CN104818021A - Near-UV excited single matrix white phosphor and preparation method thereof - Google Patents

Abstract

The invention discloses a near-UV excited single matrix white phosphor and its preparation method. Bi<3+> ion is initiatively used as a blue light activator. Bi<3+> is doped into a matrix to emit blue light in near-UV light. A matrix Ca2Y3Sb3O14 is simultaneously doped with Bi<3+> and Eu<3+>. Under near-UV excitation, blue light emitted from Bi<3+> and orange light emitted from Eu<3+> are combined to obtain white light. The near-UV excited single matrix white phosphor is prepared at a non-reducing atmosphere by a high-temperature solid phase method. The main method comprises the following steps: weighing raw materials according to stoichiometric ratio of chemical composition of the phosphor, adding a cosolvent, mixing, fully grinding, calcining at high temperature of 1300-1500 DEG C for 3-8 h; cooling the above product to room temperature, and grinding to obtain the white phosphor. A white-light LED device is obtained by coating a near-UV LED chip with the phosphor. The white light has stable color development. Color reductibility is good. The technology is simple and has high luminous efficiency.

Description

A single-matrix white light phosphor excited by near-ultraviolet light and its preparation method

technical field

The invention belongs to the field of inorganic photoluminescent materials, and in particular relates to a single-matrix fluorescent powder capable of emitting white light under near-ultraviolet light excitation and a preparation method thereof.

Background technique

White light LED is widely used in the field of lighting and display because of its many advantages such as energy saving, environmental protection, small size, long life, fast response speed, all solid state, shock resistance and good safety performance.

At present, there are two main ways to realize commercial white LED devices: one is to coat the GaInN blue chip with yellow phosphor represented by Y ₃ Al ₅ O ₁₂ :Ce ³⁺ , and use the yellow light of the phosphor to Combined with the blue light of the chip to form white light. The luminescent color of this device changes with the thickness of the phosphor powder and the change of the driving current. The color reproduction and color stability are poor, the luminescence is glaring, and the color rendering index is low. It cannot be used in occasions where the display object has a high color. The second is to coat red, green, and blue three-primary-color phosphors on the near-ultraviolet (350-410nm) chip, and reconcile the three-primary-color light emitted by the phosphors to obtain white light. Compared with the first type, the color rendering effect of this device is only determined by the phosphor and is less affected by the chip, so its color rendering index is better. However, due to the problems of color reabsorption and ratio control among the three mixed phosphors, the lumen efficiency and color reproduction of the device are greatly affected.

Contents of the invention

In order to solve the above problems, the object of the present invention is to provide a single-matrix white light phosphor Ca ₂ Y _3(1-xy) Sb ₃ O ₁₄ :xBi ³⁺ , yEu ³⁺ that can be excited by near-ultraviolet light. The wavelength range of the near ultraviolet light is 350nm-370nm. The phosphor is based on the Ca ₂ Y _3(1-xy) Sb ₃ O ₁₄ matrix material doped with Bi ³⁺ and Eu ³ two exciters, the blue light emitted by Bi ³⁺ and the orange-red light emitted by Eu ³ are intrinsically Combined to get white light. The white light LED device obtained by coating the phosphor powder on the near-ultraviolet LED chip has stable white light color, good color reproduction, simple process and high lumen efficiency.

In order to realize above-mentioned task, the present invention takes following technical solution:

(1) A single-matrix white phosphor excited by near-ultraviolet light, characterized in that the chemical formula is: Ca ₂ Y _3(1-xy) Sb ₃ O ₁₄ :xBi ³⁺ ,yEu ³⁺ , wherein, 0.08≤x ≤0.2, 0<y≤0.15.

(2) A method for preparing a single-matrix white phosphor, characterized in that the preparation method comprises: mixing calcium-containing compounds, yttrium-containing compounds, bismuth-containing compounds, europium-containing compounds and co-solvent boron-containing compounds, 1300 Calcining at ~1500° C. for 3-8 hours, cooling to obtain the single-matrix white phosphor.

