TWI585189B - Wavelength converting material - Google Patents

Description

Wavelength converting substance

The present invention discloses a wavelength converting substance that can be excited to emit a second light having a second wavelength range and a second dominant wavelength, wherein the second dominant wavelength is between 480 nm and 540 nm.

Since the incandescent lamp, the light-emitting diode (LED) has replaced the traditional lighting fixtures in various lighting applications because of its advantages of energy saving, environmental protection, long life, small size, etc. LEDs that emit white light are the focus of development for companies.

Among the related lighting technologies, the yellow-light yttrium aluminum garnet (YAG) aluminate phosphor powder combined with the blue light-emitting diode composed of indium gallium nitride has been used as a precedent for high-efficiency white light source. . There are other examples of using a blue LED as a light source, using a phosphor powder made of Cerium-doped yttrium aluminum garnet, which is doped with a rare earth element, and a blue LED to produce yellow fluorescent light, followed by an excited yellow color. A white light-emitting diode (WLED) that combines fluorescent light and blue light to produce white light. However, in the phosphor used in the above technique, the emission spectrum of cerium (Ce ³⁺ ) ions does not have continuous spectral properties, and the color rendering index (Ra) is poor (Ra < 80), which is difficult to satisfy the low color temperature for white light in daily use. The lighting needs, while the poor luminous efficiency is also an urgent problem to be overcome. With the advancement of LED technology, the use of near-ultraviolet light as the excitation source and the phosphor powder of red, green and blue has become the development direction of white LED in recent years. According to such a principle, a green fluorescent powder containing cerium and lanthanum is combined with a solid solution containing cerium and citrate and aluminate, and a phosphor powder of Sr ₃ AlO ₄ F and GdSr ₂ AlO ₅ solid solution. put forward. In addition, there is also a fluorescent material using oxyfluoride as a fluorescent powder, the composition comprising at least one element selected from the group consisting of alkaline earth and transition metal IIB, and at least one halogen and one or more selected from transition elements. The material, and comprising at least one substance selected from the group consisting of lanthanides, causes the fluorescent material to be excited to emit yellow light.

In addition, the light-emitting element having the above-mentioned fluorescent material may be further combined with other elements to form a light-emitting apparatus; wherein the light-emitting device comprises a sub-mount having at least one circuit. At least one solder is disposed on the secondary carrier, wherein the light-emitting component is bonded and fixed to the secondary carrier by the solder, and the substrate of the light-emitting component is electrically connected to the circuit on the secondary carrier; and an electrical connection structure And electrically connecting the electrode of the light-emitting element and the circuit on the secondary carrier; wherein the secondary carrier may be a lead frame or a large-sized mounting substrate to facilitate circuit planning of the light-emitting device and improve the circuit thereof heat radiation.

The present invention discloses a wavelength converting substance that can be excited to emit a second light having a second wavelength range and a second dominant wavelength, wherein the second dominant wavelength is between 480 nm and 540 nm, and the wavelength converting substance disclosed in the present invention The chemical formula is (A _2-xy M _y )Al ₃ O ₆ R: x D, where 0<x≦0.3 and 0≦y≦2, wherein the A and M systems comprise a substance selected from the group consisting of alkaline earth elements, R It contains a halogen element, and the D system contains a divalent rare earth element.

The present invention discloses a wavelength converting substance comprising an alkaline earth metal and a halogen aluminate compound which can be excited to emit a light comprising a dominant wavelength of from 480 nm to 540 nm.

The invention discloses a light-emitting device comprising a light-emitting element capable of emitting a first light having a first wavelength range and a first dominant wavelength; and a wavelength converting substance absorbing the first light to emit a second wavelength range And a second light having a second dominant wavelength; wherein the wavelength conversion substance disclosed in the present invention has a chemical formula of (A _2-xy M _y )Al ₃ O ₆ R: x D, wherein 0<x≦0.3 and 0≦y ≦2, A and M contain a substance selected from an alkaline earth element, R contains a halogen element, and D contains a divalent rare earth element.

