TW201502245A - Green phosphor and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a green phosphor and a manufacturing method thereof. The manufacturing method of the green phosphor comprises the following steps: (A) providing a Ca precursor, a Sc precursor, a Si precursor, a Ce precursor and a dopant precursor, wherein the dopant precursor comprises a Al precursor and a Zn precursor; (B) mixing the Ca precursor, the Sc precursor, the Si precursor, the Ce precursor and the dopant precursor to form a mixture by a vibrational milling; (C) placing the mixture in a reactor with a solid carbon source to obtain a green phosphor through a heat treatment.

Description

Green fluorescent material and preparation method thereof

The invention relates to a green fluorescent material and a preparation method thereof, in particular to a green fluorescent powder Ca _2.955 Sc ₂ Si ₃ O ₁₂ doped with Al ³⁺ or Zn ^{2+ in} a main body by a thermal carbon reduction method. :Ce _0.03 , featuring high luminous intensity and high quantum efficiency.

With the increasingly promoted energy-saving and carbon-reduction policies, the development of energy-saving equipment in various fields is increasingly refined. In lighting applications, white light-emitting diodes are regarded as the mainstream of next-generation lighting.

At present, white LEDs are mainly divided into the following five systems: (1) white light emitting modules composed of red, blue and green three-color light emitting diodes; (2) blue light emitting diodes with yellow fluorescent powder; (3) blue light emitting two The polar body is matched with the uniformly mixed red and green phosphor powder; (4) the ultraviolet light emitting diode is uniformly mixed with the blue, green and red fluorescent powder; (5) the ultraviolet light emitting diode is matched with the white fluorescent powder. .

In the foregoing method, mixing light with three primary color LEDs requires a complicated driving power source, and it is difficult to control the color rendering, so that the fluorescent powder conversion type LED is the main white light LED on the market, and in 1996, Japan Nichia Chemical Co., Ltd. It is proposed to use yellow-light YAG phosphor powder with blue LED. It is a high efficiency white LED light source commonly found on the market. However, the use of YAG phosphor powder with blue LED has the disadvantages of low color rendering and high color temperature in general illumination, and the thermal stability of YAG phosphor powder is poor, which is prone to color shift problem under high power long-term driving.

In view of this, the inventors have studied a method for overcoming the above problems, and the green phosphor powder achieves high luminous intensity, high thermal stability, and high quantum efficiency by a special process, so that the red fluorescent powder can be used in place of the YAG firefly. Light powder to overcome the problems of today's white LEDs.

The main object of the present invention is to provide a novel green fluorescent material preparation method, which can significantly improve the thermal stability, luminous intensity and quantum efficiency of the green fluorescent material.

Another object of the present invention is to provide a green fluorescent material which has excellent thermal stability and luminous intensity and can replace the existing white LED in combination with red fluorescent powder.

To achieve the above object, the present invention provides a method for preparing a green fluorescent material, comprising: (A) providing a calcium precursor, a germanium precursor, a germanium precursor, a germanium precursor, and a doped precursor, wherein The doped precursor includes an aluminum (Al) precursor or a zinc (Zn) precursor; (B) mixing the calcium precursor, the ruthenium precursor, the ruthenium precursor, the ruthenium precursor, and the doped precursor And oscillating grinding to form a precursor mixed powder, wherein when the doped precursor is an aluminum (Al) precursor, the calcium: 钪: 矽: 铈: aluminum molar ratio can be 2.5~3: 1.6~ 2: 2.5~3.5: 0.02~0.04: 0~0.4, preferably 2.955:1.6~2:3:0.03:0~0.4, and before doping precursor is zinc (Zn) When driving, calcium: 钪: 矽: 铈: zinc molar ratio can be 2.5~3: 1.667~2:2.5~3.5:0.02~0.04:0~0.5, preferably 2.955:1.667~2:3: 0.03: 0 to 0.5; and (C) placing the precursor mixed powder into a reaction apparatus containing a solid carbon source and performing heat treatment to form a green fluorescent material.

The solid carbon source described above is not particularly limited, and is preferably a carbon powder, whereby the green fluorescent material has excellent thermal stability, luminous intensity, and quantum efficiency.

