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A kind of red fluorescent powder for LED and preparation method thereof

A red phosphor and phosphor technology are applied in the field of red phosphor of LED and its preparation, alkaline earth metal niobate red phosphor and its preparation, and can solve the problem of low color rendering index of white light LED, poor stability of phosphor, etc. The problem of low luminous efficiency, etc., achieves the effects of stable physical and chemical properties, excellent luminous performance, and good temperature stability

Inactive Publication Date: 2016-04-06
QINGDAO UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the prior art, commercially available red phosphors mainly include (Ca, Sr)S:Eu 2+ , Y 2 o 3 :Eu 2+ , (Y, Gd)BO 3 :Eu 3+ etc., but these phosphors may have poor stability, are easy to deliquescence, and need to be coated when used, or the luminous efficiency is not high, resulting in low color rendering index or low efficiency of the packaged white LED.

Method used

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  • A kind of red fluorescent powder for LED and preparation method thereof
  • A kind of red fluorescent powder for LED and preparation method thereof
  • A kind of red fluorescent powder for LED and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] (Ca 0.98 K 0.01PR 0.01 ) 2 Nb 2 o 7 Sample preparation:

[0037] (1) Weigh raw material CaCO 3 7.8392g, K 2 CO 3 0.055g, Pr 6 o 11 0.1361g, Nb 2 o 5 10.6277g, the above raw materials are all analytically pure, put into an agate mortar and add 30g of absolute ethanol to grind for 2 hours, then dry in an oven at 60°C;

[0038] (2) Place the dried mixed powder in an alumina crucible and pre-fire it at 900°C for 4 hours in an air atmosphere;

[0039] (3) Calcining the ground calcined powder at 1400° C. for 4 hours in an air atmosphere;

[0040] (4) The cooled product is physically crushed, ground, washed with water to remove impurities, and dried to obtain a chemical composition of (Ca 0.98 K 0.01 PR 0.01 ) 2 Nb 2 o 7 LEDs use red phosphor.

[0041] The appearance of the red phosphor powder prepared by this embodiment is white, and the X-ray powder diffraction (XRD) test shows that as figure 1 As shown, the diffraction peak data of the obtained samples ...

Embodiment 2

[0043] (Ca 0.97 Na 0.015 PR 0.015 ) 2 Nb 2 o 7 Sample preparation:

[0044] (1) Weigh raw material CaCO 3 7.7592g, Na 2 CO 3 0.0633g, Pr 6 o 11 0.2041g, Nb 2 o 5 10.6277g, the above raw materials are all analytically pure, put into an agate mortar and add 25g of absolute ethanol to grind for 1.5 hours, then dry in an oven at 70°C;

[0045] (2) Place the dried mixed powder in an alumina crucible and pre-fire it at 850°C for 4 hours in an air atmosphere;

[0046] (3) Calcining the ground calcined powder at 1350° C. for 6 hours in an air atmosphere;

[0047] (4) The cooled product is physically crushed, ground, washed with water to remove impurities, and dried to obtain a chemical composition of (Ca 0.97 Na 0.015 PR 0.015 ) 2 Nb 2 o 7 LEDs use red phosphor.

[0048] The appearance of the red fluorescent powder for LEDs prepared in this example is white, and the XRD spectrum result is basically consistent with that of Example 1. The excitation peak position, em...

Embodiment 3

[0050] (Ca 0.93 Sr 0.05 K 0.01 PR 0.01 ) 2 Nb 2 o 7 Sample preparation:

[0051] (1) Weigh raw material CaCO 3 7.4392g, SrCO 3 0.5899g, K 2 CO 3 0.055g, Pr 6 o 11 0.1361g, Nb 2 o 5 10.6277g, the above raw materials are analytically pure, put into an agate mortar, add 35g of deionized water and grind for 2.5 hours, then dry in an oven at 80°C;

[0052] (2) Place the dried mixed powder in an alumina crucible and pre-burn it at 850°C for 5 hours in an air atmosphere;

[0053] (3) calcining the ground calcined powder at 1350° C. for 8 hours in an oxygen atmosphere;

[0054] (4) The cooled product is physically crushed, ground, washed with water to remove impurities, and dried to obtain a chemical composition of (Ca 0.93 Sr 0.05 K 0.01 PR 0.01 ) 2 Nb 2 o 7 LEDs use red phosphor.

[0055] The appearance of the red fluorescent powder for LEDs prepared in this example is white, and the XRD spectrum result is basically consistent with that of Example 1. The excit...

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Abstract

The invention discloses a red phosphor for LED. The red phosphor is a praseodymium activated alkaline earth metal columbate fluorescence material. The chemical expression formula of the red phosphor is (Ca1xy2zSrxBayAzPrz)2Nb2O7, wherein A represents a monovalent alkali metal element and is selected from at least one of Li, Na, K and Rb; x is not greater than 0.2 and not lower than 0; y is not greater than 0.1 and not lower than 0; and z is not greater than 0.05 and greater than 0. A preparation method of the phosphor through a high temperature solid phase process comprises the following steps: weighing compounds containing corresponding elements according to the stoichiometric ratio of the chemical expression formula, mixing, uniformly grinding, drying, pre-burning and carrying out high temperature calcining in air or oxygen environment, crushing, grinding, cleaning to remove impurities, and drying. The phosphor has the advantages of simple preparation method, no pollution, low cost, wide excitation wavelength range, excellent luminescence performance, high color rendering index, good temperature stability, moisture resistance and the like, and can be widely used in ultraviolet or blue LED chips to make white LED.

Description

technical field [0001] The invention relates to a praseodymium-activated alkaline earth metal niobate red fluorescent powder and a preparation method thereof, in particular to a red fluorescent powder suitable for LEDs and a preparation method thereof, and belongs to the technical field of rare earth luminescent materials. Background technique [0002] In the 1990s, with the advent of GaN, InGaN-based blue (450-470nm) and near-ultraviolet (380-410nm) light-emitting diodes (LEDs), a combination of blue or near-ultraviolet LED chips and light conversion phosphors appeared. And made of white LED. Compared with traditional incandescent lamps, fluorescent lamps and high-pressure mercury lamps, this new type of solid light source has many advantages such as energy saving, high efficiency, environmental protection, long life (more than 10,000 hours), small size, etc., and has huge applications in the field of lighting and display. Prospects, it is expected to realize industrializa...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C09K11/67
CPCY02B20/00
Inventor 张君诚韩文鹏龙云泽孟超张国首刘凯月刘艳杰辛星
Owner QINGDAO UNIV