JPH03109236A - Production of glass dispersed with superfine particle of semiconductor - Google Patents

Abstract

PURPOSE:To obtain the glass in a simple and safe process by utilizing water, the mixed liquid of water and an organic solvent or an acid soln. as a solvent and utilizing a raw material for a semiconductor soluble in this solvent in the case of producing the glass by sol-gel method. CONSTITUTION:A soln. is prepared which incorporates water, the mixed liquid of water and an organic solvent or an acid soln. as a solvent and also incorporates at least alkyl silicate and/or hydrolysate thereof and composite oxide such as CdSeO4 becoming the raw material of a semiconductor as a solute. Wet gel is obtained by hydrolyzing this soln. and performing dehydrating and condensating treatment and thereafter dried to give dry gel contg. composite oxide. This dry gel is heated in a reducing atmosphere to reduce the composite oxide to the semiconductor. Furthermore this dry gel is changed into porous silica glass. Thereby porous silica glass wherein the superfine particles of the semiconductor are produced in the fine holes is obtained. By this method, the aimed glass is obtained in a simple process without utilizing highly toxic H2S gas.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing porous silica glass obtained by a sol-gel method or a semiconductor ultrafine particle-dispersed glass having a matrix of silica glass. The semiconductor ultrafine particle-dispersed glass obtained by the present invention is used as a material for color filters and sharp cut filters used in optical equipment, nonlinear optical materials, and the like.

[Prior Art] Particle-dispersed glass, in which fine particles of semiconductors such as CaSx Se1-w or metals such as Au are dispersed, has been used as a glass material for sharp-cut filters, but in recent years, tertiary glass has been used in these glasses. Nonlinearity has been observed and is attracting attention.

Fine particle dispersed glass, which has traditionally been used as a sharp-cut filter material, is manufactured by a melting method that includes a melting process, an achromatic process, and a coloring heat treatment process.
The matrix is a multi-component glass that takes into consideration the melting temperature, stability of the glass, solubility of the fine particle raw material, etc.

On the other hand, since fine particle dispersed glass has attracted attention as a nonlinear optical material, silica glass has been used as a matrix for the purpose of suppressing the incorporation of impurities into fine particles and improving chemical durability, heat resistance, and environmental resistance. Attempts have been made to obtain glass in which ultrafine semiconductor particles are dispersed by a sol-gel method or a sputtering method.

For example, in the sol-gel method, after obtaining silica gel containing cadmium acetate, this cadmium acetate and hydrogen sulfide gas are reacted to precipitate cadmium sulfide fine particles in the silica gel, and semiconductor ultrafine particle-dispersed silica glass is produced. (Masayuki Nogami et al., Ceramics Association of Japan)
1989 Meeting, 2F20), and the sputtering method involves simultaneously sputtering silica and semiconductor to create a semiconductor-doped silica glass thin film on a glass substrate (Hiroyuki Nasu et al., Ceramic Society of Japan).
1989 meeting, 2F 25).

Although silica glass is not used as a matrix, as a method of obtaining semiconductor ultrafine particle dispersed glass using the sol-gel method, InGaAsP ground by a mechanical method is dispersed in a sol solution, and germanium dioxide is used as a matrix. Method for obtaining semiconductor fine particle dispersed glass (
JP-A-64-79038).

Among these methods, the method using the sol-gel method can obtain glass in a desired shape, such as bulk glass or fiber glass, and has a greater degree of freedom in the shape of the glass than the method using the sputtering method. It has the advantage of being expensive.

[Problems to be Solved by the Invention] However, Nogami et al. obtained silica gel containing cadmium acetate by a sol-gel method, and reacted this gel body with hydrogen sulfide gas to precipitate cadmium sulfide fine particles in the silica gel. This method has problems in that the hydrogen sulfide gas used as the reaction gas is extremely toxic, which not only makes the process highly dangerous but also complicates the process. This problem similarly occurs when hydrogen selenide gas is used as the reaction gas.