The method for producing a wavelength converting substance disclosed in the present invention can produce a green fluorescent light having a chemical formula of (A _2-xy M _y )Al ₃ O ₆ R: x D, wherein (A _2-xy M _y )Al ₃ O ₆ R is its host lattice structure (host), D is the activation center, where 0<x≦0.3,0≦y≦2, and wherein A and M systems contain a substance selected from alkaline earth elements, R It contains a halogen element, and the D system contains a divalent rare earth element. In the embodiment of the present invention, the method of fabricating the wavelength converting substance of the present invention is described by taking Ca and F as the substance A and the substance R in the chemical formula (A _2-xy M _y )Al ₃ O ₆ R as an example, and The characteristics of the wavelength converting substance of the present invention will be understood with reference to Figs. 1 to 3.

First, a first raw material containing Ca, a second raw material containing Al, a third raw material containing F, and a fourth raw material containing Eu are first obtained in a stoichiometric ratio to form a formula (Ca _2-xy M _y ). Al ₃ O ₆ F: a mixture of 0.05 Eu ²⁺ , where x = 0.05, y = 0. Next, a fluoride containing an appropriate proportion of alkaline earth is added as a flux to each of the aforementioned raw materials to be placed in a high temperature furnace tube. Since the fluoride has a low melting point, the previously added raw materials can be subjected to a eutectic reaction at a lower temperature to melt the respective raw materials at the first temperature. When the mixture is placed, a reducing gas is introduced into the furnace tube, at which time the fluoride is melted into a liquid state, and a reaction is carried out under a reducing gas to produce a wavelength converting substance.

In this embodiment, calcium carbonate (CaCO ₃ ) is used as the first raw material, alumina (Al ₂ O ₃ ) is used as the second raw material, calcium fluoride (CaF ₂ ) is used as the third raw material, and cerium oxide (Eu ₂ O _{3 )} As the fourth raw material, the above powder is thoroughly mixed, placed in a tube furnace at a temperature of 1250 ° C, and sintered in a mixed gas having a H ₂ /N ₂ mixing ratio of 5%/95% for 5 hours to obtain the present embodiment. Wavelength converting substance.

Among the above raw materials, the first raw material containing Ca may be replaced by a mixture of calcium carbonate (CaCO ₃ ), strontium carbonate (SrCO ₃ ), and barium carbonate (BaCO ₃ ). The ambient temperature in the foregoing reaction environment is between 1000 ° C and 1500 ° C, and the reducing gas can be determined depending on the reaction environment, and the composition ratio is less than 30% of hydrogen (H ₂ ) and more than 70% of nitrogen (N _{2 ).} Mixing or placing solid carbon into the furnace tube to produce a gas replacement requires a reaction time of 4 to 8 hours. From the above steps, different wavelength materials can be obtained with different chemical materials, such as Ca _1.95 Al ₃ O ₆ F: 0.05Eu ²⁺ , Ca _1.5 Sr _0.20 Ba _0.29 Al ₃ O ₆ F: 0.01Eu ²⁺ , CaBa _0.8 Al ₃ O ₆ F: 0.20 Eu ²⁺ or Ca _0.90 SrAl ₃ O ₆ F: 0.10 Eu ²⁺ .

Referring to FIG. 1, an X-ray diffraction pattern of a wavelength conversion substance Ca _1.95 Al ₃ O ₆ F:0.05Eu ²⁺ prepared in an embodiment of the present invention, and Ca ₂ Al ₃ O ₆ FX light in a JCPDS standard card are shown. The diffraction pattern is compared and the crystal structure of the two is approximated. 2 is a spectrum diagram of the excitation light of the wavelength conversion substance prepared in the embodiment, wherein PLE is an excitation light source having a wavelength between 280 nm and 450 nm, and PL is an excited light wave having a wavelength between 480 nm and 540 nm in the spectrum. The highest peak is 505 nm and the full width at half maximum of the peak is 75 nm. FIG. 3 discloses that the excited light of the wavelength conversion substance according to the embodiment of the present invention is located at a chromaticity coordinate value (0.171, 0.470) of the CIE chromaticity diagram, and indicates that the excited light is a mixed blue-green light.

The embodiments described above are merely illustrative of the technical spirit and the features of the present invention, and the objects of the present invention can be understood by those skilled in the art, and the scope of the present invention cannot be limited thereto. That is, the equivalent variations or modifications made by the spirit of the present invention should still be included in the scope of the present invention.

