KR100496046B1 - Silicate phosphor and a preparation method thereof - Google Patents

Abstract

The present invention relates to zinc silicate-based and yttrium silicate-based phosphors represented by the following Chemical Formulas 1 and 2, respectively, and to a method for preparing the same, wherein tetraethyl orthosilicate (TEOS) is used as a silicon precursor material. Alternatively, the silicate-based phosphor of the present invention prepared by using the compound as a whole and adding an appropriate amount of carboxylic acid has no aggregation, has a spherical shape, and exhibits excellent luminescence properties:

Where

D is one or more selected from Ba, Mg, Gd and Al, and 0.001 ≦ x <0.2, 0 ≦ y <0.008, 0 ≦ z <0.008, and z = 0 when D is Ba or Mg.

Where

M is at least one selected from Tb, Ce, and Eu, and 0 <x <0.8.

Description

Silicate Phosphor and Method for Manufacturing the Same {SILICATE PHOSPHOR AND A PREPARATION METHOD THEREOF}

The present invention relates to the production of zinc or yttrium silicate-based phosphors, and more specifically, in the production of silicate-based phosphors using a large-capacity spray pyrolysis process, TEOS is used as the silicon precursor material, and carboxylic acid such as citric acid is used as an additive. The present invention relates to a silicate-based fluorescent material having excellent particle characteristics and luminescent properties prepared by addition.

Recently, as the interest in high definition television (HDTV) increased, the development of displays has been active. Among them, the most popular displays are plasma display panel (PDP) and field emission display (FED), which are flat panel displays. field emission display). 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. Phosphors used in such flat panel displays are required to have better light emission characteristics than conventional phosphors used in cathode ray tubes, lamps, and the like. In addition, the shape and size of the phosphors are recognized as important variables.

In general, the phosphor is known to have a spherical shape and excellent in the range of 1 to 5 microns in diameter, but the phosphor prepared by the solid-state method through a long heat treatment process and a repeated milling process at high temperature Difficult to shape or size and difficult to get spherical shape. In addition, when the phosphor is manufactured by spray pyrolysis, a problem arises in that aggregated particles having irregular shapes other than spherical shape are obtained due to poor reaction conditions in a large-capacity apparatus.

The inventors of the present invention, in the production of a fluorescent material using the spray pyrolysis method, by adjusting the ratio using TEOS and nano-sized silica colloidal particles as a silicon precursor material to produce a green light emitting phosphor having a spherical shape even in a large-capacity spray pyrolysis device It was developed and filed with Korean Patent Application No. 2001-24669. However, in the manufacturing process of the green light emitting phosphor disclosed herein, when mixing the nano-sized silica colloidal particles in TEOS, the process of dispersing the colloidal particles in a solution and then crushing finely so that the resulting phosphor does not aggregate need. On the other hand, in the spray pyrolysis process using TEOS as a silicic acid precursor, a long heat treatment process at a high temperature is essential to obtain a desired crystal phase due to the phase separation characteristics of silicon components. However, this high temperature heat treatment process has a disadvantage in that it cannot maintain the spherical shape of the phosphor.

Accordingly, the present inventors have come to produce a silicate-based phosphor which is excellent in luminescence properties without particle aggregation by a simpler process than the conventional spray pyrolysis process.

Accordingly, an object of the present invention is agglomeration, prepared by adding barium (Ba), magnesium (Mg), gadolinium (Gd) and aluminum (Al), or lithium (Li) as a second activator to a zinc silicate-based phosphor. To provide a spherical green phosphor.

It is another object of the present invention to provide spherical phosphors having uniform particle crystals and excellent luminescent properties, prepared by adding europium (Eu), terbium (Tb), or cerium (Ce) as active agents to the yttrium silicate-based phosphor. .

Another object of the present invention is to use tetraethyl orthosilicate (TEOS) as part or all of silicon precursor material in preparing silicate-based phosphors by spray pyrolysis, and to add an appropriate amount of carboxylic acid in preparing spray solution. The present invention provides a method for producing a spherical phosphor having no aggregation and excellent luminescence properties.

In order to achieve the above object, the present invention provides a zinc silicate-based green phosphor represented by the following formula (1) and a method for preparing the same:

Formula 1

Where

D is at least one selected from Ba, Mg, Gd, and Al, and 0.001 ≦ x <0.2, 0 ≦ y <0.008, 0 ≦ z <0.008, and z = 0 when D is Ba, Mg.

