KR101599808B1 - Invisible Luminescent Material and Method for Preparing The Same - Google Patents

Abstract

The present invention relates to an invisible luminous body for exciting near-infrared rays excited by light in a visible light region, and more particularly, to an invisible luminous body made of lanthanum fluoride, lanthanum oxide, neodymium compounds and alkali metal salts as raw materials, And a manufacturing method thereof.
The unviscid luminous body manufactured by the manufacturing method according to the present invention can be manufactured in a simpler manufacturing process than the lanthanum fluoride luminous body manufactured by the conventional complex salt formation method and excited by the wavelength of the visible light region, It is effective as a phosphor to be applied to special security prints for prevention of forgery and tampering, since it is possible to manufacture a phosphor having an improved light emission intensity.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an invisible luminescent material,

The present invention relates to an invisible luminous body for exciting near-infrared rays excited by light in a visible light region, and more particularly to an invisible luminous body using a lanthanum fluoride, a lanthanum oxide, a neodymium compound and an alkali metal salt as raw materials, And a manufacturing method thereof.

Luminescence is a phenomenon in which light is emitted without accompanying heat, such as fluorescence or phosphorescence. A substance, such as an incandescent lamp, generally emits light when it is hot, meaning it emits light by other stimuli than heat, and is therefore also called a cold light. Generally, a substance refers to a phenomenon in which light is absorbed by light, X-rays, radiation, and chemical stimuli and absorbs the energy to emit light, except for special ones such as thermal radiation, cherenkopy radiation, Rayleigh scattering, and Raman scattering. The bioluminescence in which a creature such as a firefly or a red light is emitted by itself can be said to be a chemical luminescence which causes a redox reaction.

In some cases, luminizing is classified into fluorescence and phosphorescence, but this classification is different between inorganic and organic compounds. There are many definitions for inorganic emitters, especially fluorescence is used as a synonym. The organic compound distinguishes by the spin multiplicity of the two electron states involved in the electron transition. Light emission by the transition between electron states having the same multiplicity is referred to as fluorescence, and the other case is referred to as phosphorescence.

The materials constituting the light emitting body are largely composed of a host, an activator, and a flux. The host of the luminous body plays a role of holding the active agent which forms the luminescent center and the luminescence characteristic is represented by the active agent which is substituted with the cation of the mother. Therefore, the size of the mother cations should be small so as to be able to substitute with the active agent. An activator is an ion that actually receives light from a matrix and emits light. It is mainly substituted by a cation to the cation site of the mother to exhibit luminescence characteristics. In order to obtain the desired particle size of the light emitting body, a high temperature calcination process is performed at a temperature higher than 1,000 ° C. In this case, a substance added to help particle growth by agglomeration of particles is a flux.

Lanthanum ion-based luminous materials attract various interests as lamps, phosphors in display devices, components of optical telecommunication, active materials of lasers, and the like.

Conventional Literature Nano Letters Vol. 2, No. 7, 733 to 737 (2002) discloses a lanthanum trioxide compound which is produced by a complex salt formation method using a trivalent holmium compound such as holmium chloride, Fluoride (LaF ₃ ) phosphors are described. This document describes a method for producing nanoparticles of LaF ₃ : Ho ^{3 +} which excites at 514 nm and emits light at 1060 nm by the complex formation method. However, when phosphors are produced by the complex formation method, the cost of raw materials is high There is a problem in mass production because the production yield is low and there is difficulty in coagulation and powdering even in handling.

The light characteristic of exciting by visible light and emitting near-infrared light is suitable for prevention of forgery and modulation and mixing with printing ink to utilize for authenticity emotion but the light characteristic of the light emitter disclosed in the above paper is maintained, The study on the manufacturing method which can show

Thus, the present inventors have made many efforts, further used as a lanthanum oxide as a host, and using the alkali metal salt compound as a flux, and using a neodymium compound as active agent by the solid phase reaction method LaF ₃ in order to solve the above problems: Nd ^{3 +} , it was confirmed that the luminescence characteristics were maintained and the luminescence intensity was higher, and the present invention was completed.

