KR20010097013A - Oxide fluorescent material and producing methods of the same - Google Patents

Abstract

The present invention relates to an oxide phosphor and a method for producing the same, and provides an oxide phosphor represented by the following general formula (1).

A _2-xy B _x C _y O _3-x (1)

Wherein A is at least one member selected from gadolinium (Gd) and yttrium (Y);

B is at least one alkali metal ion selected from lithium (Li), sodium (Na) and potassium (K);

C is one or more rare earth elements selected from cerium (Ce), praseodymium (Pr), europium (Eu), terbium (Tb), erbium (Er) and thulium (Tm), and 0 <x≤0.3, 0 < y≤0.3. The phosphor according to the present invention not only improves the luminance in the UV region, but also shows particularly improved luminance in the low voltage region of 1 kV or less, and thus, when the phosphor according to the present invention is applied to a fluorescent lamp, a fluorescent display, or a low voltage FED, You can get it.

Description

Oxide fluorescent material and producing methods of the same

The present invention relates to an oxide phosphor and a method of manufacturing the same, and more particularly, to an oxide phosphor having excellent light emission luminance and color purity and a method of manufacturing the same.

FED (Field Emission Display) is interpreted to mean "field effect electron emission display device" and consists of a cathode plate panel (Cathode) and a cathode plate (Anode). The principle of operation is that the electron emitted from the cathode plate is designed to display the image by hitting the phosphor of the anode plate.

FED's thinness, low power consumption, low process cost, excellent temperature characteristics, and high speed operation make it widely used, from small color TVs to industrial products and computers. TV is plugged in.

The cathode panel of the FED is composed of a field emitter array (FEA) that emits electrons, and the anode panel is a part that represents an image that can be viewed by human beings by applying phosphors, emitters, phosphors, Various elements such as a driving device are constructed in a vacuum state in a thin panel of 1 cm or less.

Therefore, in the FED, the distance between the cathode plate and the anode plate is short, so when a high voltage of 10 kV or more is used, such as CRT, discharge occurs. Therefore, a low voltage of 5 kV or less should be used. In particular, in order to develop an FED that can operate at a voltage of 1 kV or less. Various studies are being carried out around the world. On the other hand, when the energy of electrons is lower than 1 kV, electrons can be scanned only at a depth of 20 nm or less from the surface of the phosphor, so that the efficiency of the phosphor for low voltage operation FED is higher than that of CRT using high voltage. ) Greatly decreases, and the surface state of the phosphor greatly affects the phosphor emission efficiency.

In particular, in the case of CRT, sulfide-based phosphors having high color purity and high luminous efficiency are mainly used. When using Y ₂ O ₂ S: Eu, a sulfide-based red phosphor widely used in CRTs, as a phosphor for FED, In addition to low luminous efficiency and poor color purity, a small amount of sulfur is desorbed by scanning the electron beam for a long time, so as to reduce the vacuum degree or the field emission array in a small volume having a distance of 1 mm between the cathode and anode plates, such as a FED panel. There is a problem in that the performance of the display is degraded by damaging the (FEA).

In order to solve this problem, in recent years, there is an attempt to prepare a red phosphor for a low voltage driving of the oxides of sulfur desorption without risk based FED is performed, in this related technology ATiO ₃ in Japanese Patent Application Laid-Open No. 8-85788 (A is an alkaline Phosphor containing a rare earth element and a small amount selected from Al, Ga, In, and Tl to the mother of the earth metal Mg, Ca, Sr, and Ba), in particular strontium (Sr) SrTiO ₃ : Pr, Al phosphors employing praseodymium (Pr) and aluminum (Al) are selected to reduce the emission initiation voltage to 10 V and lower the speed of various light sources at anode voltages of 1 kV or less. It has been reported that red light emission is caused by an electron beam.

On the other hand, existing studies on utilizing rare earth metal oxides as red phosphors for fluorescent lamps have been conducted by adding or substituting other metal elements to yttrium (Y) or gadolinium (Gd) oxides using europium (Eu) as an activator. Or there is a way to improve the color coordinates.

Specifically, a part of yttrium is replaced with at least one element selected from tetravalent titanium (Ti), zirconium (Zr) and hafnium (Hf) in, for example, yttrium (Y) oxide containing europium (Eu). (See Japanese Patent Application Laid-Open No. Hei 7-76687), where a part of gadolinium is replaced with a divalent alkaline metal element in a gadolinium oxide containing europium (see Japanese Patent Application Laid-Open No. Hei 7-258631, Japanese Patent Laid-Open No. Hei 8-199164). Trivalent boron (see Japanese Patent Application Laid-Open No. 7-90264) or when substituted with trivalent aluminum and gallium (see Japanese Patent Application Laid-Open No. 7-258632).