The present invention also provides a yttrium silicate-based phosphor represented by the following formula (2) and a method for preparing the same:

Formula 2

Where

M is at least one selected from Tb, Ce, and Eu, and 0 <x <0.8.

Hereinafter, the present invention will be described in detail.

Zinc silicate-based green phosphor represented by the formula (1) according to the present invention, a zinc compound; Silicon compounds including tetraethyl orthosilicate (TEOS); Manganese compounds; Barium, magnesium, gadolinium or aluminum compounds and optional lithium compounds; And a precursor spray solution having a concentration of 0.02 to 4 M by dissolving citric acid and the like in a solvent, and using the droplet generating apparatus, spraying the resulting spray solution into fine droplets having a diameter of 0.1 to 100 μm with a reactor temperature of 200 to 1500 ° C. The phosphor powder is synthesized by drying and heat-treating at, and the synthesized phosphor powder may be prepared by heat treatment at 1000 to 1500 ° C. for 1 to 10 hours.

The yttrium silicate-based phosphor represented by Chemical Formula 2 according to the present invention includes an yttrium compound; Silicon compounds including tetraethyl orthosilicate (TEOS); Europium, terbium or cerium compounds; And a precursor spray solution having a concentration of 0.02 to 4 M by dissolving citric acid and the like in a solvent, and using the droplet generating apparatus, spraying the resulting spray solution into fine droplets having a diameter of 0.1 to 100 μm with a reactor temperature of 200 to 1500 ° C. The phosphor powder is synthesized by drying and heat-treating at, and the synthesized phosphor powder may be prepared by heat treatment at 1000 to 1500 ° C. for 1 to 10 hours.

<Preparation of phosphor particle precursor solution>

In the process for producing a precursor solution for producing zinc silicate-based phosphor particles of the present invention, a zinc compound and a silicon compound are used as a matrix of the phosphor powder, and manganese (Mn) is used as an activator for doping the matrix. As the activator which is the parent doping component of 2, a compound of at least one metal selected from barium (Ba), magnesium (Mg), gadolinium (Gd), and aluminum (Al), and optionally a lithium (Li) compound is used.

As a matrix of the yttrium silicate-based phosphor powder, an yttrium compound and a silicon compound are used, and one metal compound selected from europium (Eu), terbium (Tb), and cerium (Ce) may be used as an activator for doping the matrix. .

The precursor materials and additives such as citric acid are used by dissolving in water or alcohol, preferably in the form of respective nitrates, acetates, chlorides, oxides, carbonates or sulfides so as to dissolve easily. More specifically, zinc acetate, zinc nitrate or zinc chloride is preferred as zinc precursor material, of which zinc nitrate or zinc acetate is more preferred. As the manganese precursor material, sulfides, chlorides, acetates or nitrates of manganese are preferable. Yttrium precursors are preferably nitrates or acetates, and europium, terbium and cerium precursors are preferably nitrates or acetates. The amount of these precursor materials used may be appropriately adjusted to satisfy the conditions of Formula 1 or 2 above.

As a silicon precursor material used in the preparation of the silicate phosphor of the present invention, a compound containing tetraethyl orthosilicate (TEOS) as part or all is used, and the TEOS is added in a dissolved state by causing a hydration reaction in an acid solution. , Together with the TEOS compound may be used in a state in which nanometer-sized silica powder is dispersed in a solution. Its content is added in excess of the stoichiometric ratio of the formula (1), preferably 1.05 to 1.50 times the stoichiometric ratio. The nanometer-sized silica powder is not particularly limited in size, but 3 nm fine colloids to 600 nm powders may be used in various ways, and any one produced by a gas phase method or a liquid phase method may be used. That is, both commercial colloidal silica or fumed silica produced by the aerosol method can be used.

As the organic additive used in the present invention, one or more selected from carboxylic acids having a carboxyl group (-COOH), for example, citric acid, malic acid, meso tartaric acid, grape acid, and meconic acid, may be used. It is added in an amount of 0 to 100% by weight based on the weight.

