CN103773367B - Fluorescent material for white light LED (Light Emitting Diode) and preparation method thereof - Google Patents

Abstract

The invention discloses a fluorescent material for white light LED, the chemical expression of which is: AM ^Ⅰ M ^Ⅱ M ^Ⅲ O ₆ : cR, c represents the ratio of the amount of R to AM ^Ⅰ M ^Ⅱ M ^Ⅲ O ₆ is c: 1, and 0.001 ≤ c ≤ 0.75. A is one of Na, Li, K, Ag or a combination thereof; M One or a combination of Ca, Mg, Sr, Ba, Zn, Pb; M ^Ⅱ is one or a combination of Ti, Zr, Si, Ge; M ^Ⅲ is one of Nb, Ta, V Or a combination thereof; R is one of Pr, Sm, Eu, Tb, Dy, Mn, Bi or a combination thereof. The excitation band of the fluorescent material covers the range of 200-500 nm, the emission band is narrow, that is, the half maximum width is narrow, and it can emit visible light after being excited by ultraviolet, near ultraviolet and blue light. It can be combined with other appropriate fluorescent materials of various colors to manufacture white light emitting devices. . The invention has cheap and easy-to-obtain raw materials and simple manufacturing process, and is an ideal fluorescent candidate material for white LEDs. The invention also discloses a preparation method of the fluorescent material used for the white light LED.

Description

Fluorescent material and preparation method for white light LED

technical field

The invention belongs to the technical field of fluorescent material science, and in particular relates to a fluorescent material for white LEDs that can be effectively excited by ultraviolet, near ultraviolet and blue light and a preparation method.

Background technique

White LED is a light-emitting diode that emits white light, and white light is composed of light of multiple wavelengths. It has the advantages of high efficiency, low energy consumption, low-voltage power supply, strong applicability, high stability, short response time, no pollution to the environment, and multi-color luminescence. Since the white LED was developed in 1977, after decades of development, the white LED has made great progress in many aspects such as luminous efficiency. Nowadays it has been widely used in our life, such as car lights, lighting, LCD display and screen backlight. However, it is still mainly used for screen display at present, and due to its slightly higher manufacturing cost and sensitivity to temperature requirements, certain improvements are still needed to replace existing light sources. White light LEDs are usually formed by two methods. One is to form white light through the combination of "blue light technology" and phosphor powder. According to people's research on visible light, white light that can be seen by human eyes requires at least a mixture of two kinds of light, that is, blue light. and yellow light or blue light, green light and red light mode. The above two modes of white light require blue light, so the method of absorbing blue light has become the key to making white light, the so-called blue light technology; the second is a method of mixing multiple monochromatic lights, that is, emitting light through LEDs of different colors Diodes generate white light by utilizing their different characteristics of driving voltage, luminous output, temperature characteristics, and lifetime. Currently, blue LEDs and YAG phosphors are generally used to produce white LEDs. Although the manufacturing process is relatively simple and the technical cost is low, its color rendering index is relatively low. Theoretically, white LEDs with any color temperature and higher color rendering index can be obtained by using near-ultraviolet LEDs plus RGB three-color phosphors, but the technology for ultraviolet LED phosphors is not yet mature. Moreover, some fluorescent materials that can be applied to white light LEDs currently have a narrow absorption wavelength range, resulting in low conversion efficiency, and some have poor stability. For example, although the excitation bandwidth of the Eu-doped fluorescent material containing N is wide, the emission band is also wide, which cannot meet the requirements of high-performance devices. Therefore, the development of a new type of high-efficiency fluorescent material for background light has certain research and practical application value.

Contents of the invention

The purpose of the present invention is to solve the problem that some fluorescent materials currently used in white light LEDs have narrow absorption wavelength ranges resulting in low conversion efficiency and poor stability. It is also wide and cannot meet the needs of high-performance devices. Instead, it provides an excitation band covering the range of 200-500 nm, a narrow emission band, that is, a narrow half-maximum width, and can be effectively excited by ultraviolet, near-ultraviolet and blue light. Fluorescent materials for white LEDs.

The object of the present invention is also to provide a method for preparing a fluorescent material for white LEDs.

