphine (TOP), and this is used as Solution 1. Next, 7.6 g (0.1 M) sodium sulfide manufactured by Kanto Chemical Co., Inc. is dissolved in 250 g of trioctylphosphine (TOP), and this is used as Solution 2.
Next, 5.3 g (0.02 M) of cadmium acetate manufactured by Kanto Chemical Co., Ltd. and 100 g of stearic acid were mixed and dissolved at 130 ° C. To this solution, 400 g of trioctylphosphine oxide (TOPO) was added and heated to 300 ° C. to dissolve.
To this solution, the previous solution 1 is added and reacted at 300 ° C. After completion of the reaction, it was cooled to room temperature. Further, 200 g of toluene was further added to the cooled solution and mixed uniformly, and then ethanol was further added and acceleration of 1500 G was applied for 10 minutes with a centrifuge to precipitate cadmium selenide particles. Next, 3.7 g (0.02 M) of zinc acetate and 100 g of stearic acid were mixed with the cadmium selenide particles and dissolved at 130 ° C. 400 g of trioctylphosphine oxide (TOPO) was added to this solution, heated to 300 ° C., solution 2 was added, and then cooled to room temperature. 200 g of toluene was added thereto and mixed uniformly, and then ethanol was further added, and the core-shell structured cadmium selenide particles coated with zinc sulfide were precipitated by applying an acceleration of 1500 G for 10 minutes in a centrifuge.
It was confirmed by TEM that the cadmium selenide semiconductor ultrafine particles 3 obtained by collecting the precipitate had an average particle diameter of 3 nm. In addition, the fluorescent color when the ultraviolet rays were applied to the cadmium selenide semiconductor ultrafine particles 3 was yellow. The central emission wavelength of the fluorescence peak was 580 nm.
Next, the cadmium selenide semiconductor ultrafine particles 3 obtained as described above were weighed into 2 mg portions, and the amino group, mercapto group, carboxyl group, ester group represented by the general formula (a) were measured. (Not shown), 2 g of each compound 5 each having a silicon-oxygen having an ether group (not shown) as a functional group and having a methyl group as a side chain without a functional group was added. This was stirred for 20 hours in the state heated at 90 degreeC in nitrogen atmosphere. When the stirring was completed, the amino group, mercapto group, and carboxyl group solutions were all in an orange liquid state. In addition, although the amide group and vinyl group solutions turned orange, some cadmium selenide remained as a precipitate without the compound 5 being coordinated.

  Next, the compound 5 repeatedly having excess silicon-oxygen not coordinate-bonded to the cadmium selenide semiconductor ultrafine particles 3 was removed from the cadmium selenide semiconductor ultrafine particles 3 treated in this manner. That is, 2 g of chloroform was added to the orange liquid and stirred, and then 10 g of methanol was added and stirred. After confirming that this solution became cloudy, the semiconductor ultrafine particles were precipitated by applying an acceleration of 1500 G for 30 minutes with a centrifuge. Thereafter, the chloroform and methanol solutions in the supernatant were removed with a spoid. This operation was repeated three times to remove the compound having silicon-oxygen repeatedly, whereby an ultrafine particle structure 1 was obtained.