In the preparation of silicate-based phosphors according to the invention, it is very important to use such carboxylic acids as citric acid, for the following reasons:

In laboratory-scale spray pyrolysis equipment, TEOS not only enables the preparation of precursor spray solutions of uniform composition, but also allows the formation of silicate inorganic polymer gels through sol-gel reactions of hydration and condensation as the droplets pass through high temperature reactors. By forming the highly viscous inorganic polymer gel inside the droplets, it is possible to prevent the formation of shells on the surface of the droplets due to precursor precipitation, and to prevent precipitation in the droplets by controlling the deposition rate of other components. Inducing, it serves to have a perfect spherical shape filled inside.

However, in the pilot scale for mass production, since the sol-gel reaction does not occur sufficiently due to the short residence time in the reactor, the silicate polymer gel does not grow sufficiently, so that the hollow phosphor is produced. The problem that the shape of the sphere is distorted during the heat treatment process. In addition, in the case of zinc silicate particles obtained by spray drying without heat treatment, the zinc silicate phase formed by reacting the zinc component and the silicon component due to the short residence time of the droplets in the reactor does not form properly, and the amorphous zinc oxide phase The silicon peroxide phase is likely to exist in the separated state in the particles. The particles having the separated phase thus do not maintain the spherical shape in the high temperature heat treatment process for crystal growth and activation of the activator due to the ductile nature of the zinc oxide phase, and exhibit irregularly aggregated properties.

On the other hand, in the case of the yttrium-based silicate phosphor, the luminescence properties of the phosphor particles are greatly affected by the properties of the precursor, which is related to the crystal phase of yttrium silicate. Yttrium silicate crystal (Y ₂ SiO ₅ ) is composed of an X1 phase and an X2 phase. In the conventional spray pyrolysis process using TEOS as a silicon precursor, due to the phase separation property of the silicon component, there is a problem that a high temperature and a long heat treatment process are required to obtain an X 2 phase having excellent luminescence properties.

Carboxylic acids, in particular citric acid, malic acid, meso tartaric acid, grape acid, meconic acid, etc. used in the present invention is a polymer gel formation to promote the growth of the polymer gel formed through esterification reaction with hydrated TEOS in the spray droplets In addition to acting as an accelerator, the carboxyl groups present in citric acid and the like bind to other metal components to form metal salts, and thus the metal salts are linked to the silicate polymer chains, thereby preventing phase separation between other metal components, particularly the parent zinc or yttrium and silicates. Thereby controlling the formation of coherent particles by phase separation. In addition, by adding carboxylic acid such as citric acid, the constituent components can be mixed uniformly, and even at low heat treatment temperature, phosphor particles having high crystallinity having a desired composition can be formed.

However, excessive addition of citric acid (other malic acid, meso tartaric acid, grape acid, and meconic acid) increases the content of unreacted carbon components in the particles, which are used for crystal growth of phosphor particles and activation of active agents. As the carbon dioxide or the like is released in the heat treatment process, excessive carbon components present in the particles are removed and irregular porous particles are formed. In addition, excessive carbon components present inside the particles may inhibit crystal growth of the particles by preventing contact between the constituents of the parent and the active agent.

In the preparation of the silicate phosphor according to the present invention, by controlling the content of carboxylic acid, ie citric acid, malic acid, meso tartaric acid, grape acid or meconic acid, the shape, degree of aggregation, crystal phase, crystallinity and luminescence of the phosphor particles obtained You can optimize the characteristics.

In one embodiment, a zinc compound and a silicon compound as a phosphor matrix in the production of zinc silicate-based phosphors; Manganese compounds as active agents; And a total concentration of the zinc silicate-based precursor solution comprising at least one metal compound selected from Ba, Gd, Mg, and Al as an activator and an optional lithium compound, preferably in the range of 0.02 to 4.0 M, depending on the concentration. The size of the phosphor particles is determined. When the concentration is less than 0.02M, the amount of phosphor powder obtained is small, and when the concentration is higher than 4.0M, the viscosity of the solution becomes high and it is difficult to spray.

As another embodiment, the yttrium compound and the silicon compound as a phosphor matrix in the production of yttrium silicate-based phosphor; Europium, terbium and / or cerium compounds as active agents; And the total concentration of the precursor solution including citric acid (other malic acid, meso tartaric acid, grape acid, meconic acid, etc.) as an additive is preferably in the range of 0.02 to 4.0 M, and the size of the phosphor particles is determined according to this concentration. In addition, the emission color of the phosphor varies according to the type of the active agent, that is, red light emission when the europium (Eu) is used as the active agent, green light emission when the terbium (Tb) is used, and cerium ( When Ce) is used, blue light can be emitted.