An object of the present invention is to provide an incoherent phosphor that excites at a wavelength of 590 nm and emits light at a wavelength of 1072 nm in an infrared region and a method of manufacturing the same. More particularly, the present invention relates to a lanthanum fluoride and lanthanum oxide as a matrix, And a method of manufacturing the same, which is manufactured using a neodymium compound and has high light emission intensity.

In order to accomplish the above object, the present invention provides a method for manufacturing a semiconductor device, comprising: mixing lanthanum trifluoride (LaF ₃ ), lanthanum oxide (La ₂ O ₃ ), a neodymium compound, and an alkali metal salt compound; Calcining the mixture under atmosphere; And cooling this was the calcined mixture to room temperature when the ratio including the step of grinding the light emitting _{(LaF 3) (1-x} ) · (La 2 O 3) x: Nd 3 +, M (M = an alkali metal, and 0 < x < 1) and an unvisible phosphor prepared by the above production method.

The unviscid luminous body manufactured by the manufacturing method according to the present invention can be manufactured in a simpler manufacturing process than the lanthanum fluoride luminous body manufactured by the conventional complex salt formation method and excited by the wavelength of the visible light region, It is effective as a phosphor to be applied to special security prints for prevention of forgery and tampering, since it is possible to manufacture a phosphor having an improved light emission intensity.

Fig. 1 shows excitation and emission spectra of Examples 1 to 3 and Comparative Example 1. Fig.
Fig. 2 shows excitation and luminescence intensities of Examples 1 to 3 and Comparative Example 1. Fig.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein and the experimental methods described below are well known and commonly used in the art.

The invention In one aspect, the step of mixing the lanthanum _{fluoride;; (La 2 O 3 Lanthanium} oxide), neodymium compound and an alkali metal salt compound (Lanthanium trifluoride LaF _3), lanthanum oxide; Calcining the mixture under atmosphere; And cooling this was the calcined mixture to room temperature when the ratio including the step of grinding the light emitting _{(LaF 3) (1-x} ) · (La 2 O 3) x: Nd 3 +, M (M = an alkali metal, and 0 < x < 1).

Non-visible light emitting body which is produced by the production method of the present invention _{(LaF 3) (1-x} ) · (La 2 O 3) x: Nd 3 +, M (M = an alkali metal, and 0 <x <1) has its own color And is characterized by being excited by visible light to emit near-infrared light, specifically, excited at a wavelength of about 590 nm and emitting at a wavelength of about 1072 nm.

In order to obtain strong luminescence intensity, it is preferable that the raw material is constituted by using lanthanum fluoride and lanthanum oxide as the matrix, neodymium compound as the activator, and alkali metal salt compound as the flux. In one embodiment of the present invention, it was confirmed that when the alkali metal salt compound is used as the flux, the light emission intensity is improved by 10 to 40% as compared with the case where the flux is not used.

In the present invention, the neodymium compound may be at least one selected from the group consisting of neodymium chloride, neodymium nitride, and neodymium oxide.

In the present invention, the alkali metal salt compound may be at least one selected from the group consisting of a lithium compound, a potassium compound, and a sodium compound. When the alkali metal salt compound is used as a flux, uniform mixing of the matrix and the activator occurs at the reaction temperature, so that concentration quenching due to localization of the activator does not occur and the luminous efficiency is increased. In addition, it acts not only as a flux but also as a charge compensating agent, contributing to the electrical stabilization of the final material. The charge compensation agent refers to a substance that compensates the charge when the cation charge of the mother is different from the charge amount of the substituting active agent because the charge is excessively generated. In the present invention, the lithium compound may be LiCO ₃ , Li ₂ O, LiOH or the like. The potassium compound may be K ₂ CO ₃ or KOH. The sodium compound may be Na ₂ CO ₃ , NaHCO ₃ , Can be used.