To realize the object of the present invention, the present invention takes the following technical solutions,

A fluorescent material for white light LEDs, the chemical expression of which is AM ^I M ^Ⅱ M ^Ⅲ O ₆ :cR, wherein said A is one of Na, Li, K, Ag or a combination thereof;

^MI is one or a combination of Ca, Mg, Sr, Ba, Zn, Pb;

M ^Ⅱ is one of Ti, Zr, Si, Ge or a combination thereof;

M ^Ⅲ is one or a combination of Nb, Ta, V;

O is oxygen element;

c means that the ratio of the amount of R to AM ^Ⅰ M ^Ⅱ M ^Ⅲ O ₆ is c:1, and 0.001 ≤ c ≤ 0.75;

R is one of Pr, Sm, Eu, Tb, Dy, Mn, Bi or a combination thereof.

The fluorescent material is further Na _1-x A _x CaTiNbO ₆ :cPr (A=Li, K or Ag, 0 ≤ x ≤ 1),

NaCa _1-x M ^I _x TiNbO ₆ :cPr(M =Mg, Sr, Ba, Zn or Pb, 0 ≤ x ≤ 1),

NaCaTi _1-x M ^Ⅱ _x NbO ₆ :cPr (M ^Ⅱ =Zr, Si or Ge, 0 ≤ x ≤ 1),

NaCaTiNb _1-x M ^Ⅲ _x O ₆ :cPr (M ^Ⅲ =Ta, or V, 0 ≤ x ≤ 1),

Or NaCaTiNbO ₆ : cR ₁ , cR ₂ (R ₁ , R ₂ =Pr, Sm, Eu, Tb, Dy, Mn or Bi).

This type of phosphor can realize visible light emission including red light, yellow and white light and other visible light, such as NaCaTiTaO ₆ : 0.005Pr has red light emission, NaCaTiNbO ₆ : 0.01Dy has yellow and white light emission, etc. Such phosphors include but are not limited to , the following preferred fluorescent materials: LiCaTiNbO ₆ : 0.005Pr, NaCaTiNbO ₆ : 0.005Pr, KCaTiNbO ₆ : 0.005Pr, Na _0.99 Li _0.01 CaTiNbO ₆ : 0.005Pr, Na _0.9 Ag _0.1 CaTiNbO ₆ Ti : 0.005Pr, _NaM6 0.005pr, NASRTININ: 0.005PR, Nabatinbo ₆ : 0.005pr, Nazntinbo ₆ : 0.005pr, NACA _0.99 MG _0.01 Tinbo ₆ : 0.005pr, NACA _0.99 BA _0.01 Tinbo ₆ : _0.99 SR _0.01 Tinbo ₆ : 0.01 _Tinbo , NACA _0.99 ZN ₀₁ Tinbo ₆ : 0.005pr, NACA _0.99 PB _0.01 Tinbo ₆ : 0.005pr, NacazRNBO 6: 0.005pr, NacAgenbo ₆ : 0.005pr _{6: 0.005pr 6: 0.005PR, NACATINBO 6 :} 0.005PR, NACATINBO ₆ : 0.005PR, _{NACatinbo . _ _ _ _ _}

A method for preparing a fluorescent material for a white light LED as described above, comprising the following steps:

a. Dosing according to any one of the chemical expressions of the fluorescent material composition according to the matrix material and the activator R used;

b. Put the raw materials prepared in step a into a corundum crucible with a cover after being finely ground for 30 minutes, place them in a calciner for calcination, the calcination temperature is 1100 ~ 1300 ° C, and the firing time is 7 ~ 10 hours, after Cool, crush and grind again to obtain the fluorescent material.

A method for preparing a fluorescent material for white light LEDs, further specifically comprising the following steps:

a, the oxide or carbonate containing A, containing M Oxides or carbonates, oxides or carbonates containing M ^Ⅱ , oxides or carbonates containing M ^Ⅲ , oxides or carbonates containing R, according to the composition of the fluorescent material in the chemical expression Any one of the mixed ingredients;

b. Grind and mix the mixed ingredients in the above step a, put them into a corundum crucible with a cover, place them in a calciner for calcining, the calcining temperature is 1100 ~ 1300 ° C, and the firing time is 7 ~ 10 hours. After cooling, crushing and grinding again, the fluorescent material is obtained.

Experimental scheme of the present invention is briefly described as follows:

1. Preparation of Materials

The raw materials of the fluorescent material are inorganic salts of various elements, including but not limited to oxides, carbonates and nitrates, all of which are obtained by high-temperature solid-phase method. The specific dose is calculated by the chemical formula of the fluorescent material. According to the difference of the basic material of the fluorescent powder and the activator, we choose to calcinate at the melting point of various raw materials for 10 minutes, the firing temperature is 1100 ~ 1300 ° C, and the preparation time is 7 ~ 10 minutes. Hours, the process includes weighing, calcining, and then the formed crystals are cooled, crushed and then carefully ground to obtain the fluorescent material of the present invention.

2. Performance evaluation

Optical absorption and emission properties: the fluorescent powder sample obtained in the present invention tests its ultraviolet-visible absorption and emission spectrum on the F-7000 FL Spectrophotometer of Hitachi, Japan. In a word, the present invention relates to converting ultraviolet light, near ultraviolet light and blue light into visible light with higher brightness, which can be used in white LED fluorescent materials. The fluorescent material of the present invention can be used for white light LEDs and related display and lighting devices. The raw material of the invention is simple and easy to obtain, and the manufacturing process is simple, so it is an ideal candidate material for white light LED phosphor powder.

Description of drawings

Figure 1 shows the excitation spectrum (λ _em =615 nm) and emission spectrum (λ _ex =357 nm) of NaCaTiNbO ₆ :0.01Pr, NaCaTiNbO ₆ :0.01Pr,0.01Bi materials in Example 1 of the present invention.

Fig. 2 is the excitation spectrum (λ _em =567 nm _; λ _em =602 nm) and emission spectrum (λ _ex =408 nm) of the NaCaTiNbO ₆ :0.02Sm material in Example 5 of the present invention.

Fig. 3 is the excitation spectrum (λ _em =617 nm) and emission spectrum (λ _ex =398 nm) of the NaCaTiNbO ₆ :0.07Eu material in Example 6 of the present invention.

Fig. 4 is the excitation spectrum (λ _em =485 nm _; λ _em =576 nm) and emission spectrum (λ _ex =390 nm) of the NaCaTiNbO ₆ :0.01Dy material in Example 7 of the present invention.

Fig. 5 shows the excitation spectrum (λ _em = 615 nm) and emission spectrum (λ _ex = 357 nm) of Li _0.01 Na _0.99 CaTiNbO ₆ :0.005Pr material in Example 15 of the present invention.

Fig. 6 is the excitation spectrum (λ _em = 613 nm) and emission spectrum (λ _ex = 343 nm) of NaCa _0.495 Mg _0.5 TiNbO ₆ :0.005Pr material in Example 16 of the present invention.

Fig. 7 shows the excitation spectrum (λ _em = 613 nm) and emission spectrum (λ _ex = 276 nm) of NaCa _0.495 Ba _0.5 TiNbO ₆ :0.005Pr material in Example 17 of the present invention.

Fig. 8 shows the excitation spectrum (λ _em = 615 nm) and emission spectrum (λ _ex = 344 nm) of NaCaTi _0.9 Zr _0.1 NbO ₆ :0.005Pr material in Example 18 of the present invention.

Fig. 9 shows the excitation spectrum (λ _em = 615 nm) and emission spectrum (λ _ex = 358 nm) of NaCaTiNb _0.8 Ta _0.2 O ₆ :0.005Pr material in Example 19 of the present invention.

Detailed ways

Embodiments of the present invention are described below, but the present invention is by no means limited to the embodiments

Example 1:

 Weigh the raw materials Na ₂ CO ₃ , CaCO ₃ , TiO ₂ , Nb ₂ O ₅ , and Pr ₂ O ₃ according to the stoichiometric ratio of NaCaTiNbO ₆ :0.01Pr, and mix them uniformly in a mortar for 30 minutes. The body was put into a corundum crucible with a cover and then put into a calcination furnace for calcination at 825°C (melting point of CaCO ₃ ) and 851°C (melting point of Na ₂ CO ₃ ) for 10 minutes respectively, and at 1300°C for 2 hours. After cooling and fine grinding, NaCaTiNbO ₆ :0.01Pr fluorescent material is obtained. The test results are shown in Figure 1.

Example 2:

Weigh the raw materials Na ₂ CO ₃ , CaCO ₃ , TiO ₂ , Nb ₂ O ₅ , Pr ₂ O ₃ , and Bi ₂ O ₃ according to the stoichiometric ratio of NaCaTiNbO ₆ : 0.01Pr, 0.01Bi, and mix them uniformly in a mortar , with a duration of 30 minutes, the resulting fragments were put into a corundum crucible with a lid and then put into a calciner for calcination, at 851°C (Na ₂ CO ₃ melting point), at 825°C (CaCO ₃ melting point) for 10 minutes, at 1300°C C calcined for 2 hours. After cooling and fine grinding, NaBaTiNbO ₆ : 0.01Pr, 0.01Bi fluorescent material is obtained. The test results are shown in Figure 1.

Example 3:

Weigh the raw materials Li ₂ CO ₃ , CaCO ₃ , TiO ₂ , Nb ₂ O ₅ , and Pr ₂ O ₃ according to the stoichiometric ratio of LiCaTiNbO ₆ :0.005Pr, and mix them uniformly in a mortar for 30 minutes. The body was put into a corundum crucible with a cover and then put into a calcination furnace for calcination, calcination at 618°C (melting point of Li ₂ CO ₃ ), calcination at 825°C (melting point of CaCO ₃ ) for 10 minutes, and calcination at 1200°C for 2 hours. After cooling and fine grinding, LiCaTiNbO ₆ :0.005Pr fluorescent material is obtained. It efficiently emits red light under ultraviolet excitation.

Example 4:

Weigh the raw materials K ₂ CO ₃ , CaCO ₃ , TiO ₂ , Nb ₂ O ₅ , and Pr ₂ O ₃ according to the stoichiometric ratio of KCaTiNbO ₆ :0.005Pr, and mix them uniformly in a mortar for 30 minutes. The body was put into a corundum crucible with a cover and then put into a calcination furnace for calcination at 825°C (melting point of CaCO ₃ ) and 891°C (melting point of K ₂ CO ₃ ) for 10 minutes respectively, and at 1300°C for 2 hours. After cooling and fine grinding, KCaTiNbO ₆ :0.005Pr fluorescent material is obtained. It efficiently emits red light under ultraviolet excitation.

Example 5:

Weigh the raw materials Na ₂ CO ₃ , CaCO ₃ , TiO ₂ , Nb ₂ O ₅ , and Sm ₂ O ₃ according to the stoichiometric ratio of NaCaTiNbO ₆ :0.02Sm, and mix them uniformly in a mortar for 30 minutes. The body was put into a corundum crucible with a cover and then put into a calcination furnace for calcination at 825°C (melting point of CaCO ₃ ) and 851°C (melting point of Na ₂ CO ₃ ) for 10 minutes respectively, and at 1300°C for 2 hours. After cooling and fine grinding, NaCaTiNbO ₆ :0.02Sm fluorescent material is obtained. The test results are shown in Figure 2.

Embodiment 6:

Weigh the raw materials Na ₂ CO ₃ , CaCO ₃ , TiO ₂ , Nb ₂ O ₅ , and Eu ₂ O ₃ according to the stoichiometric ratio of NaCaTiNbO ₆ :0.07Eu, and mix them uniformly in a mortar for 30 minutes. The body was put into a corundum crucible with a cover and then put into a calciner for calcination at 851°C (melting point of Na ₂ CO ₃ ), calcination at 825°C (melting point of CaCO ₃ ) for 10 minutes, and calcination at 1300°C for 2 hours. After cooling and fine grinding, NaCaTiNbO ₆ :0.07Eu fluorescent material is obtained. The test results are shown in Figure 3.

Embodiment 7:

Weigh the raw materials Na ₂ CO ₃ , CaCO ₃ , TiO ₂ , Nb ₂ O ₅ , and Dy ₂ O ₃ according to the stoichiometric ratio of NaCaTiNbO ₆ : 0.01Dy, and mix them uniformly in a mortar for 30 minutes. The body was put into a corundum crucible with a cover and then put into a calciner for calcination at 851°C (melting point of Na ₂ CO ₃ ), calcination at 825°C (melting point of CaCO ₃ ) for 10 minutes, and calcination at 1300°C for 2 hours. After cooling and fine grinding, NaCaTiNbO ₆ :0.01Dy fluorescent material is obtained. The test results are shown in Figure 4.

Embodiment 8:

Weigh the raw materials Na ₂ CO ₃ , CaCO ₃ , ZrO ₂ , Nb ₂ O ₅ , and Pr ₂ O ₃ according to the stoichiometric ratio of NaCaZrNbO ₆ :0.005Pr, and mix them uniformly in a mortar for 30 minutes. The body was put into a corundum crucible with a cover and then put into a calciner for calcination at 851°C (melting point of Na ₂ CO ₃ ), calcination at 825°C (melting point of CaCO ₃ ) for 10 minutes, and calcination at 1300°C for 2 hours. After cooling and fine grinding, NaCaZrNbO ₆ :0.005Pr fluorescent material is obtained. It efficiently emits red light under ultraviolet excitation.

Embodiment 9:

Weigh the raw materials Na ₂ CO ₃ , MgO, TiO2, Nb ₂ O ₅ , and Pr ₂ O ₃ according to the stoichiometric ratio of NaMgTiNbO ₆ :0.005Pr, and mix them uniformly in a mortar for 30 minutes. Put it into a corundum crucible with a cover and put it into a calcination furnace for calcination at 851°C (Na ₂ CO ₃ melting point) for 10 minutes and 1100°C for 2 hours. After cooling and fine grinding, NaMgTiNbO ₆ :0.005Pr fluorescent material is obtained. It efficiently emits red light under ultraviolet excitation.

Example 10:

Weigh the raw materials Na ₂ CO ₃ , ZnO, TiO ₂ , Nb ₂ O ₅ , and Pr ₂ O ₃ according to the NaZnTiNbO ₆ :0.005Pr stoichiometric ratio, and mix them uniformly in a mortar for 30 minutes. Put it into a corundum crucible with a cover and put it into a calciner for calcination at 851°C (Na ₂ CO ₃ melting point) for 10 minutes, and at 1100°C for 2 hours. After cooling and fine grinding, NaZnTiNbO ₆ :0.005Pr fluorescent material is obtained. It efficiently emits red light under ultraviolet excitation.

Example 11:

Weigh the raw materials Na ₂ CO ₃ , SrCO ₃ , TiO ₂ , Nb ₂ O ₅ , and Pr ₂ O ₃ according to the stoichiometric ratio of NaSrTiNbO ₆ :0.005Pr, and mix them uniformly in a mortar for 30 minutes. The body was put into a corundum crucible with a cover and then put into a calcination furnace for calcination at 851°C (Na ₂ CO ₃ melting point), at 1100°C (SrCO ₃ melting point) for 10 minutes, and at 1300°C for 2 hours. After cooling and fine grinding, NaSrTiNbO ₆ :0.005Pr fluorescent material is obtained. It efficiently emits red light under ultraviolet excitation.

Example 12:

Weigh the raw materials Na ₂ CO ₃ , CaCO ₃ , SiO ₂ , Nb ₂ O ₅ , and Pr ₂ O ₃ according to the stoichiometric ratio of NaCaSiNbO ₆ :0.005Pr, and mix them uniformly in a mortar for 30 minutes. The body was put into a corundum crucible with a cover and then put into a calciner for calcination at 851°C (Na ₂ CO ₃ melting point), at 825°C (CaCO ₃ melting point) for 10 minutes, and at 1100°C for 2 hours. After cooling and fine grinding, NaCaSiNbO ₆ :0.005Pr fluorescent material is obtained. It efficiently emits red light under ultraviolet excitation.

Example 13:

 The raw materials Na ₂ CO ₃ , CaCO ₃ , GeO ₂ , Nb ₂ O ₅ , and Pr ₂ O ₃ were weighed according to the stoichiometric ratio of NaCa GeNbO ₆ :0.005Pr, and uniformly mixed in a mortar for 30 minutes, and the obtained Separately put into a corundum crucible with a cover and then put into a calciner for calcination, calcination at 851°C (Na ₂ CO ₃ melting point), 825°C (CaCO ₃ melting point) for 10 minutes, and 1100°C for 2 hours. After cooling and fine grinding, NaCa GeNbO ₆ :0.005Pr fluorescent material is obtained. It efficiently emits red light under ultraviolet excitation.

