CN103074059A - Dysprosium and thulium co-doped silicon phosphoaluminate white phosphor and its preparation method - Google Patents

Abstract

The invention relates to a dysprosium-thulium co-doped silicon aluminophosphate white light phosphor and a preparation method thereof, belonging to the field of luminescent materials. The composition of the phosphor is: A _3(1-xy) Al ₂ P ₂ Si ₂ O ₁₅ :Dy _3x ,Tm _3y , where A is one of Ca and Ba, 0.01≤x≤0.15, 0.01≤y≤0.15 . As the composition changes, the excitation wavelength range of the phosphor is from ultraviolet to purple (λex=300-420nm). Under the excitation of 350nm light, the phosphor emits white light, which can be used as the luminescent powder of single-matrix white light LED excited by ultraviolet LED chip , with the change of dysprosium-thulium ion doping concentration, the color of the luminescence changes slightly.

Description

Dysprosium and thulium co-doped silicon aluminophosphate white light phosphor and preparation method thereof

Technical field:

The invention relates to a dysprosium-thulium co-doped silicon aluminophosphate white light phosphor and a preparation method thereof, belonging to the field of luminescent materials. the

Background technique:

Compared with traditional lighting sources, white light-emitting diodes (LEDs) have the advantages of energy saving, high efficiency, small size, long life, fast response, low driving voltage, and anti-vibration, and have attracted widespread attention from all over the world. From a technical point of view, there are two ways to get a white LED light source. One is to combine red, green, and blue monochromatic LEDs to produce white light; the second is to use LED chips to excite other luminescent materials to form white light, that is, use blue LEDs to excite yellow-emitting phosphors, or use near-ultraviolet LED to excite red, green and blue phosphors. The first method combines red, green, and blue single-color LEDs to produce white light, which has the advantages of high efficiency, dynamic adjustment of color temperature, and good color rendering. However, the forward voltage and light output of the three color LEDs are different, and their temperature characteristics It is also different from the light maintenance characteristic. It must have the light output signal sampling and feedback function, and perform dynamic control so that the coordinates of the chromaticity point of the emitted white light remain unchanged, so the requirements for circuit design are relatively high. Judging from the current development trend, the second method is better than the first method in terms of feasibility, practicability and commercialization by combining LED chips with phosphors, using the emitted light from LED chips to excite phosphors and mixing them to form white light. method. Therefore, high-performance light-converting phosphors become the key materials. White LEDs prepared by coating yellow phosphor YAG:Ce ³⁺ on InGaN blue diodes have low display index (CRI, Ra=75) and high color temperature (CCT=7756K) due to the lack of red components (Reference 1 : XQPiao, T.Horikawa, et al., Appl.Phys.Lett.88(2007)161908), due to the degradation of the phosphor, the color coordinates also shift with the increase of the use time. In order to obtain a white light-emitting material with a suitable color rendering index, it is necessary to add red light-emitting components to the material (Reference 2: Jong Seong Bae Won and Jung Hyun Jeon, Appl.phys.B.95 (2009) 715), that is, YAG : Ce ³⁺ is mixed with some red luminescent powders to prepare white light LEDs, but the time decay of the two different matrix luminescent materials is different, and with the use of phosphors, the color of the integrated light will change, resulting in a change in color temperature . Therefore, we need a single-matrix white light-emitting material. Patent application text of application number 201010292829 "A single-matrix white light phosphor for deep ultraviolet LED and its preparation method" (application date: September 25, 2010, publication date: April 6, 2011, publication number: 102002363A) A single-matrix white light phosphor for LED is reported, but its excitation wavelength is in the deep ultraviolet range of 320nm-330nm, which requires a higher excitation light source.

