KR101614019B1 - Phosphor comprising zinc silicate-based nanoparticles and its preparation method - Google Patents

Abstract

The phosphor of the present invention is represented by Zn ₂ SiO ₄ : xTb ^{3 +} , yYb ^{3 +} (where x is a real number of 0.01? X? 0.1 and y is a real number of 0.01? Y? 0.3) that, Tb ^3+, and Yb ^{+ 3} is doped, and a linkage of the nanoparticles Oh silicate size of 20 to 500 nm. A method for producing such a phosphor includes the steps of: (a) preparing a precursor solution; (b) adding a precipitant to form a precipitate; (c) a hydrothermal treatment step; And (d) baking the nanoparticles to produce silicic acid-based nanoparticles. The phosphor prepared as described above has down conversion characteristics and has a wide range of wavelengths that can be excited, and thus can be applied to various fields such as solar cells, ultraviolet blocking and converting agents, and materials for preventing forgery and alteration.

Description

[0001] PHOSPHOR COMPRISING ZINC SILICATE-BASED NANOPARTICLES AND ITS PREPARATION METHOD [0002]

The present invention relates to a phosphor containing silicate-based nanoparticles having downconversion characteristics, and a method for producing the phosphor.

Quantum cutting is a phenomenon in which a single incident photon with high energy is separated and emitted by two or more low-energy photons through downconversion of energy. The luminescent material has a quantum efficiency of 100% or more.

The luminescent material exhibiting such a quantum separation phenomenon can be very importantly applied to the lighting industry and display devices. In addition, in recent years, the application of a quantum-separated phosphor to a crystalline silicon solar cell has been studied in an effort to maximize the efficiency of the solar cell.

Crystalline silicon solar cells operate most efficiently in the 950 to 1100 nm spectral range, but show very low reactivity for short wavelength sunlight. Therefore, if a quantum-separated fluorescent material capable of emitting ultraviolet light having a high energy to a crystalline silicon solar cell by near-infrared light near 1000 nm located on the bandgap of silicon (E <1.12 eV) through energy down conversion is applied, The performance of the battery can be greatly improved.

Near-infrared quantum separation has been demonstrated in systems doped with various Ln ³⁺ -Yb ³⁺ (Ln = Tb, Tm, Pr, Er, Nd, Ho, and Dy) ions. J. Appl. Phys., 2009, 105, 053521) disclose that Zn ₂ SiO ₄ : Tb ³⁺ and Yb ³⁺ thin film phosphors prepared by the sol-gel process can increase the reactivity of the ultraviolet region of a silicon solar cell It has been proposed that when the phosphor is excited with light of 350 to 485 nm, strong near infrared rays are emitted near 900 to 1100 nm.

However, the Zn ₂ SiO ₄ : Tb ³⁺ , Yb ³⁺ thin film phosphor prepared by the sol-gel method excites mainly only in a specific region, that is, in a very narrow region near 485 nm, and in the ultraviolet region of 350 to 450 nm, There is a disadvantage not to do. Due to such low excitation efficiency, there is a limit to applying the phosphor to a crystalline silicon solar cell.

Accordingly, there is a desperate need for a method for manufacturing a near-infrared ray quantum luminescent material capable of emitting a photon in the vicinity of 900 to 1100 nm by down-converting a relatively wide region (300 to 500 nm) of sunlight including ultraviolet rays and visible rays have.

X. Y. Huang and Q. Y. Zhang, "Near-infrared down conversion in Zn2SiO4: Tb3 +, Yb3 + thin-films, Journal of Applied Physics, 105, (2009), pp.053521-1 - 053521-4.

It is an object of the present invention to provide a method of using a hydrothermal treatment in the production of a phosphor containing silicate-based nanoparticles having down conversion characteristics and to provide a phosphor having a wide wavelength range of absorbed light, To improve the efficiency of solar cells and to apply them to optical converters, anti-counterfeiting and anti-tampering materials, or ultraviolet light blocking agents.

The phosphor according to an embodiment of the present invention includes zinc silicate nanoparticles represented by the following formula 1 and doped with Tb ^{3 +} and Yb ³⁺ , and the zinc silicate nanoparticles have a size of 20 to 500 nm.

[Chemical Formula 1]

Zn ₂ SiO ₄ : xTb ^{3 +} , yYb ^{3 +}

In the formula (1), x is a real number with 0.01? X? 0.1 and y is a real number with 0.01? Y? 0.3.