Example 14:

Weigh the raw materials Na ₂ CO ₃ , CaCO ₃ , TiO ₂ , Ta ₂ O ₅ , and Pr ₂ O ₃ according to the stoichiometric ratio of NaCaTiTaO ₆ :0.005Pr, and mix them uniformly in a mortar for 30 minutes. The body was put into a corundum crucible with a cover and then put into a calciner for calcination. Calcined at 851°C (melting point of Na ₂ CO ₃ ), calcination at 825°C (melting point of CaCO ₃ ), and 1115°C (melting point of GeO ₂ ) for 10 minutes respectively. Calcined at 1300°C for 2 hours. After cooling and fine grinding, NaCaTiTaO ₆ :0.005Pr fluorescent material is obtained. It efficiently emits red light under ultraviolet excitation.

Example 15:

Weigh the raw materials Li ₂ CO ₃ , Na ₂ CO ₃ , CaCO ₃ , TiO ₂ , Nb ₂ O ₅ , and Pr ₂ O ₃ according to the stoichiometric ratio of Li _0.01 Na _0.99 CaTiNbO ₆ : 0.005Pr, and carry out uniform Mixed for 30 minutes, the resulting fraction was put into a corundum crucible with a lid and then put into a calciner for calcination at 618°C (Li ₂ CO ₃ melting point), 825°C (CaCO ₃ melting point), 851°C (Na ₂ CO ₃ melting point) were calcined for 10 minutes at 1300 °C for 2 hours, respectively. After cooling and fine grinding, Li _0.01 Na _0.99 CaTiNbO ₆ :0.005Pr fluorescent material is obtained. The test results are shown in Figure 5.

Example 16:

Weigh the raw materials Na ₂ CO ₃ , CaCO ₃ , MgO, TiO ₂ , Nb ₂ O ₅ , and Pr ₂ O ₃ according to the stoichiometric ratio of NaCa _0.495 Mg _0.5 TiNbO ₆ : 0.005Pr, and mix them uniformly in a mortar. For 30 minutes, the obtained fractions were put into a corundum crucible with a cover and then put into a calciner for calcination. Calcined at 825°C (melting point of CaCO ₃ ) and 851°C (melting point of Na ₂ CO ₃ ) for 10 minutes respectively, and at 1300°C Calcined for 2 hours. After cooling and fine grinding, NaCa _0.495 Mg _0.5 TiNbO ₆ :0.005Pr fluorescent material is obtained. The test results are shown in Figure 6.

Example 17:

Weigh the raw materials Na ₂ CO ₃ , CaCO ₃ , BaCO ₃ , TiO ₂ , Nb ₂ O ₅ , and Pr ₂ O ₃ according to the stoichiometric ratio of NaCa _0.495 Ba _0.5 TiNbO ₆ :0.005Pr, and mix them uniformly in a mortar. The duration is 30 minutes, and the obtained fractions are put into a corundum crucible with a cover and then put into a calciner for calcination, and calcined at 825°C (melting point of CaCO ₃ ) and 851°C (melting point of Na ₂ CO ₃ ) for 10 minutes respectively, and at 1300°C C calcined for 2 hours. After cooling and fine grinding, NaCa _0.495 Ba _0.5 TiNbO ₆ :0.005Pr fluorescent material is obtained. The test results are shown in Figure 7.

Example 18:

Weigh the raw materials Na ₂ CO ₃ , CaCO ₃ , TiO ₂ , ZrO ₂ , Nb ₂ O ₅ , and Pr ₂ O ₃ according to the stoichiometric ratio of NaCaTi _0.9 Zr _0.1 NbO ₆ :0.005Pr, and mix them uniformly in a mortar. The duration is 30 minutes, and the obtained fractions are put into a corundum crucible with a cover and then put into a calciner for calcination, and calcined at 825°C (melting point of CaCO ₃ ) and 851°C (melting point of Na ₂ CO ₃ ) for 10 minutes respectively, and at 1300°C C calcined for 2 hours. After cooling and fine grinding, NaCaTi _0.9 Zr _0.1 NbO ₆ :0.005Pr fluorescent material is obtained. The test results are shown in Figure 8.