Invention content:

The object of the present invention is to provide a single matrix silicon aluminophosphate fluorescent powder which can be excited by ultraviolet light and ultraviolet light and emit white light. The phosphor can be used as a luminescent powder for white LEDs excited by near-ultraviolet and blue light, or as a luminescent material for display devices excited by ultraviolet and violet light. the

The invention provides a dysprosium-thulium co-doped silicon aluminophosphate white light phosphor, the specific preparation steps are as follows: (1) according to the chemical formula A _3(1-xy) Al ₂ P ₂ Si ₂ O ₁₅ :Dy _3x ,Tm _3y , where A is one of Ca and Ba, 0.01≤x≤0.15, 0.01≤y≤0.15. Weigh the required amount of total raw materials: the total raw materials are one of calcium carbonate and barium carbonate, dysprosium oxide, thulium oxide, aluminum oxide, ammonium dihydrogen phosphate and silicon dioxide, and then weigh 3% to 5% of the total raw material mass. The flux H ₃ BO ₃ , grind and mix these components evenly; (2) Put the above mixture into a corundum crucible and place it in a high-temperature muffle furnace, the reaction temperature is 1300-1400°C, and the reaction time is 3-5 hours ; (3) After the sample is naturally lowered to room temperature with the muffle furnace, the sintered material is broken to the required particle size to obtain the desired product.

According to the present invention, the chemical formula A _3(1-xy) Al ₂ P ₂ Si ₂ O ₁₅ :Dy _3x , Tm _3y can be obtained, wherein A is one of Ca and Ba, 0.01≤x≤0.15, 0.01≤y≤0.15 Phosphor powder, which can be excited by ultraviolet and violet light. Under the excitation of a 350nm light source, the phosphor can emit white light, and with the change of the concentration of doped ions dysprosium and thulium, the light emission color changes within the white light range. Therefore, the phosphor powder of the present invention can be used as a luminescent powder for white LEDs, and can also be used as a luminescent material for preparing display devices excited by ultraviolet or violet light.

Description of drawings:

Figure 1 Excitation spectrum (dashed line) and emission spectrum (solid line) of dysprosium-thulium co-doped silicon aluminophosphate white phosphor

Figure 2 Color coordinates of dysprosium and thulium co-doped silicon aluminophosphate white phosphors

It can be seen from the luminescent spectrum of the solid line on the right side of Figure 1 that after adding thulium oxide, the emission of the blue light part is strengthened, and the color coordinates of Figure 2 show that the color coordinates of the example samples of the present invention are within the white range. the

Detailed ways:

Weigh the required amount of carbon calcium carbonate, barium carbonate, silicon dioxide, aluminum oxide, ammonium dihydrogen phosphate, dysprosium oxide and thulium oxide according to the chemical formula, wherein the purity of dysprosium oxide and thulium oxide is 99.99%. Among them, the number of moles of dysprosium and thulium substituted cations is between 0.01 and 0.15. Then weigh 3% to 5% of the fluxing agent boric acid at the beginning of the preparation of the total raw material mass (excluding fluxing solvent mass). They were ground in a mortar, mixed well, and filled into corundum crucibles. In the air, sinter at 1300-1400°C for 3-5 hours, and naturally drop to room temperature with the muffle furnace to obtain the desired product. the

The following examples are to further illustrate the process characteristics of the present invention without limiting the present invention. the

Example 1:

Weigh 1.581 grams of calcium carbonate (CaCO ₃ ), 0.656 grams of silicon dioxide (SiO ₂ ), 0.556 grams of aluminum oxide (Al ₂ O ₃ ), 1.256 grams of ammonium dihydrogen phosphate (NH ₄ H ₂ PO ₄ ), 1.256 grams of dysprosium oxide ( Dy ₂ O ₃ ) 0.031 g, thulium oxide (Tm ₂ O ₃ ) 0.032 g, 5% co-solvent H ₃ BO ₃ 0.211 g. Put the raw materials together in an agate mortar, grind and mix them thoroughly, put them into a corundum crucible, put them into a muffle furnace, heat them up to 1400°C and keep them warm for 5 hours, then take out the samples with the molecular formula Ca _2.94 Al ₂ P ₂ Si ₂ O ₁₅ : Dy _0.03, Tm _0.03 Calcium silicoaluminophosphate white light phosphor. Under 350nm light excitation, the color coordinates of the example sample are (0.33, 0.34).

