JPH04274224A - Manufacture of semiconductor fine grain dispersed glass - Google Patents

Abstract

PURPOSE:To rapidly disperse semiconductor grains in an uniform grain diameter through a simple method by supporting semiconductor fine grains on a porous glass having a uniform pore diameter and a wide specific surface. CONSTITUTION:A porous glass is immersed under pressure in a mixed solution composed of a semiconductor or a compound forming a semiconductor through reaction and a sol turning into a vitreous substance. The mixed solution is held in the pores of the porous glass, and heat-treated to make the porous glass support dispersed semiconductor fine grains. For instance, after impregnating a CdS sol under pressure (3atm) in the pores of a porous glass (average pore diameter : 4nm, specific surface : 200m<2>/g) being 0.5mm in thickness, it is heat-treated for dispersedly supporting CdS fine grains at 8% in weight. Since a gel exists on the circumference of the semiconductor fine grain, the semiconductor fine grains unite mutually to prevent bulking of the grains.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing semiconductor fine particle-dispersed glass, which forms the basis of optical devices and the like that utilize nonlinear optical effects.

0002

BACKGROUND OF THE INVENTION In recent years, nonlinear optical materials have been considered for use as optical devices such as high-speed optical switches and harmonic generation elements. In particular, with regard to nonlinear optical materials that use semiconductor particles or organic compounds with nonlinear optical properties, which are the core of nonlinear optical materials, the development of materials with higher performance or improved methods for producing materials are attracting attention.

As a conventional technique in this field, for example, Journal of Non-Crystalline Solids, Vol. 122, page 101 (J. Non-Crystalline Solids),
t. Solids, Vol. There is a method for producing CdS-containing silica glass by a sol-gel method as described in 122, 1990).

This method uses silicon alkoxide (Si
After hydrolyzing (OC2 H5 )4), methanol
Cd(CH3COO)2 ・2H2 dissolved in
Add O and stir. Thereafter, a mixed solution of water, ethanol, and aqueous ammonia is added and stirring is continued, and this solution is transferred to a petri dish to prepare a gel plate. This gel plate is placed in an atmosphere containing hydrogen sulfide (H2S) gas, and a CdS-containing glass is created by a sulfurization reaction.

[0005] Also, Journal of Optical Society of America Vol. 73, 647
Page (J.Opt.Soc.Am., Vol.73,
CdSX Se1 as described in (1983)
A cut-off filter glass in which -X is dispersed in borosilicate glass is used as a nonlinear optical material. This cut-off filter glass is made by placing CdSXSe1-X and borosilicate glass material in a platinum crucible at 1000°C.
It is manufactured by melting at a temperature of about

Furthermore, Journal of Applied Physics, Volume 63, page 957 (J.A.
ppl. Phys. 63(3), 957 1988)
There is a CdS fine particle doped thin film glass disclosed in .

This thin film glass is made by high-frequency magnetron sputtering using Corning's "7095 glass" (borosilicate glass containing Ba) and CdS as targets. C
2 to 4% by weight of dS is dispersed therein.

[0008]

[Problems to be Solved by the Invention] The above-mentioned method for producing glass in which semiconductor fine particles are dispersed has the following problems.

[0009] In the case of the sol-gel method: The gel body is placed in a hydrogen sulfide atmosphere and CdS-containing glass is created by a sulfurization reaction, so if the gel body is thick, CdS is uniformly dispersed even inside the gel body. The particle size of CdS differs between the surface and the inside, making it impossible to control the particle size sufficiently.

Particularly when semiconductor fine particle dispersed glass is applied to nonlinear optical materials, it is important to control the particle size of the semiconductor fine particles dispersed in the glass matrix, and this has a large effect on the performance of nonlinear optical characteristics.

B) In the case of cut-off filter-glass:
CdSX Se1-X on borosilicate glass 2-4w
It is difficult to uniformly disperse more than 10%
Since it cannot be manufactured unless it is melted at a high temperature of 00°C or higher, there are problems such as some of the constituent components evaporating and changing the composition of the target semiconductor, making it extremely difficult to control the glass composition and semiconductor composition. Become.

c) When using sputtering method: The equipment is expensive and it takes time to form a glass thin film.
(It takes 4-5 hours to reach a thickness of 1 μm, especially in the case of forming SiO2 glass, which has a low sputtering rate.) It is difficult to form thick films.