The silicic acid-based nanoparticles may have downconversion characteristics.

The silicic acid-based nanoparticles can be excited by light having a wavelength range of 300 to 500 nm.

The silicic acid-based nanoparticles may emit light having a wavelength in the range of 900 to 1100 nm.

A method of manufacturing a phosphor according to another embodiment of the present invention includes the steps of: (a) forming a precursor solution including a zinc (Zn) precursor, a silicon (Si) precursor, a terbium (Tb) precursor, a ytterbium (Yb) precursor, ; (b) adding a precipitant to the precursor solution to form a precipitate; (c) subjecting the precipitate to heat treatment in a sealed state in a reactor at a temperature of 100 to 250 ° C to obtain a solid powder; And (d) baking the solid powder to prepare zinc silicate nanoparticles, wherein the zinc silicate nanoparticles are represented by the above formula (1) and are doped with Tb ^{3 +} and Yb ^{3 +} , And the size thereof is 20 to 500 nm.

The zinc precursor may be any one selected from the group consisting of zinc chloride, zinc sulfide, zinc oxide, hydrates thereof, and combinations thereof, and the terbium precursor may be at least one selected from the group consisting of a terbium chloride, a terbium sulfide, a terbium nitrate, And the ytterbium precursor may be any one selected from the group consisting of ytterbium chloride, ytterbium sulfide, ytterbium nitrate, hydrates thereof, and combinations thereof.

The silicon precursor may comprise any one selected from the group consisting of fumed silica, colloidal silica, organosilicon compounds, and combinations thereof.

The mixed solvent includes water and an alcohol, and the alcohol may have 1 to 3 carbon atoms.

Based on 2 moles of zinc and 1 mole of silicon, the content of terbium may be 0.01 to 0.1 moles, and the content of ytterbium may be 0.01 to 0.3 moles.

The precipitant may include any one selected from the group consisting of ammonia water, tetraalkylammonium hydroxide, urea, sodium hydroxide, potassium hydroxide, and combinations thereof. The alkyl group of the tetraalkylammonium may have 1 to 4 carbon atoms have.

The precipitant may be added at a weight of 0.2 to 2 times the weight of the mixed solvent.

The calcination treatment in the step (d) may be carried out at a temperature of 300 to 1200 ° C and may be carried out in an atmosphere containing any one gas selected from the group consisting of air, nitrogen, argon, helium and combinations thereof .

The crystalline silicon solar cell, the ultraviolet ray blocking agent, the optical converter, and the anti-fake and anti-fake material according to another embodiment of the present invention include the above-described phosphor.

The present invention provides a phosphor containing silicate-based nanoparticles and a method for producing the same, and the present invention will be described in more detail as follows.

The method for producing a phosphor containing silicate-based nanoparticles according to the present invention comprises the steps of: (a) preparing a phosphor comprising a zinc (Zn) precursor, a silicon (Si) precursor, a terbium (Tb) precursor, a ytterbium (Yb) precursor and a mixed solvent Preparing a precursor solution; (b) adding a precipitant to the precursor solution to form a precipitate; (c) hydrothermally treating the precipitated liquid in a sealed state in a reactor at a temperature of 100 to 250 ° C to obtain a solid powder; And (d) calcining the solid powder to prepare silicasulfide-based nanoparticles.

The silicic acid-based nanoparticles are represented by the following formula (1), doped with Tb ^{3 +} and Yb ^{3 +} , and have a size of 20 to 500 nm.

[Chemical Formula 1]

Zn ₂ SiO ₄ : xTb ^{3 +} , yYb ^{3 +}

In the formula (1), x is a real number with 0.01? X? 0.1 and y is a real number with 0.01? Y? 0.3.

The step (a) may be a step of mixing a precursor of each element into a mixed solvent and then sufficiently stirring to prepare a precursor solution in which the precursor is almost completely dissolved.

Since the content of the terbium and ytterbium in the finally produced silicic acid-based nanoparticles is very important, it may be important to control the precursor content in the preparation of the precursor solution.

The content of the terbium may be 0.01 to 0.1 mol, preferably 0.02 to 0.05 mol, based on 2 mol of zinc and 1 mol of silicon. When the content of the terbium is less than 0.01 mol, the amount is too small to exhibit the intended luminescent effect, and when it exceeds 0.1 mol, the emission intensity may be lowered due to the concentration quenching effect.

