Tb<3+>/Eu<3+>/Tm<3+>-doped alpha-NaYF4 single crystal for white LED (light emitting diode) and preparation method thereof

A single-crystal, triple-doping technology, applied in the direction of single crystal growth, crystal growth, single crystal growth, etc., can solve the problems of affecting the transmittance of the device, low color rendering index, high cost, and achieve large-scale industrial production. The effect of high purity and lower production cost

Active Publication Date: 2015-01-28
SHANDONG XINGQIANG CHEM IND TECH RES INST CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, most LED lighting devices are made of blue-emitting LED chips (mainly InGaN) and yellow phosphors (Ce 3+ :YAG) packaged together, the blue light emitted by the chip and the yellow light generated by the phosphor excited by the blue light are mixed into white light emission, but there are the following defects: (1) the color temperature of white light is high, and the color rendering index is low; (2) White light is easy to distort and drift, resulting in slightly blue or yellowish white light; (3) the coated phosphor has an adverse effect on white light due to the uneven particle size; (4) the organic epoxy resin used for encapsulation is in the light It is easy to age under irradiation; (5) the cost is higher, etc.
[0004] So far, about NaYF 4 The reports of materials all focus on microcrystalline materials. For example, the invention patent with publication number CN102660287A discloses a preparation method of hexagonal phase upconversion nanomaterials. However, due to the strong scattering of light by nanocrystalline powder materials, Therefore, the transmittance of the device is seriously affected, thereby limiting its application in LED

Method used

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  • Tb&lt;3+&gt;/Eu&lt;3+&gt;/Tm&lt;3+&gt;-doped alpha-NaYF4 single crystal for white LED (light emitting diode) and preparation method thereof
  • Tb&lt;3+&gt;/Eu&lt;3+&gt;/Tm&lt;3+&gt;-doped alpha-NaYF4 single crystal for white LED (light emitting diode) and preparation method thereof
  • Tb&lt;3+&gt;/Eu&lt;3+&gt;/Tm&lt;3+&gt;-doped alpha-NaYF4 single crystal for white LED (light emitting diode) and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Weigh NaF, KF, YF with purity greater than 99.99% 3 , TbF 3 、EuF 3 , TmF 3 Raw material, molar ratio NaF:KF:(YF 3 +TbF 3 +EuF 3 +TmF 3 )=1.25:1:2.7, and YF 3 : TbF 3 =1:0.019, YF 3 : EuF 3 =1:0.019, YF 3 : TmF 3 =1:0.010 mixed, put NaF, KF, YF 3 , TbF 3 、EuF 3 , TmF 3 Put the raw materials in a mill, grind and mix for 5.5 hours to obtain a uniform powder mixture; put the mixture in a boat-shaped platinum crucible, and then install the boat-shaped platinum crucible in the platinum pipe of the tubular resistance furnace , and then use high-purity N 2 The gas removes the air in the platinum pipeline, and the platinum pipeline is leaked; then the furnace body temperature of the tubular resistance furnace is gradually increased to 790 ° C, HF gas is passed through, and the reaction is carried out for 2 hours to remove the H that may be contained. 2 O and oxyfluoride, in the reaction process, use NaOH solution to absorb HF gas in the exhaust gas. After the re...

Embodiment 2

[0031] Basically the same as Example 1, the only difference is the molar ratio NaF:KF:(YF 3 +TbF 3 +EuF 3 +TmF 3 )=1.25:1:2.7, and YF 3 : TbF 3 =1:0.025, YF 3 : EuF 3 =1:0.030, YF 3 : TmF 3 =1:0.010, NaF, KF, YF 3 , TbF 3 、EuF 3 , TmF 3 The raw materials are placed in the mill, the mixing time is 5 hours, the reaction time in the platinum pipeline is 2 hours, the treatment temperature is 770°C, the furnace temperature is 980°C, the inoculation temperature is 820°C, and the temperature gradient of the solid-liquid interface is 90°C / cm, the crystal growth rate is 2.0mm / h, the furnace temperature drop temperature is 80℃ / h, and Tb / Eu / Tm doped α-NaYF 4 single crystal. XRD, absorption spectrum and fluorescence spectrum are basically the same as those in Example 1, but the intensity is different. Analysis and Detection of Tb in Crystal by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP) 3+ 、Eu 3+ , Tm 3+ The actual molar percentage of rare earth ions, x...