Example 19:

Weigh the raw materials Na ₂ CO ₃ , CaCO ₃ , TiO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ , and Pr ₂ O ₃ according to the stoichiometric ratio of NaCaTiNb _0.8 Ta _0.2 O ₆ : 0.005Pr, and uniformly Mixed for 30 minutes, the obtained fraction was put into a corundum crucible with a cover and then put into a calciner for calcination, and calcined at 825°C (CaCO ₃ melting point) and 851°C (Na ₂ CO ₃ melting point) for 10 minutes, respectively. Calcined at 1300°C for 2 hours. After cooling and fine grinding, NaCaTiNb _0.8 Ta _0.2 O ₆ :0.005Pr fluorescent material is obtained. The test results are shown in Figure 9.

Claims (5)

1., for a fluorescent material for white light LEDs, its chemical expression is AM m ^iIm ^iIIo ₆: cR, wherein,

Described A is one in Na, Li, K, Ag or its combination;

M for Ca, M g, the one in Sr, Ba, Zn, Pb or its combination;

M ^iIfor the one in Ti, Zr, Si, Ge or its combination;

M ^iIIfor the one in Nb, Ta, V or its combination;

O is oxygen element;

C represents R and AM ⁱm ^iIm ^iIIo ₆the ratio of amount of substance be c:1, and 0.001≤c≤0.75;

R is one in Pr, Sm, Eu, Tb, Dy, Mn, Bi or its combination.

2. a kind of fluorescent material for white light LEDs according to claim 1, is characterized in that described fluorescent material is Na _1-xa _xcaTiNbO ₆: cPr, wherein A=Li, K or Ag, 0≤x≤1;

NaCa _1-xm _xtiNbO ₆: cPr, wherein M =Mg, Sr, Ba, Zn or Pb, 0≤x≤1;

NaCaTiNb _1-xm ^iII _xo ₆: cPr, wherein M ^iII=Ta or V, 0≤x≤1;

Or NaCaTiNbO ₆: cR ₁, cR ₂, wherein R ₁, R ₂=Pr, Sm, Eu, Tb, Dy, Mn or Bi.

3. a kind of fluorescent material for white light LEDs according to claim 1, is characterized in that described fluorescent material is one of following: LiCaTiNbO ₆: 0.005Pr, NaCaTiNbO ₆: 0.01Pr, KCaTiNbO ₆: 0.005Pr, Na _0.99li _0.01caTiNbO ₆: 0.005Pr, NaMgTiNbO ₆: 0.005Pr, NaSrTiNbO ₆: 0.005Pr, NaZnTiNbO ₆: 0.005Pr, NaCaZrNbO ₆: 0.005Pr, NaCaGeNbO ₆: 0.005Pr, NaCaSiNbO ₆: 0.005Pr, NaCaTiTaO ₆: 0.005Pr, NaCaTiNbO ₆: 0.02Sm, NaCaTiNbO6:0.07Eu, NaCaTiNbO6:0.01Dy, NaCaTiNbO6:0.01Pr, 0.01Bi, NaCa0.495Mg0.5TiNbO6:0.005Pr, NaCa0.495Ba0.5TiNbO6:0.005Pr, NaCaTi0.9Zr0.1NbO6:0.005Pr, NaCaTiNb0.8Ta0.2O6:0.005Pr.

4., as claimed in claim 1 for a preparation method for the fluorescent material of white light LEDs, comprise the following steps:

A, to prepare burden by any one in described fluorescent material composition chemical expression according to the activator of substrate material and use;

B, load joining raw material in step a after fine grinding in corundum crucible with cover through 30 minutes, be placed in calcining furnace and calcine, calcining temperature is 1100 ~ 1300 ° of C, and the firing time is 7 ~ 10 hours, by cooling, broken, and grinding obtains this fluorescent material again.

5. the preparation method of a kind of fluorescent material for white light LEDs according to claim 4, comprises the following steps:

A, will containing the oxide compound of A or carbonate, containing M oxide compound or carbonate, containing M ^iIoxide compound or carbonate, containing M ^iIIoxide compound or carbonate, carry out mix containing the oxide compound of R or carbonate according to any one in described fluorescent material composition chemical expression;

B, the mix porphyrize by above-mentioned a step, mixing, load in corundum crucible with cover, be placed in calcining furnace and calcine, and calcining temperature is 1100 ~ 1300 ° of C, and the firing time is 7 ~ 10 hours, by cooling, broken, and grinding obtains this fluorescent material again.