In addition, a method of obtaining semiconductor fine particle-dispersed glass by a sol-gel method in which a semiconductor is pulverized by a mechanical method and dispersed in a sol solution, that is, a method described in Japanese Patent Application Laid-Open No. 64-79038, can be used to obtain silica glass. It is also possible to apply it to glass in which semiconductor fine particles are dispersed as a matrix.
Since the particle size of semiconductor fine particles obtained by mechanical methods is relatively large, it is difficult to improve optical nonlinearity by increasing the quantum size effect due to the particle size of semiconductor fine particles by this method.

Therefore, it is an object of the present invention to produce silica glass in which ultrafine semiconductor particles are dispersed by a simple and safe process.
An object of the present invention is to provide a method for manufacturing ultrafine semiconductor particle-dispersed glass that can be obtained by a gel method.

[Means for Solving the Problems] The present invention has been made to achieve the above object, and the method for producing semiconductor ultrafine particle dispersed glass of the present invention includes the following steps:
Using water, a mixture of water and an organic solvent, or an acid solution as a solvent,
At least a first step of preparing a solution containing as a solute an alkyl silicate and/or a hydrolyzate of the alkyl silicate and a composite oxide serving as a raw material for a semiconductor; and a step of hydrolyzing and dehydrating the solution. After forming a wet gel, a second step of drying this wet gel to obtain a dry gel containing the complex oxide, heating the dry gel that has undergone the second step in a reducing atmosphere,
A third step of reducing the composite oxide to a semiconductor and converting the dry gel into porous silica glass to obtain porous silica glass in which semiconductor ultrafine particles are generated in the pores. be.

Further, the method for producing semiconductor ultrafine particle dispersed glass of the present invention includes:
The porous silica glass that has gone through the third step is sintered in a reducing atmosphere where the partial pressure of vapor from a semiconductor composed of the same components as the semiconductor ultrafine particles is increased to form porous silica glass in which the semiconductor ultrafine particles are dispersed. The present invention is also characterized in that it further includes a fourth step of making the silica glass non-porous.

The present invention will be explained in detail below.

In the method for producing semiconductor ultrafine particle-dispersed glass of the present invention, first, water, a mixture of water and an organic solvent, or an acid solution is used as a solvent, and at least an alkyl silicate and/or a hydrolyzate of the alkyl silicate and a semiconductor are mixed together. A first step of preparing a solution containing the raw material composite oxide as a solute is performed.

The water used as a solvent in this first step is preferably one containing few impurities, such as distilled water or purified water, which is commonly used when obtaining glass by the sol-gel method. As the organic solvent, it is preferable to use an alcohol solvent such as methanol or ethanol, and by using an alcohol solvent, the solubility of the alkyl silicate can be improved. As for the alcohol solvent used as the solvent, it is also preferable to use one with less contamination of impurities.

Further, as the acid solution, it is preferable to use a solution containing an acid such as hydrochloric acid, acetic acid, nitric acid, sulfuric acid, etc., and the above-mentioned water and/or an organic solvent, and it is preferable to use an acid with few impurities. .

Among the solutes to be dissolved in the above solvent, the alkyl silicate has the formula SI (OR) a (wherein R is an alkyl group having 1 to 4 carbon atoms such as a methyl group, ethyl group, propyl group, butyl group). (The same applies hereafter). Instead of this alkyl silicate,
Or, together with this alkyl silicate, a partial hydrolyzate of alkyl silicate, i.e. 81(OR)a (O
tri, 5I(OR)2 (0[1)t, 51(OR)
(OH)a, complete hydrolyzate, namely St (Oi
l) 4 may be used. It is desirable that these alkyl silicates and/or their hydrolysates have high purity.

In addition, the composite oxide that is one of the solutes to be dissolved in the above solvent, which is a raw material for semiconductors, refers to water, a mixture of water and an organic solvent, and/or an acid Refers to compounds that are soluble in solutions, and examples of such composite oxides include CdTeO4, Cd50a, and Cd
TeO4, Zn5eOa, etc. can be mentioned. It is desirable that this composite oxide also have high purity.

In the first step of the method for manufacturing ultrafine semiconductor particle-dispersed glass of the present invention, a solution is prepared by dissolving the above-mentioned solute in the above-mentioned solvent. This solution can be prepared by sufficiently stirring and mixing both.