Example 2:

Weigh 1.578 grams of calcium carbonate (CaCO ₃ ), 0.658 grams of silicon dioxide (SiO ₂ ), 0.559 grams of aluminum oxide (Al ₂ O ₃ ), 1.260 grams of ammonium dihydrogen phosphate (NH ₄ H ₂ PO ₄ ), 1.260 grams of dysprosium oxide ( Dy ₂ O ₃ ) 0.062 g and thulium oxide (Tm ₂ O ₃ ) 0.064 g, 5% co-solvent H ₃ BO ₃ was 0.209 g. Put the raw materials together in an agate mortar, grind and mix them thoroughly, put them into a corundum crucible, put them into a muffle furnace, heat them up to 1400°C and keep them warm for 5 hours. With the natural cooling of the furnace body, take out the sample and get the molecular formula Ca _2.88 Al ₂ P ₂ Si ₂ O ₁₅ : Dy _0.06, Tm _0.06 calcium aluminosilicate phosphate white light phosphor. Under 350nm light excitation, the color coordinates of the example sample are (0.32, 0.33).

Example 3:

Weigh 2.061 grams of barium carbonate (BaCO ₃ ), 0.435 grams of silicon dioxide (SiO ₂ ), 0.370 grams of aluminum oxide (Al ₂ O ₃ ), 0.834 grams of ammonium dihydrogen phosphate (NH ₄ H ₂ PO ₄ ), 0.834 grams of dysprosium oxide ( Dy ₂ O ₃ ) 0.041 g, thulium oxide (Tm ₂ O ₃ ) 0.042 g, 3% co-solvent H ₃ BO ₃ 0.113 g. Put the raw materials together in an agate mortar, grind and mix them thoroughly, put them into a corundum crucible, put them into a muffle furnace, heat them up to 1300°C and keep them warm for 4 hours. With the natural cooling of the furnace body, take out the samples and get the molecular formula Ba _2.88 Al ₂ P ₂ Si ₂ O ₁₅ : Dy _0.06, Tm _0.06 calcium aluminosilicate phosphate white light phosphor. Under 350nm light excitation, the color coordinates of the example sample are (0.33, 0.35).

Example 4:

Weigh 1.523 grams of calcium carbonate (CaCO ₃ ), 0.648 grams of silicon dioxide (SiO ₂ ), 0.551 grams of aluminum oxide (Al ₂ O ₃ ), 1.243 grams of ammonium dihydrogen phosphate (NH ₄ H ₂ PO ₄ ), 1.243 grams of dysprosium oxide ( Dy ₂ O ₃ ) 0.061 g, thulium oxide (Tm ₂ O ₃ ) 0.125 g, and 5% co-solvent H ₃ BO ₃ 0.207 g. Put the raw materials together in an agate mortar, grind and mix them thoroughly, put them into a corundum crucible, put them into a muffle furnace, heat them up to 1400°C and keep them warm for 5 hours. With the natural cooling of the furnace body, take out the samples and get the molecular formula Ca _2.82 Al ₂ P ₂ Si ₂ O ₁₅ : Dy _0.06, Tm _0.12 calcium aluminosilicate phosphate white light phosphor. Under 350nm light excitation, the color coordinates of the example sample are (0.31, 0.30).

Example 5:

Weigh 2.013 grams of barium carbonate (BaCO ₃ ), 0.434 grams of silicon dioxide (SiO ₂ ), 0.369 grams of aluminum oxide (Al ₂ O ₃ ), 0.832 grams of ammonium dihydrogen phosphate (NH ₄ H ₂ PO ₄ ), 0.832 grams of dysprosium oxide ( Dy ₂ O ₃ ) 0.041 g, thulium oxide (Tm ₂ O ₃ ) 0.084 g, 3% co-solvent H ₃ BO ₃ 0.109 g. Put the raw materials together in an agate mortar, grind and mix them thoroughly, put them into a corundum crucible, put them into a muffle furnace, heat them up to 1300°C and keep them warm for 4 hours. With the natural cooling of the furnace body, take out the samples and get the molecular formula Ba _2.82 Al ₂ P ₂ Si ₂ O ₁₅ : Dy _0.06, Tm _0.12 calcium aluminosilicate phosphate white light phosphor. Under 350nm light excitation, the color coordinates of the example sample are (0.31, 0.29).

