KR20020085265A - Process for silicate phosphor particles having a spherical shape - Google Patents

Abstract

PURPOSE: A spherical silicate-based fluorescent substance and its preparation method are provided, which fluorescent substance is remarkably improved in the light-emitting characteristic and is useful to a display or a lamp. CONSTITUTION: The spherical silicate-based fluorescent substance is represented by QxSiOy:D, wherein Q is Zn or Y; D is Mn, Ce, Tb or Eu; and 0.001<x<0.2 and y=4 when Q is Zn and D is Mn, and 0.0001<x<0.8 and y= 5 when Q is Y and D is Ce, Tb or Eu. The method comprises the steps of dissolving a precursor of Zn or Y, nanometer-sized silica powder or a mixture of tetraethyl orthosilicate and nanometer-sized silica powder as a precursor of silica, and a precursor of Mn, Ce, Tb or Eu, into distilled water or alcohols to prepare 0.01-4 M precursor solution; injecting the precursor solution into a spray device to produce the liquid drops with a diameter of 0.1-100 micrometers; and injecting the liquid drops into a hog pipe-shaped reactor of 200-1,500 deg.C to dry and pyrolyze them.

Description

Process for silicate phosphor particles having a spherical shape

The present invention relates to a method for producing spherical silicate-based phosphors, and more particularly, in the production of zinc silicide and yttrium oxide-based phosphors by spray pyrolysis, nanometer-sized precursors of the silicic acid constituting the mother. By using silica powder alone or by using tetraethyl orthosilicate (TEOS) and nanometer-sized silica powder, a display having a spherical shape filled with an inside and a dramatically improved luminescent property can be obtained. A method for producing spherical silicate-based phosphors suitable for lamps.

Recently, as interest in high definition television (HDTV) has increased, the development of displays has been active. Representative displays are plasma displays (PDP) and field emission displays (FED), which are recently popular flat panel displays. Unlike conventional displays, due to their lightness and thinness, these displays have many applications, such as wall-mounted TVs, computers, camcorders, and auto navigation devices.

Currently, phosphors for displays and lamps are mostly manufactured by a solid-state method that undergoes a long heat treatment process at a high temperature and a repeated milling process. The phosphor produced by such a solid phase method is greatly influenced by the shape, particle size distribution, and the like obtained depending on the substance. That is, in the solid phase method, it is difficult to control the shape and size of the phosphor. On the other hand, newly developed flat panel displays require superior characteristics than phosphors used in cathode ray tubes and lamps. In particular, the shape and size of the phosphor is recognized as a very important variable as well as the luminance of the phosphor. In general, it has been reported that phosphors have a spherical shape and have a size of 1 to 5 microns to show good characteristics. Phosphors with these requirements are difficult to manufacture in the existing phosphor manufacturing processes, and gas phase processes such as spray pyrolysis or liquid phase methods such as sol-gel have been studied as alternatives.

Recently, the spray pyrolysis method has been actively studied as a process for producing spherical phosphors. However, in general, phosphors have a small specific surface area and have low surface defects, so that they exhibit good luminescence properties, whereas phosphors produced by spray pyrolysis methods known to date have a hollow and porous form, which has been pointed out as a problem.

As a method for eliminating the disadvantages of the spray pyrolysis, a technique has been developed in which a colloidal solution is used to obtain a solid phosphor or a flux to remove surface defects to improve the characteristics of the phosphor.

Since the spray pyrolysis is a gas phase process in which droplets are obtained from one droplet through drying and pyrolysis in a high temperature electric furnace, the characteristics of the starting precursor material have a great influence on the characteristics of the manufactured phosphor. That is, various variables such as solubility, decomposition rate, drying properties, crystallization properties of the precursor material affect the properties of the phosphor. However, it is not yet clear how the properties of these precursor materials affect the properties of the phosphor, and some studies have been limited to specific precursor materials. In other words, there is no study on how the properties of the precursor materials in the three-component or more multicomponent system such as the oxide-based phosphor affects the properties of the phosphor prepared by spray pyrolysis.