The ytterbium content may be 0.01 to 0.3 mol, preferably 0.05 to 0.2 mol, based on 2 mol of zinc and 1 mol of silicon. When the content of ytterbium is less than 0.01 mol, the emission efficiency may be lowered due to the low content of light due to the low content. If the ytterbium content is more than 0.3 mol, Can result in loss without.

The content of the terbium and ytterbium is as described above, and the molar ratio of the terbium to ytterbium may be about 1: 1 to 1: 5.

The zinc precursor may be any one selected from the group consisting of zinc chloride, zinc sulfide, zinc oxide, hydrates thereof, and combinations thereof. Examples of the zinc precursor include zinc chloride (ZnCl ₂ ), zinc sulfide (ZnS) (NO ₃ ) ₂ ), zinc chloride hydrate, zinc sulfide hydrate, zinc nitrate hydrate (wherein the hydrate is 2, 4, or hexahydrate), and the like.

The terbium precursor may be any one selected from the group consisting of a terbium chloride, a terbium sulfide, a terbium nitrate, a hydrate thereof and a combination thereof. Examples of the terbium precursor include terbium chloride (TbCl ₃ ), terbium sulfide (Tb ₂ S ₃ ) terbium (Tb (NO _{3) 3),} terbium chloride hydrate, terbium sulfide hydrate, terbium nitrate hydrate (where baggage is 2, 4, or 6 hydrate) and the like can be applied.

The ytterbium precursor may be any one selected from the group consisting of ytterbium chloride, ytterbium sulphide, ytterbium nitrate, hydrates thereof, and combinations thereof. Examples of the ytterbium precursor include ytterbium chloride (YbCl ₃ ), ytterbium ₂ S ₃ ), ytterbium nitrate (Yb (NO ₃ ) ₃ ), ytterbium chloride, ytterbium sulphide hydrate, ytterbium nitrate hydrate (wherein the hydrate is 2, 4, or 6 hydrate) and the like.

The silicon precursor may be, for example, fumed silica, colloidal silica, an organosilicon compound, or a mixture thereof.

However, the zinc precursor, the terbium precursor, the ytterbium precursor, and the silicon precursor described above are exemplified and can provide zinc, terbium, ytterbium, and silicon, respectively, It is not limited to these compounds and can be applied.

The mixed solvent may include water and an alcohol, and the alcohol may have 1 to 3 carbon atoms. That is, water, methanol, ethanol or propanol may be mixed with water daily, preferably water and ethanol may be mixed daily. The water can be applied without particular limitation such as distilled water and deionized water. The mixed solvent is not limited thereto, and any solvent that can dissolve the precursor materials without affecting the reaction can be applied.

The step (b) may be a step of slowly adding a precipitant to the prepared precursor solution and stirring for about 2 to 4 hours to form a precipitate in the precursor solution.

As the precipitating agent, for example, ammonia water, tetraalkylammonium hydroxide, urea, sodium hydroxide, potassium hydroxide or a mixture thereof may be applied, and the alkyl group of the tetraalkylammonium may have 1 to 4 carbon atoms, Tetramethylammonium hydroxide having a carbon number of 1 or tetrapropylammonium hydroxide having a carbon number of 3 may be applied.

The amount of the precipitating agent to be added may be determined depending on the weight of the mixed solvent, and may be 0.2 to 2 times the weight of the mixed solvent. If the weight of the precipitant is less than 0.2 times the weight of the mixed solvent, the amount of the precipitate may be too small to form the nanoparticles intact, and even if the weight of the precipitant is more than 2 times the precipitant is not formed in proportion thereto, It can be over usage.

The step (c) may be a hydrothermal reaction step in which the precipitating solution containing the precipitated solid material is injected into a predetermined reactor according to the addition of the precipitating agent in the step (b), sealed and heated in a heating device, The reaction may be carried out for about 4 to 72 hours, and finally, a hydrothermally treated solid powder may be produced.

The hydrothermal treatment of step (c) may be performed at a temperature of 100 to 250 ° C, preferably 150 to 200 ° C, while being sealed in the reactor. If the heating temperature is lower than 100 ° C, the hydrothermal reaction rate is excessively slow and the effect obtained by the hydrothermal treatment may not be obtained. If the heating temperature is higher than 250 ° C, the internal pressure is excessively increased, have.