However, in the prior art as described above, phosphors containing a small amount of rare earth elements and trivalent metal ions in the matrix of ATiO ₃ (A is one element selected from alkaline earth metals Mg, Ca, Sr, and Ba) have a light emission starting voltage. Although it is very low and has a characteristic that the light emission luminance at low voltage is somewhat superior to the conventional phosphor, there is a problem that the increase in the light emission luminance with the acceleration voltage is significantly lower than the conventional phosphor.

In addition, the phosphor for fluorescent lamps using gadolinium or yttrium oxide as a mother matrix of phosphors has been slightly improved in color purity, but hardly in light emission luminance.

Therefore, the technical problem to be achieved by the present invention is to provide a new phosphor exhibiting a higher luminous efficiency with little change in color purity compared to the conventional phosphor by an electron or UV light source accelerated at a low voltage of 1kV or less.

Another object of the present invention is to provide a method for producing the phosphor.

1 is an X-ray diffraction diagram of a Gd _2-xy Li _x Eu _y O _3-x phosphor according to an embodiment of the present invention.

2 is an electron micrograph of a Gd _2-xy Li _x Eu _y O _3-x phosphor according to an embodiment of the present invention.

3 is a photoluminescence (PL) excitation spectrum of a Gd _2-xy Li _x Eu _y O _3-x phosphor according to an embodiment of the present invention.

4 is an emission spectrum when the Gd _2-xy Li _x Eu _y O _3-x phosphor according to the embodiment of the present invention is excited at 254 nm.

5 is a cathode luminescence (CL) spectrum at 500V for the Gd _2-xy Li _x Eu _y O _3-x phosphor according to the embodiment of the present invention.

6 is a CL spectrum at 500V for a Gd _1.84 Li _0.10 Eu _0.06 O _2.9 phosphor and a commercial phosphor according to an embodiment of the present invention.

7 is an X-ray diffraction diagram of Y _2-xy Li _x Eu _y O _3-x phosphor according to another embodiment of the present invention.

8 is a PL excitation spectrum of Y _2-xy Li _x Eu _y O _3-x phosphor according to another embodiment of the present invention.

9 is Y according to another embodiment of the present invention._2-xyLi_xEu_yO_3-x This is the emission spectrum when the phosphor is excited at 254 nm.

10 is a CL spectrum at 500V for the Y _2-xy Li _x Eu _y O _3-x phosphor according to another embodiment of the present invention.

The present invention provides an oxide phosphor represented by the following general formula (1) in order to achieve the above technical problem.

A_2-xyB_xC_yO_3-x (One)

Wherein A is at least one member selected from gadolinium (Gd) and yttrium (Y);

B is at least one alkali metal ion selected from lithium (Li), sodium (Na) and potassium (K);

C is one or more rare earth elements selected from cerium (Ce), praseodymium (Pr), europium (Eu), terbium (Tb), erbium (Er) and thulium (Tm), and 0 <x≤0.3, 0 < y≤0.3.

According to one embodiment of the present invention, it is particularly preferable that the alkali metal ion B is lithium (Li).

According to one embodiment of the invention, it is particularly preferred that the rare earth element C is europium (Eu).

According to one embodiment of the present invention, it is preferable that the ranges of x and y values are 0.08 ≦ x ≦ 0.10 and 0.05 ≦ y ≦ 0.15 because both the PL and the CL can improve the luminance.

The present invention to achieve the above other technical problem,

a) mixing an oxide or nitrate or carbonate of a rare earth element with an oxide or nitrate or carbonate of an alkali metal ion;

b) first sintering the mixture prepared in step a) in air at 600 to 700 ° C. for 5 to 20 hours;

c) pulverizing the product of step b);

d) secondary sintering of the primary sintered material pulverized in step c) for 5 to 20 hours at 900-1000 ° C .; And

e) providing a method for producing an oxide phosphor, the method comprising: sintering the secondary sintered product of step d) at 1000-1100 ° C. for 5 to 20 hours.