Accordingly, the present inventors have discovered that zinc silicate (Zn ₂ SiO ₄ : Mn) and silicate silica (Y ₂ SiO ₅ : Me (Me = Ce, Tb, Eu)), which are of great importance as silicate-based phosphors by spray pyrolysis. In order to develop a process for manufacturing phosphors, the present inventors have selected not only specific precursor materials but also optimized combinations of precursor materials to improve the properties of phosphors one step higher than existing products. As a result, the precursor material of the parent and the activator is selected and used, in particular, as a raw material of silicic acid, a mixture of tetraethyl orthosilicate (TEOS) and nanometer-sized silica powders dissolved in a weak acid is used, and the combination thereof is optimized. Was completed.

Accordingly, a main object of the present invention is to provide a method for producing zinc silicide-based and yttrium-based phosphors filled in a spherical form using an optimized combination of precursor materials of the parent and the active agent, using spray pyrolysis. It is.

1 is an electron micrograph of a phosphor (Zn ₂ SiO ₄ : Mn) prepared using tetraethyl orthosilicate (hereinafter, TEOS) as a raw material of silicic acid.

2 is an electron micrograph of a phosphor (Zn ₂ SiO ₄ : Mn) prepared using nanometer-sized silica powder as a raw material of silicic acid.

3 is an electron micrograph of a phosphor (Zn ₂ SiO ₄ : Mn) prepared by mixing TEOS and nanometer-sized silica powder as a raw material of silicic acid.

4 is an electron micrograph of a phosphor (Zn ₂ SiO ₄ : Mn) prepared using silica powder and manganese nitrate of nanometer size, respectively, as a raw material of silicic acid and manganese.

FIG. 5 is an electron micrograph of a phosphor (Zn ₂ SiO ₄ : Mn) prepared using silica powder and manganese sulfide having a nanometer size as a raw material of silicic acid and manganese, respectively.

6 is an electron micrograph of a phosphor (Zn ₂ SiO ₄ : Mn) prepared using silica powder and manganese acetate each having a nanometer size as a raw material of silicic acid and manganese.

FIG. 7 is an electron micrograph of a phosphor (Zn ₂ SiO ₄ : Mn) prepared using silica powder and manganese chloride, each having a nanometer size as a raw material of silicic acid and manganese.

8 is an electron micrograph of a phosphor (Zn ₂ SiO ₄ : Mn) prepared using a mixture of silica powder of TEOS and nanometer size, respectively, as a raw material of silicic acid and manganese, and manganese nitrate.

9 is an electron micrograph of a phosphor (Zn ₂ SiO ₄ : Mn) prepared using a mixture of silica powder of TEOS and nanometer size, respectively, as a raw material of silicic acid and manganese, and manganese sulfide.

10 is an electron micrograph of a phosphor (Zn ₂ SiO ₄ : Mn) prepared using a mixture of silica powder of TEOS and nanometer size, respectively, as a raw material of silicic acid and manganese, and manganese acetate.

FIG. 11 is an electron micrograph of a phosphor (Zn ₂ SiO ₄ : Mn) prepared using a mixture of silica powder of TEOS and nanometer size, respectively, as a raw material of silicic acid and manganese, and manganese chloride.

12 is an electron micrograph of a phosphor (Y ₂ SiO ₅ : Tb) prepared using TEOS as a raw material of silicic acid (when post-processed at 1200 ° C.).

FIG. 13 is an electron micrograph of phosphor (Y ₂ SiO ₅ : Tb) prepared using nanometer-sized silica powder as a raw material of silicic acid (when post-treated at 1200 ° C.).

14 is an electron micrograph of phosphor (Y ₂ SiO ₅ : Tb) prepared using TEOS as a raw material of silicic acid (when post-processed at 1300 ° C.).