At this time, for the purpose of adjusting the pfl of the obtained solution, improving the solubility of the composite oxide in the solvent, or controlling the pore size of the dry gel obtained in the second step described below, acid such as hydrochloric acid, acetic acid, nitric acid, etc. may be added.

In the method for manufacturing semiconductor ultrafine particle dispersed glass of the present invention, after the first step described above, the solution obtained in the first step is subjected to hydrolysis and dehydration condensation treatment to form a wet gel, and this wet gel is dried. A second step of obtaining a dry gel containing a composite oxide is performed.

Hydrolysis and dehydration condensation treatment in this second step,
The process of converting the obtained wet gel into a dry gel is carried out according to a conventional glass manufacturing method using a sol-gel method. However, when only a completely hydrolyzed alkyl silicate is used as a raw material for silica glass, only dehydration condensation is performed without hydrolysis.

In the hydrolysis and dehydration condensation treatment of the solution in the second step, for example, the solution obtained in the first step is charged into a container according to the shape of the target glass, and if necessary, water for hydrolysis treatment is added. Alternatively, it can be carried out by adding a hydrolysis catalyst consisting of an acid and allowing the mixture to stand at a temperature from room temperature to less than the boiling point of the solvent.

In addition, the process of turning the obtained wet gel into a dry gel can be carried out, for example, by setting the open area ratio of the lid of the container containing the wet gel to 0.1 to 10% and maintaining the container at a temperature of room temperature to 80°C. This can be done by

By performing such a second step, it is possible to obtain a dry gel in which a composite oxide, which is a raw material for a semiconductor, exists in the pores.

In the method for manufacturing semiconductor ultrafine particle dispersed glass of the present invention, the dry gel that has undergone the above-mentioned second step is heated in a reducing atmosphere to reduce the above-mentioned composite oxide to a semiconductor and to convert the dry gel into porous silica glass. Then, a third step is performed to obtain porous silica glass in which ultrafine semiconductor particles are formed in the pores.

The reducing atmosphere used in this third step is N2
Examples include a mixed atmosphere of an inert gas such as , Ar, t(e) and tt2, a CO atmosphere, a No atmosphere, etc. In particular, from the viewpoint of safety, a mixed atmosphere of an inert gas such as Ny, Ar, He, etc. and H
It is preferable to use a mixed atmosphere with 2. Alternatively, like the atmosphere in the fourth step described later, a reducing atmosphere may be used in which the partial pressure of vapor from a semiconductor made of the same component as the semiconductor ultrafine particles generated in the pores of the dry gel is increased.

Heating for producing semiconductor ultrafine particles from a composite oxide, which is a raw material for a semiconductor, is preferably performed at 200 to 600° C. for 1 to 30 hours.

The particle size of the semiconductor ultrafine particles produced in the third step is preferably 1 μm or less. The reason for this is that when the particle size of the semiconductor ultrafine particles exceeds 1 μm, light scattering occurs, the transmittance decreases, and the quantum size effect of optical nonlinearity becomes weaker. The particle size of the semiconductor ultrafine particles can be controlled by the concentration of the composite oxide in the solution in the first step, the pore diameter of the dry gel, the heating temperature and time in the third step, etc.

By performing such a third step, it is possible to obtain porous silica glass in which ultrafine semiconductor particles are dispersed within the pores.

Note that a porous body obtained by heat-treating a dry gel is generally recognized as different from glass, but in this specification, the above-mentioned porous body obtained by heat-treating a dry gel and having ultrafine semiconductor particles dispersed in its pores is used. The body is also included in the semiconductor ultrafine particle-dispersed glass having silica glass as a matrix.

The porous silica glass obtained in this way, in which ultrafine semiconductor particles are dispersed in the pores, generally has insufficient mechanical strength, so if you want to obtain the porous silica glass with improved mechanical strength, It is preferable to perform the above-mentioned third step after subjecting the dry gel that has undergone the above-mentioned second step to a water vapor exposure treatment. This water vapor exposure treatment can be performed by exposing the dry gel that has undergone the second step to saturated water vapor at 40 to 100°C for 5 hours to 7 days.

