KR101646675B1

KR101646675B1 - Dual-mode-emitting nanophosphor with core-multishell structure and synthetic method thereof and transparent polymer composite including the nanophosphor

Info

Publication number: KR101646675B1
Application number: KR1020150103855A
Authority: KR
Inventors: 장호성; 김수연; 김선진; 조소혜; 이승용
Original assignee: 한국과학기술연구원
Priority date: 2015-07-22
Filing date: 2015-07-22
Publication date: 2016-08-09

Abstract

The present invention relates to an up-conversion core nanoparticle comprising a first fluoride-based compound co-doped with Yb ³ ⁺ , Er ³ ⁺ ; A downconverting luminescent shell surrounding the core nanoparticles and containing a second fluoride-based compound coactivated with Ce ³ ⁺ and Tb ³ ⁺ ; And a crystalline shell surrounding the light emitting shell and containing a fluoride-based third compound, and a method of manufacturing the nanofluorescent material.
The present invention also relates to a polymer composite, a contrast agent and an anti-falsification cord comprising the nano-phosphor of the core-multi-shell structure of the present invention.

Description

TECHNICAL FIELD [0001] The present invention relates to a dual-emitting nano fluorescent material having a core-multishell structure, a method for synthesizing the same, and a transparent polymer composite including the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to an up-conversion core nanoparticle comprising a first fluoride-based compound co-doped with Yb ³ ⁺ , Er ³ ⁺ ; A downconverting luminescent shell surrounding the core nanoparticles and containing a second fluoride-based compound coactivated with Ce ³ ⁺ and Tb ³ ⁺ ; And a crystalline shell surrounding the light emitting shell and containing a fluoride-based third compound, and a method of manufacturing the nanofluorescent material.

The present invention also relates to a polymer composite, a contrast agent and an anti-falsification cord comprising the nano-phosphor of the core-multi-shell structure of the present invention.

Nano-phosphors have a structure in which a lanthanide element is doped in a matrix such as oxide, fluoride, sulfide, or nitride having a size of 100 nm or less. Nano-phosphors doped with lanthanide tribasic ions other than Ce ³ ⁺ ions exhibit intrinsic luminescent color depending on the doped lanthanide element regardless of the type of the host [Luminescent Materials (1994)]. This is because the luminescence of the nanophosphor is caused by the 4f-4f electron transition in the lanthanide tribasic ion doped into the matrix. Therefore, it is advantageous to control the size of the particles variously according to need or to maintain the desired emission wavelength even when the particle size is uneven in the synthesis.

Since these nano-phosphors vary in luminescence intensity depending on the type of host to which the same lanthanide element is doped, a proper host must be selected in order to obtain strong luminescence.

When the phosphor is irradiated with light having a large energy such as an ultraviolet ray or a visible ray from the outside, electrons at the base level are excited, and after a partial energy loss, visible light having a longer wavelength than the incident light is emitted. The difference between the absorption wavelength and the emission wavelength is referred to as Stokes shift. In this case, when the lanthanide element is doped, it emits light through the anti-Stokes shift process which is excited by the infrared ray and emits visible light having a shorter wavelength than the excitation light. In this case, it is referred to as up-conversion luminescence by distinguishing it from down-conversion in which luminescence energy is lower than excitation energy [Chem. Rev. vol. 104, 139-174 (2004)). Phosphors showing up-conversion luminescence are very suitable for application as fluorescent contrast agents because they emit light by infrared rays. When infrared imaging is used for cell imaging, self-luminescence is not induced from the cells, and fluorescence images with a high signal-to-noise ratio can be obtained when an upconverting phosphor is used. Unlike the commonly used micrometer-sized powder phosphors, nano-sized phosphors having a nanometer size can be applied to bioimages such as cell imaging or in vivo imaging because they can adhere to or enter the surface of a cell. In general, organic dyes are widely used as bio-imaging agents. Organic dyes exhibit various luminescent colors depending on the type and exhibit strong luminescence intensity, but they are disadvantageous in that their light stability is very weak and the luminescence intensity is greatly weakened even when the exposure time to excitation light is slightly increased [ACS Nano vol. 6, 3888-3897 (2012)). Recently, attempts have been made to apply an inorganic light emitting material such as a quantum dot as a bio-imaging agent in order to solve such a problem. However, flickering of a luminescence occurs in a quantum dot [Nature vol. 459, 686-689 (2009)], and it is difficult to apply a heavy metal such as Cd in the case of CdSe. On the other hand, nanoporous phosphors are excellent in light stability because they are inorganic and do not contain toxic elements such as Cd. Therefore, they are suitable to replace conventional fluorescent contrast agents. However, in the case of up-conversion luminescence, two photons having small energy are absorbed by the phosphor and one photon having a large energy is emitted, resulting in low luminous efficiency. Particularly, since the particle size of the phosphor decreases, surface defects per unit volume of the nanophosphor in a nanometer size region are greatly increased, and the efficiency of up-conversion luminescence is further lowered. Therefore, there is an urgent need to develop a nano-phosphor having small particle size, uniformity, and high up-conversion luminescence intensity in order to perform fluorescence imaging with high sensitivity. In addition, when light emitted from a single nano-fluorescent material as well as infrared light is emitted, it is possible to further enhance the accuracy of fluorescence imaging. In addition, when Gd having a paramagnetic property is present on the surface of a nano-fluorescent material, Magnetic Resonance By applying it as an imaging contrast agent, fluorescence imaging and MR imaging can be performed at the same time, which further improves imaging accuracy. In addition, when light can be emitted by infrared rays and ultraviolet rays, a transparent display material can be realized by forming a transparent luminescent material.

Therefore, there is a continuing need for the development of multifunctional nano-phosphors, which exhibit strong luminescence even at the time of infrared and ultraviolet excitation and have further paramagnetic properties.

It is an object of the present invention to provide an up-conversion core nanoparticle comprising a first fluoride-based compound co-doped with Yb ³ ⁺ , Er ³ ⁺ ; A downconverting luminescent shell surrounding the core nanoparticles and containing a second fluoride-based compound coactivated with Ce ³ ⁺ , Tb ³⁺ ; And a crystalline shell surrounding the light emitting shell and containing a fluoride-based third compound, and a method for producing the nanophosphor.

It is still another object of the present invention to provide a polymer composite, a contrast agent and an anti-falsification cord comprising the nano-phosphor of the core-multi-shell structure of the present invention.