The particle diameter of the cadmium selenide semiconductor ultrafine particles 3 of the ultrafine particle structure 1 was measured using a transmission electron microscope (TEM). The transmission electron microscope used was JEOL JEM2010F, and an acceleration voltage of 200 kV was observed according to the following procedure. The cadmium selenide semiconductor ultrafine particles 3 precipitated as described above were placed in a sample bottle, and IPA or toluene in an amount such that the particle concentration was in the range of 0.002 to 0.02 mol / liter was added and dispersed. This was scooped with a TEM observation microgrid, dried, and then set on a transmission electron microscope. The particle diameter was measured by confirming the particles from the lattice image. First, the part where the particles adhered to the mesh was searched at a low magnification. At this time, the portion where a large amount of cadmium selenide semiconductor ultrafine particles 3 are attached is not suitable for measuring the particle diameter because the particles overlap in the direction of the electron beam. Further, since the cadmium selenide semiconductor ultrafine particles 3 adhering to the Cu mesh portion of the microgrid cannot observe the lattice image, they are not suitable for observing the particle diameter. Therefore, the cadmium selenide semiconductor ultrafine particles 3 for measuring the particle diameter were selected by selecting a portion having as little overlap as possible in the resin portion of the microgrid. Next, this portion is enlarged to about 1,000,000 times to confirm the lattice image.
At this time, when many organic components used at the time of synthesis remain around the cadmium selenide semiconductor ultrafine particles 3, the lattice image is blurred, and thus the particle diameter cannot be measured correctly. In such a case, observation was performed by changing the location, or in some cases, a sample was prepared by repeatedly removing organic components during synthesis, and observation was performed.
Removal of organic components during synthesis is performed by adding chloroform, toluene, or hexane to the precipitated cadmium selenide semiconductor ultrafine particles 3 and dispersing with ultrasonic waves, and then adding alcohol (for example, ethanol) to the centrifugal separator. It can be done by calling. The organic component at the time of synthesis is dissolved in the supernatant ethanol, and the cadmium selenide semiconductor ultrafine particles 3 are precipitated. This operation was repeated as necessary. Thus, after searching for the cadmium selenide semiconductor ultrafine particles 3 with little adhesion of organic components used at the time of synthesis, a lattice image was photographed at a magnification of 4,000,000. At this time, if the electron beam is kept on for a long time, the cadmium selenide semiconductor ultrafine particles 3 move, and thus the image was taken quickly.
The particle diameter of the cadmium selenide semiconductor ultrafine particles 3 was determined by processing according to the following method based on the diameter of 200 lattice images taken.
The length average diameter was calculated by statistically calculating the diameter of the measured lattice image by writing a histogram. The length average diameter was calculated by counting the number belonging to the diameter section and dividing the sum of the product of the center value and the number of the diameter section by the total number of measured grid images (average Particle shape and calculation formula, “Ceramic manufacturing process” p.11-12, edited by ceramic industry association editorial committee lecture subcommittee). The length average diameter thus calculated was regarded as the particle diameter of the cadmium selenide semiconductor ultrafine particles 3.
Note that the length measurement was performed except for particles with a blurred lattice image. All lattice images were measured in the same direction with respect to the photographic paper so that the diameter of each lattice image would not be measured with a bias toward a long or short portion. In addition, before observation with a transmission electron microscope, observation with SEM (500 to 100,000 times) is performed to confirm that there are no large particles of the order of μm.

  The obtained ultrafine particle structure 1 was vacuum-dried and then mixed with the same two-component thermosetting silicone resin as in Example 1 to obtain a liquid uncured composite. This was poured into a fluorescence measuring cell having a thickness of 10 mm and cured by heating at 80 ° C. for 2 hours to obtain a cured composite. In these composites, any of the compounds having silicon-oxygen repeatedly emitted a yellow fluorescent color when irradiated with ultraviolet rays.

The fluorescence intensity of these composites was measured in the same manner as in Example 1. The measurement results are shown in Table 2. Sample No. 4 is an amino group (—NH ₂ ). 5 mercapto group (-SH), sample no. In the case of 6 carboxyl groups (—COOH), the fluorescence intensity was as high as 0.9. At this time, sample no. When the functional group 4 is an amino group (—NH ₂ ), modified silicone oil KF-865 manufactured by Shin-Etsu Chemical Co., Ltd. is used. The modified silicone oil X-22-167B manufactured by Shin-Etsu Chemical Co., Ltd. A modified silicone oil X-22-162C manufactured by Shin-Etsu Chemical Co., Ltd. was used for those having 6 carboxyl groups (—COOH).
Sample No. The ester group (—COO—) of No. 7 has a fluorescence intensity of 0.5. The ether group (—COC—) of 8 had a fluorescence intensity of 0.4. At this time, sample no. A modified silicone oil KF-910 manufactured by Shin-Etsu Chemical Co., Ltd. was used when the functional group 7 had an ester group (—COO—). Sample No. The modified silicone oil in which the functional group 8 is an ether group (—COC—) has the structure shown in Table 2.
In addition, as a comparative example, when treated with a modified silicone oil whose functional group is an alkyl group (KF-414, manufactured by Shin-Etsu Chemical Co., Ltd.), the semiconductor ultrafine particles were almost completely precipitated. I didn't stay there.

