White ultra-long afterglow luminescent material and preparation method thereof

Abstract

The invention belongs to the field of the materials and in particular relates to a near ultraviolet and visible light excited white ultra-long afterglow luminescent material and a preparation method thereof. The general formula of the luminescent material is (M, M*O)1-x-y.(EuO)x.(MnO)y.aAl2O3.bSiO2(1). In the formula, M and M* are one or more metallic elements selected from magnesium, calcium, strontium, barium and zinc, and a, b, x and y are amount of substance and respectively meet the following formulas: 0.5<=(a+b)<=5, b=(0.1-10)a, 0.001<=x<=0.1 and 0.001<=y<=0.5. The luminescent material is a white luminescent light storing body activated by co-doping europium and manganese or co-doping europium, manganese and one or more other rare earth (RE) elements or subjecting the elements to energy transfer with other ions. The luminescent material has the beneficial effects that the sintering body has a loose structure and is easy to break; the powder grain size is about 2-5 microns; the luminescent material has good weather resistance and acid and alkali corrosion resistance and white afterglow; and the afterglow time exceeds 12 hours.

Description

technical field [0001] The invention belongs to the field of materials, in particular to a white ultra-long afterglow luminescent material excited by near ultraviolet and visible light and a preparation method thereof. Background technique [0002] Phosphor refers to a functional material that uses external stimuli such as particle energy, electrons, and light to excite and emit light, and the luminescent body that can continue to emit light after the excitation is stopped is called "photostor", that is, long afterglow luminescence Material. Such a luminescent material is required to be practically excellent in multicoloration, afterglow performance, and good weather resistance. [0003] The long-lasting luminescent materials known so far have few types in terms of material matrix composition, and are generally limited by the shortcomings of narrow luminescence and afterglow energy distribution, monotonous color, short afterglow time, and poor weather resistance. [0004] ...

AI Technical Summary

Problems solved by technology

[0003] The long-lasting luminescent materials known so far have few types in terms of material matrix composition, and are generally limited by the shortcomings of narrow luminescence and afterglow energy distribution, monotonous color, short afterglow time, and poor weather resistance.

[0004] Taking inorganic light-emitting materials as an example, the first is a sulfide-based phosphor, such as (Ca, Sr)S:Bi that emits blue light. 3+ Phosphor, yellow-green emitting ZnS:Cu 2+ Phosphors, red-emitting (Zn, Cd)S:Cu phosphors, etc., the biggest disadvantage is poor stability, insufficient brightness and afterglow life of the luminous body

In addition, (Zn, Cd)S : Cu phosphor contains cadmium, a toxic substance, and its use is even more restricted

ZnS:Cu 2+ Phosphors are easy to decompose and turn black when exposed to ultraviolet rays under humid conditions, and the afterglow time is not enough. As cheap clock dials and evacuation guidance signs, etc., they can only be used indoors.

Oxygenate-based phosphors, such as europium-activated alkaline earth aluminate MAl 2 o 4 (Here M is one or more of magnesium, calcium, strontium, barium), although there is SrAl as reported in Journal of Electrochemical Society, volume 118, page 930 (1971) 2 o 4 :Eu phosphor exhibits relatively long life and long afterglow performance. However, due to easy deliquescence, the practical performance as a phosphor is not ideal.

As a long-lasting luminescent material, silicate-based phosphors generally have the problem of unsatisfactory afterglow performance.

On the other hand, the strontium aluminate / barium aluminate with europium as the main activator only has the maximum luminous intensity around 520nm / 500nm, and emits yellow-green light, and the brightness decays to 0.32mcd / m 2 Compared with the 200 minutes of ZnS:Cu phosphor, the afterglow characteristics are more excellent, but it still has the disadvantages of monotonous luminous color and poor weather resistance.

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