A long afterglow phosphor for LED and preparation method thereof

A technology of long-lasting phosphors and prefabricated powders, applied in chemical instruments and methods, luminescent materials, etc., can solve the problem that yellow powder does not have long-lasting characteristics, and achieve stable and reliable product quality, low cost, and simple process

Active Publication Date: 2021-08-17
NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
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  • Abstract
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Problems solved by technology

But YAG:Ce 3+ Yellow powder does not have long afterglow characteristics
At present, phosphors with long afterglow characteristics can only be effectively excited by ultraviolet light, such as SrSi 2 o 2 N 2 :Eu 2+ ,Mn 2+ Green powder (see literature Yeh, C.et al, "Appropriate green phosphor of SrSi 2 o 2 N 2 :Eu 2+ ,Mn 2+ for ACLEDs, Opt.Express, 2012, 20, 18031-18034.") and SrAl 2 o 4 :Eu 2+ , R 3+ Green powder (see literature Chen, L. et al, The green phosphor SrAl 2 o 4 :Eu 2+ , R 3+ (R=Y, Dy) and its application in alternating current light-emitting diodes, Funct. Mater. Lett., 2013, 6, 1350047.)

Method used

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  • A long afterglow phosphor for LED and preparation method thereof
  • A long afterglow phosphor for LED and preparation method thereof
  • A long afterglow phosphor for LED and preparation method thereof

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preparation example Construction

[0044] The invention also provides a preparation method of the long afterglow fluorescent powder applied to the LED. The preparation method comprises the following steps:

[0045] S1, providing raw materials and grinding and mixing to obtain a mixture;

[0046] S2, in an oxygen atmosphere, the mixture is sintered for the first time to obtain a first sintered body, and the first sintered body is ground into a prefabricated powder;

[0047] S3, in a reducing atmosphere, the prefabricated powder is sintered for a second time to obtain a second sintered body;

[0048] S4, grinding the second sintered body to obtain long afterglow phosphors.

[0049] In step S1, according to (A 1-x B x ) m-y C y (D 1-z E z ) 8-m O 12 The reaction raw materials were weighed in the stoichiometric ratio. Commercially available micro- or nano-scale raw materials with a purity of more than 99% can be used without reprocessing the raw materials, which can save costs for industrialization.

[...

Embodiment 1

[0062] The general chemical formula of the long afterglow phosphor is Gd 2.98 Ce 0.02 Al 2 Ga 3 O 12 , that is, x=0, y=0.02, z=0.4, m=3, A is Gd, C is Ce, D is Ga, and E is Al.

[0063] The preparation method of the long afterglow phosphor is as follows:

[0064] Commercially available high-purity (99%) Gd 2 O 3 , Ce 2 (CO 3 ) 3 , Al 2 O 3 , Ga 2 O 3 As starting materials, accurately weigh the mass of each oxide or carbonate according to the above formula, mix the weighed reaction materials in an agate mortar and grind them uniformly to obtain a mixture.

[0065] The mixture was put into a high-purity corundum crucible, and the 2 Under the atmosphere, it was sintered in a tube furnace at 1400° C. for 4 hours to obtain a first sintered body. After cooling to room temperature with the furnace, the obtained first sintered body is ground to obtain a prefabricated powder.

[0066] The prefabricated powder was immersed in a volume fraction of 5% H 2 with a volume fr...

Embodiment 2

[0069] The general chemical formula of the long afterglow phosphor is Gd 2.98 Ce 0.02 Al 2 Ga 3 O 12 , that is, x=0, y=0.02, z=0.4, m=3, A is Gd, C is Ce, D is Ga, and E is Al.

[0070] The preparation method of the long afterglow phosphor is basically the same as that in Example 1, except that the temperature during the second sintering is 1400°C.

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Abstract

The present invention relates to a kind of long afterglow fluorescent powder that is applied to LED, and its general chemical formula is (A 1‑x B x ) m‑y C y (D 1‑z E. z ) 8‑m o 12 , wherein, A is at least one of Y, Gd, Tb, Lu; B is at least one of La, Yb; C is Ce, Pr, Nd, Sm, Eu, Dy, Ho, Er, Tm, Ti At least one of , Cr, Mn; D is Ga; E is at least one of B, Al, In, Sc; wherein, x, y, z, m represent the mole fraction of the corresponding element, and 0≤x≤ 0.2, 0.0001≤y≤0.2, 0≤z≤0.8, 2.5≤m≤3.5. The present invention also provides a preparation method of long afterglow phosphor. In the method, a two-step sintering process of oxidizing atmosphere and then reducing atmosphere is adopted to obtain long afterglow phosphor that can be effectively excited by blue light, has high luminous intensity and long afterglow time. The long afterglow phosphor can meet the application requirements of DC / AC LEDs, has practical application value and broad commercial prospects.

Description

technical field [0001] The invention relates to the field of luminescent materials, in particular to a long afterglow fluorescent powder applied to LEDs and a preparation method thereof. Background technique [0002] With the advancement of light-emitting diode (Light Emitting Diode, LED) technology, white LEDs have gradually entered the field of general lighting from the application field of special light sources. White LEDs are considered to be the fourth generation of lighting sources after incandescent lamps, fluorescent lamps and high-intensity gas discharge lamps because of their high brightness, high color rendering index, energy saving, environmental protection, long life, small size, and high reliability. [0003] The price of high-performance white LED lamps is relatively high, which is mainly caused by two factors. On the one hand, existing white LED products are mainly driven by direct current, which means that additional electronic components are required. Thr...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C09K11/80
CPCC09K11/7774
Inventor 刘永福乔建伟刘普蒋俊江浩川
Owner NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
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