In the present invention, the calcium precursor is at least one selected from the group consisting of CaB ₆ , CaC ₂ , CaCO ₃ , CaC ₂ O ₄ , CaCl ₂ , CaF ₂ , Ca(NO ₃ ) ₂ , CaO, Ca ₃ (BO _{3 2} , a group consisting of Ca ₃ (C ₆ H ₅ O ₇ ) ₂ and Ca ₃ (PO ₄ ) ₂ , preferably at least one selected from the group consisting of CaB ₆ , CaC ₂ , CaCO ₃ , CaC ₂ O ₄ , A group consisting of CaCl ₂ and CaF ₂ is more preferably CaCO ₃ . The ruthenium precursor may be at least one selected from the group consisting of: ScB ₁₂ , ScC ₁₃ , ScF ₃ , ScH ₃ , Sc(NO ₃ ) ₃ , Sc ₂ O ₃ , Sc ₂ S ₃ , preferably at least one selected Free: a group consisting of Sc(NO ₃ ) ₃ , Sc ₂ O ₃ , and Sc ₂ S ₃ , more preferably Sc ₂ O ₃ . The at least one of the foregoing ruthenium precursors may be selected from the group consisting of SiO ₂ , SiF ₄ , SiC ₁₄ , SiC, Si ₂ N ₃ , preferably at least one selected from the group consisting of: SiO ₂ , SiF ₄ , and SiC ₁₄ . Group, more preferably SiO ₂ . The at least one of the above ruthenium precursors may be selected from the group consisting of: CeO ₂ , Ce ₂ (C ₂ O ₄ ) ₃ ‧9H ₂ O, Ce(SO ₄ ) ₂ , CeCl ₃ , Ce(NO ₃ ) ₃ . The group consisting of 6H ₂ O, preferably at least one selected from the group consisting of: CeO ₂ , Ce ₂ (C ₂ O ₄ ) ₃ ‧9H ₂ O, Ce(SO ₄ ) ₂ , more preferably Ce ₂ (C ₂ O ₄ ) ₃ ‧9H ₂ O. The above aluminum precursor may be at least one selected from the group consisting of: AlCl ₃ , AlF ₃ , AlN, Al(NO ₃ ) ₃ , Al(OH) ₃ , AlPO ₄ , Al ₂ O ₃ , Al ₂ (SO ₄ ) ₃ , Al ₄ C The group consisting of ₃ is preferably at least one selected from the group consisting of AlPO ₄ , Al ₂ O ₃ , Al ₂ (SO ₄ ) ₃ , and Al ₄ C ₃ , more preferably Al ₂ O ₃ . The above zinc precursor may be at least one selected from the group consisting of: ZnCl ₂ and ZnF ₂ . a group consisting of Zn(NO ₃ ) ₂ , ZnO, Zn(OH) ₂ , ZnSO ₄ , Zn ₂ P ₂ O ₇ , Zn ₃ N ₂ , and Zn ₃ (PO ₄ ) ₂ , preferably at least one selected Free: Group of ZnO, Zn(OH) ₂ , ZnSO ₄ , Zn ₂ P ₂ O ₇ , Zn ₃ N ₂ , Zn ₃ (PO ₄ ) ₂ , more preferably ZnO.

In the step (C) of the above method, the precursor mixed powder may be placed in a first reaction vessel, the first reaction vessel may be placed in a second reaction vessel containing carbon powder, and the second reaction vessel is It is placed in a reaction apparatus to perform heat treatment. The carbon powder may be added to about 16-20 g, preferably 18 g; the heat treatment temperature is preferably between 1300 and 1600 ° C, and the better is between 1400 and 1500 ° C; the heat treatment time is preferably between 1 and 10. Hours, then the best is between 2 and 8 hours, and the better is between 2 and 4 hours. The above conditions are not limited to this and can be adjusted according to the situation.

After the completion of the thermal reaction, the carbon powder in the second reaction vessel preferably retains about 0 to 10 g, more preferably about 4 to 6 g, depending on the case.

The green fluorescent material obtained by the above method is characterized by the following chemical formula: [Chemical Formula] Ca _x Sc _2-a-2b/3 Al _a Zn _b Si ₃ O ₁₂ : Ce _z

Where 0 ≦ a ≦ 0.4, 0 ≦ b ≦ 0.5, 2.95 ≦ x + z ≦ 3, when b = 0, 0.05 ≦ a ≦ 0.4; When a = 0, 0.1 ≦ b ≦ 0.5.

Preferably, when b = 0, a = 0.15; when a = 0, b = 0.3. More preferably, the green fluorescent powder obtained by the above method has a chemical formula of Ca _2.955 Sc _1.85 Al _0.15 Si ₃ O ₁₂ :Ce _0.03 or Ca _2.955 Sc _1.8 Zn _0.3 Si ₃ O ₁₂ :Ce _0.03 .