However, when using a complex oxide that is easily soluble in water as a semiconductor, it is possible to prevent water droplets from adhering to the dry gel from the wall of the container for water vapor exposure treatment, thereby minimizing the outflow of the complex oxide. Take care to keep it to a minimum.

By performing the water vapor exposure treatment, the unhydrolyzed alkyl silicate remaining during the hydrolysis in the second step is completely hydrolyzed, and as a result, during the heating to generate semiconductor ultrafine particles in the third step, 3l- 0-
Since the 8i bonds are more easily formed, the mechanical strength of the porous silica glass that has undergone the third step is improved. Due to this improvement in mechanical strength, for example, in the third step, 5
Even porous silica glass heated to 00°C can be polished.

Additionally, since the porous silica glass that has gone through the third process is not made non-porous, its properties may change depending on the application due to environmental changes such as humidity or the adhesion of organic matter in the atmosphere into the pores. There is. Such changes in properties can be suppressed by converting the porous silica glass that has gone through the third step described above into semiconductor ultrafine particle dispersed glass that has been made non-porous through the fourth step described below. .

In this fourth step, the porous silica glass that has gone through the third step described above is heated to increase the partial pressure of vapor from a semiconductor made of the same component as the semiconductor ultrafine particles generated within the pores of this porous silica glass. This is a step of sintering in a reducing atmosphere to make the silica glass in which ultrafine semiconductor particles are dispersed non-porous.

For example, a reducing atmosphere with increased vapor partial pressure from a semiconductor composed of the same components as the semiconductor ultrafine particles generated in the pores is placed in a heating furnace for sintering the porous silica glass that has undergone the third step. A semiconductor device made of the same components as the semiconductor ultrafine particles generated in the pores of this porous silica glass is manufactured, and the atmosphere in the heating furnace is a mixed atmosphere of an inert gas such as N2, Ar, Ile, etc. and OX, or a CO atmosphere. , No atmosphere or the like, and then heating the heating furnace in a closed system. By setting the atmosphere in the heating furnace to such an atmosphere, even when making porous silica glass in which a semiconductor such as Cd5eSCdTe, which easily volatizes during heat treatment for sintering as described later, is dispersed, the silica glass can be made non-porous during sintering. Since volatilization of the semiconductor or semiconductor component in the process is prevented, a non-porous semiconductor ultrafine particle-dispersed glass can be obtained while suppressing a decrease in the concentration of semiconductor ultrafine particles.

The temperature and sintering time when sintering the porous silica glass are determined to suppress volatilization and enlargement of semiconductor ultrafine particles generated in the pores of the porous silica glass in the third step, or to prevent devitrification of the glass. From the viewpoint of suppression, etc., 700 to 1200
It is desirable to set it as 0.5 to 10 hours at °C.

Note that this fourth step can also be performed continuously from the third step by performing the heat treatment in the third step described above under the same atmospheric conditions as the heat treatment in the fourth step described above.

By performing such a fourth step, it is possible to obtain ultrafine semiconductor particle-dispersed glass having a matrix of non-porous silica glass.

In addition, when performing this fourth step, the particle size of the semiconductor ultrafine particles in the semiconductor ultrafine particle dispersed glass finally obtained is 1 μm, taking into account the growth of the semiconductor ultrafine particles accompanying sintering.
It is preferable that the particle size of the semiconductor ultrafine particles produced in the third step be smaller than 1 μm so as to be as follows.

[Example] Examples of the present invention will be described below.

Example 1 Commercially available tetramethyl orthosilicate (1MO8), tetraethyl orthosilicate (TE
01), ethanol, hydrochloric acid, and cadmium tellurate (CdTe04) (all of the above are special grade reagents, the same applies below)
In the first step, 1MO8 was added to 3°19 gST in a 200ml container made of polypropylene in a water bath at 5°C.
4.33 g of EO8 and 7.73 g of ethanol were added. Next, while stirring the contents in the container, O,
Log of CdTe0a was added to 17.3 g of distilled water and 0.0 g of distilled water.
An aqueous solution dissolved in a solution consisting of 1 g of hydrochloric acid was added dropwise to the above contents and stirring was continued for an additional 10 minutes to obtain a homogeneous solution.