FIG. 15 is an electron micrograph of phosphor (Y ₂ SiO ₅ : Tb) prepared using nanometer-sized silica powder as a raw material of silicic acid (when post-treated at 1300 ° C.).

FIG. 16 is an electron micrograph of a phosphor (Y ₂ SiO ₅ : Tb) prepared by mixing TEOS and nanometer-sized silica powder as a raw material of silicic acid.

The present invention in the production of silicate-based phosphor by spray pyrolysis,

1) a precursor material of zinc or a precursor material of yttrium; Nanometer-sized silica powder or a mixture of tetraethyl orthosilicate (TEOS) and nanometer-sized silica powder as a precursor material of silicic acid; Dissolving a precursor material of manganese, cerium, terbium or europium in distilled water or alcohol to prepare a precursor solution of 0.02 to 4 M;

2) injecting the precursor solution into a spray device to generate droplets of 0.1 to 100 ㎛ diameter; And

3) preparing the phosphor represented by the following Chemical Formula 1 by introducing the generated droplets into a high temperature tubular reactor (200 to 1500 ° C.), drying and pyrolysing;

It characterized by a method for producing a spherical silicate-based phosphor comprising a.

Formula 1

Q _x SiO _y : D

In Formula 1 above:

Q is Zn or Y, D is Mn, Ce, Tb or Eu,

Iii) when Q is Zn and D is Mn, then 0.001 <x <0.2 and y = 4;

Ii) when Q is Y and D is Ce, Tb or Eu, 0.0001 <x <0.8 and y = 5.

Such a method of manufacturing the spherical silicate-based phosphor of the present invention will be described in more detail by dividing each step as follows.

First Step: Preparation of the Phosphor Precursor Solution

In order to obtain the phosphor represented by Chemical Formula 1, a process of preparing a precursor solution is performed by dissolving or dispersing a precursor material of a phosphor and an activator doping the parent material in water or alcohol.

As precursor materials of zinc and yttrium constituting the matrix of the phosphor, acetates, nitrates, chlorides, and the like, which are easily dissolved in a solvent such as water or alcohol, may be used, and an optimum composition ratio may be derived by combination with each other. That is, zinc nitrate, zinc acetate and zinc chloride, such as zinc nitrate and zinc acetate, may be used as the zinc precursor material. Further, as a precursor material of yttrium, yttrium nitrate, yttrium acetate and chloride, such as nitrate, may be preferably used. In addition, it is preferable to use sulfides, chlorides, acetates, nitrates, and the like as precursor materials of manganese, cerium, terbium, and europium as activators for doping the matrix.

As the precursor material of silicic acid, only nanometer-sized silica powder is used, or tetraethyl orthosilicate (hereinafter referred to as TEOS) and nanometer-sized silica powder are used, and the TEOS is hydrated in an acid solution to dissolve. And the nanometer-sized silica powder is added in a dispersed state to the solution. At this time, TEOS and nanometer-sized silica powder is added in a molar ratio of 0: 100 to 99: 1, and the precursor material of such silicic acid is added in excess of the stoichiometric ratio of Chemical Formula 1, and the range is 1.05 to 1.50 molar ratio with respect to stoichiometric ratio. Range is preferred. Here, the nanometer-sized silica powder may be used in a variety of fine colloids of 3 nm to 600 nm as the size of the silica powder, it can be used for all produced by the gas phase method or liquid phase method. That is, both commercial colloidal silica or silica produced by the aerosol method (Fumed silica) can be used. In this case, when the silica powder prepared by the gas phase method is used in the present invention, the primary particles are very fine, approximately several to several tens of nm, but since the aggregation occurs among the powders, the particles have a size of several hundred nm or more. Therefore, a process of dispersing in a solution and then crushing finely using a mixer or ultrasonic wave is necessary.