1 is a schematic view of a spray pyrolysis process apparatus. The spray pyrolysis processing apparatus includes an ultrasonic droplet generator 1, a tubular reactor 2 for drying and pyrolyzing the generated droplets, a filter 3 for recovering formed phosphor particles, and the like. Droplets of several micron size produced in the ultrasonic droplet generator 1 are conveyed into the reactor 2 by a carrier gas, where spherical precursor powder is obtained by drying and pyrolysis.

<Spray of droplets>

The precursor solution obtained above is sprayed onto the droplets using a spray apparatus, and the diameter of the droplets preferably ranges from 0.1 to 100 µm. If the diameter of the droplet is less than 0.1 mu m, the size of the resulting phosphor particles is too small, and if larger than 100 mu m, the size of the phosphor particles is too large.

The spray apparatus may be an ultrasonic spray apparatus, an air nozzle spray apparatus, an ultrasonic nozzle spray apparatus, a filter expansion aerosol generator (FEAG), an electrostatic spray apparatus, or the like. The ultrasonic nebulizer and the FEAG can produce fine phosphor powder having a sub-micron size at a high concentration, and the air nozzle and the ultrasonic nozzle can produce a large amount of submicron-sized particles at the micron. In the case of using the ultrasonic nebulizer, an industrial ultrasonic nebulizer, in which six or more ultrasonic vibrators are connected, may be used to generate an excessive amount of liquid droplets, thereby increasing the amount of droplets generated by increasing the number of vibrators to hundreds or more. Easily increased, commercial mass production is possible.

<Generation of Spherical Phosphor Powder>

Fine droplets generated from the droplet generator are converted into precursors of phosphor particles in a hot tubular reactor. At this time, the temperature of the reaction furnace is preferably 200 to 1500 ℃ range that can dry the precursor materials. In addition, as a heat source, a flame or plasma reactor capable of maintaining a high temperature in addition to the high temperature tubular reactor and having a low cost may also be used.

The phosphor particles thus dried and heat-treated may be subjected to secondary heat treatment to maintain sufficient crystal growth and spherical shape. Such post-treatment may be a direct oxidation heat treatment process, or first heat treatment in an oxidizing atmosphere and then reheat treatment in a reducing atmosphere. There is an oxidation / reduction complex process. The direct oxidation heat treatment process is preferably performed in the air at 1000 to 1500 ° C. for 1 to 10 hours, in which the characteristics of the resulting phosphor depend on the type of starting precursor material. The oxidation / reduction complex process is performed in air at 1000 to 1500 ° C. for 1 to 10 hours, and then undergoes a reduction process for 10 minutes to 5 hours using 2 to 10% hydrogen / nitrogen mixed gas at 700 to 1200 ° C. It is preferable, but it is also possible to heat-treat directly at 1000-1500 degreeC under hydrogen / nitrogen atmosphere. At this time, the flow rate of the hydrogen / nitrogen mixed gas may be adjusted according to the amount of the phosphor to be heat-treated. In the production of the silicate-based phosphor of the present invention, an oxidation / reduction heat treatment step is more preferable.

According to the method of the present invention, a parent compound, a zinc compound and tetraethyl orthosilicate (TEOS) or a silicon compound composed of TEOS and nano silica powder; Manganese compounds as active agents; A precursor solution containing a metal (barium, gadolinium, magnesium, and aluminum) compound as an activator and citric acid (other malic acid, meso tartaric acid, grape acid, and meconic acid) as additives was generated as a droplet using a spray droplet apparatus, followed by dry heat treatment. The Zn _2-x Si _1-yz O ₄ : Mn _x , D _y , Li _z green phosphor of the present invention is stable even in a high temperature heat treatment process and can maintain a spherical shape without aggregation. It can be applied as a high luminescence green phosphor of plasma displays and field emission displays requiring high luminescence phosphors by exhibiting excellent luminescence brightness in the ultraviolet region.

Also according to the method of the present invention, a yttrium compound and tetraethyl orthosilicate (TEOS) or a silicon compound composed of TEOS and nanosilica powder as a parent; The present invention is prepared by generating a precursor solution containing europium, terbium or cerium compounds as an active agent and citric acid (other malic acid, meso tartaric acid, grape acid, and meconic acid) as droplets using a spray droplet apparatus, followed by dry heat treatment. Y _2-x SiO ₅ : M _x phosphors are stable even in high temperature heat treatment process and can maintain spherical shape without aggregation and exhibit excellent luminescence brightness in the ultraviolet region. It can be applied as a high light emitting phosphor.