One aspect of the present invention is to provide a nano-phosphor having a core-multi-shell structure, which comprises a first fluorine-based compound co-doped with Yb ³ ⁺ , Er ³ ⁺ Upconversion core nanoparticles; A downconverting luminescent shell comprising a second fluoride-based compound co-activated with Ce ³ ⁺ and Tb ³ ⁺ represented by the following formula (2) to surround the core nanoparticles; And a crystalline shell containing a third fluoride compound represented by the following general formula (3) to surround the light emitting shell.

[Chemical Formula 1]

LiGd ₁ _-xy- _z L _z F ₄ : Yb ³ ⁺ _x , Er ³ ⁺ _y

Wherein x is a real number of 0.1? X? 0.9, y is a real number of 0 <y? 0.1 and 0.1 <x + y? 1, z is a real number of 0.3? Z? Is selected within a range satisfying 0.3? Z? 1-xy, and L is any one selected from the group consisting of Y, Dy, Ho, Tm, Lu and combinations thereof.

(2)

_{LiY 1 -p- q F 4: Ce} 3 + p, Tb 3 + q

In the formula (2), p is a real number of 0 < p < = 0.25, and q is a real number of 0 <

(3)

LiY ₁ _- _r M _r F ₄

In the formula (3), r is a real number of 0? R? 1 and M is a group consisting of La, Ce, Pr, Nd, Pm, Sm, Dy, Ho, Er, Tm, Yb, Lu, Any one selected.

In certain embodiments, the nanophosphor may further include a paramagnetic shell surrounding the crystalline shell and comprising a fourth compound represented by Formula 4:

[Chemical Formula 4]

LiGdF ₄ _.

The nanophosphor of the present invention comprises up-converted core nanoparticles and a shell located on the surface of the core nanoparticles, wherein the shell is in the form of a multishell having two or more multi-layer structures.

Thus, in certain embodiments, the nanophosphors of the present invention may have a multi-layer structure of core / shell / shell or core / shell / shell / shell, and each shell may be a downconverted emissive shell, a crystalline shell or a paramagnetic shell have.

In a specific embodiment, the nanophosphor of the present invention comprises upconverted core nanoparticles comprising a first fluoride-based compound co-activated with Yb ³⁺ , Er ³ ⁺ represented by Formula 1, wherein the core nanoparticles And a fluoride-based second compound co-activated with Ce ³ ⁺ , Tb ³ ⁺ represented by the above-mentioned formula (2), and a ^third fluoride-based compound represented by formula Or a core / luminescent shell / crystalline shell structure comprising a crystalline shell comprising the compound. The up conversion compound Li (Gd, L) F ₄ : Yb, Er contained in the nanophosphor of the present invention is a tetragonal nanoparticle having high emission intensity and the down conversion compounds LiYF ₄ , Ce, and Tb have high quantum efficiency, , It shows a strong green light emission, and even when excited by an ultraviolet light lamp, it can show strong green light emission. In addition, by further including a crystalline shell in the upper layer of the light emitting shell and including LiYF ₄ in the crystalline shell, the effects of upconversion and downconversion enhancement can be significantly increased.

Wherein x is a real number of 0.1? X? 0.9, y is a real number of 0 <y? 0.1 and 0.1 <x + y? 1, z is a real number of 0.3? Z? Is selected within a range satisfying 0.3? Z? 1-xy, and L is any one selected from the group consisting of Y, Dy, Ho, Tm, Lu and combinations thereof. Under these conditions, Can increase the ratio of the green emission peak to the red emission peak of the light obtained therefrom, so that excellent green emission can be obtained.

In the formula (2), p is a real number of 0 <p? 0.25, and q is a real number of 0 <q? 0.5. Under these conditions, the nanophosphorescent material of the present invention minimizes the concentration quenching phenomenon, A strong green luminescence can be obtained.

In the formula (3), r is a real number of 0? R? 1 and M is a group consisting of La, Ce, Pr, Nd, Pm, Sm, Dy, Ho, Er, Tm, Yb, Lu, Under these conditions, the nano-phosphors of the present invention can reduce surface defects and increase up-conversion and down-conversion luminescence.

In another specific embodiment, the nanophosphor of the present invention may further comprise a paramagnetic shell comprising the fourth compound represented by Formula 4 formed on the crystalline shell.

In the formula (4), the fourth compound may be LiGdF _4. By forming the outermost layer as a shell having paramagnetic properties in the upper layer of the crystalline shell as described above, the up-conversion and down-conversion effects of the nano- It can be a factor to make. As a result, the nanophosphor of the present invention may have magnetic properties as well as strong upconversion and downconversion characteristics. That is, since the nanofluorescent material of the present invention can obtain not only up-conversion using infrared rays but also additional emission signal of down conversion using ultraviolet rays, bio-imaging by two modes of fluorescence can be performed, The accuracy can be further improved and the magnetic contrast can be enhanced, so that the contrast of the image can be enhanced with the magnetic resonance imaging contrast agent, and a stronger and more accurate image signal can be obtained. Furthermore, when applied to a living tissue, it is possible to selectively obtain an image of a deep tissue of a living tissue by applying infrared rays and ultraviolet rays selectively or simultaneously.

In certain embodiments, the first to fourth compounds that may be included in the core and shell may be crystalline. When these compounds are crystalline, it is possible to further enhance up-conversion / down-conversion luminescence.

In the nanophosphor, the core nanoparticles may have a tetragonal lattice structure. In this case, a nanophosphor having a strong luminescence intensity can be obtained.

In the nanophosphor, the particle size of the core nanoparticles may be 1-70 nm. The nanophosphor may have a particle size of 2-100 nm. The nanofluorescent material of the present invention has a structure of core and shell, but can be implemented in a considerably small size and exhibits strong luminescence in spite of its small size, so that it can be applied to a living body such as a cell experiment with a contrast agent ( ex vivo ), in vivo ( in vivo ).

Another aspect of the present invention provides a method for producing a nano-phosphor having a core-multi-shell structure, which comprises the steps of (i) mixing Yb ³ ⁺ , Er ³ ⁺ Forming an upconversion core nanoparticle comprising a fluoride-based first compound; (ii) forming a downconversion luminous shell nanoparticle comprising the second fluoride-based compound coexisting with Ce ³ ⁺ and Tb ³ ⁺ represented by the following formula (2) to surround the core nanoparticles; And (iii) forming a crystalline shell nanoparticle comprising the third fluoride compound represented by the following formula (3) to surround the light emitting shell nanoparticles.

[Chemical Formula 1]

LiGd ₁ _-xy- _z L _z F ₄ : Yb ³ ⁺ _x , Er ³ ⁺ _y

(2)

_{LiY 1 -p- q F 4: Ce} 3 + p, Tb 3 + q

(3)

LiY ₁ _- _r M _r F ₄

The method may further include (iv) forming paramagnetic shell nanoparticles containing the fourth compound represented by the following formula (4) to surround the crystalline shell nanoparticles.

[Chemical Formula 4]

LiGdF ₄

In the method for producing a nano-phosphor according to the present invention, the first to fourth compounds of the formulas (1) to (4) will be described in detail since they are the same as those in the description of the nano-phosphor according to one aspect of the present invention.

In the method for manufacturing a nano-fluorescent material, the step (i) may include: preparing a first mixed solution containing a gadolinium precursor, a yttrium precursor, an ytterbium precursor, an erbium precursor, and an oleic acid salt, 1 complex solution; Adding oleic acid and 1-octadecene to the first complex solution and heating to form a first reaction solution; And a core forming step of adding an alcohol solution containing a lithium precursor and a fluorine precursor to the first reaction solution and heating to form core nanoparticles.

In the method for producing a nano-phosphor, the step (ii) may include the steps of preparing a second mixed solution containing an yttrium precursor, a cerium precursor, a terbium precursor and an oleic acid salt, heating the second mixed solution, ; Adding oleic acid and 1-octadecene to the second complex solution and heating to form a second reaction solution; And adding core nanoparticles to be contained in the light emitting shell nanoparticles to the second reaction solution, adding an alcohol solution containing a lithium precursor and a fluorine precursor, and heating the resultant to form a light emitting shell on the surface of the core nanoparticle To form a light-emitting shell.

In the method for manufacturing a nano-phosphor, the step (iii) may include the steps of: preparing a third mixed solution containing an yttrium precursor and an oleic acid salt; and heating the third mixed solution to form a third complex solution; Adding oleic acid and 1-octadecene to the third complex solution and heating to form a third reaction solution; And the third reaction solution is added with the light emitting shell nanoparticles to be contained in the crystalline shell nanoparticles, an alcohol solution containing a lithium precursor and a fluorine precursor is added, and the mixture is heated to form a crystalline shell To form a crystalline shell.

In the method for manufacturing a nano-phosphor, the step (iv) may include: preparing a fourth mixed solution containing a gadolinium precursor and an oleic acid salt, and heating the fourth mixed solution to form a fourth complex solution; Adding oleic acid and 1-octadecene to the fourth complex solution and heating to form a fourth reaction solution; And crystalline aluminosilicate nanoparticles to be contained in the paramagnetic shell nanoparticles are added to the fourth reaction solution and an alcohol solution containing a lithium precursor and a fluorine precursor is added and heated to form a paramagnetic shell nanoparticle on the surface of the paramagnetic shell, To form a paramagnetic shell.

The oleic acid salt used in the complex solution solution forming step (i) to (iv) may be any one selected from the group consisting of sodium oleate, potassium oleate, and a combination thereof. The lanthanide precursor May be applied if they are capable of reacting to form a complex, and preferably the oleic acid salt may be sodium oleate.

The lanthanide complex includes gadolinium oriate formed by reacting the gadolinium precursor and the oleic acid salt, yttrium oleate formed by the reaction of the yttrium precursor and the oleic acid salt, the ytterbium precursor and the oleic acid salt reacting , Erbium oresite formed by reacting the erbium precursor and the oleic acid salt, cerium oleate formed by the reaction of the cerium precursor and the oleic acid salt, and the terbium precursor and the oleic acid salt And a terbium precursor formed by the reaction.

The complex solution forming step may include a heating step, which may be performed at 50 to 80 ° C for 1 to 4 hours, and preferably at about 70 ° C. When the heating is carried out over the time in the range of the above temperature, the above-mentioned complex compound such as gadolinium oleate, yttrium oleate, ytterbium orioate, erbium oleate, cerium oleate and terbium oleate may be added to oleic acid and 1-octadisene It can be dissolved well.

The reaction solution forming step included in steps (i) to (iv) includes a heating step of forming a reaction solution. The heating can be performed at 130 to 160 ° C for 15 minutes to 2 hours, and preferably at 150 ° C for 30 minutes. When the heating is performed in the range of the above temperature, the lanthanide precursor may be dissolved in the solvent and be uniformly dispersed.

The forming of the core, the luminescent shell, the crystalline shell and the paramagnetic shell included in the steps (i) to (iv) may be performed by adding an alcohol solution containing a lithium precursor and a fluorine precursor to the reaction solution, Shell nanoparticles, crystalline shell nanoparticles, and paramagnetic shell nanoparticles. The sodium precursor may be any one selected from the group consisting of sodium hydroxide, sodium fluoride, sodium oleate, and combinations thereof. The fluorine precursor may be any one selected from the group consisting of ammonium fluoride, sodium fluoride, and combinations thereof. . In the above, sodium fluoride can act as both the sodium precursor and the fluorine precursor. In addition, the alcohol may be a lower alcohol having 1 to 6 carbon atoms, and may be methanol. The heating process in the nanoparticle formation step may be performed at a temperature of 200 to 370 ° C, more preferably 250 to 330 ° C, for 10 minutes to 4 hours, more preferably for 1 hour To 3 hours. At this time, when the heat treatment temperature is lower than 200 ° C, a single tetragonal nanocrystal is not completely formed and the phosphor does not exhibit strong luminescence. If the temperature is higher than 370 ° C, aggregation of particles occurs due to excessive reaction, resulting in a very large particle size, a uniform distribution of the size, and a disadvantage that the luminance is lowered. Therefore, it is preferable that the heat treatment temperature is 200-370 占 폚 and the heat treatment time is 10 minutes to 4 hours. When the heat treatment time is less than 10 minutes, crystal formation in the nanophosphor may be insignificant. When the heat treatment time exceeds 4 hours, the size of the nanophosphor may be increased due to agglomeration or the like. The heat treatment in the heating process may be performed in an inert gas atmosphere. Since the alcohol is contained in the nanoparticle forming step, the nanoparticle forming step may include a step of removing the alcohol before the final heat treatment.

The gadolinium precursor used in the method for producing a nano-phosphor according to the present invention may be one selected from the group consisting of gadolinium acetate (Gd (CH ₃ COO) ₃ ), gadolinium chloride (GdCl ₃ ), gadolinium chloride hydrate (GdCl ₃ .6H ₂ O) Lt; / RTI > The yttrium precursor may be any one selected from the group consisting of yttrium acetate (Y (CH ₃ COO) ₃ ), yttrium chloride (YCl ₃ ), yttrium chloride hydrate (YCl ₃ .6H ₂ O), and combinations thereof. The ytterbium precursor may be any one selected from the group consisting of ytterbium acetate (Yb (CH ₃ COO) ₃ ), ytterbium chloride (YbCl ₃ ), ytterbium chloride (YbCl ₃ .6H ₂ O) . The erbium precursor may be any one selected from the group consisting of erbium acetate (Er (CH ₃ COO) ₃ ), erbium chloride (ErCl ₃ ), erbium chloride (ErCl ₃ .6H ₂ O), and combinations thereof. The cerium precursor may be any one selected from the group consisting of cerium acetate (Ce (CH ₃ COO) ₃ ), cerium chloride (CeCl ₃ ), cerium chloride hydrate (CeCl ₃ .7H ₂ O), and combinations thereof. The terbium precursor may be any one selected from the group consisting of terbium acetate (Tb (CH ₃ COO) ₃ ), terbium chloride (TbCl ₃ ), terbium chloride (TbCl ₃ .6H ₂ O), and combinations thereof.

The nanophosphor of the present invention may be stored in a nonpolar solvent after being cooled and washed at a normal temperature. The nonpolar solvent may be hexane, toluene or chloroform, but is not limited thereto.

In order to achieve the above object, a polymer composite according to another embodiment of the present invention includes the nanophosphor of the present invention. The use of the nano-phosphors of the present invention makes it possible to produce highly transparent polymer composites due to their uniform and small size.

In order to achieve the above object, the contrast agent according to another embodiment of the present invention includes the nanophosphor of the present invention.

In certain embodiments, the contrast agent may be a fluorescent contrast agent or a magnetic resonance contrast agent.

Since the contrast agent exhibits a dual emission characteristic that is sufficiently excited to be applicable to a living body by being excited by infrared rays and ultraviolet rays despite the small particle size of the nanophosphor, the contrast of the biosynthesized image is higher than that of the conventional contrast agent And the accuracy of the image contrast agent can be improved. In addition, a deep image of the living tissue can be obtained. In addition, when the nanophosphor of the present invention includes a paramagnetic shell on the outermost surface, the magnetic property enables the nanophosphor of the present invention to be used not only as a fluorescent contrast agent but also as a magnetic resonance imaging agent.

According to another aspect of the present invention, there is provided an anti-fake cord comprising the nanophosphor of the present invention. The anti-falsification cord has a characteristic of emitting light simultaneously under invisible infrared rays and ultraviolet rays, and has a magnetic property according to need, so that it can be applied to a high-grade security code by further improving security. Further, since the size of the nanoporous phosphor is very small in nanoseconds, it can not be easily detected by a general method, and thus it can be used as an anti-falsification code such as an anti-counterfeit code.

In addition, the nanophosphor of the present invention can be incorporated into an infrared sensor or an ultraviolet sensor to provide a highly sensitive sensor, and the efficiency of the solar cell can be enhanced by being included in the solar cell. The infrared sensor includes the nanophosphor that is excited by infrared rays to emit light, thereby improving the sensitivity of the infrared sensor. Since the solar cell includes the nano-fluorescent substance that can convert infrared rays and ultraviolet rays, which can not be utilized in solar cells, into visible light usable in solar cells, it can contribute to improvement of efficiency of solar cells.

(Gd, Y) F ₄ : Yb having a single tetragonal structure and LiYF ₄ : Ce, Li 2 F ₄ , and Li ₂ O ₄ in an Er-upconverted nano-phosphor core have been proposed to solve the problems of the above- Tb down conversion luminescent shell, a fluorine-based nano-fluorescent material having a LiGaF ₄ inorganic shell crystal formed to increase the down-conversion luminescence and a LiGdF ₄ paramagnetic shell formed at the outermost of the nano- And a transparent polymer composite using the nanophosphor.

As described in detail above, according to the present invention, a core-multi-shell, for example, a core-multi-shell having a strong up-conversion / down- An inorganic nano fluorescent material having a shell / shell or core / shell / shell / shell structure can be obtained.

The inorganic nanophosphor core prepared by the present invention can be utilized not only as a bio-imaging contrast agent but also as a disease diagnosis field because it uses up-conversion luminescence. Since an additional emission signal can be obtained by using ultraviolet rays simultaneously with the emission using infrared rays, there is an advantage that the accuracy of fluorescence imaging can be improved. In addition, it can be used as a sensor for detecting infrared rays which are hard to detect by using a strong up-conversion luminescence obtained through a core-multi-shell structure.

In addition, if a paramagnetic shell exhibiting paramagnetic properties is formed at the outermost part of the nanophosphor, it can be used as a contrast agent for magnetic resonance imaging. When the multifunctional core-multi-shell nano fluorescent material of the present invention is applied to a magnetic resonance image, the contrast of the image is increased and a stronger image signal can be obtained. In addition, have. In addition, the sensitivity of the infrared sensor can be improved due to the improved efficiency of the photoluminescence property, and the efficiency of the solar cell can be improved by converting infrared rays, which can not be utilized in the solar cell, into visible light.

In addition, since the core nanoparticles included in the nanophosphor of the present invention exhibit up-conversion characteristics and can be applied to security related fields because infrared light is invisible to the naked eye, the light emission is simultaneously generated under infrared rays and ultraviolet rays, And it can be used as a counterfeit prevention code. In addition, since the nanoporous phosphor of the present invention has a particle size of 100 nm or less and is very small, it can not be easily detected and can be applied to a high-grade security code with up-conversion, down-conversion luminescence and magnetic characteristics. In addition, it is possible to manufacture a highly transparent polymer composite due to its uniform and small size, and the prepared polymer composite can exhibit both up-conversion and down-conversion characteristics, and thus can be applied to transparent display devices in the future.

In addition, since the efficiency of converting ultraviolet rays to green is high, it can be utilized in various fields such as expected to increase the efficiency of solar cell when applied to the front part of single junction amorphous Si solar cell.

1 is a conceptual diagram showing a cross section of a nano-phosphor having a core / shell / shell / shell structure which is one embodiment of the present invention.
2 is a transmission electron micrograph and a high-resolution transmission electron micrograph of the core nanoparticles contained in the nanophosphor of the present invention.
3 is a transmission electron micrograph of the core / light emitting shell nanoparticles contained in the nanophosphor of the present invention.
FIG. 4 is a transmission electron micrograph of a core / light emitting shell / crystalline shell structure nanoporous phosphor according to an embodiment of the present invention.
FIG. 5 is a transmission electron micrograph of a core / light emitting shell / crystalline shell / paramagnetic shell structure nano phosphor according to an embodiment of the present invention.
FIG. 6 is a graph showing the X-ray diffraction patterns of core nanoparticles, core / light emitting shell nanoparticles, core / light emitting shell / crystalline shell nanoparticles, core / light emitting shell / crystalline shell / paramagnetic shell nanoparticles, to be.
FIG. 7 is an up-conversion emission spectrum of core nanoparticles, core / light emitting shell nanoparticles, core / light emitting shell / crystalline shell nanoparticle, core / light emitting shell / crystalline shell / paramagnetic shell nanoparticle constituting the nanophosphor of the present invention .
8 is a down conversion luminescence spectrum of core nanoparticles, core / light emitting shell nanoparticles, core / light emitting shell / crystalline shell nanoparticles, core / light emitting shell / crystalline shell / paramagnetic shell nanoparticle constituting the nanophosphor of the present invention .
FIG. 9 is a graph showing the relationship between the refractive index of the core nanoparticles, core / light emitting shell nanoparticles, core / light emitting shell / crystalline shell nanoparticles, core / light emitting shell / crystalline shell / paramagnetic shell nanoparticles, As shown in Fig.
10 is a graph showing the relationship between the core nanoparticles, the core / light emitting shell nanoparticles, the core / light emitting shell / crystalline shell nanoparticles, the core / light emitting shell / crystalline shell / paramagnetic shell nanoparticles constituting the nanophosphor of the present invention It is a transmission electron microscope photograph of nanoparticles.
FIG. 11 is a graph showing the relationship between the core nanoparticles, the core / light emitting shell nanoparticles, the core / light emitting shell / crystalline shell nanoparticles, the core / light emitting shell / crystalline shell / paramagnetic shell nanoparticles constituting the nanophosphor of the present invention, X-ray diffraction pattern of nanoparticles.
12 is a graph showing the relationship between the core nanoparticles, the core / light emitting shell nanoparticles, the core / light emitting shell / crystalline shell nanoparticles, the core / light emitting shell / crystalline shell / paramagnetic shell nanoparticles constituting the nanophosphor of the present invention And the nanoparticle solution is excited by infrared and ultraviolet rays.
FIG. 13 is a photograph of a transparent polymer composite in which a core / luminescent shell / crystalline shell / paramagnetic shell structure nanosphere phosphor according to an embodiment of the present invention is dispersed in PDMS polymer, and a photo when excited by infrared rays and ultraviolet rays.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Example 1 Production of Nanophosphorescent Core / Emitting Shell / Crystalline Shell Structure

1. 0.18 mmol Yb ³ ⁺ , 0.02 mmol Er ³ ⁺ Revived Upconversion Preparation of core nanoparticles

Gadolinium chloride hydrate _{(GdCl 3 .6H 2 O) 0.35} mmol, yttrium chloride hydrate _{(YCl 3 .6H 2 O) 0.45} mmol, ytterbium chloride hydrate _{(YbCl 3 .6H 2 O) 0.18} mmol, erbium chloride hydrate (ErCl _3. (H ₂ O) and 3.1 mmol of sodium oleate (C ₁₈ H ₃₃ O ₂ Na) were weighed and then heat-treated at 70 ° C. by adding a mixed solvent of water, ethanol and hexane to obtain a lanthanide complex (Formation of complex solution solution). The complex was mixed with a solution containing oleic acid and 1-octadecene and heat-treated at 150 ° C for 30 minutes to prepare a reaction solution containing a lanthanide complex (reaction solution forming step). To the reaction solution, 10 ml of a methanol solution containing 2.5 mmol of lithium hydroxide and 4 mmol of ammonium fluoride was added and added. After sufficiently mixing, the methanol was removed and heat treatment was performed at 320 ° C. for 90 minutes in an inert gas atmosphere (nanoparticle formation step). After the heat treatment was completed, the mixture was cooled to room temperature and colloidal nanoparticles having a diameter of 1-40 nm were obtained. The nanoparticles thus formed were washed with acetone or ethanol and dispersed in a non-polar solvent such as hexane, toluene or chloroform.

Transmission electron micrographs of the upconverted core nanoparticles synthesized in FIG. 2 are shown. The transmission electron microscope photograph shown in FIG. 2 was measured using a TECNAI F20 G ² model of FEI. The core nanoparticles synthesized through the present invention exhibited a uniform size of 40 nm or less. Referring to the high-resolution transmission electron microscope photograph shown in FIG. 2, a distinct lattice pattern can be confirmed in one particle, which means that the synthesized nanoparticles have very high crystallinity. In order to obtain strong luminescence from the phosphor, the crystallinity of the phosphor matrix must be high, so that it is possible to obtain a nanophosphor exhibiting excellent luminescence characteristics from the high crystallinity of the nanoparticles according to the present invention.

2. 0.15 mmol Ce ³ ⁺ , 0.15 mmol Tb ³ ⁺ in Revived ball Fluoride Shell Through formation Upconversion core/ Down conversion Luminescent shell Nanoparticle fabrication of structures

The LiGd ₀ _.35 Y ₀ _.45 F ₄ was prepared in 1: a core for ^{_{^{Yb 3 + 0.18, Er 3 +}}} 0.02 nanoparticle cores to the Ce ³⁺ and Tb ³ ⁺ ion include a fluoride-based compounds ball resurrection / Shell structure was prepared.

Hydrate yttrium chloride _{(YCl 3 .6H 2 O) 0.7} mmol, cerium chloride hydrate _{(CeCl 3 .7H 2 O) 0.15} mmol, terbium chloride hydrate _{(TbCl 3 .6H 2 O) 0.15} mmol, sodium oleic acid (C ₁₈ H ₃₃ O ₂ Na) was weighed, and then a mixed solvent of water, ethanol, and hexane was added thereto, followed by heat treatment at 70 ° C to form a lanthanide complex. The complex was mixed with a solution containing oleic acid and 1-octadecene and heat-treated at 150 ° C for 30 minutes to prepare a reaction solution containing a lanthanide complex (reaction solution forming step). A mixed solution was prepared by mixing LiGd ₀ _.35 Y ₀ _.45 F ₄ : Yb ³ ⁺ _0.18 and Er ³ ⁺ _0.02 nanoparticles prepared in 1 above in the reaction solution. To the mixed solution, 10 ml of a methanol solution containing 2.5 mmol of lithium hydroxide and 4 mmol of ammonium fluoride was added and added. After sufficiently mixing, methanol was removed and heat treatment was performed at 300 ° C. for 110 minutes in an inert gas atmosphere (nanoparticle formation step). After cooling to room temperature after the heat treatment, colloidal nanoparticles with diameters of 1-50 nm are obtained. The nanoparticles thus formed were washed with acetone or ethanol and dispersed in a non-polar solvent such as hexane, toluene or chloroform.

FIG. 3 shows a transmission electron microscope photograph of the core / shell nanoparticles synthesized in FIG. Transmission electron microscopy (TEM) images show that the size of the particles increases as the shell is formed around the core.

3. Core / Luminescent shell / Crystalline shell Nano Phosphor Production of Structure

Core including a compound LiYF ₄ using ^{_{^{Ce 3 + 0.15, Tb 3 +}}} 0.15 nanoparticles: the LiGd ₀ _.35 Y ₀ _.45 F ₄ was prepared in ^{_{2: Yb 3 + 0.18, Er}} 3 + 0.02 / LiYF 4 / Shell / shell structure.

1 mmol of yttrium chloride hydrate (YCl ₃ .6H ₂ O) and 3.1 mmol of sodium oleate (C ₁₈ H ₃₃ O ₂ Na) were weighed and mixed with a mixed solvent of water, ethanol and hexane, A heat treatment was performed to form a lanthanide complex (a complex formation step). The complex was mixed with a solution containing oleic acid and 1-octadecene and heat-treated at 150 ° C for 30 minutes to prepare a reaction solution containing a lanthanide complex (reaction solution preparation step). A solution containing LiGd _0.35 Y _0.45 F ₄ : Yb ³⁺ _0.18 , Er ³⁺ _0.02 / LiYF ₄ : Ce ³⁺ _0.15 and Tb ³⁺ _0.15 nanoparticles prepared in 2 above was mixed in the reaction solution, . To the mixed solution, 10 ml of a methanol solution containing 2.5 mmol of lithium hydroxide and 4 mmol of ammonium fluoride was added and added. After sufficiently mixing, methanol was removed and heat treatment was performed at 300 ° C. for 110 minutes in an inert gas atmosphere (nanoparticle formation step). After the heat treatment is completed and the mixture is cooled to room temperature, a colloidal nanoporous phosphor having a diameter of 1-55 nm is obtained. The nano-phosphors thus prepared were washed with acetone or ethanol and dispersed in a non-polar solvent such as hexane, toluene or chloroform.

FIG. 4 shows a transmission electron micrograph of the synthesized core / shell / shell double-emitting nano fluorescent substance. Transmission electron micrographs show that the size of the shell increases as the shell is formed around the core / shell.

<Example 2> Preparation of nano-phosphors having core / luminescent shell / crystalline shell / paramagnetic shell structure

Example 1 was prepared in LiGd _0.35 _{^{_{Y 0.45 F 4: Yb 3+ 0.18}}} , Er 3+ 0.02 / LiYF 4: Ce 3+ 0.15, and Tb using the ³⁺ _0.15 / LiYF ₄ nanoparticles comprising a compound LiGdF ₄ A core / shell / shell / shell structure was prepared.

1 mmol of gadolinium chloride hydrate (GdCl ₃ .6H ₂ O) and 3.1 mmol of sodium oleate (C ₁₈ H ₃₃ O ₂ Na) were weighed and mixed with a mixed solvent of water, ethanol and hexane, A heat treatment was performed to form a lanthanide complex (a complex formation step). The complex was mixed with a solution containing oleic acid and 1-octadecene and heat-treated at 150 ° C for 30 minutes to prepare a reaction solution containing a lanthanide complex (reaction solution preparation step). A solution containing LiGd _0.35 Y _0.45 F ₄ : Yb ³⁺ _0.18 , Er ³⁺ _0.02 / LiYF ₄ : Ce ³⁺ _0.15 , and Tb ³⁺ _0.15 / LiYF ₄ nanoparticles prepared in Example 1 was added to the reaction solution, Were mixed to prepare a mixed solution. To the mixed solution, 10 ml of a methanol solution containing 2.5 mmol of lithium hydroxide and 4 mmol of ammonium fluoride was added and added. After sufficiently mixing, methanol was removed and heat treatment was performed at 300 ° C. for 110 minutes in an inert gas atmosphere (nanoparticle formation step). After the heat treatment is completed and cooled to room temperature, a colloidal nanoporous phosphor having a diameter of 1-60 nm is obtained. The nano-phosphors thus prepared were washed with acetone or ethanol and dispersed in a non-polar solvent such as hexane, toluene or chloroform.

FIG. 5 shows a transmission electron micrograph of the synthesized core / shell / shell / shell up-conversion / downconversion double-emitting nano-phosphor. Transmission electron microscope photographs show that the size of the shell increases as the shell is formed around the core / shell / shell. It can be seen that the core, core / shell, core / shell / shell, core / shell / shell / shell nanoparticles synthesized from the X-ray diffraction pattern shown in FIG. 6 all have a single tetragonal structure. 7 and 8, only up-conversion emission peaks are observed in the core, whereas in the core / shell, core / shell / shell, and core / shell / shell / shell nanoparticles, up- Downconvergence emission peak were all observed, and it can be seen that the upconversion and downconvergence luminescence intensities were increased as the shell was formed around the core. 9, only up-conversion luminescence was observed, and in the case of core / shell, core / shell / shell, core / shell / shell / shell nano phosphor, upconversion and down- As the shell increases, the brightness becomes brighter.

Example 3: Fabrication of a core / luminescent shell / crystalline shell structure of a nano phosphor of 20 nm or less

Hydrate yttrium chloride _{(YCl 3 .6H 2 O) 0.8} mmol, ytterbium chloride hydrate _{(YbCl 3 .6H 2 O) 0.18} mmol, erbium chloride hydrate _{(ErCl 3 .6H 2 O) 0.02} mmol, sodium oleic acid (C ₁₈ H ₃₃ O ₂ Na) was weighed, and then a mixed solvent of water, ethanol and hexane was added thereto, followed by heat treatment at 70 ° C. to form a lanthanide complex (complex formation step). The complex was mixed with a solution containing oleic acid and 1-octadecene and heat-treated at 150 ° C for 30 minutes to prepare a reaction solution containing a lanthanide complex (reaction solution forming step). 10 ml of a methanol solution containing 2.5 mmol of lithium hydroxide and 4 mmol of ammonium fluoride was added to the reaction solution, followed by the addition of a lanthanide complex. After sufficiently mixing, methanol was removed and heat treatment was performed at 320 ° C. for 90 minutes in an inert gas atmosphere. (Nanoparticle formation step). After the heat treatment and cooling to room temperature, colloidal nanoparticles with a diameter of 1-10 nm are obtained. The nano-phosphors thus prepared were washed with acetone or ethanol and dispersed in a non-polar solvent such as hexane, toluene or chloroform.

A core / shell structure nanoparticle containing a fluoride compound in which Ce ³ ⁺ and Tb ³ ⁺ ions were coactivated was prepared using the LiYF ₄ : Yb ³ ⁺ _0.18 and Er ³ ⁺ _0.02 nanoparticles prepared in the above 1 .

Hydrate yttrium chloride _{(YCl 3 .6H 2 O) 0.7} mmol, cerium chloride hydrate _{(CeCl 3 .7H 2 O) 0.15} mmol, terbium chloride hydrate _{(TbCl 3 .6H 2 O) 0.15} mmol, sodium oleic acid (C ₁₈ H ₃₃ O ₂ Na) was weighed, and then a mixed solvent of water, ethanol and hexane was added thereto, followed by heat treatment at 70 ° C. to form a lanthanide complex (complex formation step). The complex was mixed with a solution containing oleic acid and 1-octadecene and heat-treated at 150 ° C for 30 minutes to prepare a reaction solution containing a lanthanide complex (reaction solution forming step). A mixed solution was prepared by mixing LiGd ₀ _.35 Y ₀ _.45 F ₄ : Yb ³ ⁺ _0.18 and Er ³ ⁺ _0.02 nanoparticles prepared in 1 above in the reaction solution. To the mixed solution, 10 ml of a methanol solution containing 2.5 mmol of lithium hydroxide and 4 mmol of ammonium fluoride was added and added. After sufficiently mixing, methanol was removed and heat treatment was performed at 300 ° C. for 110 minutes in an inert gas atmosphere. (Nanoparticle formation step). After the heat treatment is completed and cooled to room temperature, colloidal nanoparticles having a diameter of 1-12 nm are obtained. The nanoparticles thus formed were washed with acetone or ethanol and dispersed in a non-polar solvent such as hexane, toluene or chloroform.

The LiYF ₄ was prepared in ^{_{2: Yb 3 + 0.18, Er}} 3 + 0.02 / LiYF 4: Ce 3 + 0.15, Tb 3 + 0.15 using a nanoparticle nano fluorescent material of the core / shell / shell structure comprising a LiYF ₄ compound .

1 mmol of yttrium chloride hydrate (YCl ₃ .6H ₂ O) and 3.1 mmol of sodium oleate (C ₁₈ H ₃₃ O ₂ Na) were weighed and mixed with a mixed solvent of water, ethanol and hexane, A heat treatment was performed to form a lanthanide complex (a complex formation step). The complex was mixed with a solution containing oleic acid and 1-octadecene and heat-treated at 150 ° C for 30 minutes to prepare a reaction solution containing a lanthanide complex (reaction solution forming step). A solution containing LiGd _0.35 Y _0.45 F ₄ : Yb ³⁺ _0.18 , Er ³⁺ _0.02 / LiYF ₄ : Ce ³⁺ _0.15 and Tb ³⁺ _0.15 nanoparticles prepared in 2 above was mixed in the reaction solution, . To the mixed solution, 10 ml of a methanol solution containing 2.5 mmol of lithium hydroxide and 4 mmol of ammonium fluoride was added and added. After sufficiently mixing, methanol was removed and heat treatment was performed at 300 ° C. for 110 minutes in an inert gas atmosphere. (Nanoparticle formation step). After the heat treatment is completed and the mixture is cooled to room temperature, a colloidal nanophosphor having a diameter of 1-16 nm is obtained. The nano-phosphors thus prepared were washed with acetone or ethanol and dispersed in a non-polar solvent such as hexane, toluene or chloroform.

<Example 4> Manufacture of nano-fluorescent substance having a core / luminescent shell / crystalline shell / paramagnetic shell structure of 20 nm or less

A core / shell / shell structure containing LiGdF ₄ compound was prepared using the LiYF ₄ : Yb ³ ⁺ _0.18 , Er ³ ⁺ _0.02 / LiYF ₄ : Ce ³ ⁺ _0.15 and Tb ³ ⁺ _0.15 / LiYF ₄ nanoparticles prepared in Example 3, A shell / shell structure nano-phosphor was prepared.

1 mmol of gadolinium chloride hydrate (GdCl ₃ .6H ₂ O) and 3.1 mmol of sodium oleate (C ₁₈ H ₃₃ O ₂ Na) were weighed and mixed with a mixed solvent of water, ethanol and hexane, A heat treatment was performed to form a lanthanide complex (a complex formation step). The complex was mixed with a solution containing oleic acid and 1-octadecene and heat-treated at 150 ° C for 30 minutes to prepare a reaction solution containing a lanthanide complex (reaction solution forming step). A solution containing LiGd _0.35 Y _0.45 F ₄ : Yb ³⁺ _0.18 , Er ³⁺ _0.02 / LiYF ₄ : Ce ³⁺ _0.15 and Tb ³⁺ _0.15 / LiYF ₄ nanoparticles prepared in Example 3 was added to the reaction solution, Were mixed to prepare a mixed solution. To the mixed solution, 10 ml of a methanol solution containing 2.5 mmol of lithium hydroxide and 4 mmol of ammonium fluoride was added and added. After sufficiently mixing, methanol was removed and heat treatment was performed at 300 ° C. for 110 minutes in an inert gas atmosphere. (Nanoparticle formation step). After cooling to room temperature after the heat treatment, a colloidal nanophosphor having a diameter of 1-18 nm is obtained. The nano-phosphors thus prepared were washed with acetone or ethanol and dispersed in a non-polar solvent such as hexane, toluene or chloroform.