Next, in the second step, the uniform solution obtained in the first step is mixed with a diameter of 6 mm. A 20ml aliquot was placed in a 5cm x 9cm high polypropylene container, covered with a lid with an opening ratio of 0.1% with a pinhole of 1ffiI11 in diameter, and kept at 70°C to promote hydrolysis and dehydration condensation. The mixture was allowed to rise to obtain a wet gel, and then kept at 70°C to dry the wet gel to obtain a dry gel. It was confirmed that CdTe0a was distributed in the pores of this dry gel.

After this, the dry gel was immersed in saturated steam at 70°C for 7 days, taking care not to allow water droplets to adhere to the dry gel.
The mechanical strength of the dry gel was improved by leaving it for a day and subjecting it to water vapor exposure treatment.

Next, in the third step, the dry gel subjected to the water vapor exposure treatment is placed in a heating furnace, and the atmosphere in the furnace is changed to 1% or more N.
The temperature was raised from room temperature to 700°C at a temperature increase rate of 150°C/hr while creating a reducing atmosphere consisting of N2-He containing 2 and flowing this atmospheric gas at a rate of 100cc/lllIn.
By raising the temperature to C and keeping it at this temperature for 3 hours,
CdTe is generated from dTe0a and CdT is formed in the pores.
A semiconductor ultrafine particle dispersed glass (porous silica glass) in which e was produced was obtained.

By X-ray diffraction of the obtained semiconductor ultrafine particle dispersed glass,
It was confirmed that this glass contained CdTe, and furthermore, from the half-value width of the (110) peak, dispersed CdTe was confirmed.
The particle size of dTe was found to be approximately 80 mm.

When this semiconductor ultrafine particle-dispersed glass was polished to a thickness of 100 μm and its optical absorption spectrum was measured, an absorption curve with an absorption edge near about 800 nm was obtained as shown in FIG. The position of this absorption edge is shifted to the shorter wavelength side, whereas the absorption edge of the CdTe bulk body is 838 nm, but this shift to the shorter wavelength side is due to the quantum size effect and is due to the third-order This leads to an increase in nonlinear optical properties. Furthermore, in the wavelength range of 800 nm or less, the absorption gradually increases from the long wavelength range to the short wavelength range, so it was confirmed that it can be used as an amber color filter.

Example 2 As a starting material, TM01. Using TE01, ethanol and cadmium selenate (Cd5eOa), as a first step, a polypropylene 2
3. TM01 in 00ml container. 19 gSTIEO3
4.33 g of ethanol and 10.0 g of ethanol were added respectively.

Next, while stirring the contents in the container, the temperature was increased to 0°22
An aqueous solution in which 1 g of CdSe04 was dissolved in 20.0 g of distilled water was added dropwise to the above contents, and stirring was continued for an additional 10 minutes to obtain a homogeneous solution.

Next, as a second step, the solution obtained in the first step was subjected to the same treatment as the second step in Example 1,
A dry gel in which CdSe04 was distributed in the pores was obtained.

Next, as a third step, the obtained dry gel is placed in a heating furnace, and the atmosphere in the furnace is changed to +12 containing 1% or more of 112.
- While creating a reducing atmosphere consisting of N2 and flowing this atmospheric gas at a rate of 100 cc/min,
Raise the temperature from room temperature to 500 °C at a temperature increase rate of °C/hr,
By holding at this temperature for 6 hours, CdSe was generated from CdSeO4, and a semiconductor ultrafine particle dispersed glass (porous silica glass) in which CdSe was generated in the pores was obtained.

Furthermore, as a fourth step, CdSe is placed in a heating furnace, and the atmosphere in the furnace is changed to 112-N containing 1% or more of 112.
After sealing as a reducing atmosphere consisting of 2, 300℃/h
The semiconductor ultrafine particle dispersed glass (porous silica glass) was sintered in a reducing atmosphere in which the CdSe vapor partial pressure was increased by heating by continuing heating at a temperature increase rate of r and holding at 1050 ° C. for 1 hour. Made non-porous, 3cm in diameter
A CdSe ultrafine particle-dispersed silica glass having a thickness of 3 mm was obtained.