The calcium-containing compound is at least one of calcium oxide or oxysalt, the bismuth-containing compound is bismuth oxide, and the yttrium-containing compound is yttrium oxide or oxysalt At least one, the europium-containing compound is at least one of europium oxide or oxysalt.

The co-solvent is preferably H ₃ BO ₃ , which accounts for 3%-5% by mass of the raw material.

Compared with the prior art, the present invention has the advantages of:

By screening a large number of matrix materials, an antimonate matrix material (ie Ca ₂ Y ₃ Sb ₃ O ₁₄ ) with the characteristics of “mixed arrangement of cations” was prepared, such that Ca ₂ Y ₃ Sb ₃ O ₁₄ : Bi ³⁺ ,Eu ³ The excitation wavelength (350-370nm) of ⁺ can well match the near-ultraviolet LED chip. The material can emit white light and can adjust the spectrum. The color of white light is stable, the color reproduction is good, and the lumen efficiency is high. Trivalent bismuth and trivalent europium are selected as activator ions, so that the material preparation process does not need to use a reducing atmosphere, simplifies equipment, reduces costs, no waste water and waste gas discharge, and is environmentally friendly.

Description of drawings

FIG. 1 is an X-ray diffraction pattern of the single-matrix white phosphor powder prepared in Example 1.

FIG. 2 is the excitation spectrum of the single-matrix white phosphor powder obtained in Example 1 under monitoring at 615 nm.

Fig. 3 is the emission spectrum of the single-matrix white phosphor powder prepared in Example 1 under the excitation of 350nm near-ultraviolet light.

FIG. 4 is an X-ray diffraction pattern of the single-matrix white phosphor powder prepared in Example 2. FIG.

FIG. 5 is the excitation spectrum of the single-matrix white phosphor powder obtained in Example 2 under monitoring at 615 nm.

FIG. 6 is the emission spectrum of the single-matrix white phosphor powder prepared in Example 2 under the excitation of 350 nm near-ultraviolet light.

FIG. 7 is an X-ray diffraction pattern of the single-matrix white phosphor powder prepared in Example 3. FIG.

FIG. 8 is the excitation spectrum of the single-matrix white phosphor powder prepared in Example 3 under monitoring at 615 nm.

FIG. 9 is the emission spectrum of the single-matrix white phosphor powder prepared in Example 3 under the excitation of 350 nm near-ultraviolet light.

FIG. 10 is an X-ray diffraction pattern of the single-matrix white phosphor powder prepared in Example 4.

FIG. 11 is the excitation spectrum of the single-matrix white phosphor powder prepared in Example 4 under monitoring at 615 nm.

Fig. 12 is the emission spectrum of the single-matrix white phosphor powder prepared in Example 4 under the excitation of 350nm near-ultraviolet light.

Figure 13 shows the positions of the luminescent color coordinates and color temperature values of the single-matrix white phosphors obtained in Examples 1, 2, 3, and 4 in the chromaticity diagram (CIE 1931) formulated by the International Commission on Illumination.

FIG. 14 is the reflection spectrum of the matrix Ca ₂ Y ₃ Sb ₃ O ₁₄ .

Fig. 15 is the excitation spectrum of the prepared single-doped Bi ³⁺ ion phosphor Ca ₂ Y _2.55 Sb ₃ O ₁₄ :0.15Bi ³⁺ monitored at 460 nm.

Fig. 16 is the emission spectrum of the single-doped Bi ³⁺ ion phosphor Ca ₂ Y _2.55 Sb ₃ O ₁₄ :0.15Bi ³⁺ under excitation at 350 nm.

The specific content of the invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

Detailed ways

The purpose of the present invention is to synthesize white fluorescent powder that can be applied to LED devices, and creatively select Bi ³⁺ ions as blue light stimulators.