In addition, the present invention is a method for producing the oxide phosphor,

a) dissolving an oxide or nitrate or carbonate of a rare earth element and an oxide or nitrate or carbonate of an alkali metal ion in an aqueous citric acid solution;

b) adjusting the pH of the aqueous citric acid solution prepared in step a) to about pH 4-7;

c) gelling the resultant of step b) by heating to about 80 to 100 ° C. with stirring;

d) burning the gelate to obtain a powder;

e) first sintering the powder obtained in step d) in air at 600 to 700 ° C. for 5 to 20 hours;

f) pulverizing the product of step e); and

g) providing a second sintering of the primary sintered product at 900-1000 ° C. for 5 to 20 hours.

According to one embodiment of the present invention, in step a), the oxides or nitrates or carbonates of the rare earth elements are weighed by chemical equivalents, and the oxides or nitrates or carbonates of alkali metal ions are weighed by 100 to 500 of the chemical equivalents and mixed. It is desirable to.

In the present invention, by replacing a part of the gadolinium or yttrium element with a monovalent alkali metal element in the gadolinium (Gd) or yttrium (Y) oxide in which trivalent ions of the rare earth element are mixed, the luminous intensity by UV light source is superior to that of a conventional phosphor. Provide a phosphor.

The oxide phosphor according to the present invention can be prepared by using the two methods described above, namely, the solid phase reaction method and the sol-gel method.

In the case of the solid phase reaction, the raw materials are weighed and mixed well in the mortar, followed by primary sintering at 600-700 ° C for 5-20 hours using an electric furnace, and then finely ground, and then 5-20 hours at 900 -1000 ° C. Fire in air at 1000-1100 ° C for 5-20 hours.

In the sol-gel method, a predetermined amount of each raw material is weighed and dissolved in an aqueous solution in which citric acid is dissolved, and then the pH is adjusted to about 4-7 using a weak alkaline aqueous solution. Next, the citric acid aqueous solution is heated at about 80 to 100 ° C. while stirring, gelled, and burned to obtain a powder. The powder is first sintered at 600-700 ° C for 5-20 hours using an electric furnace, and then pulverized well and calcined again at 900-1100 ° C for 5-20 hours in air.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments of the present invention. However, the following examples are only examples to help understanding of the present invention, but the scope of the present invention is not limited thereto.

<Example 1>

Gd _2-xy Li _x Eu _y O _3-x phosphor in which gadolinium (Gd) as A, lithium (Li) as B, and europium (Eu) as C was selected in Formula (1).

Gd ₂ O ₃ or Gd (NO ₃ ) ₃ was used as the mother raw material, and Eu ₂ O ₃ or Eu (NO ₃ ) ₃ and LiNO ₃ or Li ₂ CO ₃ were used as raw materials of the added substance.

The synthesis method used two methods, the conventional solid phase reaction method and the sol-gel method. In the case of the solid phase method, the raw materials are weighed and mixed well in the mortar, followed by primary sintering at 600 ° C. for 5 hours using an electric furnace, and then finely ground. It was.

In the sol-gel method, a predetermined amount of each raw material is weighed and dissolved in an aqueous solution of citric acid, and the pH is adjusted to about 4-7 using a weak alkaline aqueous solution, followed by heating and gelling at about 80 to 100 ° C. with stirring. Combustion gave a powder. The powder was first sintered at 600 ° C. for 5 hours using an electric furnace, and then ground well and calcined again at 900 ° C. for 5 hours in air.

In both methods, raw materials of lithium were weighed in at 120 or more. Basically, there was no difference according to the two synthesis methods, but in the case of the sol-gel method, it was possible to slightly reduce the heat treatment temperature and time.

The x value was changed in the range of 0 to 0.30, and the y value was changed in the range of 0.03 to 0.30. When excited at 254 nm according to the change of x and y values, the relative luminance of PL (photoluminescence) and electron beam acceleration voltage at the cathode were changed. Relative luminance of CL (cathodoluminescence) was measured. The relative luminance value is a value when the luminance with respect to the commercial phosphor Y ₂ O ₃ : Eu is set to 100.

The relative luminance values of PL and CL measured while changing x to 0, 0.03, 0.08, 0.15 and 0.3 and y to 0.03 to 0.30 are shown in Tables 1 to 6, respectively.