The hydrothermal treatment is a step of sealing and heat-treating the reactor using water as a solvent. As the material to be treated is sealed in the reactor, a self-generated pressure may be generated in the reactor. As a result, Since it may be processed by pressure, a product different from the heat treatment generally performed can be formed.

Therefore, the zinc silicate nanoparticles of the present invention formed through the hydrothermal treatment as described above may be locally different from the case of the sol-gel method by the surrounding structure of the rare earth element contained therein, The wavelength at which the silicate-based nanoparticles of the present invention can be excited is not a specific wavelength, but can be a broad range of wavelengths, as distinguished from silicic acid-based materials.

The hydrothermal reaction is a reaction in an environment of high temperature or high temperature / high pressure water. The reactor may preferably be a material having a high strength such as Teflon, and an electric oven may be preferable as the heating apparatus.

The solid powder produced after the hydrothermal treatment in the step (c) may be washed and dried several times, and the washing may be made of distilled water. It is preferable that the washing is performed at least three times or more than one time, And the drying can be performed at a temperature of about 100 to 130 &lt; 0 &gt; C.

The step (d) may be a step of calcining the solid powder, and may be a step of producing silicic acid-based nanoparticles by heating at a temperature of 300 to 1200 ° C, preferably 500 to 1000 ° C.

If the calcination temperature is less than 300 ° C., the stability of the finally prepared nanoparticles may deteriorate. If the calcination temperature exceeds 1200 ° C., vitrification of the nanoparticles may occur and rare-earth ions may aggregate to lower the emission efficiency of the phosphor have.

The firing treatment may be performed in an air atmosphere or an inert gas atmosphere, and the inert gas atmosphere may be, for example, an atmosphere composed of nitrogen, argon, helium, or a mixture thereof.

The phosphor according to another embodiment of the present invention includes zinc silicate nanoparticles represented by the following formula 1 and doped with Tb ^{3 +} and Yb ^{3 +} .

[Chemical Formula 1]

Zn ₂ SiO ₄ : xTb ^{3 +} , yYb ^{3 +}

In the formula (1), x is a real number with 0.01? X? 0.1 and y is a real number with 0.01? Y? 0.3.

The description of the contents of the above-mentioned terbium and ytterbium is the same as the above description, so that the description thereof will be omitted.

The silicic acid-based nanoparticles may have downconversion characteristics. Down conversion is a characteristic that absorbs light of a short wavelength having a high energy and emits light of a long wavelength having a low energy. The phosphor having a down conversion characteristic has a considerably high quantum efficiency and is applied to electronic materials such as display devices and solar cells Can be advantageous.

For example, when a crystalline silicon solar cell that reacts only at long wavelengths of light is designed to perform a function of converting light of a short wavelength into long wavelength by applying a phosphor having a down conversion characteristic, the efficiency of the solar cell is greatly enhanced .

Since the silicic acid-based nanoparticles have the down conversion characteristics, they can be excited by absorbing light of a short wavelength, that is, ultraviolet rays or visible light, and the wavelength range is preferably 300 to 500 nm. As such, the zinc silicate nanoparticles are excited not limited to any particular wavelength and can be excited by a wide range of wavelengths.

When the excited light is excited by absorbing the short wavelength light, the incident one photon can be separated into two or more photons to emit long wavelength light, i.e., near infrared rays. The wavelength range is preferably 900 to 1100 nm .

The silicic acid-based nanoparticles may have a size of 20 to 500 nm. When the size of the nanoparticles is smaller than 20 nm, secondary application may be difficult due to agglomeration. When the size of the nanoparticles is larger than 500 nm, the nanoparticles may be limited to thin film.

The crystalline silicon solar cell according to another embodiment of the present invention includes the above-described phosphor containing silicate-based nanoparticles. When the crystalline silicon solar cell includes the phosphor, the short wavelength light can be converted into a long wavelength due to the down conversion characteristics of the zinc silicate nanoparticles, so that the efficiency of the solar cell can be maximized, And ultimately, a potential effect that the solar cell as an alternative energy can be activated can be obtained.

In addition, the ultraviolet screening agent according to another embodiment of the present invention includes a phosphor including the above-described silicic acid-based nanoparticles. Since the phosphor absorbs light of a short wavelength and emits light of a long wavelength, it can block ultraviolet rays, and thus it can be applied to cosmetic products such as sunscreen.