The reason why Bi ³⁺ ions are not widely used is that although Bi ³⁺ ions can emit blue light in the matrix, their excitation band is mainly in the ultraviolet region rather than the near-ultraviolet region, as shown in the literature Z.Yang et al./ Journal of Alloys and Compounds 559(2013) 142-145 reported Ca ₁₂ Al ₁₄ O ₃₂ Cl ₂ :Bi ³⁺ , whose peak excitation wavelength is 320nm.

Figure 15 shows that the fluorescent powder Ca ₂ Y _2.55 Sb ₃ O ₁₄ :0.15Bi ³⁺ doped only with Bi ³⁺ can be effectively excited by near-ultraviolet light, and the excitation wavelength is determined to be 350nm, while the emission spectrum peak in Figure 16 is located at 460nm , that is, single-doped Bi ³⁺ ion phosphor Ca ₂ Y _2.55 Sb ₃ O ₁₄ :0.15Bi ³⁺ emits blue light under near-ultraviolet light, and the blue light emitted by it and the orange-red light emitted by Eu ³⁺ are combined to obtain white light. Because the activator ions are in a high-valence state, the present invention can for the first time prepare a material emitting blue light in a non-reducing atmosphere.

The composition of the phosphor is "matrix lattice" and "activator ions". Figure 14 proves that the Ca ₂ Y ₃ Sb ₃ O ₁₄ matrix does not absorb ultraviolet light, so it cannot be excited by near ultraviolet light, that is, it is excited by near ultraviolet light. Under no light. The joint action of Bi ³⁺ and the matrix makes Bi ³⁺ emit blue light in the specific matrix Ca ₂ Y ₃ Sb ₃ O ₁₄ under the excitation of near-ultraviolet light at 350-370nm, which is used as a single-matrix white phosphor synthesized by the exciter Ca ₂ Y _3(1-xy) Sb ₃ O ₁₄ :xBi ³⁺ , yEu ³⁺ can match the near-ultraviolet LED chips well.

The single-matrix white phosphor powder Ca ₂ Y _3(1-xy) Sb ₃ O ₁₄ :xBi ³⁺ , yEu ³⁺ prepared by the present invention has an effective excitation waveband of 250-370nm, and the strongest excitation waveband of 320-370nm. Among them, 350-370nm belongs to the near ultraviolet light region.

The single-matrix white fluorescent powder Ca ₂ Y _3(1-xy) Sb ₃ O ₁₄ :xBi ³⁺ , yEu ³⁺ prepared by the present invention, when its chemical composition is 0.08≤x≤0.2 and 0.02<y≤0.15, in Under the excitation of 350-370nm near-ultraviolet light, the luminous color is white light; when y>0.15, the luminous color is orange-red light.

The color temperature of the white light emitted by the single-matrix white phosphor powder prepared by the present invention is related to the values of x and y. When x is fixed, the smaller the value of y, the larger the color temperature value, that is, the more inclined to cool white light; the larger the value of y, the larger the color temperature value, and the smaller the color temperature value, that is, the more inclined to warm white light; that is, white light The color temperature value of the LED can be controlled by changing the values of x and y in its composition, so as to meet the different requirements for the color temperature of light in different application fields.

In the embodiments, measure the sample phase with X-ray powder diffractometer (Bruker D8ADVANCE); Measure the sample emission spectrum with FLS920T type fluorescence spectrometer;

Example 1:

According to the value ranges of x and y of the fluorescent powder, if x=0.15 and y=0.05, the chemical composition of the fluorescent powder is Ca ₂ Y _2.4 Sb ₃ O ₁₄ :0.15Bi ³⁺ , 0.05Eu ³⁺ . According to this chemical composition, the proportioning ratio of each raw material is calculated as shown in Table 1.