FIG. 2 shows the X-ray diffraction pattern of the obtained CdSe ultrafine particle dispersed glass. This X-ray diffraction reveals that there is C in this glass.
It was confirmed that dSe was included, and also (110
) From the half width of the peak, the particle size of dispersed CdSe is approximately 1
It turned out that there were 60 people.

When the optical absorption spectrum of this CdSe ultrafine particle dispersed glass was measured in the same manner as in Example 1, a spectrum with a plurality of undulations was obtained as shown in FIG. This undulation is caused by absorption of discrete bands due to quantum size effects, and leads to an increase in third-order nonlinear optical characteristics.

Furthermore, in the wavelength range of 700 nm or less, the absorption gradually increases from the long wavelength range to the short wavelength range, so it was confirmed that it can be used as an infrared absorption filter or a sharp cut filter.

In semiconductor ultrafine particle-dispersed glass, the development of quantum size effects greatly influences the increase in nonlinearity, and this quantum size effect shifts the absorption peak to the higher energy side. The following equation holds true between the particle size (a) of the semiconductor ultrafine particles and the amount of change in energy band gap (ΔE).

h = Niji (h blank constant), total...quantum number, m6... effective mass of electrons, so the heat treatment temperature in the third and fourth steps mentioned above was set to 500
Cd obtained by varying the temperature within the range of ~1050°C
The particle size of the CdSe ultrafine particles in the Se ultrafine particle dispersed glass was varied, and the relationship between the particle size of the CdSe ultrafine particles and the longest wavelength peak position (absorption peak) of the CdSe ultrafine particle dispersed glass was determined. The results shown are obtained. From FIG. 4, it was found that the above relationship of Formula 1 was established in the CdSe ultrafine particle dispersed glass of this example, and it was confirmed that the quantum size effect, which is important for optical nonlinearity, was obtained.

Further, the glass transition point (Tg) of the obtained CdSe ultrafine particle dispersed glass was 850°C, and it was confirmed that it had excellent heat resistance. Furthermore, when chemical durability was measured using a powder method based on JOGIS-1975 (Japan Optical Glass Industry Standards), water resistance (Dw) was 0.01%.
The acid resistance (Da) was 0.03%, and it was confirmed that the material had excellent chemical durability.

Example 3 In the first step, when mixing each starting material, Cd
0.0 to improve the solubility of 5eOa in solvents.
A CdSe ultrafine particle dispersed glass was obtained in the same manner as in Example 2, except that 20.0 g of 1N hydrochloric acid was added and distilled water was not added.

When the particle size of the CdSe ultrafine particles in the obtained CdSe ultrafine particle dispersed glass was measured in the same manner as in Example 2, it was found to be 1
There were 60 people. Further, when the light absorption spectrum of this CdSe ultrafine particle dispersed glass was measured in the same manner as in Example 2, a light absorption spectrum similar to that shown in FIG. 3 was obtained.

Example 4 After carrying out the first step and second step in the same manner as in Example 2, the obtained dry gel was subjected to a water vapor exposure treatment in the same manner as in Example 1, and further in the same manner as in Example 2. Third
and the fourth step to obtain a particle size of 160 C.
A semiconductor ultrafine particle-dispersed glass in which dSe ultrafine particles were dispersed was obtained.

In addition, by subjecting the dry gel obtained in the second step to water vapor exposure treatment, the mechanical strength of the dry gel is improved, and the porous silica glass is prevented from cracking during the heat treatment in the third and fourth steps. The rate of occurrence has decreased.

The light absorption characteristics of the CdSe ultrafine particle-dispersed glass thus obtained showed a light absorption spectrum similar to that shown in FIG.

Example 5 Using TMO8STEO8, ethanol, and cadmium sulfate (CdSOa) as starting materials, as a first step, a polypropylene 200n+ was heated in an ice bath at 5°C.
3.19g of 7MO8 and 4.33g of 5TEO3 in one container
.