The raw materials are uniformly mixed and subjected to a calcination and heat treatment step in an electric furnace under the atmosphere. In the conventional solid-phase reaction method, firing and heat treatment are carried out under a nitrogen atmosphere. However, in the present invention, by reacting in an atmospheric environment without using a gas for artificially forming an oxidation and reduction atmosphere, And it was confirmed that the nonvisible phosphor of the present invention can be manufactured stably even in an atmosphere other than a nitrogen atmosphere. The specific composition of the air atmosphere of the present invention is the same as that of general air, specifically, a composition in which nitrogen and oxygen are mixed at a ratio of about 2: 8.

In the present invention, the sintering step may be performed by heating the sintering furnace to 200 to 400 ° C. for 1 to 3 hours in an electric furnace under an atmospheric pressure, maintaining the temperature for 1 hour, raising the temperature to 900 to 1200 ° C. for 2 to 4 hours, .

For the mixing of the preferable raw material, the content of the lanthanum oxide may be 25 to 40 moles per 100 moles of lanthanum fluoride. When the lanthanum oxide is contained in an amount of less than 25 moles per 100 moles of fluoroalkane, the amount of the lanthanum oxide is too small to exhibit a stable luminescent effect. When the lanthanum oxide is contained in an amount exceeding 40 moles, the luminescent effect tends to be rather reduced. To 25 mol% based on the total molar amount of the catalyst.

In the present invention, the content of the neodymium compound may be 0.5 to 5 moles per 100 moles of lanthanum fluoride. Since the neodium compound is used as an activator in the process of producing the phosphor of the present invention, when the amount of the neodymium compound exceeds 5 moles per 100 moles of lanthanum fluoride, the luminescence intensity is not further increased.

In the present invention, the content of the alkali metal salt compound is 0.5 to 5 moles with respect to 100 moles of lanthanum fluoride. When the alkali metal salt compound used as the flux is contained in an amount exceeding 5 mol, the chemical resistance of the produced non-visible luminous body may be deteriorated.

That is, the non-visible luminous body manufactured by the manufacturing method of the present invention may have a constitution expressed by the following formula.

_{(LaF 3) (1-x} ) · (La 2 O 3) x: Nd 3 +, M (M = an alkali metal, and 0 <x <1)

It was confirmed that the unvis- ible light emitting body manufactured by the manufacturing method of the present invention was excited by the light of 590 nm in the visible light region and emitted strong light at the wavelength of 1072 nm in the infrared region.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are only for illustrating the present invention and that the scope of the present invention is not construed as being limited by these embodiments.

LaF ₃ 57.75 mol

La ₂ O ₃ 19.13 mol

Nd ₂ O ₃ 1.00 mol

Na ₂ CO ₃揃 10H ₂ O 1.00 mol

Each of the above materials was weighed and uniformly mixed. The mixture was charged in an alumina crucible under an air atmosphere, heated to 300 DEG C over 1 hour in an electric furnace, maintained for 1 hour, elevated to 1,000 DEG C over 3 hours, maintained for 2 hours, Lt; / RTI &gt;

The thus obtained phosphor was pulverized using a mortar, and the excitation, emission spectrum and emission intensity were measured using a fluorescence spectrophotometer, and the results are shown in FIGS. 1 and 2. FIG.

LaF ₃ 57.75 mol

La ₂ O ₃ 19.13 mol

Nd ₂ O ₃ 1.00 mol

K ₂ CO ₃ 1.00 mol

Each of the above materials was weighed and uniformly mixed. The mixture was charged in an alumina crucible under an air atmosphere, heated to 300 DEG C over 1 hour in an electric furnace, maintained for 1 hour, elevated to 1,000 DEG C over 3 hours, maintained for 2 hours, Lt; / RTI &gt;

The thus obtained phosphor was pulverized using a mortar, and the excitation, emission spectrum and emission intensity were measured using a fluorescence spectrophotometer, and the results are shown in FIGS. 1 and 2. FIG.