The present invention further provides a green fluorescent material having the following chemical formula: [Chemical Formula] Ca _x Sc _2-a-2b/3 Al _a Zn _b Si ₃ O ₁₂ :Ce _z

Where 0 ≦ a ≦ 0.4, 0 ≦ b ≦ 0.5, 2.95 ≦ x + z ≦ 3, when b = 0, 0.05 ≦ a ≦ 0.4; when a = 0, 0.1 ≦ b ≦ 0.5.

Preferably, in the chemical formula of the green fluorescent material of the present invention, when b = 0, a = 0.15; when a = 0, b = 0.3. Further preferably, the chemical formula of the green fluorescent material is Ca _2.955 Sc _1.85 Al _0.15 Si ₃ O ₁₂ :Ce _0.03 or Ca _2.955 Sc _1.8 Zn _0.3 Si ₃ O ₁₂ :Ce _0.03 .

Here, the step of preparing the green fluorescent material comprises: (A) providing a calcium precursor, a germanium precursor, a germanium precursor, a germanium precursor, and a doped precursor, wherein the doped precursor comprises a An aluminum (Al) precursor or a zinc (Zn) precursor; (B) mixing the calcium precursor, the ruthenium precursor, the ruthenium precursor, the ruthenium precursor, and the doped precursor, and oscillating and grinding, To form a precursor mixed powder, wherein when the doped precursor is aluminum (Al) For precursors, calcium: 钪: 矽: 铈: aluminum molar ratio can be 2.5~3:1.6~2:2.5~3.5:0.02~0.04:0.05~0.4, preferably 2.955:1.6~2:3:0.03 :0~0.4; When the doped precursor is zinc (Zn) precursor, calcium: 钪: 矽: 铈: zinc molar ratio can be 2.5~3: 1.667~2: 2.5~3.5: 0.02~0.04: 0~0.5, preferably 2.955:1.6~2:3:0.03:0~0.5; and (C) placing the precursor mixed powder into a reaction device containing a solid carbon source, heat treatment at 1300~1500 °C 2 to 4 hours, more preferably between 1400 and 1500 ° C to form the green fluorescent material.

Here, the solid carbon source is not particularly limited, and is preferably a carbon powder.

The calcium precursor may be at least one selected from the group consisting of CaB ₆ , CaC ₂ , CaCO ₃ , CaC ₂ O ₄ , CaCl ₂ , CaF ₂ , Ca(NO ₃ ) ₂ , CaO, Ca ₃ (BO ₃ ) ₂ , Ca ₃ ( A group consisting of C ₆ H ₅ O ₇ ) ₂ and Ca ₃ (PO ₄ ) ₂ is preferably CaCO ₃ . The ruthenium precursor may be at least one selected from the group consisting of ScB ₁₂ , ScC ₁₃ , ScF ₃ , ScH ₃ , Sc(NO ₃ ) ₃ , Sc ₂ O ₃ , Sc ₂ S ₃ , preferably Sc ₂ O ₃ . The ruthenium precursor may be at least one selected from the group consisting of SiO ₂ , SiF ₄ , SiC ₁₄ , SiC, Si ₂ N ₃ , preferably SiO ₂ . At least one of the above ruthenium precursors is selected from the group consisting of: Ce ₂ (C ₂ O ₄ ) ₃ ‧9H ₂ O, CeO ₂ , Ce(SO ₄ ) ₂ , CeCl ₃ , Ce(NO ₃ ) ₃ . The group consisting of 6H ₂ O is preferably Ce ₂ (C ₂ O ₄ ) ₃ ‧9H ₂ O. At least one of the above aluminum precursors is selected from the group consisting of: AlCl ₃ , AlF ₃ , AlN, Al(NO ₃ ) ₃ , Al(OH) ₃ , AlPO ₄ , Al ₂ O ₃ , Al ₂ (SO ₄ ) ₃ , Al ₄ C The group consisting of ₃ is preferably Al ₂ O ₃ . At least one of the above zinc precursors is selected from the group consisting of: ZnCl ₂ and ZnF ₂ . The group consisting of Zn(NO ₃ ) ₂ , ZnO, Zn(OH) ₂ , ZnSO ₄ , Zn ₂ P ₂ O ₇ , Zn ₃ N ₂ , and Zn ₃ (PO ₄ ) ₂ is preferably ZnO.

