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Phosphor powder in use for light emitting diode (LED), and preparation method

A technology of light-emitting diodes and phosphors, applied in the field of phosphors, can solve the problems of large particle size distribution, reduced luminous efficiency, large sample particles, etc., and achieve the effects of small particle size, high luminous brightness, and strong excitation and absorption

Inactive Publication Date: 2007-12-26
李瑞
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

At present, the solid phase method is mostly used to synthesize phosphors for LEDs. The sample particles obtained by this method are relatively large. After ball milling, the crystal structure will be destroyed and the luminous efficiency will be reduced. The shape is irregular, the particle size distribution range is large, and the synthesis temperature is high. High energy consumption, contrary to the energy-saving concept of LED

Method used

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  • Phosphor powder in use for light emitting diode (LED), and preparation method
  • Phosphor powder in use for light emitting diode (LED), and preparation method

Examples

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Effect test

example 1

[0021] A molybdate red phosphor powder, which is a solid solution R 2-x-y Eu x A y (MoO 4 ) 3 , where R is La, x=0.8, y=0 (that is, without A), the solid solution can be expressed as La 1.2 Eu 0.8 (MoO 4 ) 3 . Weigh La 2 o 3 0.1278g, Eu 2 o 3 0.0893g, heat and dissolve with 40% hydrochloric acid (volume ratio), continue heating for a period of time to remove excess hydrochloric acid on the electric furnace, add 0.9567 grams of citric acid, (NH 4 ) 6 Mo 7 o 24 4H 2 O0.3449g, ultrasonically dispersed to make a transparent solution, with NH 3 ·H 2 O to adjust the pH to ≈7.5, keep it in an oven at 60°C for 72 hours, then raise the temperature to 240°C and keep it dry for 12 hours to obtain a black dry glue. Then the black dry glue is slightly baked on the electric furnace to make it carbonized and pre-fired in a high-temperature furnace at 600°C for 1h, and then the sample is calcined at 700°C and 900°C for 3h to obtain the desired red phosphor, and the powder di...

example 2

[0024] A molybdate red phosphor powder, which is a solid solution R 2-x-y Eu x A y (MoO 4 ) 3 , where R is Gd, x=0.8, y=0 (that is, without A), the solid solution can be expressed as Gd 1.2 Eu 0.8 (MoO 4 ) 3 . Measure 0.02mol / L of Eu(NO 3 ) 3 Solution 26ml, 0.01mol / L Gd(NO 3 ) 3 Solution 78ml, add citric acid 0.9343 grams, (NH 4 ) 6 Mo 7 o 24 4H 2 O0.3366g, ultrasonically dispersed to make a transparent solution, with NH 3 ·H 2 O to adjust the pH to ≈8, keep it in an oven at 90°C for 24 hours, then raise the temperature to 120°C and keep it dry for 24 hours to obtain a black dry glue. Then the black dry glue is slightly baked on the electric furnace to make it carbonized and pre-fired in a high-temperature furnace at 450°C for 5 hours, and then the sample is calcined at 900°C for 3 hours to obtain the required red phosphor. The phosphor is shown in Figure 1 The XRD pattern at 900°C, the particle size and morphology were observed by scanning electron microsco...

example 3

[0026] A molybdate red phosphor powder, which is a solid solution R 2-x-y Eu x A y (MoO 4 ) 3 , where R is Gd, x=1.2, y=0 (that is, without A), the solid solution can be expressed as Gd 0.8 Eu 1.2 (MoO 4 ) 3 . Measure 0.02mol / L of Eu(NO 3 ) 3 Solution 39ml, 0.01mol / L of Gd(NO 3 ) 3 Solution 52ml, add citric acid 0.9343 grams, (NH 4 ) 6 Mo 7 o 24 4H 2 O0.3366g, ultrasonically dispersed to make a transparent solution, with NH 3 ·H 2 O to adjust the pH to ≈8, keep it in an oven at 60°C for two days, heat it up to 100°C and dry it for 72 hours to obtain a black dry glue. Then the black dry glue is slightly baked on the electric furnace to make it carbonized and pre-fired in a high-temperature furnace at 500°C for 3h, and then the samples are calcined at 900°C and 800°C for 3h to obtain the required red phosphors, and their fluorescence spectra They are shown in Figure 3(d) and (e) respectively. It can be seen from the figure that their fluorescence spectra are d...

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Abstract

This invention relates to a sol-gel method for preparing red fluorescent powder used in light emitting diode. The chemical formula of the red fluorescent powder is R2-x-yEuxAy(MO4)3, wherein x is within 0-2; R is one or more of Sc, Y, La, Gd and Lu; A is one or two of Sm and Bi; y is within 0-0.3; M is one or two of Mo and W. The red fluorescent powder has an average particle size less than 2 mu.m, a main emission peak of 616 nm, and a synthesis temperature of 650-1000 deg.C. The red fluorescent powder has strong excitation absorption at 370-500 nm near-UV wave band and blue light wave band, high luminescence intensity, high color purity and high stability. The sol-gel method utilizes citric acid as the complexing agent to prepare high-brightness red fluorescent powder, the reaction temperature is largely lower than that of the solid phase method, and the obtained red fluorescent powder has small and uniform sizes, spherical particle shape, high purity, high quantum efficiency, and good luminescent property, and can be used in light emitting diode and fluorescent lamp excited by near-UV and blue light.

Description

technical field [0001] The invention relates to a fluorescent powder for a light-emitting diode (LED), in particular to a red fluorescent powder for a light-emitting diode and other preparation methods. Background technique [0002] The rapid rise of the semiconductor lighting industry based on light-emitting diodes (LEDs) has triggered a revolution in the traditional lighting field. Compared with traditional lighting technology, LED has the characteristics of small size, high efficiency, strong power saving, low pollution, long life, fast response speed, and maintenance-free. As a colored light source, the power consumption of LED is only that of ordinary incandescent lamps at the same height. 1 / 8-1 / 10 of that, and the service life can reach more than 80,000 hours. It is widely used in urban landscape lighting, large-screen display, traffic signal lights, LCD backlight, instrumentation indication, vehicle lighting, aviation, military, industry and home, etc. It is developi...

Claims

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Application Information

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IPC IPC(8): C09K11/77H01L33/00
CPCC09K11/7792C09K11/7794
Inventor 李瑞
Owner 李瑞
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