Furthermore, other embodiments of the present invention, optical converters or anti-counterfeiting and anti-tampering materials, include the above-described phosphors. The phosphor can be applied to an optical converter because ultraviolet rays are converted into near infrared rays. The anti-falsification and anti-falsification material can be applied when printing documents related to security. Even if fake or modulated, It can be applied to security related documents using the principle of making the form visible.

In the case of manufacturing by the hydrothermal treatment as in the method of producing the phosphor including the silicic acid-based nanoparticles of the present invention, the wavelength range of the absorbed light is widened as compared with the phosphor having the conventional down conversion characteristic, So that the luminous efficiency can be improved.

Accordingly, the phosphor containing the silicic acid-based nanoparticles of the present invention can be applied for improving the efficiency of various materials such as crystalline silicon solar cells, and because of the nanoscale particle size, It may be applied as a preventive material.

1 is a graph showing the results of X-ray diffraction pattern analysis of the phosphor prepared in Example 1 according to an embodiment of the present invention.
2 is a graph showing the results of X-ray diffraction pattern analysis of the phosphor prepared in Example 3 according to an embodiment of the present invention.
3 is a graph showing excitation spectra of the phosphors prepared in Examples 1 to 3 and Comparative Example 1 according to an embodiment of the present invention.
4 is a graph showing emission spectra of the phosphors prepared in Examples 1 to 3 and Comparative Example 1 according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Example  1: Through water heat treatment Zn ₂ SiO ₄ : 0.05 Tb ^{3 +} , 0.1 Yb ^{3 +} Nanoparticle manufacturing

In a polyethylene container, 24.8 g of Zn (NO ₃ ) ₃ .6H ₂ O is dissolved in 20 g of distilled water and 25 g of ethanol and 8.32 g of tetraethyl orthosilicate (TEOS) are added. To this was added 0.91 g of Tb (NO ₃ ) ₃ .6H ₂ O, 1.87 g of Yb (NO ₃ ) ₃ .6H ₂ O, and 2 g of 0.1 M HCl and stirred for 2 hours.

50 g of ammonia water was slowly added as a precipitant to the solution, stirred for 4 hours, transferred to a Teflon reactor, sealed with stainless steel, and heat-treated by heating in an electric oven at 150 ° C for 15 hours. After the completion of the hydrothermal reaction, the solid powder was washed several times with distilled water, filtered and dried at 110 ° C.

Finally, the prepared solid powder was calcined at 900 ° C. for 1 hour in an air atmosphere to obtain silicic acid-based nanoparticles, which were subjected to X-ray diffraction analysis to obtain nanoparticles having a crystalline silicate-based structure Respectively.

Example  2: Through water heat treatment Zn ₂ SiO ₄ : 0.05 Tb ^{3 +} , 0.1 Yb ^{3 +} Nanoparticle manufacturing

A solid powder was prepared in the same manner as in Example 1 except that the water heat treatment was conducted in an electric oven at 200 ° C for 15 hours.

Finally, the prepared solid powder was calcined at 900 ° C. for 1 hour in an air atmosphere to obtain silicic acid-based nanoparticles, which were subjected to X-ray diffraction analysis to obtain nanoparticles having a crystalline silicate-based structure Respectively.

Example  3: Through water heat treatment Zn ₂ SiO ₄ : 0.05 Tb ^{3 +} , 0.1 Yb ^{3 +} Nanoparticle manufacturing

The solid powder prepared in Example 1 was calcined at 700 ° C. for 1 hour in an air atmosphere to obtain silicic acid-based nanoparticles. X-ray diffraction analysis showed that the nanoparticles having an amorphous silicate-based structure were obtained Respectively.

Example  4: Through hydrothermal treatment Zn ₂ SiO ₄ : 0.05 Tb ^{3 +} , 0.1 Yb ^{3 +} Nanoparticle manufacturing

The solid powder prepared in Example 2 was calcined at 700 ° C for 1 hour in an air atmosphere to obtain silicic acid-based nanoparticles. The resultant was subjected to X-ray diffraction analysis to obtain nanoparticles having an amorphous silicate-based structure Respectively.