In the above step (C), the precursor mixed powder is placed in a In the first reaction vessel, the first reaction vessel is placed in a second reaction vessel containing 16-20 g, preferably 18 g of the carbon powder, and the second reaction vessel is placed in the reaction apparatus. For heat treatment. The heat treatment conditions and the amount of carbon powder added are the same as described above. After the completion of the thermal reaction, the carbon powder in the second reaction vessel preferably retains about 0 to 10 g, more preferably about 4 to 6 g, depending on the case.

1‧‧‧First Reaction Vessel

2‧‧‧Toner

3‧‧‧Second reaction vessel

1 is a flow chart of a method for preparing a green fluorescent material of the present invention.

Figure 2 is a schematic view of a reaction apparatus of the present invention.

Figure 3 is an X-ray diffraction pattern of the green fluorescent powders of Preparation Examples 1 to 6 of the present invention.

Figure 4 is an X-ray diffraction pattern of the green fluorescent powder of Preparation Examples 7 to 12 of the present invention.

Figure 5 is a FTIR spectrum of the green fluorescent powders of Preparation Examples 1 to 6 of the present invention.

Figure 6 is a FTIR spectrum of the green fluorescent powder of Preparation Examples 7 to 12 of the present invention.

Figure 7 is a fluorescence excitation spectrum (PLE) of the green fluorescent powders of Preparation Examples 1 to 6 of the present invention.

Figure 8 is a fluorescence emission spectrum (PL) of the green fluorescent powders of Preparation Examples 1 to 6 of the present invention.

Figure 9 is a fluorescence excitation spectrum (PLE) of the green fluorescent powder of Preparation Examples 7 to 12 of the present invention.

Figure 10 is a fluorescence emission spectrum (PL) of the green fluorescent powder of Preparation Examples 7 to 12 of the present invention.

Fig. 11 is a graph showing the results of thermal stability of the green fluorescent powder and the commercial green fluorescent powder of the present invention.

Fig. 12 is a graph comparing the luminescence intensity of the green fluorescent powder obtained by the hot carbon reduction method of the present invention and the conventional heat treatment under the atmosphere.

The embodiments of the present invention are described below by way of specific examples, and those skilled in the art can readily appreciate the other advantages and advantages of the present invention. In addition, the present invention may be embodied or modified by various other embodiments without departing from the spirit and scope of the invention.

Preparation Examples 1 to 6

Please refer to the experimental flow chart of FIG. 1 and the schematic diagram of the reaction device of FIG. 2 . First, the required reactants were separately weighed to the S1 in the HDPE tank according to the chemical dosage. As shown in Table 1 and Table 2, the mixture was mixed in a high-energy vibrating ball mill for 15 minutes, and then the homogeneous reactant powder was placed in the alumina crucible. (first reaction vessel), and placing the alumina crucible in a large crucible 3 (second reaction vessel) covered with 20 g of carbon powder 2, and then placing the crucible 3 in a high temperature furnace The hot carbon reduction reaction is heat-treated at 1450 ° C for 3 hours (heating rate 5 ° C / min) S3, and naturally falls to room temperature, and then the product after the reaction is ground S4 to obtain the desired green fluorescent powder Ca _2.955 Sc _2-a Al _a Si ₃ O ₁₂ :Ce _0.03 S5, wherein after the reaction is completed, the residual amount of the carbon powder is about 4 to 6 g.

Preparation Examples 7 to 12

The preparation method of this preparation example is the same as that of Preparation Example 1, except that the reactant composition and the mixing amount are as shown in Table 2. The obtained green fluorescent powder is represented by Ca _2.955 Sc _2-2b/3 Zn _b Si ₃ O ₁₂ : Ce _0.03 .

Test example 1

The green fluorescent powder Ca _2.955 Sc _2-a Al _a Si ₃ O ₁₂ :Ce _0.03 of Preparation Examples 1 to 6 and the green fluorescent powder of Preparation Examples 7 to 12 using an X-ray diffractometer (Rigaku D/max IIIV) Ca _2.955 Sc _2-2b/3 Zn _b Si ₃ O ₁₂ :Ce _0.03 was identified as components, as shown in Figs. 3 and 4, respectively. In the results of Fig. 3, the diffraction peak positions of Preparation Examples 1 to 6 coincided with Ca ₃ Sc ₂ Si ₃ O ₁₂ (JCPDS PDF #72-1969), meaning that Preparation Examples 1 to 6 were able to synthesize Ca ₃ Sc _{2 .} Si ₃ O ₁₂ , however, when the doping amount of Al ³⁺ is 40 mol% or more (a 0.4), there will be a heterogeneous phase of Ca ₃ Al ₂ Si ₃ O ₁₂ (JCPDS PDF #83-2207).