また、前述のアミノ基を官能基とする超微粒子構造体１を０．０１ｇ量り取り、これにトルエン２０ｇを加えた。これらのトルエン溶液の蛍光強度をトルエン溶液調整直後とトルエン溶液調整から１４日後に測定し、大気中の水分による蛍光強度の低下を調べた。蛍光の波長及び強度の測定はＳＨＩＭＡＺＵ製ＰＦ−５３００ＰＣで行った。
結果を表３に示す。表３に示されるように、本発明の比較例である試料Ｎｏ．９、１０では、トルエン溶液調整直後の蛍光強度が０．９であったものが、試料Ｎｏ．９では１４日後に０．７となり、また、試料Ｎｏ．１０では１４日後に０．７となり、蛍光強度の低下が見られた。また、試料Ｎｏ．１１は、試料Ｎｏ．４と同様にして作製した超微粒子構造体１を０．０１ｇ量り取りこれにトルエン２０ｇを加えたものである。この試料ではトルエン溶液調整直後およびトルエン溶液調整から１４日後の蛍光強度はいずれも０．９であり、蛍光強度の低下は見られなかった。

As another comparative example, 0.01 g of cadmium selenide particles before being treated with the above-described compound 5 in the examples was weighed, and 20 g of toluene was added thereto. TOPO used as a solvent in the step of producing semiconductor ultrafine particles is coordinated to the surface of the cadmium selenide particles.
In addition, a compound represented by the following formula having only one silicon-oxygen bond is added to a mixed solution in which semiconductor fine particles are dispersed in a mixed solution of ethanol and water, dried, and a comparative example on the surface of the semiconductor fine particles. The compound of this was combined, and the semiconductor ultrafine particle of the comparative example was produced. 0.01 g of semiconductor ultrafine particles of this comparative example were weighed and 20 g of toluene was added thereto.

Further, 0.01 g of the ultrafine particle structure 1 having an amino group as a functional group was weighed, and 20 g of toluene was added thereto. The fluorescence intensity of these toluene solutions was measured immediately after the toluene solution adjustment and 14 days after the toluene solution adjustment, and the decrease in the fluorescence intensity due to moisture in the atmosphere was examined. The measurement of the wavelength and intensity of the fluorescence was performed with PF-5300PC manufactured by SHIMAZU.
The results are shown in Table 3. As shown in Table 3, Sample No. which is a comparative example of the present invention. In Samples Nos. 9 and 10, the sample No. 9 had a fluorescence intensity immediately after preparation of the toluene solution of 0.9. 9 was 0.7 after 14 days. In 10, it became 0.7 after 14 days, and a decrease in fluorescence intensity was observed. Sample No. 11 is a sample No. 11; The ultrafine particle structure 1 produced in the same manner as in No. 4 was weighed out by 0.01 g, and 20 g of toluene was added thereto. In this sample, the fluorescence intensity immediately after the toluene solution adjustment and 14 days after the toluene solution adjustment was 0.9, and no decrease in the fluorescence intensity was observed.