The invention can be better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

Example 1: Preparation of Zn _1.9 Si _1-y O ₄ : Mn _0.1 Phosphor

As a raw material, a spray solution was prepared using zinc nitrate, manganese acetate, tetraethyl orthosilicate (TEOS) and citric acid so that the total concentration of the solution was 2M. 1.17 mol and 0.1 mol, and the content of citric acid as an additive was added in the amount of 10 to 70% by weight based on the TEOS content. The resulting spray solution was placed in an ultrasonic nebulizer and generated as fine droplets on the order of 5 microns. The generated droplets were dried and pyrolyzed at a reactor temperature of 800 ° C. to be converted into fine powders, and the phosphor particles thus obtained were heat-treated at 1120 ° C. for 5 hours under an air atmosphere, and then 775 ° C. using 5% hydrogen / nitrogen mixed gas. Crystallization was carried out by reduction for 1 hour at to give the title compound. An electron micrograph of Zn _1.9 SiO ₄ : Mn _0.1 phosphor particles when the amount of citric acid added was 33% of the TEOS content is shown in FIG. 2.

Example 2 Preparation of Zn _1.9-x SiO ₄ : Mn _0.1 Mg _z (0.0001 ≦ _z ≦ 0.008) Phosphor

The title compound was prepared by changing the concentration of magnesium (z) from 0.0001 to 0.008 in the same manner as in Example 1, except that magnesium nitrate was further added as a starting material, and the content of citric acid added to the spray solution Is added at 33% of the TEOS content, and when the concentration (z) of the magnesium is 0.001, that is, electron micrographs of Zn _1.9-0.001 SiO ₄ : Mn _0.1 , Mg _0.001 phosphor particles are shown in FIG. 3.

Comparative Example 1: Preparation of Zn _1.9 SiO ₄ : Mn _0.1 Phosphor without Addition of Citric Acid

The title compound was prepared in the same manner as in Example 1, except that citric acid, an organic additive, was not added. An electron micrograph of this particle is shown in FIG. 4.

Comparative Example 2: Preparation of Zn _1.9 SiO ₄ : Mn _0.1 Phosphor Added Excess Citric Acid

The title compound was prepared in the same manner as in Example 1, except that citric acid, an organic additive, was used as a content of 100% of the TEOS content, and an electron micrograph of the particle is shown in FIG. 5.

2 to 5, in the spray pyrolysis method using TEOS as a raw material of silicon, the addition of citric acid promotes the growth of the polymer gel in the droplets to form a compact form of the phosphor as the salt of the component precipitates as a whole. It can be seen that the phosphor powder has a form filled with the inside, and a phosphor having a smooth surface is obtained. In addition, the metal-citrate is combined with the silicate polymer hydrated by the esterification reaction to suppress the phase separation of the silicon oxide component and the zinc oxide component, thereby confirming that a perfect spherical phosphor without aggregation is obtained even after a high temperature heat treatment process. Can be. In addition, as shown in FIG. 3, when the activator component (magnesium) is added (Example 2), even when citric acid is added, the spherical shape without particle aggregation is maintained. That is, the phosphors prepared in Examples 1 and 2 according to the present invention both maintain a full spherical shape, whereas when no citric acid is added (Comparative Example 1), the particles do not maintain the spherical shape and have a distorted shape. In the case where citric acid is added in an excessive amount (Comparative Example 2), it can be seen that aggregation between particles is severe.

Test Example 1: Luminescent Properties

Using the fluorescent materials prepared in Examples 1-3 and Comparative Examples 1-2, the emission spectrum under the vacuum ultraviolet region having a wavelength of 147 nm is shown in FIG. 6, and also the fluorescent materials prepared in Examples 1 and 2 were used. The emission spectrum is shown in FIG.

In FIG. 6, phosphors prepared by adding an appropriate amount of citric acid (Examples 1, 2 and 3) were prepared without adding citric acid (Comparative Example 1) or prepared by adding citric acid in an excessive amount (Comparative Example 2). Compared with the above, it exhibits excellent light emission characteristics in the vacuum ultraviolet region. It is believed that this is due to the perfect spherical shape without aggregation of the particles produced by the addition of an appropriate amount of citric acid, and high crystallinity, pure crystalline phase free of impurities.