In the results of FIG. 4, the diffraction peak positions of the green fluorescent powders of Preparation Examples 7 to 12 coincided with Ca ₃ Sc ₂ Si ₃ O ₁₂ (JCPDS PDF #72-1969), meaning that Preparation Examples 7 to 12 were able to be synthesized. Ca ₃ Sc ₂ Si ₃ O ₁₂ , however, when the doping amount of Zn ²⁺ is 40 mol% or more (b 0.4), there will be a heterogeneous Ca ₃ Si ₃ O ₉ (JCPDS PDF #74-0874).

Test example 2

Fourier transform infrared spectroscopy (Jasco model-460) Preparation of a green fluorescent powder 1-6 of _{Ca 2.955 Sc 2-a Al a} Si 12 3 O: Ce 0.03 phosphor and a green powder prepared in Example 7-12 of Ca _2.955 Sc 2 _-2b/3 Zn _b Si ₃ O ₁₂ :Ce _0.03 was measured by FTIR spectroscopy, and the scanning range was 400-4000 cm ^-1 . The results are shown in Fig. 5 and Fig. 6, respectively.

Please refer to FIG. 5. FIG. 5 is a FTIR spectrum measurement result of the green fluorescent powders of Preparation Examples 1 to 6. The green fluorescent powder doped with Al ³⁺ can effectively suppress the residual of Sc ₂ O ₃ (such as the heart symbol). The luminescent property is improved due to a decrease in the residual amount of Sc ₂ O ₃ .

Please refer to FIG. 6. FIG. 6 is a FTIR spectrum measurement result of the green fluorescent powders of Preparation Examples 7 to 12. After doping with Zn ²⁺ , the residual of Sc ₂ O ₃ in the green phosphor can be effectively suppressed. However, when the concentration of Zn ²⁺ is more than 40 mol% (b) 0.4), a hetero phase of Ca ₃ Si ₃ O ₉ occurs, thereby weakening the luminescence intensity.

Test Example 3

By fluorescence spectrometer (Hitachi F-7000) was prepared green fluorescence measurement Example 1-6 of Powder _{Ca 2.955 Sc 2-a Al a} Si 3 O 12: Ce 0.03 phosphor and a green powder prepared in Example 7-12 of Ca _2.955 Sc _2-2b/3 Zn _b Si ₃ O ₁₂ :Ce _0.03 . Here, both the excitation light grating and the emission light grating are set to 2.5 nm and the scanning rate is 240 nm/min.

7 is a fluorescence excitation spectrum (PLE) of the green fluorescent powders of Preparation Examples 1 to 6. From the results of FIG. 7, it can be found that the green fluorescent powder doped with Al ^{3+ in} Preparation Examples 1 to 6 does not change its excitation peak 450. The wavelength of nm, and its wavelength of light falls in the range of 504 nm to 506 nm, which can be determined that Al ³⁺ doping does not affect Ca _2.955 Sc _2-a Al _a Si ₃ O ₁₂ :Ce _0.03 on blue LED Applicability.

Figure 8 is a fluorescence emission spectrum (PL) of the green fluorescent powders of Preparation Examples 1 to 6, excited by light having a wavelength of 450 nm, and the emission spectrum is a broad peak of 450 nm to 650 nm, and after doping with Al ³⁺ , The luminous intensity of green phosphor powder is improved, especially when doping 15 mol% (a=0.15) Al ³⁺ , the strongest luminous intensity can be achieved. In addition, the results of Fig. 8 can also be found with Al ³⁺ doping. As the amount increases, the wavelength of the green fluorescent powder has a red shift.

9 is a fluorescence excitation spectrum (PLE) of the green fluorescent powders of Preparation Examples 7 to 12. From the results of FIG. 9, it can be found that the green fluorescent powder doped with Zn ^{2+ in} Preparation Examples 7 to 12 does not change its excitation peak 450. The wavelength position of nm, and its emission wavelength falls in the range of 505 nm to 506 nm, which can be determined that Zn ²⁺ doping does not affect Ca _2.955 Sc _2-2/3b Zn _b Si ₃ O ₁₂ :Ce _0.03 in blue light Applicability on LEDs.

Figure 10 is the fluorescence emission spectrum (PL) of the green fluorescent powders of Preparation Examples 7 to 12, which are also excited by light having a wavelength of 450 nm, and the emission spectrum is a broad peak of 450 nm to 650 nm, and is doped with Zn ²⁺ . The luminous intensity of the green fluorescent powder is improved, especially when doping 30 mol% (b=0.3) Zn ²⁺ , the strongest luminous intensity can be achieved.

