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Green fluorescent material for alternating current - light-emitting diode (AC-LED) and preparation method thereof

A technology of green fluorescence and mixing materials, which is applied in the field of green fluorescent materials and their preparation, can solve the problems of reduced luminous efficiency, color change of emission spectrum, and reduced luminous intensity, so as to improve luminous intensity, reduce power consumption, and eliminate flickering problems Effect

Active Publication Date: 2012-08-01
HEFEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, using H 3 BO 3 Synthesis of SrAl as Flux 2 o 4 :Eu 3+ , Dy 3+ The problem always faced is: when H 3 BO 3 When adding a large amount, Sr always appears 4 Al 14 o 25 Impurities accompanied by SrAl 2 o 4 On the one hand, this kind of impurity phase reduces the luminous intensity, on the other hand, it changes the color of the emission spectrum, and on the other hand, it makes the synthetic material agglomerate and becomes very hard, which must be crushed and destroyed, and the crystal defects produced by the crushing process The luminous efficiency is sharply reduced; if the addition amount is small, boric acid is difficult to play the role of flux

Method used

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  • Green fluorescent material for alternating current - light-emitting diode (AC-LED) and preparation method thereof
  • Green fluorescent material for alternating current - light-emitting diode (AC-LED) and preparation method thereof
  • Green fluorescent material for alternating current - light-emitting diode (AC-LED) and preparation method thereof

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Experimental program
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Effect test

Embodiment 1

[0040] Embodiment 1: (Sr 0.98 Eu 0.02 )Al 2 o 4 +zH 3 BO 3

[0041] The values ​​of z of samples prepared in this embodiment are 0, 0.05, 0.1, 0.2 and 0.3 respectively.

[0042] SrCO 3 、Al 2 o 3 、Eu 2 o 3 and H 3 BO 3 As raw materials, weigh various raw materials according to the ratio, use agate mortar to fully grind various raw materials to obtain a mixture, put the mixture into a crucible, press it tightly and cover it, and pre-fire it in the atmosphere at 800 ° C for 2 Hours, after being out of the furnace, carry out secondary grinding, then put it into the crucible, press it tightly and cover it, then put the crucible with the sample into the high temperature tube furnace, raise and lower the temperature at 5°C / min respectively, at the volume ratio H 2 / N 2 =5 / 95 Sintering at 1300°C for 4 hours under a reducing atmosphere. After being released from the furnace, put the sample into a ball mill jar according to the weight ratio—ball:sample:alcohol=10:1:3, and ...

Embodiment 2

[0045] Embodiment 2: (Sr 1-y Eu y )Al 2 o 4 +0.1H 3 BO 3

[0046] The values ​​of sample y prepared in this embodiment are 0.01, 0.02, 0.03 and 0.04 respectively.

[0047] The method for synthesizing fluorescent materials in this embodiment is the same as in Example 1, and the flux H 3 BO 3 Added amount z=0.1M.

[0048] Different concentrations of Eu 2+ Activate SrAl 2 o 4 The emission spectrum of a substance is as image 3shown, from which it can be seen that Eu 2+ The optimum concentration y=0.02. τ of the best sample 1 / 10 The afterglow decay time is 4.7 seconds, such as Figure 9 shown. Therefore, the use of such fluorescent materials can effectively compensate for the lack of luminescence during the dark period.

Embodiment 3

[0049] Embodiment 3: (Sr 0.98-x Eu 0.02 Y x ) Al 2 o 4 +0.15H 3 BO 3

[0050] The values ​​of the samples x prepared in this embodiment are 0, 0.005, 0.01, 0.02 and 0.03, respectively.

[0051] The method for synthesizing fluorescent materials in this embodiment is the same as in Example 1, and the flux H 3 BO 3 Added amount z=0.15, use Y 3+ The raw material of the substance is Y 2 o 3 .

[0052] For 0.02M Eu 2+ Activate SrAl 2 o 4 substances, into which different Y 3+ , its emission spectrum varies with Y 3+ Concentration changes as Figure 4 shown, from which it can be seen that Y 3+ The optimal concentration x=0.01. τ of the best sample 1 / 10 The afterglow decay time is 6.5 seconds, such as Figure 9 shown. Therefore, the use of such fluorescent materials can effectively compensate for the lack of luminescence during the dark period.

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Abstract

The invention discloses a green fluorescent material for an alternating current - light-emitting diode (AC-LED) and a preparation method thereof. A constitution general formula of the green fluorescent material is (M1-x-yIxEuy) Al2O4, wherein the x is larger than 0 and smaller than or equal to 0.04, and the y is larger than 0 and smaller than or equal to 0.05. In a compound processing of the fluorescent material, H3BO3 and rare earth elements are added in combination mode, half-mixed-phase Sr4Al14O25 of a SrAl2O4 material can be effectively restrained, and luminous intensity is obviously improved. Appropriate afterglow of the fluorescent material is matched with alternating current driving LED chips to pack white light LEDs. By means of the afterglow of the fluorescent material, a dark period of the alternating current LED between two times of continuous lightening is offset, and the problem of sparking of the alternating current LED is eliminated.

Description

1. Technical field [0001] The invention relates to an LED fluorescent material and a preparation method thereof, in particular to a green fluorescent material for AC-LED and a preparation method thereof. 2. Background technology [0002] LED is a solid-state semiconductor device that can directly convert electrical energy into light energy. The lighting system that uses LED as a light source is commonly known as solid-state semiconductor lighting. Notable advantages such as mercury pollution, it is called the fourth generation of green lighting after incandescent lamps, tungsten halogen lamps and fluorescent lamps. At present, LEDs have been successfully applied to LCD backlights, large-screen displays, automobiles, landscape decoration, and wind-solar hybrid street lights, etc. The application of LEDs in large-screen displays and LCD backlights not only changes the way traditional cultural information is transmitted, but also significantly improves the quality of human lif...

Claims

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Application Information

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IPC IPC(8): C09K11/64
Inventor 陈雷张耀刘法涌罗安琪王雷刘衍芳蒋阳
Owner HEFEI UNIV OF TECH
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