In Fig. 7, the phosphor doped with magnesium as the activator component (Example 2) exhibits better luminescence properties under vacuum ultraviolet region than the phosphor powder not dope with the activator component of Example 1. This is believed to result from the interaction of manganese used as the activator with the activator components.

Example 3 Preparation of Y _2-x SiO ₅ : Ce _x (0.001 ≦ _x <0.5) Phosphor

The total concentration of the solution was 2M by using yttrium nitrate as the precursor material of yttrium constituting the mother material, cerium nitrate as the precursor material of cerium as an activator, and tetraethyl orthosilicate (TEOS) as the raw material of silicon. A spray solution was prepared. In this case, the concentration (x) of cerium added was changed in the range of 0.001 to 0.5, and the content of citric acid as an additive was changed to 10 to 150% by weight based on the TEOS content. The resulting spray solution was placed in an ultrasonic nebulizer and generated as fine droplets of about 5 microns, and the resulting droplets were dried and pyrolyzed at a reactor temperature of 900 ° C. to be converted into fine powders, and the phosphor particles thus obtained were converted to 1300 ° C. in an air atmosphere. Heat treatment for 3 hours gave the title compound. An electron micrograph of Y _2-0.1 SiO ₅ : Ce _0.1 phosphor particles when the amount of citric acid added was 75 wt% of the TEOS content is shown in FIG. 8.

Comparative Example 3: _Preparation of Y _2-0.1 SiO ₅ : Ce _0.1 Phosphor without Addition of Citric Acid

The title compound was prepared in the same manner as in Example 3, except that citric acid, an organic additive, was not added. An electron micrograph of the obtained phosphor particles is shown in FIG. 9.

As shown in FIGS. 8 and 9, the yttrium silicate-based phosphor prepared by adding an appropriate amount of citric acid has relatively pure Y ₂ SiO ₅ crystals. That is, in the case of the phosphor prepared without the addition of citric acid (Comparative Example 3), the mixed phase of the X1 and X2 phases after the post-heat treatment at 1300 ℃, while the phosphor prepared by adding the appropriate citric acid (Example 3) It can be seen that it has a pure X2 phase. From this, it can be predicted that addition of citric acid can promote the growth of crystals even at relatively low heat treatment temperatures by suppressing phase separation of the constituent components and making the mixing between the components uniform. In addition, the phosphor prepared by adding an appropriate amount of citric acid (Example 3) exhibits excellent luminescent properties in the ultraviolet region than the phosphor (Comparative Example 3) powder without citric acid added. It can be seen that with the addition of an appropriate amount of citric acid, the particles may have a spherical shape and have a pure crystalline phase free of high crystallinity and impurities.

As described above, the spherical zinc silicate-based phosphor according to the present invention can be applied to a plasma display or a light emitting lamp because the spherical zinc silicate-based phosphor is excellent in light emission characteristics under vacuum ultraviolet rays and ultraviolet rays, while maintaining a shape in which there is no aggregation and the inside is filled. Yttrium silicate-based phosphors can be applied to electroluminescent displays and light emitting lamps because of their excellently improved luminescent properties in the ultraviolet region, while maintaining the spherical shape of which they are filled.

1 is a schematic diagram of a conventional spray pyrolysis process apparatus;

FIG. 2 is an electron micrograph of an activator-doped zinc silicate-based phosphor (Zn ₂ SiO ₄ : Mn) powder prepared by adding an appropriate amount of citric acid according to Example 1 of the present invention; FIG.

3 is an electron micrograph of a zinc silicate-based phosphor powder doped with magnesium as an activator component by adding citric acid in an appropriate amount according to Example 2 of the present invention;

4 is an electron micrograph of a zinc silicate-based phosphor powder prepared without adding citric acid according to Comparative Example 1 of the present invention;

5 is an electron micrograph of zinc silicate-based phosphor powder prepared by adding an excessive amount (100%) of citric acid according to Comparative Example 2 of the present invention;

6 is a light emission spectrum under vacuum ultraviolet rays of phosphor powders prepared in Examples 1 to 3 and Comparative Examples 1 and 2, respectively;

7 is a light emission spectrum under vacuum ultraviolet rays of the phosphor powders prepared in Examples 1 and 2, respectively;

8 is an electron micrograph of a yttrium silicate-based (Y ₂ SiO ₅ : Ce) phosphor powder prepared by adding an appropriate amount of citric acid according to Example 3 of the present invention;

9 is an electron micrograph of the yttrium silicate-based phosphor powder prepared without adding citric acid according to Comparative Example 3 of the present invention.