In the present invention, only the nanometer-sized silica powder may be used alone as a raw material of the silicic acid, and more preferably, the TEOS and the nanometer-sized silica powder are used together for the following reasons. The TEOS is preferred to make the particle size of the phosphor uniform by allowing the production of a uniform solution in a small lab scale device, but to produce a hollow phosphor in a pilot scale for mass production. There is a problem in that the spherical shape is partially distorted during the high temperature heat treatment process, and has a disadvantage in that the price is higher than that of the silica powder. In addition, when the nanometer-sized silica powder is used, the solution is well sprayed, and thus a high concentration of the solution can be used, and thus the size of the phosphor can be controlled. After all, in the present invention, the TEOS is used in terms of uniformizing the size of the phosphor and compacting the structure of the phosphor, and the nanometer-sized silica powder is used in terms of controlling the shape of the resulting phosphor. By adjusting the addition ratio thereof, it is possible to maximize the use as well as achieve the above purpose of use.

Since the particle size of the phosphor prepared according to the concentration of the precursor solution is determined, the concentration of the precursor solution should be appropriate to prepare a phosphor having a desired size, and the total concentration of the precursor solution is preferably in the range of 0.02 to 4.0 M. If the total concentration of the precursor does not reach 0.02 M, there is a problem that the amount of phosphor particles produced is too small, and it is difficult to obtain a precursor solution having a concentration exceeding 4.0 M because of the solubility of the precursor material, If exceeded, there is a problem spraying the solution.

Second Process: Spraying Droplets

Next, a process of spraying the precursor solution prepared in the first process into a droplet using a spray device is performed.

As a spray device for spraying the droplets in the present invention, an ultrasonic spray device, an electrostatic spraying device, an air nozzle spraying device, an ultrasonic nozzle spraying device, a filter droplet generating device (filter expansion aerosol generator, FEAG) and the like may be used. Here, using the ultrasonic atomizer and the filter droplet generator, it is possible to produce a sub-micron-sized fine phosphor at high concentrations, and the use of an air nozzle and an ultrasonic nozzle sprayer enables the mass production of phosphors of a micron submicron size. Do. In the case of using an ultrasonic nebulizer, an industrial ultrasonic nebulizer connected with six or more ultrasonic vibrators may be used to generate excess droplets. That is, in the ultrasonic spray pyrolysis, commercial mass production is possible because the amount of droplets generated by increasing the number of vibrators to hundreds or more is easily increased.

In addition, the sprayed droplets have a diameter of 0.1 to 100 μm, and if the diameter of the droplets is less than 0.1 μm, there is a problem that the size of the resulting particles is too small. If the diameter of the droplets exceeds 100 μm, on the contrary, The problem arises that the size of the particles produced is too large.

Third Step: Generation of Spherical Phosphors

The droplet generated in the process is converted into a phosphor in a high temperature tubular reactor.

The inside of the tubular reactor is maintained at a high temperature by an electric furnace, the temperature of the electric furnace is preferably 200 to 1,500 ℃ for drying the precursor materials. In addition, it is possible to maintain a high temperature as a heat source and to use a flame or a plasma reactor having low cost. Since the silicate-based phosphor is a substance obtained by a reaction of several hours or more at a high temperature of 1,100 ° C. or higher in a general solid phase method, a desired crystal phase cannot be obtained in a spray pyrolysis process having a residence time of several seconds.

Therefore, a post-treatment step is required for crystal growth of the phosphor obtained by spray pyrolysis, and the present invention further includes a step of post-treating the phosphor. As the post-treatment process, all three methods may be used: a direct oxidation heat treatment process, a direct reduction heat treatment process, or an oxidation / reduction heat treatment process of first undergoing heat treatment in an oxidizing atmosphere and then reheating in a reducing atmosphere. Can be. In the production of the yttrium-based phosphor of the present invention, crystal growth of the phosphor is possible only through a heat treatment in an oxidizing atmosphere. However, in the production of a zinc silicate phosphor, it is preferable to undergo heat treatment in a reducing atmosphere or to undergo both oxidation / reduction processes. Do.