Example  5: Through water heat treatment Zn ₂ SiO ₄ : 0.05 Tb ^{3 +} , 0.05 Yb ^{3 +} Nanoparticle manufacturing

A solid powder was prepared in the same manner as in Example 1, except that 0.94 g of Yb (NO ₃ ) ₃ .6H ₂ O was used.

Finally, the prepared solid powder was calcined at 900 ° C. for 1 hour in an air atmosphere to obtain silicic acid-based nanoparticles, which were analyzed by X-ray diffraction and found that nanoparticles having crystalline silicate-based structure were obtained Respectively.

Example  6: Through hydrothermal treatment Zn ₂ SiO ₄ : 0.05 Tb ^{3 +} , 0.2 Yb ^{3 +} Nanoparticle manufacturing

A solid powder was prepared in the same manner as in Example 1 except that 3.74 g of Yb (NO ₃ ) ₃ .6H ₂ O was used.

Finally, the prepared solid powder was calcined at 900 ° C. for 1 hour in an air atmosphere to obtain silicic acid-based nanoparticles, which were analyzed by X-ray diffraction and found that nanoparticles having crystalline silicate-based structure were obtained Respectively.

Example  7: Through hydrothermal treatment Zn ₂ SiO ₄ : 0.02 Tb ^{3 +} , 0.1 Yb ^{3 +} Nanoparticle manufacturing

A solid powder was prepared in the same manner as in Example 1 except that 0.36 g of Tb (NO ₃ ) ₃ .6H ₂ O was used.

Finally, the prepared solid powder was calcined at 900 ° C. for 1 hour in an air atmosphere to obtain silicic acid-based nanoparticles, which were analyzed by X-ray diffraction and found that nanoparticles having crystalline silicate-based structure were obtained Respectively.

Comparative Example  One: Sol-gel method  through Zn ₂ SiO ₄ : 0.05 Tb ^{3 +} , 0.1 Yb ^{3 +} Nanoparticle manufacturing

The zinc silicate nanoparticles having the same composition as in Example 1 were prepared by the sol-gel method for comparison with the phosphor prepared by the hydrothermal method in Example 1 above.

In a polyethylene container, 24.8 g of Zn (NO ₃ ) ₃ .6H ₂ O is dissolved in 20 g of distilled water and 25 g of ethanol and 8.32 g of TEOS are added. To this was added 0.91 g of Tb (NO ₃ ) ₃ .6H ₂ O, 1.87 g of Yb (NO ₃ ) ₃ .6H ₂ O and 2 g of 0.1 M HCl, stirred for 2 hours, And dried for 15 hours to prepare a solid powder.

Finally, the prepared solid powder was calcined in an air atmosphere at 900 ° C. for 1 hour to obtain silicic acid-based nanoparticles. From the results of the X-ray diffraction analysis, it was found that the nanocrystals having the same crystalline silicate- It was confirmed that the particles were obtained.

Table 1 summarizes the reaction conditions of the above Examples and Comparative Examples.

Tb: Yb Water heat treatment
Temperature Water heat treatment
time Calcination treatment
Temperature Calcination treatment
time Decision whether Example 1 0.05: 0.1 150 15 900 One Crystallinity Example 2 0.05: 0.1 200 15 900 One Crystallinity Example 3 0.05: 0.1 150 15 700 One Amorphous Example 4 0.05: 0.1 200 15 700 One Amorphous Example 5 0.05: 0.05 150 15 900 One Crystallinity Example 6 0.05: 0.2 150 15 900 One Crystallinity Example 7 0.02: 0.1 150 15 900 One Crystallinity Comparative Example 1 0.05: 0.1 Sol-gel application 900 One Crystallinity

X-ray diffraction  Pattern analysis result

1 and 2 are graphs showing the results of X-ray diffraction analysis of Examples 1 and 3, respectively. It can be seen from FIG. 1 that several peaks appear at various positions because the nanoparticles of Example 1 are crystalline, Since the nanoparticles of Example 3 were amorphous, no particular peak appeared.

That is, when the nanoparticles are crystalline, the same results as in Example 1 shown in FIG. 1 are obtained through the X-ray diffraction analysis. When the nanoparticles are amorphous, The same result can be seen.

Silicic acid coupling  Excitation and emission spectral analysis of nanoparticles

Excitation and emission spectra of the zinc silicate nanoparticles obtained in Examples 1-7 and Comparative Examples were measured using a fluorescence spectrophotometer and shown in FIGS. 3 and 4.