Table 1: Raw material ratio of Ca ₂ Y _2.4 Sb ₃ O ₁₄ :0.15Bi ³⁺ , 0.05Eu ³⁺ phosphor

raw material quality CaCO ₃ 2.022 grams Y ₂ O ₃ 2.709 grams Sb ₂ O ₃ 4.417 grams Bi ₂ O ₃ 1.048 grams Eu ₂ O ₃ 0.264 grams H ₃ BO ₃ 0.3 grams

Accurately weigh the above raw materials, grind them carefully in an agate mortar, and put them into a small alumina crucible. Calcined at 1350° C. for 8 hours, cooled naturally to room temperature, taken out, and crushed and ground the resultant to obtain the white phosphor material in Example 1.

As shown in FIG. 1 , the X-ray diffraction (XRD) pattern of the sample in Example 1 was compared with the standard card of Ca ₂ Y ₃ Sb ₃ O ₁₄ , and it was determined that the obtained sample was a pure phase.

As shown in Figure 2, the excitation spectrum of the sample in Example 1, the excitation band of the sample is located at 320-370nm.

As shown in Figure 3, the emission spectrum of the implementation 1 sample. Its emission spectrum consists of a broadband spectrum between 370-560nm and a line spectrum between 560-650nm. After calculation, as shown in Figure 13, the color coordinate value of the luminescence is (0.38,0.30), and the color temperature value is 3500K.

Example 2:

According to the value range of x and y of the fluorescent powder, x=0.15, y=0.02, the chemical composition of the fluorescent powder is Ca ₂ Y _2.49 Sb ₃ O ₁₄ :0.15Bi ³⁺ , 0.02Eu ³⁺ . According to this chemical composition, calculate the proportioning ratio of each raw material as shown in Table 2.

Table 2: Raw material ratio of Ca ₂ Y _2.4 Sb ₃ O ₁₄ :0.15Bi ³⁺ , 0.02Eu ³⁺ phosphor

raw material quality CaCO ₃ 2.022 grams Y ₂ O ₃ 2.811 grams Sb ₂ O ₃ 4.417 grams Bi ₂ O ₃ 1.048 grams Eu ₂ O ₃ 0.105 grams H ₃ BO ₃ 0.3 grams

Accurately weigh the above raw materials, grind them carefully in an agate mortar, and put them into a small alumina crucible. Calcined at 1400°C for 6 hours, cooled naturally to room temperature, taken out, crushed and ground the resultant to obtain the example material.

As shown in Fig. 4, the X-ray diffraction (XRD) spectrum of the sample of Example 2 is compared with the standard card of Ca ₂ Y ₃ Sb ₃ O ₁₄ , and it is determined that the obtained sample is a pure phase.

As shown in FIG. 5 , the excitation spectrum of the sample in Example 2, the excitation band of the sample is located at 320-370 nm.

As shown in Figure 6, the emission spectra of the 2 samples were implemented. Its emission spectrum consists of a broadband spectrum between 370-560nm and a line spectrum between 560-650nm. After calculation, as shown in Figure 13, the color coordinate value of the luminescence is (0.29, 0.27), and the color temperature value is 10000K.

Example 3:

According to the value ranges of x and y of the fluorescent powder, if x=0.15 and y=0.03, the chemical composition of the fluorescent powder is Ca ₂ Y _2.52 Sb ₃ O ₁₄ :0.15Bi ³⁺ , 0.03Eu ³⁺ . According to this chemical composition, the proportioning ratio of each raw material is calculated as shown in Table 3.

Table 3: Raw material ratio of Ca ₂ Y _2.52 Sb ₃ O ₁₄ :0.15Bi ³⁺ , 0.03Eu ³⁺ phosphor

raw material weight CaCO ₃ 2.022 grams Y ₂ O ₃ 2.777 grams Sb ₂ O ₃ 4.417 grams Bi ₂ O ₃ 1.048 grams Eu ₂ O ₃ 0.158 grams H ₃ BO ₃ 0.3 grams

Accurately weigh the above raw materials, grind them carefully in an agate mortar, and put them into a small alumina crucible. Calcined at 1500°C for 4 hours, cooled naturally to room temperature, taken out, and the resultant was crushed and ground to obtain the example material.