Mol of Eu ³⁺ Li ⁺ of mol PL relative luminance at 254 nm excitation light source CL relative luminance according to cathode voltage () 500 V 800 V 1000 V 5 0 62 81 74 68 8 0 76 79 72 69 12 0 82 88 85 70 15 0 72 - - -

Mol of Eu ³⁺ Li ⁺ of mol PL relative luminance at 254 nm excitation light source CL relative luminance according to cathode voltage () 500 V 800 V 1000 V 5 3 100 - - - 10 3 108 - - - 15 3 114 124 111 102 20 3 119 123 106 80

Mol of Eu ³⁺ Li ⁺ of mol PL relative luminance at 254 nm excitation light source CL relative luminance according to cathode voltage () 500 V 800 V 1000 V 5 8 111 167 135 101 8 8 135 181 178 131 10 8 141 168 156 115 15 8 122 - - -

Mol of Eu ³⁺ Li ⁺ of mol PL relative luminance at 254 nm excitation light source CL relative luminance according to cathode voltage () 500 V 800 V 1000 V 3 10 114 166 165 115 4 10 126 182 169 120 5 10 139 185 158 120 6 10 148 194 157 129 8 10 155 172 151 122 10 10 164 163 144 101 15 10 126 - - -

Mol of Eu ³⁺ Li ⁺ of mol PL relative luminance at 254 nm excitation light source CL relative luminance according to cathode voltage () 500 V 800 V 1000 V 10 15 114 124 111 102 15 15 119 123 106 80 20 15 116 - - - 30 15 110 - - -

Mol of Eu ³⁺ Li ⁺ of mol PL relative luminance at 254 nm excitation light source CL relative luminance according to cathode voltage () 500 V 800 V 1000 V 10 30 106 152 118 81 15 30 118 143 124 104 20 30 124 126 101 87 30 30 116 - - -

From the results of Tables 1 to 6, it can be seen that the relative luminance of PL increases as the content of Li or Eu increases, but rather decreases when it exceeds a certain content. In particular, the ranges of x and y exhibiting excellent luminance characteristics are 0.08 ≦ x ≦ 0.10 and 0.05 ≦ y ≦ 0.15. The relative luminance of CL is excellent in the same range of x and y values. In addition, in the case of CL, there is a slight difference in the x and y values indicating the best luminance according to the cathode voltage. In particular, the lower the cathode voltage, the greater the relative luminance improvement.

Table 7 shows the relative luminance of the commercially synthesized phosphor Y ₂ O ₃ : Eu of the sample synthesized by using the lithium material (x value) in excess of 2 to 5 times in preparing the phosphor in the same manner as in Table 3. Indicates.

Mol of Eu ³⁺ Mol of Li ⁺ used PL relative luminance at 254 nm excitation light source CL relative luminance according to cathode voltage () 500 V 800 V 1000 V 5 16 130 178 137 72 24 126 161 135 107 32 113 141 110 88 40 110 - - - 8 16 107 - - - 24 110 - - - 32 105 - - - 40 118 - - - 10 16 116 - - - 24 117 - - - 32 126 - - - 40 122 - - - 15 16 147 110 120 97 24 148 110 139 118 32 155 136 160 111 40 128 - - -

As shown in Table 7, lithium added in excess acts as a solvent as well as quantitative solid solution of lithium into the lattice. many.

1 is an X-ray diffraction diagram of a sample synthesized in Example 1. FIG. It can be seen from the X-ray diffraction diagram of FIG. 1 that all samples have no peaks due to by-products and have a tetragonal crystal structure. As the amount of Eu or Li increases, the unit cell size slightly increases. Able to know. From this fact, it can be considered that Eu or Li are well employed in the crystallization site of Gd in the composition range of the present invention.

2 (a) to 2 (d) are SEM images of some of the phosphors of Example 1. FIG. Figure 2 (a) is Gd _1.92 Eu _0.08 O ₃ does not contain Li, Figure 2 (b) is Gd _1.84 Eu _0.08 Li _0.08 O _2.92 , Figure 2 (c) is Gd _1.82 Eu _0.1 Li _0.08 O _2.92, Figure 2 (d) is a SEM image of the Gd _1.85 Eu _0.08 Li _0.1 O _2.9 phosphor, and in the case of FIGS. 2 (b) to 2 (d), which are phosphors containing Li, they are composed of spherical particles unlike FIG. 2 (a). It can be seen that. Since the spherical particle size is an essential factor in forming a fluorescent film having good fluorescence efficiency, it can be considered as another advantage of the present invention.

3 shows that as the excitation spectrum of some of the phosphors prepared in Example 1 of the present invention increases, the intensity of the spectrum increases as well as the maximum excitation wavelength increases little by little. This change in the spectrum also supports the formation of a single phase as can be seen from the X-ray diffractogram.