[0013] The present invention enables semiconductor fine particles to be dispersed to a uniform particle size more quickly by a simple method by supporting semiconductor fine particles on porous glass having a uniform pore diameter and a large specific surface area. It is an object of the present invention to provide a method for manufacturing semiconductor fine particle dispersed glass having greater third-order nonlinear optical characteristics.

[0014]

[Means for Solving the Problems] In order to solve the above problems, the present invention has the following configuration.

(1) In a mixed solution of a semiconductor or a compound that can react to form a semiconductor and a sol that becomes glassy,
Porous glass is immersed under pressure, the mixed solution is held in the pores of the porous glass, the sol held in the porous glass is gelled, and the semiconductor is applied to the porous glass by heat treatment. A method for manufacturing semiconductor fine particle-dispersed glass, which comprises dispersing and supporting fine particles.

(2) Porous glass is immersed under pressure in a vitreous sol solution in which cadmium, zinc, or lead is dissolved, and the solution is held in the pores of the porous glass. A semiconductor fine particle dispersed glass characterized in that CdS, CdSe, ZnS, ZnSe, PbS or PbSe is dispersed and supported on the porous glass by gelling a sol held in the glass and further reacting with hydrogen sulfide or selenium sulfide gas. manufacturing method.

(3) The average pore diameter of the porous glass is 10n
The method for producing a glass in which semiconductor fine particles are dispersed according to any one of the above (1) or (2), wherein the particle diameter is less than or equal to m.

[0018]

[Function] In the method for manufacturing semiconductor fine particle-dispersed glass of the present invention, in the process of producing semiconductor fine particle-dispersed glass in which compound semiconductor fine particles are supported on porous glass, a semiconductor or a compound that can react to form a semiconductor, and glass A porous glass is immersed under pressure in a mixed solution with a sol that will serve as a quality material, and the sol retained in the porous glass is gelled, and then heat treated to quickly bring semiconductor fine particles into the porous glass at a high concentration. It is possible to carry out dispersion and support uniformly and strongly. Furthermore, since the gel is present around the semiconductor fine particles, it is easier to prevent the semiconductor fine particles from coalescing and becoming coarse.

In the method for manufacturing semiconductor fine particle dispersed glass according to item (2) of the present invention, porous glass is immersed under pressure in a vitreous sol solution in which cadmium, zinc, or lead is dissolved. holding the solution in the pores of the glass and gelling the sol held in the porous glass;
Furthermore, by reacting with hydrogen sulfide or selenium sulfide gas, CdS, CdSe, ZnS, ZnSe,
PbS or PbSe can be quickly, highly concentrated, uniformly and firmly dispersed and supported on the porous glass. Furthermore, since the gel is present around the precipitated semiconductor fine particles, it is easier to prevent the semiconductor fine particles from coalescing and becoming coarse.

Furthermore, the average pore diameter of the porous glass is 10n.
According to a preferred embodiment of the present invention that uses porous glass with a size of less than m, it is easier to control the particle diameter of the semiconductor fine particles to a small enough extent that the quantum size effect appears.
A method for manufacturing semiconductor fine particle dispersed glass having excellent nonlinear optical properties can be provided.

[0021]

[Example] The porous glass used as a carrier in the present invention is
SiO2 glass, which is chemically stable and optically transparent over a wide wavelength range, is preferred. The average pore diameter of porous glass is 10 nm, where the quantum size effect of semiconductor particles can be seen.
The following are preferred. By using porous glass with an average pore diameter of 10 nm or less, it becomes easier to control the particle diameter of the precipitated semiconductor fine particles to a small enough extent that the quantum size effect appears, which is preferable.

The lower limit of the average pore diameter of the porous glass is not particularly limited, but it is preferably equal to or larger than the Bohr radius of the semiconductor to be deposited, and is usually about 0.5 nm.

When using a semiconductor in the present invention,
As the semiconductor fine particles to be dispersed, it is preferable to use a semiconductor that can exhibit nonlinear optical properties, such as Cu.
Metal halides such as Cl, CuBr, PbI2, BiI3, CdS, CdSe, CdO, ZnS, Zn
II-VI group compound semiconductors such as Se and ZnO, GaA
III-V compound semiconductors such as s, InP, PbS
Preferred examples include IV-VI group compound semiconductors such as , PbSe, and the like.

When the semiconductor itself is used in this manner, the semiconductor is used in the form of a solution in order to form a glassy sol and mixed solution. To make these semiconductors into solutions, a solvent that can dissolve the semiconductors is used, but this solvent is
A solvent that completely hydrolyzes the sol will be difficult to gel, so it is best to choose a solvent that can dissolve the semiconductor but does not completely hydrolyze the sol, usually a relatively dilute aqueous hydrochloric acid solution. etc. can be applied.

In the present invention, the compound that reacts to form a semiconductor is a combination of a compound containing a cation component and a compound containing an anion component constituting the semiconductor as described above, and these compounds react to form a semiconductor. In the present invention, usually by adding these to a sol solution, these cation components and anion components react in the sol solution to form a semiconductor compound. It is something. Usually, each of these components is used in the form of an alcoholic solution or an aqueous solution.

Among the above, for example, CdS, ZnS,
Taking an example such as PbS, examples of compounds containing a cationic component include cadmium compounds such as CdCl2, CdCO3, and Cd(NO3)2.
, Cd(CH3COO)2 ,Cd(HCOO)2
Examples of zinc compounds include ZnCl2, Zn(
CH3COO)2, etc., and lead compounds include, for example, PbCl2, PbCO3, Pb(NO3)2,
It is prepared by dissolving Pb(CH3COO)2 etc. in alcohol.

Furthermore, examples of compounds containing sulfur that serve as anionic components include NaSH, (NH4)2
It is prepared by dissolving S, SC(NH2)2, etc. in alcohol.

[0028] Furthermore, in the present invention, cadmium, zinc,
Alternatively, the solution in which lead is dissolved may be any solution in which cadmium, zinc, or lead ions are present. Specific examples of cadmium compounds used as a component of such a solution include, for example, CdCl2, CdCO3, CdCl2, CdCO3,
d(NO3)2, Cd(CH3COO)2, C
d(HCOO)2, etc., and specific examples of zinc compounds include, for example, ZnCl2, Zn(CH3
COO)2, etc., and specific examples of lead compounds include PbCl2, PbCO3, Pb(NO3)2, etc.
, Pb(CH3COO)2, etc., and solutions are usually prepared by dissolving these compounds in water or alcohol.

[0029] As the alcohol, lower alcohols are preferred, and methanol, ethanol, etc. are preferred.

[0030] The solution that becomes the sol is a solution that gels and becomes glassy, particularly preferably SiO2.
It is preferable to use a solution such that hand,
A partially hydrolyzed product is used, to which is added a solution of the aforementioned semiconductor or a solution of a compound capable of reacting to form a semiconductor, or, in the case of the second aspect of the invention, cadmium, zinc, or Adjust by adding an alcoholic solution of a lead compound.

[0031] Porous glass is immersed in these sol solutions under pressure to introduce and hold the sol in the pores of the porous glass. The sol solution can be quickly introduced into the pores.

The degree of pressurization is not particularly limited, but is, for example, about 2 to 60 atmospheres.

[0033] These sols are gelled after being introduced into the pores of the porous glass, but the gelation may be carried out by vacuum drying or left at room temperature to remove moisture. After evaporation, a method such as leaving it for a long time at 60 to 80° C. can be adopted.

[0034] The heat treatment performed after the gelation in the first aspect of the present invention is usually carried out at 60 to 500°C for 1 minute to 10 minutes.
It takes about an hour.

Furthermore, in the second aspect of the present invention, the porous glass holding the sol solution in which cadmium, zinc, or lead prepared as described above is Although it varies depending on the type of compound, the metal and/or its oxide is supported in the pores of the porous glass by heat treatment at 300 to 600°C for about 10 minutes to 10 hours.

Next, this is further reacted with hydrogen sulfide or selenium sulfide gas to form CdS, CdSe, ZnS, and Zn.
Se, PbS or PbSe is deposited and supported on the porous glass, and this reaction is carried out in the atmosphere of the gas,
Usually, a method of reacting at room temperature to 500°C for about 1 minute to 2 hours can be adopted.

Specific embodiments of the present invention will be described below.

Example 1 Porous glass with a thickness of 0.5 mm (average pore diameter 4 nm,
Specific surface area: 200m2/g) (Hereinafter, porous glass will be referred to as PV
It is abbreviated as G. ) was dispersed and supported with CdS fine particles by the method shown below.

1.0mol%Cd(NO3)2 and S
C(NH2)2 of the composition shown in Table 1 dissolved with C(NH2)2
A sol containing SiO2 in which d and S were dispersed was prepared. Porous glass was placed in this sol in an autoclave, immersed for 30 minutes at 3 atm at room temperature, dried under vacuum, and then heated at 400°C in air.
CdS is supported by heating at a temperature of 1 hour (CdS/
PVG). The particle size of CdS in the obtained CdS/PVG was 3 to 3.5 nm, and the amount of CdS supported was 9 wt%.
Met. The band gap determined from the absorption spectrum of CdS/PVG is 0 compared to the band gap of bulk CdS.
．． A blue shift of 85 eV was observed, suggesting that CdS was a quantum dot.

(Comparative Example) In Example 1, autoclave
In the case where CdS was supported on porous glass at room temperature under atmospheric pressure without using a glass plate, it took a long time to support CdS inside the porous glass.

[0041]

[Table 1] Example 2 Porous glass with a thickness of 0.5 mm (average pore diameter 4 nm,
specific surface area 200m2/g) by the method shown below.
dS fine particles were dispersed and supported.

1) 1.0 mol% Cd(NO3)2
A Cd-dispersed SiO2 sol having the composition shown in Table 1 of Example 1 was prepared. Porous glass was placed in an autoclave and immersed in this sol for 30 minutes at 3 atm at room temperature, dried under vacuum, and heated in air at 400° C. for 1 hour to support Cd and its oxides.

2) The above porous glass is reacted in a hydrogen sulfide atmosphere at 150° C. for 10 minutes to produce a CdS-supported porous glass (CdS/PVG). CdS
The supported amount was 8 wt%.

The particle size of CdS in the obtained CdS/PVG was 3 to 3.5 nm, and the amount of CdS supported was 9 wt.
%Met.

The band gap determined from the absorption spectrum of CdS/PVG shows a 0.85 eV blue shift compared to the band gap of bulk CdS.
It is suggested that these are quantum dots.

CdSe/PVG was synthesized by using hydrogen selenide instead of hydrogen sulfide in the above process, and the quantum size effect of CdSe was confirmed in this sample as well.

(Comparative Example) In Example 2, the autoclave
When Cd was supported on porous glass at room temperature under atmospheric pressure without using a glass, it took a long time to support Cd inside the glass.

Example 3 Porous glass with a thickness of 0.5 mm (average pore diameter 4 nm,
specific surface area 200m2/g) by the method shown below.
nS fine particles were dispersed and supported.

1) 1.0mol%Zn(CH3COO
)2 was dissolved to prepare a Zn-dispersed SiO2 sol having the composition shown in Table 1 of Example 1. A porous glass was placed in an autoclave and immersed in this sol for 30 minutes at 3 atm at room temperature, dried under vacuum, and then heated in air at 400° C. for 1 hour to support Zn and its oxides.

2) The above porous glass was reacted at 150° C. for 10 minutes in a hydrogen sulfide atmosphere to produce a porous glass supporting ZnS (ZnS/PVG).

The particle size of ZnS in the obtained ZnS/PVG was 3 to 3.5 nm, and the amount of ZnS supported was 7.5 nm.
It was wt%. The band gap determined from the absorption spectrum of this ZnS/PVG shows a 0.8 eV blue shift compared to the band gap of bulk ZnS.
It is suggested that S is a quantum dot.

When hydrogen selenide was used instead of hydrogen sulfide in the above process, ZnSe/PVG could be synthesized, and the quantum size effect of ZnSe was confirmed in this sample as well.

(Comparative Example) In Example 3, autoclave
When Zn was supported on porous glass at room temperature under atmospheric pressure without using a glass plate, it took a long time to support Zn inside the glass.

Example 4 Porous glass with a thickness of 0.5 mm (average pore diameter 4 nm,
specific surface area 200m2/g) by the method shown below.
bS fine particles were dispersed and supported.

1) 1.0 mol% Pb(NO3)2
A Pb-dispersed SiO2 sol having the composition shown in Table 1 of Example 1 was prepared. A porous glass was placed in this sol in an autoclave, immersed at room temperature for 30 minutes at 3 atmospheres, dried under vacuum, and then heated in air at 400° C. for 1 hour to support Pb and its oxides.

2) The above porous glass was reacted at 150° C. for 10 minutes in a hydrogen sulfide atmosphere to produce a porous glass supporting PbS (PbS/PVG). PbS
The amount supported was 8.5 wt%.

The band gap determined from the absorption spectrum of this PbS/PVG shows a blue shift of 0.8 eV compared to the band gap of bulk PbS.
It is suggested that these are quantum dots.

When hydrogen selenide was used instead of hydrogen sulfide in the above process, PbSe/PVG could be synthesized, and the quantum size effect of PbSe was confirmed in this sample as well.

(Comparative Example) In Example 4, autoclave
When Pb was supported on porous glass at room temperature under atmospheric pressure without using a glass, it took a long time for Pb to be supported inside the porous glass.

Example 5 An optical bistable device was fabricated using the thin film shown in Example 1.

When laser light with a wavelength of 380 nm was incident on this device with a spot diameter of 5 μm and the relationship between the intensity of the incident light and the intensity of the emitted light was measured at room temperature (25° C.), it showed bistable characteristics.

[0062]

Effects of the Invention: A porous glass is immersed under pressure in a mixed solution of a semiconductor or a compound capable of reacting to form a semiconductor of the present invention and a sol that becomes glassy, and the sol retained in the porous glass is removed. According to the manufacturing method of semiconductor fine particle dispersed glass, in which compound semiconductors are dispersed and supported on porous glass by gelation and heat treatment, excellent nonlinear optical properties can be quickly achieved by supporting semiconductors with a uniform particle size at a high concentration. It becomes possible to obtain a glass in which semiconductor fine particles are dispersed. Furthermore, the presence of the gel makes it possible to more easily prevent semiconductor fine particles from coalescing and becoming coarse.

Further, porous glass is immersed under pressure in a vitreous sol solution in which cadmium, zinc, or lead of the present invention is dissolved, and the solution is held in the pores of the porous glass. According to the method of gelling the sol held in the porous glass and further reacting it with hydrogen sulfide or selenium sulfide gas, in addition to the above-mentioned effects, it becomes possible to more uniformly precipitate the semiconductor dispersion to the inside.

Furthermore, the average pore diameter of the porous glass is 10n.
According to a preferred embodiment of the present invention using a porous glass with a size of less than m, it is easier to control the particle diameter of the precipitated semiconductor fine particles to a small enough extent that the quantum size effect appears, and the semiconductor has excellent nonlinear optical properties. A quick and simple manufacturing method for fine particle dispersed glass can be provided.

Claims (3)

[Claims] 1. Porous glass is immersed under pressure in a mixed solution of a semiconductor or a compound that can react to form a semiconductor and a sol that becomes glassy, and the mixed solution is poured into the pores of the porous glass. A method for manufacturing a semiconductor fine particle-dispersed glass, characterized in that the semiconductor fine particles are dispersed and supported on the porous glass by gelling the sol held on the porous glass and heat-treating the sol. 2. Porous glass is immersed under pressure in a vitreous sol solution in which cadmium, zinc, or lead is dissolved, and the solution is held in the pores of the porous glass,
A semiconductor characterized in that CdS, CdSe, ZnS, ZnSe, PbS or PbSe is dispersed and supported on the porous glass by gelling the sol held in the porous glass and further reacting with hydrogen sulfide or selenium sulfide gas. A method for manufacturing fine particle dispersed glass. [Claim 3] The average pore diameter of the porous glass is 10 nm.
The method for producing semiconductor fine particle dispersed glass according to claim 1 or 2, wherein the method is as follows.