Yellow phosphor for white light LED, preparation method and white light LED device

Abstract

The present invention relates to the technical field of white light LEDs, and in particular to a yellow phosphor for white light LEDs, a preparation method, and a white light LED device. The raw materials of each element are weighed in proportion according to a chemical formula, and after weighing, they are directly dissolved in a solvent such as acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol, or acetonitrile, stirred, or ultrasonically reacted. The mixed solution after adding the raw materials is directly filtered to obtain a crude product of powder particles. The crude product is cleaned with acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol, or acetonitrile, dried, crushed, and sieved to obtain a yellow phosphor. The simplest and most direct aqueous solution synthesis method is adopted, which is easy to operate, has a low reaction temperature, a rapid reaction, does not require additional energy consumption, has strong repeatability, avoids the shortcomings of traditional phosphor preparation such as high temperature and high pressure, and can emit white light without adding other phosphors; the raw material source is abundant, the production cost is low, the commercial use value is high, and it is conducive to long-term development.

Description

Technical Field

[0001] The present invention relates to the technical field of white light LEDs, and in particular to a yellow phosphor for white light LEDs, a preparation method thereof, and a white light LED device. Background Art

[0002] White LEDs are created by coating a blue LED chip with a highly efficient phosphor that is effectively excited by blue light and emits yellow light. The successful development of white LED light sources has paved the way for their application in general lighting. White LEDs, also known as the fourth generation of green lighting, are widely used in everyday lighting, room temperature supplemental lighting, traffic lights, and other fields.

[0003] Currently, most commercial phosphors are inorganic phosphors doped with rare earth elements (REEs), including oxides, sulfides, phosphorus oxides, and nitrogen oxides. However, this type of phosphor is overly dependent on REEs, which poses certain supply and price risks. Furthermore, the high energy consumption required to synthesize REEs hinders long-term development.

[0004] To address these issues, there is an urgent need to find new environmentally friendly, resource-rich phosphors that do not contain rare earth elements to improve the performance of commercial LEDs. Summary of the Invention

[0005] The purpose of the present invention is to provide a yellow phosphor for white light LEDs, a preparation method and a white light LED device, which solves the problems that existing commercial phosphors are usually inorganic compounds doped with rare earth elements, which pose supply and price risks, and the high energy consumption of rare earth phosphors is not conducive to long-term development.

[0006] To achieve the above object, the present invention provides a method for preparing yellow phosphor for white light LED, comprising the following steps:

[0007] Weigh the corresponding element compound raw materials according to the chemical formula, and dissolve the raw materials in a solvent to react;

[0008] The mixed liquid after the reaction is filtered to obtain a coarse powder particle product;

[0009] The crude product is treated with a solvent to obtain yellow phosphor.

[0010] The corresponding element compound raw materials are weighed according to the chemical formula, and the raw materials are dissolved in a solvent to react. The steps further include:

[0011] The chemical formula is Ma(18-crown-6)bCucId·Xe·fH2O, wherein M is composed of at least one of Mg, Ca, Sr, and Ba, X is composed of at least one of CH3OH, C3H7NO, C2H6OS, H3PO2, C3H6O, and CH3CN, and a, b, c, d, e, and f are molar coefficients in the range of 1≤a≤3, 1≤b≤2, 1≤c≤6, 2≤d≤8, 0≤e≤3, and 1≤f≤6.

[0012] The corresponding element compound raw materials are weighed according to the chemical formula, and the raw materials are dissolved in a solvent to react. The steps further include:

[0013] The raw materials used are BaI2, CaI2, SrI2, MgI2, CuI, C 12 H 24 O618-crown-6), H3PO2.

[0014] The corresponding element compound raw materials are weighed according to the chemical formula, and the raw materials are dissolved in a solvent to react. The step further includes:

[0015] The solvent is acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol or acetonitrile.

[0016] The crude product is treated with a solvent to obtain yellow phosphor, and the step further comprises:

[0017] The crude product is washed with acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol or acetonitrile, dried, crushed and sieved to obtain yellow phosphor.