Embodiment 3

[0033] Basically the same as Example 1, the only difference is the molar ratio NaF:KF:(YF 3 +TbF 3 +EuF 3 +TmF 3 )=1.25:1:2.7, and YF 3 : TbF 3 =1:0.020, YF 3 : EuF 3 =1:0.019, YF 3 : TmF 3 =1:0.010, NaF, KF, YF 3 , TbF 3 、EuF3 , TmF 3 The raw materials were placed in the mill, the mixing time was 6 hours, the reaction time in the platinum pipeline was 1 hour, the treatment temperature was 800 °C, the furnace temperature was 960 °C, the inoculation temperature was 820 °C, and the temperature gradient at the solid-liquid interface was 60 °C / cm, the crystal growth rate is 0.2mm / h, the furnace temperature drop temperature is 80℃ / h, and Tb / Eu / Tm doped α-NaYF is obtained 4 single crystal. XRD, absorption spectrum and fluorescence spectrum are basically the same as in Example 1, but the intensity is different. Analysis and detection of Tb in crystals by inductively coupled plasma atomic emission spectrometry (ICP) 3+ , Eu 3+ , Tm 3+ The actual mole percentage of rar...

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Abstract

The invention discloses a Tb<3+> / Eu<3+> / Tm<3+>-doped alpha-NaYF4 single crystal for a white LED (light emitting diode) and a preparation method thereof. The preparation method is characterized in that KF (potassium fluoride) is used as a cosolvent and added into NaF, YF3, TbF3, EuF3 and TmF3 raw materials to generate the Tb<3+> / Eu<3+> / Tm<3+>-doped alpha-NaYF4 single crystal. The single crystal and the preparation method thereof have the advantages that a certain quantity of KF (the melting point is 858 DEG C) serving as a cosolvent is added into the initial raw materials, and the cosolvent KF reduces the melting point of the alpha-NaYF4 crystal and changes the phase equilibrium relation in a melt, so that when crystal is preliminarily separated from the melt, only alpha-NaYF4 solid-phase crystals and other liquid-phase crystals are separated out, and large-sized alpha-NaYF4 crystal is finally obtained with the nucleation and growth of alpha-NaYF4 crystal; the sodium yttrium fluoride single crystal has high rare earth dissolubility, and has good thermal, mechanical and chemical stability; and the light emitting efficiency of rare earth ions doped with the single crystal is high.

Description

technical field [0001] The invention relates to a preparation method of a fluoride single crystal, in particular to a Tb used for white light LEDs 3+ / Eu 3+ / Tm 3+ Tri-doped α-NaYF 4 Single crystal and preparation method thereof. Background technique [0002] LED (Light-emitting diode) is a new semiconductor solid-state light source that converts electrical energy into light energy. Due to its characteristics of energy saving, environmental protection, long life, low voltage safety, miniaturization and not easy wear and tear, it has become the fourth generation of new lighting sources to achieve true energy saving and green lighting. At present, most LED lighting devices use blue-emitting LED chips (mainly InGaN) and yellow phosphors (Ce 3+ :YAG) packaged together, the blue light emitted by the chip and the yellow light generated by the blue light excited phosphors are mixed into white light emission, but there are the following defects: (1) The color temperature of whi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C30B29/12C30B11/00C30B33/02
CPCC30B11/00C30B29/12C30B33/02
Inventor 夏海平姜永章杨硕张加忠符立董艳明李珊珊张约品
Owner SHANDONG XINGQIANG CHEM IND TECH RES INST CO LTD
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