7.73g of ethanol was added to each. Next, while stirring the contents in the container, 0. 18g Cd5
An aqueous solution of Oa dissolved in 17.3 g of distilled water was added dropwise to the above contents, and stirring was continued for an additional 10 minutes to obtain a homogeneous solution.

Next, a second step and a third step were performed in the same manner as in Example 2 to obtain semiconductor ultrafine particle dispersed glass (porous silica glass) in which CdS was generated in the pores.

After this, as a fourth step, CdS is placed in a heating furnace, and the atmosphere in the furnace is changed to 112-Ar containing 1% or more of 112.
After sealing as a reducing atmosphere consisting of
By continuing heating at a heating rate of By forming pores, a CdS ultrafine particle-dispersed silica glass having a diameter of 3 cm and a thickness of 3 mm was obtained.

By X-ray diffraction of the obtained CdS ultrafine particle dispersed glass,
It was confirmed that this glass contained CdS, and furthermore, the half-value width of the (110) peak revealed that CdS was dispersed in the glass.
The particle size of S was found to be approximately 150.

When the optical absorption spectrum of this CdS ultrafine particle dispersed glass was measured in the same manner as in Example 1, a spectrum as shown in FIG. 5 was obtained. Furthermore, in the wavelength range of 500 nm or less, the absorption gradually increases from the long wavelength range to the short wavelength range, so it was confirmed that it can be used as an infrared absorption filter or a sharp cut filter.

[Effects of the Invention] As explained above, the method for producing semiconductor ultrafine particle-dispersed glass of the present invention uses water, a mixed solution of water and an organic solvent, among composite oxides that produce semiconductors by heat treatment, as raw materials for semiconductors. Alternatively, since a material soluble in an acid solution is used, a semiconductor ultrafine particle-dispersed glass having silica glass as a matrix can be obtained by a sol-gel method through a simple and safe process.

Therefore, by carrying out the present invention, an infrared transmission filter, a color filter, a sharp cut filter, or It becomes possible to obtain semiconductor ultrafine particle-dispersed glass for nonlinear optical materials with few impurities in ultrafine particles through a simple and safe process.

[Brief explanation of drawings]

FIG. 1 is a graph showing the light absorption curve of the CdTe ultrafine particle dispersed glass obtained by the method of the present invention, and FIG. 2 is a graph showing the optical absorption curve of the CdSe ultrafine particle dispersed glass obtained by the method of the present invention.
Line diffraction diagram, Figure 3 shows CdS obtained by the method of the present invention.
e Graph showing the light absorption curve of ultrafine particle dispersed glass, 4th
The figure is a graph showing the relationship between the particle size of CdSe ultrafine particles in the CdSe ultrafine particle dispersed glass obtained by the method of the present invention and the longest wavelength peak position (absorption peak) of the optical absorption spectrum. 1 is a graph showing a light absorption curve of a CdS ultrafine particle-dispersed glass obtained by the method. (cm”1

Claims (2)

[Claims] (1) A solution in which water, a mixture of water and an organic solvent, or an acid solution is used as a solvent, and at least an alkyl silicate and/or a hydrolyzate of the alkyl silicate and a complex oxide, which is a raw material for a semiconductor, are used as solutes. a first step of preparing a wet gel by subjecting the solution to hydrolysis and dehydration condensation, and a second step of drying the wet gel to obtain a dry gel containing the complex oxide; The dry gel that has gone through the second step is heated in a reducing atmosphere to reduce the composite oxide to a semiconductor, and the dry gel is made into porous silica glass, thereby producing porous silica glass in which semiconductor ultrafine particles are generated in the pores. and a third step of obtaining semiconductor ultrafine particle dispersed glass. (2) The porous silica glass that has undergone the third step is sintered in a reducing atmosphere in which the partial pressure of vapor from a semiconductor composed of the same components as the semiconductor ultrafine particles is increased, so that the semiconductor ultrafine particles are dispersed. The fourth step is to make porous silica glass non-porous.
The method for producing ultrafine particle dispersed glass according to claim 1, further comprising the step of: