KR20120104818A - Fabrication method of silicate glass including lead sulfide quantum dots containing silver nano-particle - Google Patents

Abstract

PURPOSE: A manufacturing method of glass including lead sulfide quantum dot which contains silver nano-particles is provided to easily control size or distribution of lead sulfide quantum dots by adjusting addition amount of nucleation auxiliary materials. CONSTITUTION: A manufacturing method of glass including lead sulfide quantum dot which contains silver nano-particles comprises the following steps: manufacturing a base mixture by mixing lead sulfide compound and silver oxide with a base glass material(s140); manufacturing a glass molten body by melting the base mixture; manufacturing a glass by cooling the glass molten body(s160); segregating the lead sulfide quantum dots by heat treating the glass; and completing the glass including the lead sulfide quantum dots which contains silver nano-particles(s220). The size or the distribution of the lead sulfide quantum dots are controlled by the concentration of the silver oxide. The base glass material has a composition of 50SiO2-35Na2O-5Al2O3-10ZnO, the lead sulfides have a composition of 2ZnS- xPbO (x=0.8-1.0), and silver oxide has a composition of yAg2O (y=10-30ppm). [Reference numerals] (S100) Preparing substrate glass; (S120) Preparing lead sulfide compound and silver compound; (S140) Manufacturing a substrate mixture by mixing silver oxide with a substrate glass material and lead sulfide; (S160) Fusing base mixture to form glass molten body; (S180) Manufacturing glass in which lead sulfide and silver are contained by cooling the glass molten body; (S190) Annealing glasses in which lead sulfide and silver are contained; (S200) Heat treating the glasses in which lead sulfide and silver are contained and precipitating lead sulfide quantum dots and silver nano particles in which the size or distribution is controlled by silver concentration; (S220) Completing glasses including lead sulfide quantum dots

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for manufacturing a glass containing red sulfide quantum dots containing silver nanoparticles (manufacturing method of silicate glass including lead sulfide quantum dots containing silver nano-particles)

The present invention relates to a process for producing glass, and more particularly to a process for producing glass containing lead sulfide (PbS) quantum dots.

The quantum dot is a semiconductor particle of several nanometers in size, and the wavelength of light emitted varies depending on the particle size. The light emitted by the quantum dot is generated by electrons coming from the conduction band to the valence band. Fluorescence (light emission) generated at this time generates light of a shorter wavelength as the particles of the quantum dots become smaller, and generates light of a longer wavelength as the particle size increases.

Therefore, by controlling the size of the quantum dots, the band gap can be controlled to obtain various wavelengths of energy. However, it is not easy to control the size and distribution of the quantum dots, and the process cost is high. It is also necessary to adjust the size and distribution of the quantum dots without deteriorating the characteristics of the quantum dots.

A problem to be solved by the present invention is to provide a method for manufacturing a glass including red sulfide quantum dots containing silver nanoparticles, which is designed to easily control the size and distribution of the quantum dots.

According to an aspect of the present invention, there is provided a method of manufacturing a glass according to one embodiment of the present invention includes the steps of preparing a base mixture by mixing a base glass material with a red sulfide compound and silver oxide, A step of producing a glass by cooling the glass melt; a step of heat treating the glass to precipitate red sulfide quantum dots whose size or distribution is controlled according to the concentration of the silver oxide; And completing the glass comprising red sulfide (PbS) quantum dots containing the contained silver nanoparticles.

The glass base material _{50SiO 2 -35Na 2 O-5Al 2} O ₃ has a composition of -10ZnO, the red sulfide compound has a composition of 2ZnS-xPbO (x = 0.8 to 1.0), wherein the silver oxide is yAg ₂ O (y = 10 to 30 ppm). As the silver oxide concentration increases from 10 ppm to 30 ppm, the radius of the red sulfide quantum dot may increase.

And after the step of cooling the glass melt to produce glass, annealing the glass. The step of cooling the glass melt may be performed by rapidly quenching the glass melt to room temperature.

According to another aspect of the present invention, there is provided a method of manufacturing a glass, comprising: preparing a base mixture by mixing a red sulfide compound with a base glass material; melting the base mixture to produce a glass melt; The method of claim 1, further comprising the steps of: preparing silver halide grains by cooling the silver halide grains to form silver halide grains; ; And completing the glass comprising red sulfide quantum dots containing the silver nanoparticles.

The base glass material has a composition of 50SiO ₂ -35Na ₂ O-5Al ₂ O ₃ -10ZnO, and the red sulfide compound may have a composition of 2ZnS-xPbO (x = 0.8-1.0). The silver ion implantation can be performed using AgNO ₃ distilled water solution or AgNO ₃ -NaO ₃ molten salt.

According to one embodiment of the present invention, a method of manufacturing glass containing red sulfide quantum dots uses silver nanoparticles as a nucleation auxiliary material in a glass to control the size or distribution of red sulphide (PbS) quantum dots.

In other words, the process for preparing glass containing red sulfide quantum dots according to an embodiment of the present invention controls precipitation of red sulfide quantum dots as a nucleation generating auxiliary material such as silver nanoparticles. Silver nanoparticles contribute to the formation of red sulfide QDs in the glass.

In addition, according to one embodiment of the present invention, a method of manufacturing a glass including red sulfide quantum dots can control the size or distribution of red sulfide quantum dots by controlling the addition amount of a nucleation auxiliary material such as silver nanoparticles, And the light absorption and fluorescence intensity of the quantum dots can be controlled.

The method for producing glass containing red sulfide quantum dots according to the present invention can be applied to optical devices, photonics, or micro optical devices by providing better and uniform properties to red sulfide quantum dots formed in glass.

1 is a flow chart for explaining a method of manufacturing a glass including red sulfide quantum dots according to a first embodiment of the present invention.
FIG. 2 is a flowchart for explaining a method of manufacturing a glass including red sulfide quantum dots according to a second embodiment of the present invention.
FIG. 3 is a diagram showing an absorption spectrum of a glass including red sulfide quantum dots containing silver nanoparticles prepared by the first embodiment of the present invention. FIG.
FIG. 4 is a cross-sectional photograph of a glass including red sulfide quantum dots containing silver nanoparticles prepared according to the second embodiment of the present invention.
FIGS. 5 and 6 are diagrams showing fluorescence spectra of a glass containing red nanoparticle-containing red sulfide quantum dot prepared by the second embodiment of the present invention. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. The present invention is capable of various modifications and various forms, and specific embodiments are illustrated and described in detail in the drawings. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for similar elements in describing each drawing.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a part or a combination thereof is described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as ideal or overly formal in the sense of the art unless explicitly defined herein Do not.

Quantum dots can be tuned to adjust the band gap to obtain various wavelengths of energy. This effect is called the quantum confinement effect. The present invention can be applied to a display apparatus, a quantum dot laser, a solar cell, a sensor, and an amplifier for optical communication using a quantum limiting effect.

The production method of the quantum dots can be classified into a chemical synthesis method of forming quantum dots by chemical synthesis and a precipitation method of depositing quantum dots in a glass (also referred to as "silicate glass") through heat treatment. In the case of the chemical synthesis method, the synthesis of the quantum dots is easy, but since the quantum dots are dispersed in the organic solution and the aqueous solution, there is a limit to apply to practical devices.

The quantum dot precipitation method using heat treatment uses a thermodynamic phase separation mechanism by ion diffusion in supersaturated solid solution. For smooth diffusion of the quantum dots, annealing is performed at a temperature before and after the glass transition point, that is, annealing is performed. The precipitation of quantum dots in glass can be divided into three stages: (1) nucleation, (2) individual growth, and (3) coordination.

When the quantum dots are formed by precipitation in the glass, it is advantageous in that it has excellent mechanical strength and chemical stability and is easy to optical fiber applicable to amplifiers, sensors, or laser devices. Therefore, an embodiment of the present invention uses a method of precipitating and forming quantum dots in glass.

One embodiment of the present invention controls the size or distribution of quantum dots by adding silver nanoparticles as a nucleation-generating auxiliary material in the glass. One embodiment of the present invention adjusts the size or distribution of quantum dots by varying the concentration of silver oxide added to the glass. In this case, it can be very usefully applied to electronic devices and optical device manufacturing fields.

One embodiment of the present invention provides a method for producing glass comprising red sulfide quantum dots containing silver nanoparticles. Glass with a single addition of silver or a semiconductor material is relatively easy to manufacture. However, when the silver and the semiconductor material are mixedly added, the solubility is very low. Therefore, it is difficult to produce glass containing silver and a red sulphide (PbS) as a semiconductor material.

Therefore, in one embodiment of the present invention, glass formation was facilitated by limiting the addition amount of silver to a very small amount, and the effect of silver addition on the formation of red sulfide quantum dots was investigated. In one embodiment of the present invention, a glass containing red sulfide quantum dot containing silver nanoparticles is produced by using a heat treatment method and an ion implantation method, and will be described in the following examples. Ion implantation method was used to observe red sulfide quantum dots by further increasing the amount of silver added.

Example 1

1 is a flow chart for explaining a method of manufacturing a glass including red sulfide quantum dots according to a first embodiment of the present invention.

Specifically, the first embodiment relates to a method for producing glass containing red sulfide quantum dots containing silver nanoparticles using heat treatment. A base glass material is prepared (step S100).

As an example of the base glass, an initial composition of 50SiO ₂ -35Na ₂ O-5Al ₂ O ₃ -10ZnO having a high solubility (up to about 1 mol%) of IV-VI semiconductor quantum dots was used. The base glass material is in powder form and its composition is expressed in mol%. Silicon oxide (SiO ₂ ) was added as a glass network agent, zinc oxide (ZnO) and aluminum oxide (Al ₂ O ₃ ) were added as additive oxides, and sodium carbonate (Na ₂ CO ₃ ) was added to lower the melting point of glass .

A red sulfide compound including red (Pb) and sulfur (S) and a silver oxide are prepared (step S120). In this embodiment, 2ZnS-xPbO (x = 0.8-1.0) was used as an example of the red sulfide compound, and yAg ₂ O (y = 10-30 ppm) was used as an example of the silver oxide. In the red sulphide compound, ZnS was added in large amount instead of PbS together with PbO to suppress volatilization of sulfur (S). The composition of the red sulfide compound and the silver oxide is represented by mol%.

Subsequently, a base mixture is prepared by mixing red sulfide compound and silver oxide in a base glass material (step S140). That is, a base mixture was prepared by adding 2ZnS-xPbO (x = 0.8 to 1.0) and yAg ₂ O (y = 10 to 30 ppm) to a base glass of 50SiO ₂ -35Na ₂ O-5Al ₂ O ₃ -10ZnO do. In this example, the base mixture was prepared by mixing in a ball mill or the like for about 12 hours.

The base mixture is melted to form a glass melt (step S160). In this embodiment, the base mixture is placed in an alumina (Al ₂ O ₃ ) crucible and melted in a furnace at 1300 to 1350 ° C for about 30 minutes to 1 hour to form a glass melt.

Next, the glass melt is cooled to produce glass containing red sulphide and silver (step S180). In this embodiment, the glass melt was poured into a bronze mold and pressed with a bronze plate to quench it to room temperature to produce glass.

Subsequently, the glass can be annealed as required (step S190). The annealing treatment is performed to remove the stress that may occur in the glass when the glass melt is cooled. In this embodiment, the annealing is performed at about 350 DEG C, which is lower than the glass transition temperature, for about 3 hours, and the furnace is cooled. The annealing treatment may not be performed as described above.

The glass thus formed is heat-treated to deposit silver nanoparticles and red sulfide quantum dots in the glass (Step S200). In this embodiment, a glass sample according to the concentration of silver oxide was cut into 10 mm (length) X 10 mm (width) X 2 mm (thickness) and then heat-treated.

The heat treatment was performed at a temperature at which silver nanoparticles and red sulfide quantum dots could be precipitated in the glass. That is, the heat treatment conditions were 5 to 20 hours at a temperature of 430 to 500 ° C. The radius of the red sulfide quantum dots deposited after the heat treatment had a size distribution of 1 to 8 nm. Absorption (absorption coefficient) and fluorescence intensity increased with the addition of silver.

In glass doped with 20 ppm, absorption started at 365 nm when heat treatment was performed at 460 ° C for 10 hours. This absorption data is evidence that silver forms silver clusters such as Ag ₇ and Ag ₉ in the glass material and that the nanoclusters have a significant effect on the formation of red sulfide quantum dots. Silver nanocrystals are believed to promote the formation of red sulfide quantum dots and enhance optical effects.

), 흡수 계수(

), 양자점 크기(반지름)의 계산값(

)의 일부를 나타낸 것이다. Table 1 below shows absorption wavelengths depending on the amount of silver added

), Absorption coefficient (

), The calculated value of the quantum dot size (radius)

). ≪ / RTI >

Heat treatment
Temperature
(° C)

(nm)

(nm)

(

) R (nm) 0 10
ppm 20
ppm 0 10
ppm 20
ppm 0 10
ppm 20
ppm 440 695 702 751 0.05 0.14 0.48 1.2 1.2 1.4 450 783 793 841 0.16 0.29 0.94 1.4 1.5 1.6 460 976 978 977 0.28 0.71 1.91 1.9 1.9 1.9 470 1232 1235 1256 0.75 1.42 3.65 2.4 2.4 2.5 480 1580 1587 1583 1.00 2.10 5.05 3.4 3.4 3.4

As shown in Table 1, the increase of the absorption coefficient due to the addition of silver at 460 ° C. and 10 hours for the heat treated specimen is very large, and this tendency is similar in other heat treatment conditions. The absorption coefficient is closely related to the formation density of the quantum dots and the concentration of the quantum dots is increased due to the addition of silver. Also, as the concentration of silver oxide increases from 10 ppm to 20 ppm, the radius of the red sulfide quantum dot can increase. Of course, although not shown in Table 1, the radius of red sulfide quantum dots increases further when the concentration of silver oxide increases to 30 ppm.

Finally, when the silver nanoparticles and the red sulfide quantum dots are precipitated through the heat treatment, a glass containing the red sulfide quantum dots containing the silver nanoparticles is completed (step S220).

Example 2

FIG. 2 is a flowchart for explaining a method of manufacturing a glass including red sulfide quantum dots according to a second embodiment of the present invention.

Specifically, the second embodiment relates to a method of manufacturing a glass including red sulfide quantum dots containing silver nanoparticles using an ion implantation method. The base glass is prepared as in the first embodiment (step S300). In other words, the base glass is prepared from the same material as the step 100 of the first embodiment.

A red sulfide compound containing red (Pb) and sulfur (S) is prepared (step S320). In this embodiment, 2ZnS-xPbO (x = 0.8-1.0) is used as an example of the red sulfide compound as in the first embodiment. In the red sulphide compound, ZnS was added in large amount instead of PbS together with PbO to suppress volatilization of sulfur (S). The composition of the red sulfide compound is expressed in mol%.

Subsequently, the base glass is mixed with the red sulfide compound to prepare a base mixture (step S340). That is, a base mixture is prepared by adding 2ZnS-xPbO (x = 0.8 to 1.0) composition to a base glass of 50SiO ₂ -35Na ₂ O-5Al ₂ O ₃ -10ZnO. In this example, the base mixture was prepared by mixing in a ball mill or the like for about 12 hours.

The base mixture is melted to form a glass melt (step S360). In this embodiment, the base mixture is placed in an alumina (Al ₂ O ₃ ) crucible and melted in a furnace at 1300 to 1350 ° C for about 30 minutes to 1 hour to form a glass melt.

Next, the glass melt is cooled to produce glass containing red sulfide (step S380). In this embodiment, the glass melt was poured into a bronze mold and pressed with a bronze plate to quench it to room temperature to produce glass.

Subsequently, the glass containing red sulfide may be annealed (step 390) if necessary. The annealing treatment is performed to remove the stress that may occur in the glass when the glass melt is cooled. In this embodiment, the annealing is performed at about 350 DEG C, which is lower than the glass transition temperature, for about 3 hours, and the furnace is cooled. The annealing treatment may not be performed as described above.

Silver ions are implanted into the glass containing red sulfide with a silver solution (step S400). That is, the glass was cut into a size of 10 mm ㅧ 10 mm ㅧ 2 mm, and then subjected to optical polishing, followed by ion implantation with AgNO ₃ solution or AgNO ₃ -NaNO ₃ molten salt.

In the case of AgNO ₃ , ion implantation was performed at 20 to 90 ° C for 5 to 50 hours in a solution diluted with distilled water at a concentration of 0.5 to 10 mol / L. The silver ion-implanted layer in the glass showed up to 50 to 1000 nm. In the case of the AgNO ₃ -NaNO ₃ molten salt, the concentration of AgNO ₃ was adjusted to 0.5 to 5 mol / L, the ion implantation temperature was 310 to 330 ° C., and the time was 1 to 30 minutes. In this case, the silver ion-implanted layer was 1 to 10 mu m.

The glass thus formed is heat-treated to deposit silver nanoparticles and red sulfide quantum dots in the glass (Step S420). After the ion implantation, the specimens were annealed to precipitate silver nanoparticles and red sulfide quantum dots. The heat treatment was carried out at a temperature of 400 to 500 DEG C for 5 to 20 hours.

The radius of the red sulfide quantum dots ranged from 1 to 10 nm. In the silver ion implantation layer, the size of the quantum dots was larger and the size of the quantum dots was divided into two groups.

According to the ion implantation conditions, the formation of the quantum dot is different, which means that the size of the quantum dot changes according to the amount of silver added. In other words, the size and location of the red sulfide quantum dot can be controlled by silver nanoparticles precipitated by ion implantation.

Finally, when the silver nanoparticles and red sulfide quantum dots are precipitated through the heat treatment, a glass containing red sulfide quantum dots containing silver nanoparticles is completed (step S440).

FIG. 3 is a diagram showing an absorption spectrum of a glass including red sulfide quantum dots containing silver nanoparticles prepared by the first embodiment of the present invention. FIG.

Specifically, the absorption spectrum of the glass according to the concentration of the oxide after heat treatment at 460 占 폚 for 10 hours according to Example 1 is shown. The X axis is the wavelength, the left Y axis is the absorption coefficient, and the right Y axis is the fluorescence intensity. In Figure _{3, 20 Ag 2 O, 10Ag} 2 O is means that the 20ppm and 10ppm concentration of oxides and, No Ag ₂ O is shows the case the oxide is not added. As shown in FIG. 3, it can be seen that light absorption and fluorescence intensity are increased by the addition of silver.

FIG. 4 is a cross-sectional photograph of a glass including red sulfide quantum dots containing silver nanoparticles prepared according to the second embodiment of the present invention.

Specifically, FIG. 4 shows the results of the injection of a glass specimen prepared by ion-implanting AgNO ₃ at 80 ° C. using a solution diluted with distilled water at a concentration of 0.5 to 10 mol / L and heat-treating the specimen at 440 ° C. for 10 hours It is an electron microscope photograph. As shown in FIG. 4, an ion implanted layer of 500 nm can be confirmed. 4, the upper layer is a Pt coating layer, the IE Area is an ion implanted layer, and the Non IE Area is a layer not implanted with ions.

FIGS. 5 and 6 are diagrams showing fluorescence spectra of a glass containing red nanoparticle-containing red sulfide quantum dot prepared by the second embodiment of the present invention. FIG.

5 and 6 are graphs _showing the results of the ion implantation at 60 ° C. and 80 ° C. using a solution diluted to a concentration of 0.5 to 10 mol / L with distilled water for AgNO ₃ , (Photoluminescence (PL)) spectrum of fluorescence.

The X-axis is the wavelength, and the fluorescence intensity of the Y-axis is the normalized value. 5 and 6, the IE area means that the ion-implanted layer is formed, and the all area means the sample in which the ion-implanted layer is not formed. It can be seen that the fluorescence wavelength of the glass, that is, the peak wavelength, shifts toward 1150 nm or 1510 nm or 1420 nm long wavelength due to the presence of the ion implanted layer. This means that the size and density of the red sulfide quantum dot are increased.

As described above, one embodiment of the present invention controls precipitation of red sulfide quantum dots using a nucleation auxiliary material such as silver nanoparticles. One embodiment of the present invention can control the size, distribution, or density of red sulfide quantum dots by controlling the addition amount of nucleation auxiliary material such as silver nanoparticles, and can control light absorption and fluorescence intensity of the quantum dots.

S100-S220: a step of preparing a glass containing red sulfide quantum dots containing silver nanoparticles by heat treatment; S300-S440: a step of preparing glass containing red sulfide quantum dots containing silver nanoparticles by ion implantation

Claims (8)

Mixing a base glass material with a red sulfide compound and a silver oxide to prepare a base mixture;
Melting the base mixture to produce a glass melt;
Cooling the glass melt to produce glass;
Heat treating the glass to precipitate a red sulfide quantum dot whose size or distribution is controlled according to the concentration of the silver oxide; And
(PbS) quantum dots containing silver nanoparticles contained in said silver oxide. ≪ RTI ID = 0.0 > 8. < / RTI > The method of claim 1, wherein the base glass has a composition of 50SiO ₂ -35Na ₂ O-5Al ₂ O ₃ -10ZnO, the red sulfide compound has a composition of 2ZnS-xPbO (x = 0.8-1.0) and yAg ₂ O (y = 10 to 30 ppm). 3. The method of claim 2, wherein as the concentration of the silver oxide increases from 10 ppm to 30 ppm, the radius of the red sulfide quantum dot is increased. The method of manufacturing a glass according to claim 1, further comprising a step of annealing the glass after cooling the glass melt to produce glass. The method of claim 1, wherein cooling the glass melt comprises:
Wherein the glass melt is quenched to room temperature. Mixing a base glass material with a red sulfide compound to prepare a base mixture;
Melting the base mixture to produce a glass melt;
Cooling the glass melt to produce glass;
Performing silver ion implantation on the glass;
Heat-treating the silver-ion-implanted glass to deposit red sulfide quantum dots whose size or distribution is controlled according to the ion-implanted silver concentration; And
Wherein the silver nanoparticles comprise a red sulfide quantum dot containing silver nanoparticles. The glass according to claim 6, wherein the base glass has a composition of 50SiO ₂ -35Na ₂ O-5Al ₂ O ₃ -10ZnO, and the red sulfide compound has a composition of 2ZnS-xPbO (x = 0.8-1.0) ≪ / RTI > The method of claim 6, wherein the silver ion implantation is performed using a AgNO ₃ distilled water solution or AgNO ₃ -NaO ₃ molten salt.

Images