Claims (17)

A spherical green light emitting phosphor represented by Formula 1a: Zn _2-x Si _1-y O ₄ : Mn _x , Mg _y Where 0.001 ≦ x <0.2 and 0 ≦ y <0.008. Zinc (Zn) compounds; Silicon compounds comprising some or all of tetraethyl orthosilicate (TEOS); Manganese (Mn) compounds; At least one metal compound selected from barium (Ba), gadolinium (Gd), magnesium (Mg), and aluminum (Al); Lithium compound when the metal compound is gadolinium or an aluminum compound; And dissolving the carboxylic acid in a solvent, and then spraying the resulting precursor mixed solution into fine droplets using a droplet generating apparatus to dry and heat treatment at a reactor temperature of 200 to 1500 ° C. to synthesize phosphor powder, and synthesize the phosphor powder. Method for producing a zinc silicate-based phosphor of the general formula (1) comprising a heat treatment for 1 to 10 hours at 1000 to 1500 ℃: Formula 1 Where D is one or more selected from Ba, Mg, Gd and Al, and 0.001 ≦ x <0.2, 0 ≦ y <0.008, 0 ≦ z <0.008, and z = 0 when D is Ba or Mg. The method of claim 2, Wherein the zinc compound, silicon compound, manganese compound, or metal (D) compound is in the form of its nitrate, acetate, chloride, oxide, carbonate or sulfide. The method of claim 2, Wherein the carboxylic acid is selected from citric acid, malic acid, meso tartaric acid, vitric acid and meconic acid. The method of claim 2, Characterized in that the total concentration of the precursor mixed solution is from 0.02 to 4M. The method of claim 2, The diameter of the fine droplets is characterized in that 0.1 to 100㎛. The method of claim 2, Wherein the droplet generating device is selected from ultrasonic waves, air nozzles, ultrasonic nozzles, electrostatic spraying devices, and filter expanding droplet generating devices. The method of claim 2, After the heat treatment process further comprising the step of reducing heat treatment using a 1 to 10% hydrogen / nitrogen mixed gas at 700 to 1000 ℃. A plasma display or light emitting lamp comprising the zinc silicate-based phosphor of claim 1 in a light emitting layer. A spherical yttrium silicate-based phosphor represented by Formula 2 below: Formula 2 Where M is at least one selected from Tb, Ce, and Eu, and 0 <x <0.8. Yttrium compounds; Silicon compounds comprising some or all of tetraethyl orthosilicate (TEOS); At least one metal compound selected from europium (Eu), terbium (Tb), and cerium (Ce); And dissolving the carboxylic acid in a solvent, and then spraying the resulting precursor mixed solution into fine droplets using a droplet generating apparatus to dry and heat treatment at a reactor temperature of 200 to 1500 ° C. to synthesize phosphor powder, and synthesize the phosphor powder. Method for producing a yttrium silicate-based light emitting phosphor of formula 2 comprising the heat treatment for 1 to 10 hours at 1000 to 1500 ℃: Formula 2 Where M is at least one selected from Tb, Ce, and Eu, and 0 <x <0.8. The method of claim 11, Wherein the yttrium compound, silicon compound or metal (D) compound is in the form of its nitrate, acetate, chloride, oxide, carbonate or sulfide. The method of claim 11, Wherein the carboxylic acid is selected from citric acid, malic acid, meso tartaric acid, vitric acid and meconic acid. The method of claim 11, Characterized in that the total concentration of the precursor mixed solution is from 0.02 to 4M. The method of claim 11, The diameter of the fine droplets is characterized in that 0.1 to 100㎛. The method of claim 11, And wherein the droplet generating device is selected from the group consisting of an ultrasonic wave, an air nozzle, an ultrasonic nozzle, an electrostatic spraying device, and a filter expanding droplet generating device. An electroluminescent display or light emitting lamp comprising the yttrium silicate-based phosphor of claim 10 in a light emitting layer.