When only the direct oxidation heat treatment step is performed, it is preferable that the phosphor obtained by spray pyrolysis is heat treated in air for 1 to 10 hours at a high temperature of 1000 to 1500 ° C. In this case, in the case of the oxidizing heat treatment process, the characteristics of the generated phosphor depend on the kind of starting precursor material to be used.

In the case where only the direct reduction heat treatment process is performed, it is preferable to perform heat treatment for 10 minutes to 5 hours at a temperature of 1000 to 1500 ° C. using a 2 to 10% hydrogen / nitrogen mixed gas.

In the case of the oxidation / reduction complex process, after a heat treatment process for 1 to 10 hours at a temperature of 1000 ~ 1500 ℃, 10 minutes using a 2-10% hydrogen / nitrogen mixed gas at a temperature of 700 ~ 1200 ℃ It is preferable to undergo a reduction treatment for ˜5 hours. At this time, the flow rate of the hydrogen / nitrogen mixed gas is changed according to the amount of the phosphor to be heat-treated.

By the above-described method, the light-emitting characteristics of the silicate-based phosphors obtained by changing the precursor materials were compared under vacuum ultraviolet (VUV) and ultraviolet (UV) regions in order to determine the application characteristics to the plasma display. As a result of the analysis, the present invention can be applied to plasma displays and field emission displays that require high luminance phosphors due to higher emission intensity than commercial products.

Hereinafter, the present invention will be described in more detail with reference to Examples, but these Examples are only for illustrating the present invention in more detail, the scope of the present invention is not limited by these Examples in accordance with the spirit of the present invention. It will be obvious to those of ordinary skill in the art.

Example 1 Preparation of Zinc Silicate Phosphor

First, a precursor solution was prepared such that the composition of the phosphor was Zn _1.92 SiO ₄ : Mn _0.08 . Nitrate was used as a precursor material of zinc constituting the mother, and nitrate was used as a precursor material of manganese, a doping material. As a raw material of the silicic acid, TEOS and nano-sized silica powder (aerosil200, Degussa) were mixed and used at a molar ratio of 1: 1 to observe changes in their properties. The addition amount of silicic acid was added in 1.17 molar ratio with respect to stoichiometry, the total concentration of the solution was 2 M, and the doping concentration of manganese which is an activator was 0.08 molar ratio. A droplet was then generated from the prepared precursor solution using an ultrasonic nebulizer, dried and pyrolyzed at 1,000 ° C. Thus, the phosphor obtained by spray pyrolysis was heat-treated at 1150 ° C. for 3 hours in an air atmosphere, and then crystallized by reducing treatment at 850 ° C. for 30 minutes using a 5% hydrogen / nitrogen mixed gas (see FIG. 3).

Example 2: Preparation of Zinc Silicate Phosphor

A Zn _1.92 SiO ₄ : Mn _0.08 phosphor was prepared in the same composition and method as Example 1, except that only nanometer-sized silica powder was used as a raw material of silicic acid (see FIG. 2).

Reference Example 1 Preparation of Zinc Silicate Phosphor (using TEOS)

A Zn _1.92 SiO ₄ : Mn _0.08 phosphor was prepared in the same composition and method as Example 1 except that only TEOS was used as a raw material of silicic acid (see FIG. 1).