4 shows emission spectra at wavelengths exhibiting maximum intensity as excitation spectra for some of the phosphors of Example 1. FIG. As can be seen in FIG. 4, as the amount of Eu is increased, the shape of the spectrum hardly changes, but the intensity of red light emission increases.

FIG. 5 shows the CL spectrum when the electron beam acceleration voltage at the cathode is 500 V for some of the phosphors of Example 1 of the present invention. 6 is a commercial Y₂O₃: Eu³⁺For Gd_1.84Li_0.10Eu_0.06O_2.9Is a comparison of the CL spectra. 5 and 6, the phosphor of the present invention is commercially available Y₂O₃: Eu³⁺It shows the shape of the same red emission spectrum as, but it can be seen that the emission intensity is very excellent compared to the conventional commercial products.

<Example 2>

In the general formula (1), a Y _2-xy Li _x Eu _y O _3-x phosphor in which A selected yttrium (Y) and alkali metal element B selected Li was prepared.

Y ₂ O ₃ or Y (NO ₃ ) ₃ was used as the mother raw material and Eu ₂ O ₃ or Eu (NO ₃ ) ₃ and LiNO ₃ or Li ₂ CO ₃ were used as raw materials of the added material. Synthesis method used a conventional solid-phase reaction method, the raw material was weighed and mixed in the mortar in the same manner as in Example 1, and then sintered first at 600 ℃ using an electric furnace for 5 hours and then changed again It was calcined in air at 900 ° C. for 5 hours and at 1000 ° C. for 5 hours.

The x value is in the range of 0.00-0.30, the y value is in the range of 0.03-0.30, and the relative luminance of PL when excited at 254 nm according to the content of Li and Eu, and the CL Relative luminance was measured. The luminance for commercial Y ₂ O ₃ : Eu ³⁺ was set to 100. The results for the x, y content range showing desirable characteristics among the measurement results are shown in Tables 8 to 10 below.

Mol of Eu ³⁺ Li ⁺ of mol PL relative luminance at 254 nm excitation light source CL relative luminance according to cathode voltage () 500 V 800 V 1000 V 5 5 108 94 90 69 8 5 126 97 94 82 10 5 126 100 80 82 12 5 128 - - - 15 5 120 - - -

Mol of Eu ³⁺ Li ⁺ of mol PL relative luminance at 254 nm excitation light source CL relative luminance according to cathode voltage () 500 V 800 V 1000 V 5 8 112 96 95 87 8 8 - 98 83 94 10 8 128 106 90 81 12 8 124 - - - 15 8 125 - - -

Mol of Eu ³⁺ Li ⁺ of mol PL relative luminance at 254 nm excitation light source CL relative luminance according to cathode voltage () 500 V 800 V 1000 V 3 10 91 89 71 67 4 10 102 95 82 70 5 10 110 97 95 82 6 10 113 - - - 8 10 120 97 90 86 10 10 125 104 92 78 12 10 128 - - - 15 10 121 - - -

From the results of Tables 8 to 10, it can be seen that as the Li or Eu content increases, the relative luminance of PL increases, but rather decreases when it exceeds a certain content. In particular, the ranges of x and y exhibiting excellent luminance characteristics were 0.05 ≦ x ≦ 0.10 and 0.05 ≦ y ≦ 0.15. The relative luminance of CL was excellent in the same range of x and y values. In addition, in the case of CL, there is a slight difference in the x and y values indicating the best luminance according to the cathode voltage. In particular, it can be seen that the lower the cathode voltage, the higher the luminance improvement.

In the sample synthesized in Example 2, the case where y = 0 or 0.08 and the commercial phosphor Y ₂ O ₃ : Eu ³⁺ X-ray diffractogram are shown in FIG. 7. From the X-ray diffractogram, it can be seen that all samples have no peaks due to by-products and have a tetragonal crystal structure. As in Example 1, it can be seen that the size of the unit cell increases slightly as the amount of Eu or Li increases. From this fact, it can be considered that Eu or Li are well employed in the crystallographic site of Y in the composition range of the present invention as in Example 1.

FIG. 8 is an excitation spectrum according to a change of y value in the phosphor of Example 2 of the present invention, as in Example 1, as the amount of Eu increases, the intensity of the spectrum increases and the maximum excitation wavelength is increased. It can be seen that the increase. This change in the spectrum also supports the formation of a single phase as can be seen from the X-ray diffractogram.