As shown in FIG. 7 , the X-ray diffraction (XRD) pattern of the sample in Example 3 was compared with the standard card of Ca ₂ Y ₃ Sb ₃ O ₁₄ , and it was determined that the obtained sample was a pure phase.

As shown in FIG. 8 , the excitation spectrum of the sample in Example 3, the excitation band of the sample is located at 320-370 nm.

As shown in Figure 9, the emission spectra of the implemented 3 samples. Its emission spectrum consists of a broadband spectrum between 370-560nm and a line spectrum between 560-650nm. After calculation, as shown in Figure 13, the color coordinate value of the luminescence is (0.34, 0.29), and the color temperature value is 5000K.

Example 4:

According to the value ranges of x and y of the fluorescent powder, if x=0.15 and y=0.1, the chemical composition of the fluorescent powder is Ca ₂ Y _2.25 Sb ₃ O ₁₄ :0.15Bi ³⁺ , 0.1Eu ³⁺ . According to this chemical composition, calculate the proportioning ratio of each raw material as shown in Table 4.

Table 4: Raw material ratio of Ca ₂ Y _2.31 Sb ₃ O ₁₄ :0.15Bi ³⁺ , 0.1Eu ³⁺ phosphor

raw material quality

CaCO ₃ 2.022 grams Y ₂ O ₃ 2.54 grams Sb ₂ O ₃ 4.417 grams Bi ₂ O ₃ 1.048 grams Eu ₂ O ₃ 0.528 grams H ₃ BO ₃ 0.3 grams

Accurately weigh the above raw materials, grind them carefully in an agate mortar, and put them into a small alumina crucible. Calcined at 1400°C for 6 hours, cooled naturally to room temperature, taken out, crushed and ground the resultant to obtain the example material.

As shown in FIG. 10 , the X-ray diffraction (XRD) pattern of the sample in Example 4 was compared with the standard card of Ca ₂ Y ₃ Sb ₃ O ₁₄ , and it was determined that the obtained sample was a pure phase.

As shown in FIG. 11 , the excitation spectrum of the sample in Example 4, the excitation band of the sample is located at 320-370 nm.

As shown in Fig. 12, the emission spectra of 4 samples were implemented. Its emission spectrum consists of a broadband spectrum between 370-560nm and a line spectrum between 560-650nm. After calculation, as shown in Figure 13, the color coordinate value of the luminescence is (0.40,0.31), and the color temperature value is 3000K.

Claims (4)

1. A single-matrix white phosphor excited by near-ultraviolet light, characterized in that the chemical formula is: Ca ₂ Y _3(1-xy) Sb ₃ O ₁₄ : xBi ³⁺ , yEu ³⁺ , wherein, 0.08≤x≤ 0.2, 0<y≤0.15. 2. the preparation method of single-matrix white phosphor powder described in claim 1 is characterized in that, described preparation method comprises: The calcium-containing compound, the yttrium-containing compound, the bismuth-containing compound, the europium-containing compound and the cosolvent-containing boron-containing compound are mixed, calcined at 1300-1500° C. for 3-8 hours, and cooled to obtain the single-matrix white phosphor. 3. The preparation method of white fluorescent powder as claimed in claim 2, is characterized in that, described calcium-containing compound is at least one in the oxide of calcium or oxysalt, and described bismuth-containing compound is bismuth Oxide, the yttrium-containing compound is at least one of yttrium oxide or oxo-salt, and the europium-containing compound is at least one of europium oxide or oxo-salt. 4 . The preparation method of white phosphor according to claim 2 , wherein the co-solvent is preferably H ₃ BO ₃ , which accounts for 3%-5% by mass of the raw material.