1 is an electron micrograph of a phosphor (reference example 1) obtained when only TEOS is used as a raw material of silicic acid. Phosphors have a spherical shape but some crushed shape. The reason is that since the phosphor produced by the spray pyrolysis method has a hollow shape, it is distorted in a high temperature heat treatment process. On the other hand, the zinc silicide-based phosphor (Example 2) obtained by using the nanometer-sized silica powder shown in Fig. 2 as a raw material has a perfect spherical shape. In the case of using silica powder, the solid substance is obtained because precipitation of solutes occurs in the whole inside of the droplet. That is, the phosphor having a solid shape is stable even at a high temperature heat treatment to have a perfect spherical shape. 3 is an electron micrograph of a phosphor (Example 1) obtained when TEOS and nanometer-sized silica powder are used in half of the stoichiometric ratio as a raw material of silicic acid. Referring to FIG. 3, it can be seen that the phosphor obtained as a result of using the nanometer-sized silica powder and TEOS together with the case of using only TEOS maintains a spherical shape. In addition, in FIG. 2, in which all nanometer-sized silica powders are used, the spherical phosphor has a porous form consisting of nanometer-sized primary particles, while in FIG. 3, the obtained phosphor has a dense form. That is, the TEOS component dissolved at the molecular level precipitates as a whole particle, thereby densifying the phosphor during the heat treatment process. Therefore, it was confirmed that the use of TEOS alone as a raw material of silicic acid or the appropriate combination of these two components is advantageous in controlling the characteristics of the zinc silicate-based phosphor, rather than using only nanometer-sized silica powder.

In addition, the phosphor prepared in Example 1 exhibited excellent light emission characteristics in both vacuum ultraviolet and ultraviolet regions.

Example 3 Influence of Manganese Precursor Material I

A phosphor of Zn _1.92 SiO ₄ : Mn _0.08 composition was prepared in the same manner as in Example 1, except that nanometer-sized silica powder (aerosil200, Degussa) was added as a raw material of silicic acid at a 1.1 molar ratio of stoichiometric ratio. Manganese precursor materials were then converted to nitrates, sulfides, acetates and chlorides.

4, 5, 6 and 7 are electron micrographs of phosphors obtained by post-treatment at 1150 ° C. for 3 hours when manganese nitrate, sulfide, acetate and chloride are used as raw materials of manganese, respectively. The phosphor obtained when chloride was used as a raw material of manganese (FIG. 7) has a much more spherical shape and has a more porous shape. In addition, in the phosphor obtained when acetate was used as a raw material of manganese (FIG. 6), aggregation occurred between some phosphors. On the other hand, the phosphors (FIGS. 4 and 5) obtained when nitrates and sulfides are used as the raw materials of manganese have a porous characteristic but maintain a spherical shape. That is, the raw material of manganese used as a trace doping material affected the shape of the Zn ₂ SiO ₄ : Mn phosphor. This is because the degree of dispersion of manganese in the Zn ₂ SiO ₄ matrix and the rate of doping into the matrix are different depending on the precursor type of manganese. Therefore, it can be seen that it is advantageous to use manganese nitrate and sulfide in terms of morphology of the phosphor when preparing Zn ₂ SiO ₄ : Mn phosphor by spray pyrolysis.

Example 4 Influence of Manganese Precursor Material II

In the same manner as in Example 3, as a raw material of silicic acid was prepared by mixing TEOS and nanometer-sized silica powder (aerosil200, Degussa) in a molar ratio of 1: 1, the heat treatment temperature was 1175 ℃.

8, 9, 10 and 11 are electron micrographs of phosphors obtained when manganese nitrate, sulfide, acetate and chloride are used as raw materials of manganese, respectively. 8, 9, 10 and 11 it can be seen that the surface is smoother than the phosphor of Example 3 prepared by using only nanometer-sized silica powder as the raw material of silicic acid, and the pores were reduced much. That is, the zinc silicide phosphor manufactured using only nanometer-sized silica powder is partially affected by the type of manganese precursor, but has a very porous form overall. On the other hand, the phosphor prepared from a mixture of silica powder and TEOS has a much reduced porosity and smooth surface of the phosphor regardless of the precursor type of manganese. Therefore, in terms of the form of the zinc silicate-based phosphor, it is more preferable to use nanometer-sized silica powder and TEOS at a constant ratio as a raw material of the silicic acid.

Example 5 Preparation of Sittrium-Based Phosphor

A phosphor having a Y _1.96 SiO ₅ : Tb _0.11 composition was prepared in the same manner as in Example 1, except that yttrium was used instead of zinc. That is, TEOS and nanometer-sized silica powder were used in a molar ratio of 1: 1 as a raw material of silicic acid. For this purpose, the doping concentration of terbium as an activator was set at 0.11 molar ratio. Spray pyrolysis temperature was 900 ℃, the post-treatment was heat-treated for 3 hours at 1200 ℃ under an air atmosphere (see Fig. 16).

Example 6 Preparation of Sittrium-Based Phosphor

A Y _1.96 SiO ₅ : Tb _0.11 phosphor was prepared in the same composition and method as Example 5, except that only nanometer-sized silica powder was used as a raw material of silicic acid (see FIG. 13).

Reference Example 2: Preparation of yttrium-based phosphor (using TEOS)

A Y _1.96 SiO ₅ : Tb _0.11 phosphor was prepared in the same composition and method as Example 5, except that only TEOS was used as a raw material of silicic acid (see FIG. 12).

Example 7: Preparation of yttrium-based phosphor

A Y _1.96 SiO ₅ : Tb _0.11 phosphor was prepared in the same composition and method as Example 6 except that the post-treatment temperature was 1300 ° C. (see FIG. 15).

Reference Example 3: Preparation of yttrium-based phosphor (using TEOS)

A Y _1.96 SiO ₅ : Tb _0.11 phosphor was prepared in the same composition and method as in Reference Example 2 except that the post-treatment temperature was 1300 ° C. (see FIG. 14).

12 and 13 are electron micrographs of the phosphors obtained when only TEOS was used as a raw material of silicic acid (Reference Example 2) and when only nanometer-sized silica (Fumed silica) powder was used (Example 6). 12 and 13 have a spherical shape, regardless of the raw material of silicic acid. On the other hand, there are some differences in the shape of the phosphor in Fig. 14 (Reference Example 3) and Fig. 15 (Example 7), which are phosphors obtained at a heat treatment temperature of 1300 ° C. The phosphor of FIG. 14, which is manufactured using only TEOS, shows some hollow particles. On the other hand, in FIG. 15, which is manufactured using only nanometer-sized silica powder, the phosphor has an overall solid form. Therefore, it can be predicted that the phosphor has a hollow shape although it has a spherical shape. FIG. 16 is an electron micrograph of a phosphor (Example 5) obtained when TEOS and nanometer-sized silica powder were used in half of the stoichiometric ratio as a raw material of silicic acid. Referring to FIG. 16, it has a form that is colder than the case of FIG. 14, in which only TEOS is used. That is, when using the silica powder of nanometer size or TEOS as the raw material of silicic acid, or only using the nanometer size silica powder, it can be seen that the shape of the silica-based phosphor can be controlled.

In addition, similarly to the Y ₂ SiO ₅ : Tb phosphor, the production of the Y ₂ SiO ₅ : Ce and Y ₂ SiO ₅ : Eu phosphors can be produced by the same method. That is, cerium or europium may be added instead of terbium which is a doping material. Only differences in the preparation of these three phosphors differ in the optimum doping concentration and in the heat treatment temperature. In the production of these Y ₂ SiO ₅ : Ce and Y ₂ SiO ₅ : Eu phosphors, nanometer-sized silica powder and TEOS were used to obtain phosphors with excellent characteristics. Therefore, by using a nanometer-sized silica powder instead of TEOS as a raw material of silicic acid, not only the shape and luminescence properties of the silicate phosphors manufactured can be improved, but also the nanometer-sized silica powder can be obtained in terms of competitiveness of raw materials. It is preferable because it is inexpensive.

As described and demonstrated in detail above, the method for producing a spherical silicate-based phosphor according to the present invention is characterized in that in the production of silicate-based phosphors by spray pyrolysis, by selecting precursor materials and combining them in an appropriate ratio, Maximized. In particular, by using tetraethyl orthosilicate (TEOS) and nanometer-sized silica powder as a raw material of silicic acid, it is possible to produce a solid silicate-based phosphor which has not been achieved conventionally. In addition, the silica powder is relatively inexpensive compared to tetraethyl orthosilicate (TEOS) has an economically excellent effect.