Example 6:

Weigh 0.976 grams of calcium carbonate (CaCO ₃ ), 0.558 grams of silicon dioxide (SiO ₂ ), 0.474 grams of aluminum oxide (Al ₂ O ₃ ), 1.069 grams of ammonium dihydrogen phosphate (NH ₄ H ₂ PO ₄ ), 1.069 grams of dysprosium oxide ( Dy ₂ O ₃ ) 0.390 g, thulium oxide (Tm ₂ O ₃ ) 0.404 g, 5% co-solvent H ₃ BO ₃ 0.194 g. Put the raw materials together in an agate mortar, grind and mix them thoroughly, put them into a corundum crucible, put them into a muffle furnace, heat them up to 1400°C and keep them warm for 5 hours. With the natural cooling of the furnace body, take out the samples and get the molecular formula Ca _2.10 Al ₂ P ₂ Si ₂ O ₁₅ : Dy _0.45, Tm _0.45 calcium aluminosilicate phosphate white light phosphor. Under 350nm light excitation, the color coordinates of the example sample are (0.25, 0.27).

Example 7:

Weigh 1.463 grams of barium carbonate (BaCO ₃ ), 0.483 grams of silicon dioxide (SiO ₂ ), 0.411 grams of aluminum oxide (Al ₂ O ₃ ), 0.926 grams of ammonium dihydrogen phosphate (NH ₄ H ₂ PO ₄ ), 0.926 grams of dysprosium oxide ( Dy ₂ O ₃ ) 0.338 g and thulium oxide (Tm ₂ O ₃ ) 0.350 g, 3% co-solvent H ₃ BO ₃ 0.103 g. Put the raw materials together in an agate mortar, grind and mix them thoroughly, put them into a corundum crucible, put them into a muffle furnace, heat them up to 1300°C and keep them warm for 4 hours. With the natural cooling of the furnace body, take out the samples and get the molecular formula Ba _2.10 Al ₂ P ₂ Si ₂ O ₁₅ : Dy _0.45, Tm _0.45 calcium silicoaluminophosphate white light phosphor. Under 350nm light excitation, the color coordinates of the example sample are (0.24, 0.26).

Claims (3)

1. a dysprosium thulium is mixed the Silicophosphoaluminaand white emitting fluorescent powder altogether, it is characterized in that the consisting of of this fluorescent material: A _{3 (1-x-y)}Al ₂P ₂Si ₂O ₁₅: Dy _3x, Tm _3y, wherein, A is Ca, one of Ba, 0.01≤x≤0.15,0.01≤y≤0.15.

2. the preparation method who mixes altogether the Silicophosphoaluminaand white emitting fluorescent powder according to a kind of dysprosium thulium claimed in claim 1, it is characterized in that concrete preparation process is as follows: (1) presses chemical formula A _{3 (1-x-y)}Al ₂P ₂Si ₂O ₁₅: Dy _3x, Tm _3y, wherein, A is Ca, one of Ba, 0.01≤x≤0.15,0.01≤y≤0.15; Take by weighing the total raw material of requirement: total raw material is one of calcium carbonate and barium carbonate, dysprosium oxide, trioxide, aluminum oxide, primary ammonium phosphate and silicon-dioxide, takes by weighing the fusing assistant H of total raw material quality 3%～5% again ₃BO ₃, with these former abrasive lappings, evenly mixed; (2) said mixture is packed into corundum crucible, and place in the retort furnace, temperature of reaction is 1300～1400 ℃, the reaction times is 3～5 hours; (3) after sample drops to room temperature naturally with retort furnace, namely obtain required product.

3. in accordance with the method for claim 2, it is characterized in that described dysprosium oxide and trioxide, molecular formula is Dy ₂O ₃And Tm ₂O ₃, purity all is more than 99.99%.

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