FIG. 9 shows light emission spectra at wavelengths showing maximum intensity in an excitation spectrum according to a change in y value when x = 0.10 in the phosphor of Example 2 of the present invention. As can be seen in FIG. 9, as the amount of Eu added increases, the shape of the spectrum hardly changes, but the intensity of red light emission increases.

FIG. 10 shows the CL spectrum when the electron beam acceleration voltage at the cathode is 500 V for some of the phosphors of Example 2 of the present invention.

The phosphor according to the present invention is a matrix represented by A ₂ O ₃ (A is an element of Gd or Y), and C is cerium (Ce), praseodymium (Pr), europium (Eu), terbium (Tb), A phosphor in which a predetermined amount of one selected from alkali metal elements lithium (Li), sodium (Na), and potassium (K) is added while using a trivalent rare earth element selected from erbium (Er) and thulium (Tm). Has the same effect.

First, when UV is used as the excitation light source, it is possible to significantly improve the emission intensity compared to the conventional phosphor. It is possible to obtain excellent luminescence brightness compared to the conventional phosphors by the accelerated electron beam at low cathode voltage below 1 kV. Especially, Gd _2-xy Li _x using Gd ₂ O ₃ as a matrix and Li in alkali metal element In the case of the Eu _y O _3-x phosphor, it is possible to obtain a very good luminance of about twice that of a commercially available oxide red phosphor.

Second, the existing phosphor is impossible to obtain the spherical particle size unless a separate flux is used, but the phosphor of the present invention has a spherical particle size without the use of a separate flux to form a fluorescent film having good luminous efficiency in the future. It is advantageous.

Third, since the phosphor according to the present invention is an oxide-based phosphor that is safe against thermal stimulation or other external stimuli such as electron injection, when the phosphor according to the present invention is applied to a fluorescent display or used as a positive electrode plate of an FED phosphor, a long time electron scanning is performed. Nevertheless, the destruction of the phosphor can be prevented and thus the vacuum of the space between the negative electrode plate and the positive electrode plate is not broken, so that the performance of the panel can be maintained for a long time.

Therefore, the phosphor according to the present invention can be applied to a fluorescent display can exhibit excellent performance such as high brightness, high definition, etc., and is expected to greatly contribute to the commercialization of low-voltage FED.

Claims (8)

An oxide phosphor represented by the following general formula (1). A _2-xy B _x C _y O _3-x (1) Wherein A is at least one member selected from gadolinium (Gd) and yttrium (Y); B is at least one alkali metal ion selected from lithium (Li), sodium (Na) and potassium (K); C is one or more rare earth elements selected from cerium (Ce), praseodymium (Pr), europium (Eu), terbium (Tb), erbium (Er) and thulium (Tm), and 0 <x≤0.3, 0 < y≤0.3. The oxide phosphor according to claim 1, wherein the alkali metal ion B is lithium (Li). The oxide phosphor according to claim 1, wherein the rare earth element C is europium (Eu). The oxide phosphor according to claim 1, wherein the range of x values is 0.08 ≦ x ≦ 0.10. The oxide phosphor according to claim 1, wherein the y value ranges from 0.05 ≦ y ≦ 0.15. a) mixing an oxide or nitrate or carbonate of a rare earth element with an oxide or nitrate or carbonate of an alkali metal ion; b) first sintering the mixture prepared in step a) in air at 600 to 700 ° C. for 5 to 20 hours; c) pulverizing the product of step b); d) secondary sintering of the primary sintered material pulverized in step c) for 5 to 20 hours at 900-1000 ° C .; And e) The oxide phosphor manufacturing method of claim 1, comprising the step of sintering the secondary sintered product of step d) for 5 to 20 hours at 1000-1100 ℃. a) dissolving an oxide or nitrate or carbonate of a rare earth element and an oxide or nitrate or carbonate of an alkali metal ion in an aqueous citric acid solution; b) adjusting the pH of the aqueous citric acid solution prepared in step a) to about pH 4-7; c) gelling the resultant of step b) by heating to about 80 to 100 ° C. with stirring; d) burning the gelate to obtain a powder; e) first sintering the powder obtained in step d) in air at 600 to 700 ° C. for 5 to 20 hours; f) pulverizing the product of step e); and g) The method of claim 1 comprising the step of secondary sintering the primary sintered product at 900-1000 ℃ for 5 to 20 hours. 8. The method of claim 6 or 7, wherein in step a), the oxide or nitrate or carbonate of the rare earth element is weighed in chemical equivalents, and the oxide or nitrate or carbonate in alkali metal ions is weighed in 100 to 500 equivalents. Characterized by mixing.