Claims (11)

In preparing the silicate-based phosphor by spray pyrolysis, 1) a precursor material of zinc or a precursor material of yttrium; Nanometer-sized silica powder or a mixture of tetraethyl orthosilicate (TEOS) and nanometer-sized silica powder as a precursor material of silicic acid; Dissolving a precursor material of manganese, cerium, terbium or europium in distilled water or alcohol to prepare a precursor solution of 0.02 to 4 M; 2) injecting the precursor solution into a spray device to generate droplets of 0.1 to 100 ㎛ diameter; And 3) preparing the phosphor represented by the following Chemical Formula 1 by introducing the generated droplets into a high temperature tubular reactor (200 to 1500 ° C.), drying and pyrolysing; Method for producing a spherical silicate-based phosphor comprising a. Formula 1 Q _x SiO _y : D In Formula 1 above: Q is Zn or Y, D is Mn, Ce, Tb or Eu, Iii) when Q is Zn and D is Mn, then 0.001 <x <0.2 and y = 4; Ii) when Q is Y and D is Ce, Tb or Eu, 0.0001 <x <0.8 and y = 5. The method of claim 1, wherein the tetraethyl orthosilicate (TEOS) and the nanometer-sized silica powder is added in a molar ratio of 0: 100 to 99: 1, the precursor material of the silicic acid is 1.05 ~ 1 with respect to the stoichiometric ratio of the formula (1) A method for producing a spherical silicate-based phosphor, which is added in a range of 1.50 molar ratio. The method of claim 1, wherein the tetraethyl orthosilicate (TEOS) is added in a dissolved state by hydration reaction in an acid solution, and the nanometer-sized silica powder is prepared by gas phase or liquid phase and dispersed in the solution A method for producing a spherical silicate-based phosphor, which is added. The method of claim 1, wherein the precursor material of zinc is selected from nitrates, acetates and chlorides of zinc, and the precursor material of yttrium is selected from nitrates, acetates and chlorides of yttrium. . The method of claim 1, wherein the precursor material of manganese, cerium, terbium or europium is selected from sulfides, chlorides, acetates and nitrates. The spherical silicate-based phosphor according to claim 1, further comprising a direct oxidation step, a direct reduction step, or an oxidation / reduction complex step as a post-treatment step after the steps 1), 2), and 3). Manufacturing method. The method of claim 6, wherein the direct oxidation process is a heat treatment for 1 to 10 hours at a temperature of 1000 ~ 1500 ℃. The method of claim 6, wherein the direct reduction step is a spherical silicate-based fluorescent material manufacturing method characterized in that the heat treatment for 1 to 10 hours using a 2 to 10% hydrogen / nitrogen mixed gas at a temperature of 1000 ~ 1500 ℃. The method of claim 6, wherein the oxidation / reduction composite process is heat-treated for 1 to 10 hours at a temperature of 1000 to 1500 ℃, and then heat-treated using a 2 to 10% hydrogen / nitrogen mixed gas at a temperature of 700 to 1200 ℃ A method for producing a spherical silicate-based phosphor, characterized in that. According to claim 1, wherein the spray device is an ultrasonic atomizer, electrostatic spraying device, air nozzle spraying device, ultrasonic nozzle spraying device or filter droplet generator (filter expansion aerosol generator, FEAG) characterized in that the zinc silicide system and silicified Method for producing yttrium-based phosphor. Silicate-based phosphor represented by the following formula (1), characterized in that prepared by the method of claim 1. Formula 1 Q _x SiO _y : D In Formula 1 above: Q is Zn or Y, D is Mn, Ce, Tb or Eu, Iii) when Q is Zn and D is Mn, then 0.001 <x <0.2 and y = 4; Ii) when Q is Y and D is Ce, Tb or Eu, 0.0001 <x <0.8 and y = 5.