[0018] A yellow phosphor for white light LEDs has a structural formula of Ma(8-crown-6)bCucId·Xe·fH2O, wherein M is composed of at least one of Mg, Ca, Sr, and Ba, X is composed of at least one of CH3OH, C3H7NO, C2H6OS, H3PO2, C3H6O, and CH3CN, and a, b, c, d, e, and f are molar coefficients in the range of 1≤a≤3, 1≤b≤2, 1≤c≤6, 2≤d≤8, 0≤e≤3, and 1≤f≤6.

[0019] A white light LED device comprises a blue light emitting chip and yellow phosphor arranged on the blue light emitting chip.

[0020] The yellow phosphor is mixed with UV glue or PDMS colloid and then packaged on the blue light-emitting chip.

[0021] The present invention relates to a yellow phosphor for white light LEDs, a preparation method, and a white light LED device. The raw materials of each element are weighed in proportion according to the chemical formula Ma(18-crown-6)bCucId·Xe·fH2O, and then directly dissolved in a solvent such as acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol, or acetonitrile, and stirred or ultrasonically reacted. The mixed solution after adding the raw materials is directly filtered to obtain a crude powder particle product. The crude product is washed with acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol, or acetonitrile, dried, crushed, and sieved to obtain a yellow phosphor. The raw materials used in the above method are BaI2, CaI2, SrI2, MgI2, CuI, C 12 H 24 O618-crown-6), H3PO2. A white light LED device comprises the blue light-emitting chip and the yellow phosphor disposed on the blue light-emitting chip. The yellow phosphor can be directly disposed on the blue light-emitting chip or can be mixed with a colloid such as UV glue or PDMS and then encapsulated on the blue light-emitting chip. After encapsulation, a white light LED device with stable light emission and resistance to damage can be obtained. The device adopts the simplest and most direct aqueous solution synthesis method, which is easy to operate, has a low reaction temperature, a rapid reaction, does not require additional energy consumption, and has high reproducibility. This method avoids the disadvantages of traditional phosphor preparation, such as high temperature and high pressure. By replacing or adjusting the element ratio, a yellow phosphor for white LEDs with blue light excitation having a wide excitation range (250-500nm) and a wide emission range (450-800nm) can be obtained. The yellow phosphor does not require the addition of other phosphors to emit white light. The device has abundant raw material sources, low production costs, high commercial value, and is conducive to long-term development. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art.

[0023] Figure 1 This is the XRD pattern of the Ba(18-crown-6)2Cu4I6·H3PO2·H2O phosphor of the present invention.

[0024] Figure 2 The emission spectrum of Ba(18-crown-6)2Cu4I6·H3PO2·H2O of the present invention is excited at 450nm and monitored at 538nm.

[0025] Figure 3 The coordinates of the fluorescent pink color of Ba(18-crown-6)2Cu4I6·H3PO2·H2O of the present invention are (x=0.39, y=0.55).

[0026] Figure 4 This is a light emission spectrum diagram of a white light LED device based on Ba(18-crown-6)2Cu4I6·H3PO2·H2O phosphor of the present invention.

[0027] Figure 5 This is the XRD pattern of the Ca(18-crown-6)Cu5I7·3H2O phosphor of the present invention.

[0028] Figure 6 The emission spectrum of Ca(18-crown-6)Cu5I7·3H2O4 of the present invention is excited at 22nm and monitored at 528nm.

[0029] Figure 7 The coordinates of the fluorescent pink color of Ca(18-crown-6)Cu5I7·3H2O of the present invention are (x=0.36, y=0.54).

[0030] Figure 8 This is a light emission spectrum diagram of a white light LED device containing the Ca(18-crown-6)Cu5I7·3H2O phosphor of the present invention.

[0031] Figure 9 The present invention is a flowchart of the steps of the method for preparing yellow phosphor for white light LED.

[0032] Figure 10 It is a schematic structural diagram of the white light LED device of the present invention.