It can be understood from the results of Test Example 3 that doping Al ³⁺ or Zn ²⁺ instead of Sc ³⁺ does not shift the position of the excitation light, so it is suitable for a 450 nm blue LED die.

Test Example 4

The green fluorescent powder Ca _2.955 Sc _2-a Al _a Si ₃ O ₁₂ :Ce _0.03 of Preparation Examples 1 to 6 and the green fluorescence of Preparation Examples 7 to 12 were prepared using a fluorescence spectrometer (Hitachi F-7000) together with an integrating sphere. The powder Ca _2.955 Sc _2-2b/3 Zn _b Si ₃ O ₁₂ :Ce _0.03 was measured for quantum efficiency and absorbance. The quantum efficiency and absorption rate were calculated by excitation at 450 nm blue light.

Table 3 shows the results of quantum efficiency measurement of the green fluorescent powder prepared by the preparation of hot carbon reduction in Preparation Examples 1 to 6. The quantum efficiency of undoped Al ³⁺ green phosphor is 47.3%, and the absorption rate is 65.1%. With the increase of Al ³⁺ doping amount, the quantum efficiency and absorption rate also increase, especially when Al ^{3+ is} doped. When the amount of impurities is 15 mol% (a=0.15), the quantum efficiency reaches 51.6%. When the Al ³⁺ doping amount is 40 mol% (a=0.4), the absorption rate reaches 77.4%. This result indicates that doping Al ³⁺ can effectively increase the quantum efficiency and absorption rate of the green phosphor.

Table 4 shows the results of quantum efficiency measurement of the green fluorescent powder prepared by the hot carbon reduction of Preparation Examples 7 to 12. The quantum efficiency of undoped Zn ²⁺ green phosphor is 48.6%, and the absorption rate is 64.5%. With the increase of Zn ²⁺ doping amount, the quantum efficiency and absorption rate also increase, especially when Zn ^{2+ is} mixed. When the amount of impurities is 30 mol% (a=0.3), the quantum efficiency reaches 58.0% and the absorption rate reaches 72.1%. Therefore, the results in Table 4 show that doping Zn ²⁺ can effectively increase the quantum efficiency and absorption rate of the green phosphor.

Comparative example 1

In order to confirm that the green phosphor powder produced by the hot carbon reduction method of the present invention has excellent thermal stability, a commercially available commercial green fluorescent powder and a green fluorescent powder Ca _2.955 prepared by the hot carbon reduction method of the present invention are _used. Sc ₂ Si ₃ O ₁₂ :Ce _0.03 (undoped Al ³⁺ or Zn ²⁺ ), Ca _2.955 Sc _1.85 Al _0.15 Si ₃ O ₁₂ :Ce _0.03 (doped 15 mol% of Al ³⁺ ) and Ca _2.955 Sc _1.8 Zn _0.3 Si ₃ O ₁₂ :Ce _0.03 (doped with 30 mol% of Zn ²⁺ ) was compared for thermal stability, and the results are shown in FIG.

As the temperature increases, the commercial green phosphor at 100 ° C, its relative intensity of light is significantly reduced, to 175 ° C, the relative intensity of the light is reduced to about 10%; otherwise, the green fluorescent light produced by the hot carbon reduction method of the present invention Powder, its thermal stability is _remarkable , especially Ca _2.955 Sc _1.8 Zn _0.3 Si ₃ O ₁₂ :Ce _0.03 green phosphor has more excellent thermal stability.

Comparative example 2

In order to confirm that the green fluorescent powder prepared by the hot carbon reduction method of the present invention has an excellent luminous intensity improvement effect compared to the green fluorescent powder prepared by heat treatment in the conventional atmosphere, the same reaction materials are separately prepared by different preparations. The method was made into a green fluorescent powder to measure individual fluorescence emission spectra (PL), and the results are shown in FIG.

Excited by light with a wavelength of 450 nm, the emission spectrum is a broad peak from 450 nm to 650 nm. The Ca _2.955 Sc ₂ Si ₃ O ₁₂ :Ce _0.03 green phosphor formed by heat treatment under atmospheric pressure has a relative luminescence intensity of about 450 (au), however, Ca _2.955 made by the hot carbon reduction method of the present invention. Sc ₂ Si ₃ O ₁₂ :Ce _0.03 green phosphor with a relative intensity of light up to nearly 700 (au). Therefore, it is apparent that the green fluorescent powder obtained by adding the carbon powder to the crucible before the reaction and performing the reduction reaction is more improved than the conventional preparation method of heat treatment in the atmosphere without adding the carbon powder, and the Ca _2.955 Sc is further improved. ₂ Si ₃ O ₁₂ :Ce _0.03 Green fluorescent powder luminous intensity effect.