次に、アルミナ基板上に中心発光波長３９５ｎｍの発光素子をフリップチップ実装法にて実装した。これに、官能基がアミノ基で官能基の付かない側鎖がメチル基である化合物をセレン化カドミウム半導体超微粒子３に配位結合させた超微粒子構造体１とシリコーン樹脂を混合して厚み１ｍｍのコンポジットを作製した。この時、コンポジット内部のセレン化カドミウム半導体超微粒子３の分散状態および粒子径はＴＥＭにより確認した。まず、分散状態はコンポジットを割り、その破断面をＳＥＭにより５００〜１００，０００倍で観察した。このとき、セレン化カドミウム半導体超微粒子３が均一に分散している場合は倍率が低いため樹脂中に粒子を見つけることが出来ない。続いて、このコンポジットをミクロトームで厚み３０〜２００ｎｍを目安として薄切片加工した。切片の厚みはセレン化カドミウム半導体超微粒子３の粒子径により使い分けることが望ましく、粒子径の５〜１０倍を目安とするとセレン化カドミウム半導体超微粒子３をきれいに観察することが出来た。この時コンポジットがやわらかい場合には、薄い切片を得ることが出来ず、液体窒素で冷却して厚み５０ｎｍを狙って切片加工を行なった。この切片のナノ蛍光体粒子の部分を透過型電子顕微鏡で観察し、格子像を倍率４，０００，０００倍で写真撮影した。透過型電子顕微鏡はJEOL製ＪＥＭ２０１０Ｆを使用し、加速電圧２００kＶの条件で観察を行った。セレン化カドミウム半導体超微粒子３の凝集の有無を再度５００，０００倍で確認した後、倍率を４，０００，０００倍としてセレン化カドミウム半導体超微粒子３の格子像の観察を行なった。このときセレン化カドミウム半導体超微粒子３は樹脂で完全に固定化されているためか、合成後のセレン化カドミウム半導体超微粒子３を観察した時に比べて電子線を長く当て続けても粒子が移動するようなことは無かった。
また、格子像の確認できたナノ蛍光体粒子２００個を選び、各々のナノ蛍光体粒子の格子像の直径を測長した。測定した格子像の直径を、前記と同様にしてヒストグラムを書いて統計的に計算することで、長さ平均直径を算出し、これをセレン化カドミウム半導体超微粒子３の粒子径とみなした。
このとき、格子像の直径は径の長い部分または短い部分に偏って測長することが無い様に、全ての格子像を写真紙に対して同一の方向に測長した。このようにして求めたコンポジット中のセレン化カドミウム半導体超微粒子３の粒子径は合成時のセレン化カドミウム半導体超微粒子３の粒子径と変わることはなかった。
次に、このコンポジットで発光素子を覆うようにかぶせて接着し、発光装置を得た。この発光装置の発光効率は３０Ｌｍ／Ｗであった。これに対して、上記化合物５を用いずにセレン化カドミウム半導体超微粒子３をシリコーン樹脂に混合したものを厚み１ｍｍのコンポジットに形成した場合、得られた発光装置の発光効率は１０Ｌｍ／Ｗであった。 Next, as shown in the general formula (b), using the compound 5 in which the functional group X is an amino group and the side chain Y having no functional group is an ethyl group and an n-propyl group, respectively, the same as described above The operation was performed.
At this time, cadmium selenide and compound 5 were mixed, and after stirring for 20 hours in a state heated to 90 ° C., the solution became orange. This was mixed with the silicone resin in the same manner as described above and cured in the cell. Table 4 shows the measured fluorescence intensity of these composites. Sample No. 12 is a sample No. in Table 1. 1 is the same sample. In addition, in the sample No. in which the side chain without a functional group is an ethyl group. 13 and a sample No. in which the side chain without a functional group is an n-propyl group. All 14 had a fluorescence intensity of 0.9.