LaF ₃ 57.75 mol

La ₂ O ₃ 19.13 mol

Nd ₂ O ₃ 1.00 mol

Li ₂ CO ₃ 1.00 mol

Each of the above materials was weighed and uniformly mixed. The mixture was charged in an alumina crucible under an air atmosphere, heated to 300 DEG C over 1 hour in an electric furnace, maintained for 1 hour, elevated to 1,000 DEG C over 3 hours, maintained for 2 hours, Lt; / RTI &gt;

The thus obtained phosphor was pulverized using a mortar, and the excitation, emission spectrum and emission intensity were measured using a fluorescence spectrophotometer, and the results are shown in FIGS. 1 and 2. FIG.

Comparative Example  One

LaF ₃ 57.75 mol

La ₂ O ₃ 19.13 mol

Nd ₂ O ₃ 1.00 mol

Each of the above materials was weighed and uniformly mixed. The mixture was charged in an alumina crucible under an air atmosphere, heated to 300 DEG C over 1 hour in an electric furnace, maintained for 1 hour, elevated to 1,000 DEG C over 3 hours, maintained for 2 hours, Lt; / RTI &gt;

The thus obtained phosphor was pulverized using a mortar, and the excitation, emission spectrum and emission intensity were measured using a fluorescence spectrophotometer, and the results are shown in FIGS. 1 and 2. FIG.

In FIG. 1, it can be seen that in Examples 1 to 3 and Comparative Example 1, light is excited at a wavelength of 590 nm, which is a visible light region, and emitted at a wavelength of 1072 nm, which is a near infrared region.

The light emission intensity shown in FIG. 2 is shown in the following Table 1. In Table 1, when the luminescence intensity of the comparative example is 1.00, the luminescence intensities of the other examples are corrected and shown.

LaF ₃ (mol) La ₂ O ₃ (mol) Nd ₂ O ₃ (mol) Ho ₂ O ₃ (mol) Alkali metal salts Emission intensity Example 1 57.75 19.13 1.00 - Na / 1.00 1.09 Example 2 57.75 19.13 1.00 - K / 1.00 1.02 Example 3 57.75 19.13 1.00 - Li / 1.00 1.40 Comparative Example 1 57.75 19.13 1.00 - - 1.00

As shown in Table 1, when the alkali metal salt compound was used as a starting material, it was confirmed that the light emission intensity was improved by 2 to 40%. Among the alkali metal salt compounds, when lithium was used It was possible to obtain the effect of increasing the light emission intensity most.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. something to do. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (8)

Mixing Lanthanium trifluoride (LaF ₃ ), lanthanum oxide (La ₂ O ₃ ), a neodinium compound, and an alkali metal salt compound;
Calcining the mixture under atmosphere; And
The was the was fired mixture was cooled to room temperature, and then the milling step non-visible light emitting body including a to _{(LaF 3) (1-x} ) · (La 2 O 3) x: Nd 3 +, M (M = an alkali metal, and 0 < x < 1).
The method according to claim 1, wherein the neodymium compound is at least one selected from the group consisting of neodymium chloride, neodymium nitride, and neodymium oxide.
The method according to claim 1, wherein the alkali metal salt compound is at least one selected from the group consisting of a lithium compound, a potassium compound, and a sodium compound.
The method according to claim 1, wherein the calcination step is performed in an electric furnace under an atmospheric temperature for 1 to 3 hours to 200 to 400 ° C, maintained for about 1 hour, raised to 900 to 1200 ° C for 2 to 4 hours, And firing the mixture.
The production method according to claim 1, wherein the content of the lanthanum oxide is 25 to 40 moles per 100 moles of lanthanum fluoride.
The production method according to claim 1, wherein the content of the neodymium compound is 0.5 to 5 moles per 100 moles of lanthanum fluoride.
The method according to claim 1, wherein the content of the alkali metal salt compound is 0.5 to 5 moles with respect to 100 moles of lanthanum fluoride.
(LaF ₃ ) _(1-x) (La ₂ O ₃ ) _x : Nd ³ , which is prepared by the method of any one of claims 1 to 7 and excites at a wavelength of about 590 nm and emits at a wavelength of about 1072 nm ⁺ , M (M = alkali metal and 0 < x < 1) phosphor.

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