In the excitation spectrum of FIG. 3, it can be seen that the silicic acid-based nanoparticles prepared in Examples 1 to 3 can see a plurality of peaks in the region of 300 to 500 nm wavelength and are excited in a wide region. However, it was confirmed that the zinc silicate nanoparticles prepared in Comparative Example 1 exhibit a very small peak only at about 485 nm, but do not exhibit a distinct excitation peak in the other regions.

The emission spectrum of the near infrared region in FIG. 4 is the emission spectrum measured after the nanoparticles of Examples 1 to 3 and Comparative Example 1 were excited by a photon with a wavelength of 360 nm, As described above, since the zinc-based nanoparticles can not be excited when the wavelength is not 485 nm, they can be excited by a photon with a wavelength of 360 nm and then emitted at an emission peak at a wavelength of 900 to 1100 nm , While the zinc silicate nanoparticles prepared in Examples 1 to 3 exhibited excellent luminescence performance in the 900 to 1100 nm wavelength region.

In order for the nanoparticles of Comparative Example 1 to emit light, a photon having a wavelength of 485 nm is required. However, in order for the nanoparticles of Examples 1 to 3 to emit light, a wavelength range of 300 to 500 nm It can be seen that a wide range of light can be used.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

Claims (18)

delete delete delete delete (a) preparing a precursor solution comprising a zinc (Zn) precursor, a silicon (Si) precursor, a terbium (Tb) precursor, a ytterbium (Yb) precursor, and a mixed solvent;
(b) adding a precipitant to the precursor solution to form a precipitate;
(c) subjecting the precipitate to heat treatment in a sealed state in a reactor at a temperature of 100 to 250 ° C to obtain a solid powder; And
(d) calcining the solid powder to prepare a silicic acid-based nanoparticle,
The zinc silicate based nanoparticles are represented by the following formula 1 and are doped with Tb ³⁺ and Yb ^{3+ and} have a size of 20 to 500 nm. The zinc silicate based nanoparticles have a wavelength range of 300 to 500 wherein the phosphor is excited by light having a wavelength of 900 to 1100 nm and emits light having a wavelength of 900 to 1100 nm.
[Chemical Formula 1]
Zn ₂ SiO ₄ : xTb ³⁺ , yYb ³⁺
In the formula (1), x is a real number with 0.01? X? 0.1 and y is a real number with 0.01? Y? 0.3. 6. The method of claim 5,
Wherein the zinc precursor is any one selected from the group consisting of zinc chloride, zinc sulfide, zinc oxide, hydrates thereof, and combinations thereof,
Wherein the terbium precursor is any one selected from the group consisting of a terbium chloride, a terbium sulfide, a terbium oxide, a hydrate thereof, and combinations thereof,
Wherein the ytterbium precursor is any one selected from the group consisting of ytterbium chloride, ytterbium sulphide, ytterbium nitrate, hydrates thereof, and combinations thereof. 6. The method of claim 5,
Wherein the silicon precursor comprises any one selected from the group consisting of fumed silica, colloidal silica, organosilicon compound, and combinations thereof. 6. The method of claim 5,
Wherein the mixed solvent comprises water and an alcohol, and the alcohol has 1 to 3 carbon atoms. 6. The method of claim 5,
Wherein the content of the terbium is 0.01 to 0.1 mole based on 2 moles of zinc and 1 mole of silicon. 6. The method of claim 5,
Wherein the content of ytterbium is 0.01 to 0.3 moles based on 2 moles of zinc and 1 mole of silicon. 6. The method of claim 5,
Wherein the precipitating agent comprises any one selected from the group consisting of ammonia water, tetraalkylammonium hydroxide, urea, sodium hydroxide, potassium hydroxide, and combinations thereof,
Wherein the alkyl group of the tetraalkylammonium has 1 to 4 carbon atoms. 6. The method of claim 5,
Wherein the precipitant is added at a weight of 0.2 to 2 times the weight of the mixed solvent. 6. The method of claim 5,
Wherein the calcination treatment in step (d) is carried out at a temperature of 300 to 1200 占 폚. 6. The method of claim 5,
Wherein the calcination treatment in the step (d) is performed in an atmosphere containing air, nitrogen, argon, helium, and any one selected from the group consisting of combinations thereof. delete delete delete delete

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