Next, a light emitting element having a central emission wavelength of 395 nm was mounted on an alumina substrate by a flip chip mounting method. To this, an ultrafine particle structure 1 in which a compound in which a functional group is an amino group and a side chain having no functional group is a methyl group is coordinated to cadmium selenide semiconductor ultrafine particles 3 and a silicone resin are mixed, and the thickness is 1 mm. A composite was prepared. At this time, the dispersion state and the particle diameter of the cadmium selenide semiconductor ultrafine particles 3 inside the composite were confirmed by TEM. First, the dispersed state was divided into composites, and the fracture surface was observed by SEM at 500 to 100,000 times. At this time, when the cadmium selenide semiconductor ultrafine particles 3 are uniformly dispersed, the particles cannot be found in the resin because the magnification is low. Subsequently, the composite was processed into a thin slice with a microtome with a thickness of 30 to 200 nm as a guide. It is desirable that the thickness of the section is properly selected depending on the particle diameter of the cadmium selenide semiconductor ultrafine particles 3, and the cadmium selenide semiconductor ultrafine particles 3 can be clearly observed when the particle diameter is 5 to 10 times as a guide. At this time, when the composite was soft, a thin slice could not be obtained, and the slice was processed with a liquid nitrogen to aim at a thickness of 50 nm. The portion of the nanophosphor particles in this section was observed with a transmission electron microscope, and the lattice image was photographed at a magnification of 4,000,000. As the transmission electron microscope, JEOL JEM2010F was used, and observation was performed under the condition of an acceleration voltage of 200 kV. The presence or absence of aggregation of the cadmium selenide semiconductor ultrafine particles 3 was confirmed again at 500,000 times, and then the lattice image of the cadmium selenide semiconductor ultrafine particles 3 was observed at a magnification of 4,000,000 times. At this time, because the cadmium selenide semiconductor ultrafine particles 3 are completely fixed by the resin, the particles move even if the electron beam is kept applied for a longer time than when the synthesized cadmium selenide semiconductor ultrafine particles 3 are observed. There was no such thing.
In addition, 200 nanophosphor particles having a confirmed lattice image were selected, and the diameter of the lattice image of each nanophosphor particle was measured. The diameter of the measured lattice image was statistically calculated by writing a histogram in the same manner as described above to calculate the length average diameter, and this was regarded as the particle diameter of the cadmium selenide semiconductor ultrafine particles 3.
At this time, all the lattice images were measured in the same direction with respect to the photographic paper so that the diameter of the lattice image was not measured with a bias toward a long portion or a short portion. The particle size of the cadmium selenide semiconductor ultrafine particles 3 in the composite thus obtained did not change from the particle size of the cadmium selenide semiconductor ultrafine particles 3 at the time of synthesis.
Next, the composite was covered and adhered so as to cover the light emitting element to obtain a light emitting device. The luminous efficiency of this light emitting device was 30 Lm / W. On the other hand, when the mixture of the cadmium selenide semiconductor ultrafine particles 3 mixed with the silicone resin without using the compound 5 is formed into a 1 mm thick composite, the luminous efficiency of the obtained light emitting device is 10 Lm / W. It was.

(A) is the schematic diagram which shows an example of the ultrafine particle structure of this invention, (b) is the elements on larger scale. It is a molecular structure which shows an example of the compound used for the ultrafine particle structure of this invention. It is a schematic diagram which shows the composite of this invention. It is a schematic sectional drawing which shows an example of the light-emitting device of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Ultrafine particle structure 3 ... Semiconductor ultrafine particle 5 ... Compound 5a ... Main chain 5b ... Side chain 5c ... Side chain 7 having a functional group 7 ... Resin material 9 ..Composite 13 ... Light emitting element 11 ... Light emitting device

Claims (5)

(Sr, Ca, Ba, Mg ) 10 (PO 4) 6 C1 2: Eu, La 2 O 2 S: Eu, and BaMgAl ₁₀ O _17: Eu, the surface of any one of phosphor among the M n but an amino group, comprises one single closed side chain functional group selected from the group consisting of mercapto group and a carboxyl group, a side chain used without the said functional group, free of silicon, methyl group, ethyl A fluorescent structure having one kind selected from the group of a group and a propyl group and coated with a compound having a silicon-oxygen repeating number of 5 to 500.   A composite comprising the fluorescent structure according to claim 1 dispersed in a resin matrix.   The composite according to claim 2, wherein the resin matrix is a liquid resin.   4. The composite according to claim 2, wherein the light-emitting element is provided on a substrate and emits excitation light, and the composite is located in front of the light-emitting element and converts the wavelength of the excitation light to emit output light having a wavelength different from the excitation light. And a light emitting device.   A light emitting device assembly comprising a plurality of the light emitting devices according to claim 4.

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