[0033] In the picture: 301-blue light-emitting chip, 302-yellow phosphor. DETAILED DESCRIPTION

[0034] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0035] The first embodiment of this application is:

[0036] See also Figures 1 to 9 ,in, Figure 1 This is the XRD pattern of the Ba(18-crown-6)2Cu4I6·H3PO2·H2O phosphor of the present invention. Figure 2 This is an emission spectrum diagram of Ba(18-crown-6)2Cu4I6·H3PO2·H2O of the present invention under 450nm excitation and an excitation spectrum diagram monitored at 538nm. Figure 3 The coordinates of the fluorescent pink color of Ba(18-crown-6)2Cu4I6·H3PO2·H2O of the present invention are (x=0.39, y=0.55). Figure 4This is a light emission spectrum diagram of a white light LED device based on Ba(18-crown-6)2Cu4I6·H3PO2·H2O phosphor of the present invention. Figure 5 This is the XRD pattern of the Ca(18-crown-6)Cu5I7·3H2O phosphor of the present invention. Figure 6 The emission spectrum of Ca(18-crown-6)Cu5I7·3H2O of the present invention is excited at 422nm and monitored at 528nm. Figure 7 The coordinates of the fluorescent pink color of Ca(18-crown-6)Cu5I7·3H2O of the present invention are (x=0.36, y=0.54). Figure 8 This is a light emission spectrum diagram of a white light LED device containing the Ca(18-crown-6)Cu5I7·3H2O phosphor of the present invention. Figure 9 The present invention provides a method for preparing yellow phosphor 302 for white light LEDs, which includes the following steps:

[0037] S101: Weigh corresponding element compound raw materials according to the chemical formula, and dissolve the raw materials in a solvent to react;

[0038] S102: filtering the reaction mixture to obtain a coarse powder particle product;

[0039] S103: The crude product is treated with a solvent to obtain yellow phosphor 302.

[0040] Specifically, the raw materials of each element are weighed in proportion according to the chemical formula Ma(18-crown-6)bCucId·Xe·fH2O, where M is composed of at least one of Mg, Ca, Sr, and Ba; X is composed of at least one of CH3OH, C3H7NO, C2H6OS, H3PO2, C3H6O, and CH3CN; a, b, c, d, e, and f are molar coefficients within the range of 1≤a≤3, 1≤b≤2, 1≤c≤6, 2≤d≤8, 0≤e≤3, and 1≤f≤6. After weighing, the raw materials are directly dissolved in a solvent such as acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol, or acetonitrile and reacted by stirring or ultrasonication. The mixture after the raw materials are added is directly filtered to obtain a crude powder product. The crude product is then washed with acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol, or acetonitrile, dried, crushed, and sieved to obtain yellow phosphor 302. The raw materials used are BaI2, CaI2, SrI2, MgI2, CuI, C 12 H 24 O6(18-crown-6), H3PO2.

[0041] It adopts the simplest and most direct aqueous solution synthesis method, which is easy to operate, has a low reaction temperature, a rapid reaction, does not require secondary energy consumption, and has strong repeatability. It avoids the shortcomings of traditional phosphor preparation such as high temperature and high pressure, and can emit white light without adding other phosphors. It has abundant raw material sources, low production costs, high commercial value, and is conducive to long-term development.

[0042] In a specific embodiment 1, the present invention provides a blue light excited yellow phosphor 302, whose chemical formula is Ba(18-crown-6)2Cu4I6·H3PO2·H2O. XRD diffraction pattern shows that the yellow phosphor has a monoclinic P21 / c structure.

[0043] The present invention also provides a method for preparing the blue light excited yellow phosphor, comprising the following steps:

[0044] Step 1: Weigh the corresponding element compound raw materials, barium iodide, cuprous iodide, 18-crown-6, and H3PO2 according to the chemical formula, and place them in a reaction vessel such as a reaction vessel beaker or reactor.

[0045] Step 2: Add a reaction solvent such as acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol, or acetonitrile to a reaction vessel containing the raw materials, stir or ultrasonicate the reaction, and obtain a mixed solution after the reaction is completed.

[0046] Step 3: Filter the mixed solution to obtain a yellow powder solid.

[0047] Step 4: Wash, dry, grind and sieve the powdered solid product to obtain the blue light excited yellow phosphor 302.

[0048] In a specific embodiment 2, the present invention provides a blue light excited yellow phosphor 302, whose chemical formula is Ca(18-crown-6)Cu5I7·3H2O. The XRD diffraction pattern shows that the yellow phosphor has a Pbcm space group.

[0049] The present invention also provides a method for preparing the blue light excited yellow phosphor, comprising the following steps:

[0050] Step 1: Weigh the corresponding element compound raw materials according to the chemical formula, calcium iodide, cuprous iodide, and 18-crown-6 and place them in a reaction vessel such as a reaction vessel beaker or a reactor.