The above-mentioned embodiments are merely examples for convenience of description, and the scope of the claims is intended to be limited to the above embodiments.

1‧‧‧First Reaction Vessel

2‧‧‧Toner

3‧‧‧Second reaction vessel

Claims (17)

A method for preparing a green fluorescent material, comprising the steps of: (A) providing a calcium precursor, a precursor, a precursor, a precursor, and a doped precursor, wherein the doped precursor comprises an aluminum (Al) a precursor or a zinc (Zn) precursor; (B) mixing the calcium precursor, the ruthenium precursor, the ruthenium precursor, the ruthenium precursor, and the doped precursor and performing oscillating grinding to form a precursor mixed powder, wherein, when the doped precursor is the aluminum (Al) precursor, the calcium: 钪: 矽: 铈: aluminum molar ratio is 2.955: 1.6~2:3:0.03:0~0.4 And when the doped precursor is the zinc (Zn) precursor, the calcium:钪:矽:铈:zinc ratio is 2.955:1.667~2:3:0.03:0~0.5; and (C) The precursor mixed powder is placed in a reaction apparatus containing a solid carbon source and heat-treated to form a green fluorescent material. The method of claim 1, wherein the solid carbon source is a carbon powder. The method of claim 1, wherein the calcium precursor is at least one selected from the group consisting of CaB ₆ , CaC ₂ , CaCO ₃ , CaC ₂ O ₄ , CaCl ₂ , CaF ₂ , Ca(NO ₃ ) ₂ , a group consisting of CaO, Ca ₃ (BO ₃ ) ₂ , Ca ₃ (C ₆ H ₅ O ₇ ) ₂ , and Ca ₃ (PO ₄ ) ₂ , the at least one precursor selected from the group consisting of: ScB ₁₂ , ScC ₁₃ a group consisting of ScF ₃ , ScH ₃ , Sc(NO ₃ ) ₃ , Sc ₂ O ₃ , and Sc ₂ S ₃ , the at least one precursor selected from the group consisting of: SiO ₂ , SiF ₄ , SiC ₁₄ , SiC, A group consisting of Si ₂ N ₃ , the at least one precursor of which is selected from the group consisting of: Ce ₂ (C ₂ O ₄ ) ₃ . 9H ₂ O, CeO ₂ , Ce(SO ₄ ) ₂ , CeCl ₃ , Ce(NO ₃ ) ₃ . a group consisting of 6H ₂ O, the aluminum precursor being at least one selected from the group consisting of: AlCl ₃ , AlF ₃ , AlN, Al(NO ₃ ) ₃ , Al(OH) ₃ , AlPO ₄ , Al ₂ O ₃ , Al ₂ (SO ₄ ) ₃ , a group consisting of Al ₄ C ₃ , the zinc precursor is at least one selected from the group consisting of: ZnCl ₂ , ZnF ₂ . a group consisting of Zn(NO ₃ ) ₂ , ZnO, Zn(OH) ₂ , ZnSO ₄ , Zn ₂ P ₂ O ₇ , Zn ₃ N ₂ , and Zn ₃ (PO ₄ ) ₂ . According to the method of claim 2, in the step (C), the precursor mixed powder is placed in a first reaction vessel, and the first reaction vessel is placed in a volume of 16-20 g. One of the second reaction vessels of the carbon powder, and the second reaction vessel is placed in the reaction apparatus for heat treatment. The method of claim 4, wherein the second reaction vessel retains 4 to 6 g of the carbon powder after the reaction is completed. The method according to claim 1, wherein the step (C) is heat treatment at 1300 to 1500 ° C for 2 to 4 hours. The method of claim 1, wherein the green fluorescent material has the following chemical formula: [Chemical Formula] Ca _x Sc _2-a-2b/3 Al _a Zn _b Si ₃ O ₁₂ : Ce _z wherein, 0≦ a ≦ 0.4, 0 ≦ b ≦ 0.5, 2.95 ≦ x + z ≦ 3, when b = 0, 0.05 ≦ a ≦ 0.4; when a = 0, 0.1 ≦ b ≦ 0.5. The method of claim 7, wherein a = 0.15 when b = 0; and b = 0.3 when a = 0. The method of claim 7, wherein the green fluorescent material has a chemical formula of Ca _2.955 Sc _1.85 Al _0.15 Si ₃ O ₁₂ :Ce _0.03 or Ca _2.955 Sc _1.8 Zn _0.3 Si ₅ O ₁₂ :Ce _0.03 . A green fluorescent material having the following chemical formula: [Chemical Formula] Ca _x Sc _2-a-2b/3 Al _a Zn _b Si ₃ O ₁₂ :Ce _z wherein 0≦a≦0.4,0≦b≦0.5, 2.95≦ x+z≦3, when b=0, 0.05≦a≦0.4; when a=0, 0.1≦b≦0.5. The green fluorescent material according to claim 10, wherein when b=0, a=0.15; when a=0, b=0.3. The green fluorescent material according to claim 10, wherein the green fluorescent material has a chemical formula of Ca _2.955 Sc _1.85 Al _0.15 Si ₃ O ₁₂ :Ce _0.03 or Ca _2.955 Sc _1.8 Zn _0.3 Si ₃ O ₁₂ : Ce _0.03 . The green fluorescent material according to claim 10, wherein the step of preparing the fluorescent material comprises: (A) providing a calcium precursor, a precursor, a precursor, and a precursor. And a doped precursor, wherein the doped precursor comprises an aluminum (Al) precursor or a zinc (Zn) precursor; (B) the calcium precursor, the ruthenium precursor, the ruthenium precursor, the ruthenium The precursor and the doped precursor are mixed and oscillated to form a a precursor mixed powder, wherein when the doped precursor is the aluminum (Al) precursor, the calcium:钪:矽:铈: aluminum molar ratio is 2.955:1.6~2:3:0.03:0~0.4, And when the doped precursor is the zinc (Zn) precursor, the calcium:钪:矽:铈:zinc ratio is 2.955:1.667~2:3:0.03:0~0.5; and (C) The precursor mixed powder is placed in a reaction apparatus containing a solid carbon source and heat-treated at 1300 to 1500 ° C for 2 to 4 hours to form the green fluorescent material. The green fluorescent material according to claim 13, wherein the solid carbon source is a carbon powder. The green fluorescent material according to claim 13, wherein the calcium precursor is at least one selected from the group consisting of CaB ₆ , CaC ₂ , CaCO ₃ , CaC ₂ O ₄ , CaCl ₂ , CaF ₂ , Ca(NO ₃ ) ₂ , a group consisting of CaO, Ca ₃ (BO ₃ ) ₂ , Ca ₃ (C ₆ H ₅ O ₇ ) ₂ , and Ca ₃ (PO ₄ ) ₂ , the at least one precursor of the ruthenium precursor is selected from the group consisting of: ScB ₁₂ , a group consisting of ScC ₁₃ , ScF ₃ , ScH ₃ , Sc(NO ₃ ) ₃ , Sc ₂ O ₃ , and Sc ₂ S ₃ , the at least one precursor selected from the group consisting of: SiO ₂ , SiF ₄ , SiC ₁₄ , A group consisting of SiC and Si ₂ N ₃ , the at least one precursor of which is selected from the group consisting of: Ce ₂ (C ₂ O ₄ ) ₃ . 9H ₂ O, CeO ₂ , Ce(SO ₄ ) ₂ , CeCl ₃ , Ce(NO ₃ ) ₃ . a group consisting of 6H ₂ O, the aluminum precursor being at least one selected from the group consisting of: AlCl ₃ , AlF ₃ , AlN, Al(NO ₃ ) ₃ , Al(OH) ₃ , AlPO ₄ , Al ₂ O ₃ , Al ₂ (SO ₄ ) ₃ , a group consisting of Al ₄ C ₃ , the zinc precursor is at least one selected from the group consisting of: ZnCl ₂ , ZnF ₂ . a group consisting of Zn(NO ₃ ) ₂ , ZnO, Zn(OH) ₂ , ZnSO ₄ , Zn ₂ P ₂ O ₇ , Zn ₃ N ₂ , and Zn ₃ (PO ₄ ) ₂ . The green fluorescent material according to claim 13 , wherein in the step (C), the precursor mixed powder is placed in a first reaction container, and the first reaction container is placed in the first reaction container. 20 g of the second reaction of the toner The container is placed in the reaction apparatus for heat treatment. The green fluorescent material according to claim 16, wherein the second reaction vessel retains 4 to 6 g of the carbon powder after the reaction is completed.