Figure 1 is a diagram showing the X-ray diffraction pattern of the phosphor powder of Example 1 of the present invention, and juxtaposed with the X-ray diffraction pattern of Ca ₂ Al ₃ O ₆ F in the JCPDS standard card.

FIG. 2 is a spectrum diagram showing the excitation light source and the phosphor powder after being excited by the excitation light source in the first embodiment of the present invention. The highest peak of the emission spectrum is 505 nm, and the half-height of the peak is 75 nm.

FIG. 3 shows the measured CIE chromaticity coordinate value and its position in the CIE chromaticity diagram of the light emitted by the phosphor in the first embodiment of the present invention after being excited.

Claims (8)

A wavelength converting substance having a chemical formula of (A _2-xy M _y )Al ₃ O ₆ R:xD, capable of absorbing the first light to emit a second light having a peak having a full width at half maximum of 75 nm, wherein The M system contains an alkaline earth element, the R system contains a halogen element, and the D system contains a divalent rare earth element, and the sum of the compositional coefficients of A and the compositional coefficients y of M and the doping coefficient x of D is 2, wherein A comprises calcium (Ca), and/or R comprises fluorine (F), and/or M comprises at least one element selected from the group consisting of strontium (Sr) and barium (Ba), and/or D Contains divalent europium (Eu ²⁺ ). The wavelength converting substance according to claim 1 of the patent application can be excited to emit a light comprising a dominant wavelength of between 480 nm and 540 nm. A wavelength converting substance comprising a rare earth element, an alkaline earth metal element and a halogen element of a barium aluminate compound, which can be excited to emit a light having a main wavelength of 480 nm to 540 nm and a peak having a full width at half maximum of 75 nm, wherein the alkaline earth The metal element comprises calcium (Ca) or at least one element selected from the group consisting of strontium (Sr) and barium (Ba), and/or the halogen element comprises fluorine (F), and/or the rare earth element comprises divalent europium (Eu ²⁺ ). A light emitting device comprising: a light emitting element emitting a first light having a first dominant wavelength; and a wavelength converting substance absorbing the first light to emit a second dominant wavelength and a full width at half maximum of the peak a second light of 75 nm; wherein the wavelength conversion substance has a chemical formula of (A _2-xy M _y )Al ₃ O ₆ R:xD, wherein A and M are alkaline earth elements, R series halogen elements, and D series two The valence rare earth element, the sum of the constituent coefficients of A and the compositional coefficient y of M and the doping coefficient x of D is 2, wherein A contains calcium (Ca), and/or R contains fluorine (F), And/or M comprises at least one element selected from the group consisting of strontium (Sr) and barium (Ba), and/or the D system comprises divalent europium (Eu ²⁺ ). The illuminating device of claim 4, wherein the first dominant wavelength is between 280 nm and 450 nm. The illuminating device of claim 4, wherein the second dominant wavelength is between 480 nm and 540 nm. The wavelength conversion substance according to claim 1, wherein the step of synthesizing the wavelength conversion substance comprises the steps of: providing a suitable mixture comprising CaCO ₃ , BaCO ₃ , Al ₂ O ₃ , SrCO ₃ , CaF ₂ , and Eu ₂ O ₃ ; and sintering the mixture at a temperature of 1000 ° C to 1500 ° C and having a reducing gas for 4 to 8 hours; wherein the reducing gas consists of hydrogen and nitrogen or is placed in an environment where the mixture is sintered The solid carbon produces the reducing gas wherein the proportion of hydrogen is less than 30% and the proportion of nitrogen is greater than 70%. The illuminating device of claim 4, wherein the step of synthesizing the wavelength converting substance comprises the steps of: providing a suitable mixture comprising CaCO ₃ , BaCO ₃ , Al ₂ O ₃ , SrCO ₃ , CaF ₂ , and Eu ₂ O ₃ ; and sintering the mixture at a temperature of 1000 ° C to 1500 ° C and having a reducing gas for 4 to 8 hours; wherein the reducing gas consists of hydrogen and nitrogen, or is placed in a solid state in the environment in which the mixture is sintered Carbon produces the reducing gas wherein the proportion of hydrogen is less than 30% and the proportion of nitrogen is greater than 70%.