[0051] Step 2: Add a reaction solvent such as acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol, or acetonitrile to a reaction vessel containing the raw materials, stir or ultrasonicate the reaction, and obtain a mixed solution after the reaction is completed.

[0052] Step 3: Filter the mixed solution to obtain a yellow powder solid.

[0053] Step 4: Wash, dry, grind and sieve the powdered solid product to obtain the blue light excited yellow phosphor 302.

[0054] The second embodiment of this application is:

[0055] Based on the first embodiment, this embodiment provides a yellow phosphor 302 for white light LEDs having a structural formula of Ma(18-crown-6)bCucId·Xe·fH2O, where M is composed of at least one of Mg, Ca, Sr, and Ba, X is composed of at least one of CH3OH, C3H7NO, C2H6OS, H3PO2, C3H6O, and CH3CN, and a, b, c, d, e, and f are molar coefficients in the range of 1≤a≤3, 1≤b≤2, 1≤c≤6, 2≤d≤8, 0≤e≤3, and 1≤f≤6.

[0056] The third embodiment of this application is:

[0057] Based on the second embodiment, please refer to Figure 10 ,in, Figure 10 3 is a schematic structural diagram of a white light LED device of the present invention. A white light LED device of this embodiment includes a blue light emitting chip 301 and yellow phosphor 302.

[0058] According to this specific embodiment, the yellow phosphor is mixed with UV glue or PDMS colloid and then encapsulated on the blue light-emitting chip 301 .

[0059] The yellow phosphor 302 can be placed directly on the blue light-emitting chip 301, or it can be mixed with UV glue or PDMS and then encapsulated on the blue light-emitting chip 301. After encapsulation, a white light LED device with stable light emission and not easy to be damaged can be obtained. The yellow phosphor 302 is the yellow phosphor 302 excited by blue light of the present invention.

[0060] The blue light LED chip of the present invention can adopt an InGnN semiconductor LED chip with a light emission wavelength of 460nm.

[0061] The present invention does not specifically limit the amount of yellow phosphor 302 used; it can be adjusted according to actual needs. The blue LED chip is a GaN semiconductor chip, such as an InGnN semiconductor LED chip, with a peak emission wavelength of 460 nm. The blue-light-excited yellow phosphor 302 provided by the present invention has advantages such as a wide excitation range in the blue light region, high color purity, and good thermal and chemical stability. It is suitable for blue-light chips and blue-light-excited LED devices. The white-light LED device provided by the present invention overcomes the shortcomings of traditional commercial white-light LED devices due to the lack of directly assembled yellow phosphor 302.

[0062] The above disclosure is merely one or more preferred embodiments of the present application and is not intended to limit the scope of the present application. A person skilled in the art will understand that all or part of the processes of the above embodiments and equivalent changes made in accordance with the claims of the present application are still within the scope of the present application.

Claims

1. A yellow phosphor for white light LED, characterized in that: The yellow phosphor for white light LED has a structural formula of Ba(18-crown-6)2Cu4I6·H3PO2·H2O.

2. A method for preparing yellow phosphor for white light LED according to claim 1, characterized in that: The following steps are involved: Weigh the corresponding element compound raw materials according to the chemical formula, and dissolve the raw materials in a solvent to react. The raw materials used are BaI2, CuI, 18-crown-6, and H3PO2; The mixed liquid after the reaction is filtered to obtain a coarse powder particle product; The crude product is treated with a solvent to obtain yellow phosphor.

3. The method for preparing yellow phosphor for white light LED according to claim 2, wherein: The solvent is acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol or acetonitrile.

4. The method for preparing yellow phosphor for white light LED according to claim 2, wherein: The crude product is washed with acetone, N,N-dimethylformamide, dimethyl sulfoxide, methanol or acetonitrile, dried, crushed and sieved to obtain yellow phosphor.

5. A white light LED device, characterized in that: The invention comprises a blue light emitting chip and the yellow phosphor for white light LED as claimed in claim 1 arranged on the blue light emitting chip.

6. The white light LED device according to claim 5, wherein: The yellow fluorescent powder is mixed with UV glue or PDMS colloid and then packaged on the blue light emitting chip.

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