FIG. 10 shows the transmittance of the core nanoparticles and core / light emitting shell nanoparticles, core / light emitting shell / crystalline shell, core / light emitting shell / crystalline shell / paramagnetic shell nanoparticle synthesized through Examples 3 to 4 according to the present invention Microscopic photographs are shown. It can be confirmed through the transmission electron microscope that the particle size increases with the formation of the shell around the core. From the X-ray diffraction pattern of FIG. 11, it can be seen that, even for a very small-sized nanophosphor, even if it has a core, a core / shell, a core / shell / shell, a core / shell / shell / shell structure, . FIG. 12 shows photoluminescent images of core nanoparticles and core / light emitting shell nanoparticles, core / light emitting shell / crystalline shell, core / light emitting shell / crystalline shell / paramagnetic shell nanoparticles. Referring to FIG. 12, core nanoparticles emit light only when excited by infrared rays, whereas core / light emitting shell nanoparticles, core / light emitting shell / crystalline shell and core / light emitting shell / crystalline shell / paramagnetic shell nanoparticles are infrared And ultraviolet rays, and it was confirmed that the brightness increased as the shell increased.

Example 5 LiGd ₀ _.35 Y ₀ _.45 F ₄ : Yb ³ ⁺ _0.18 , Er ³ ⁺ _0.02 / LiYF ₄ : Ce ³ ⁺ _0.15 , Tb ³ ⁺ _0.15 / LiYF ₄ / LiGdF _4- core / shell / shell / shell structure nano-phosphor

0.4 ml of LiGd _0.35 Y _0.45 F ₄ : Yb ³⁺ _0.18 , Er ³⁺ _0.02 / LiYF ₄ : Ce ³⁺ _0.15 and Tb ³⁺ _0.15 / LiYF ₄ / LiGdF ₄ nanofluorophors obtained through Example 4 were mixed with 10 ml of poly Dimethylsiloxane (PDMS) and 1 ml of curing agent. The mixture was maintained at 80 DEG C for 1 hour and then cooled to room temperature to obtain a nanophosphor-polymer composite.

13 is a photograph of the nano-phosphor composite prepared according to the present invention. As shown in FIG. 13, the polymer composite in which the nano-fluorescent material is dispersed is very transparent, so that the text of the document placed under the polymer composite can be clearly identified, and bright green light emission is observed when excited by an infrared laser or ultraviolet lamp. In addition, it was confirmed that green luminescence appears when the phosphor is simultaneously excited by using an infrared laser and an ultraviolet lamp. Thus, it can be confirmed that a nanophosphor-polymer composite having excellent transparency and excellent luminescence characteristics is manufactured.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

Claims

An up-conversion core nanoparticle comprising a first fluorine-based compound co-doped with Yb ³ ⁺ and Er ³ ⁺ represented by the following formula (1);
A downconverting luminescent shell comprising a second fluoride-based compound co-activated with Ce ³ ⁺ and Tb ³ ⁺ represented by the following formula (2) to surround the core nanoparticles; And
A crystalline shell containing a third fluoride compound represented by the following general formula (3)
&Lt; RTI ID = 0.0 > nano < / RTI >
[Chemical Formula 1]
LiGd ₁ _-xy- _z L _z F ₄ : Yb ³ ⁺ _x , Er ³ ⁺ _y
X is a real number of 0.1? X? 0.9, y is a real number of 0 <y? 0.1 and 0.1 <x + y? 1, and z is a real number of 0.3? Z? 1, 1-xy, wherein L is any one selected from the group consisting of Y, Dy, Ho, Tm, Lu, and combinations thereof,
(2)
_{LiY 1 -p- q F 4: Ce} 3 + p, Tb 3 + q
P is a real number of 0 <p? 0.25, q is a real number of 0 <q? 0.5,
(3)
LiY ₁ _- _r M _r F ₄
R is a real number of 0? R? 1, and M is any one selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Dy, Ho, Er, Tm, Yb and Lu and combinations thereof.

The nanophosphor compound according to claim 1, further comprising a paramagnetic shell comprising a fourth compound which surrounds the crystalline shell and is represented by the following formula:
[Chemical Formula 4]
LiGdF ₄ .

The nanophosphor according to claim 1, wherein the core nanoparticles have a tetragonal lattice structure.

The nanophosphor according to claim 1, wherein the core nanoparticles have a particle size of 1-70 nm.

The nanophosphor according to claim 1, having a particle size of 2-100 nm.

(i) a step of forming a core up-conversion nanoparticles comprising a resurrection the ball (co-doped) fluoride-based compound of claim 1 to ³ ⁺ Yb, Er ⁺ ³ represented by the following formula (1);
(ii) forming a downconversion luminous shell nanoparticle comprising the second fluoride-based compound coexisting with Ce ³ ⁺ and Tb ³ ⁺ represented by the following formula (2) to surround the core nanoparticles; And
(iii) forming crystalline shell nanoparticles comprising the fluoride-based compound 3 represented by the following formula (3) to surround the light-emitting shell nanoparticles
A method for producing the nanoporous phosphor of the core-multi-shell structure according to claim 1 comprising:
[Chemical Formula 1]
LiGd ₁ _-xy- _z L _z F ₄ : Yb ³ ⁺ _x , Er ³ ⁺ _y
X is a real number of 0.1? X? 0.9, y is a real number of 0 <y? 0.1 and 0.1 <x + y? 1, and z is a real number of 0.3? Z? 1, 1-xy, wherein L is any one selected from the group consisting of Y, Dy, Ho, Tm, Lu, and combinations thereof,
(2)
_{LiY 1 -p- q F 4: Ce} 3 + p, Tb 3 + q
P is a real number of 0 <p? 0.25, q is a real number of 0 <q? 0.5,
(3)
LiY ₁ _- _r M _r F ₄
R is a real number of 0? R? 1, and M is any one selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Dy, Ho, Er, Tm, Yb and Lu and combinations thereof.

7. The method of claim 6, further comprising: (iv) forming paramagnetic shell nanoparticles comprising the fourth compound represented by the following formula (4)
[Chemical Formula 4]
LiGdF ₄ .

7. The method of claim 6, wherein step (i)
Preparing a first mixed solution including a gadolinium precursor, an yttrium precursor, an ytterbium precursor, an erbium precursor, and an oleic acid salt, and heating the first mixed solution to form a first complex solution;
Adding oleic acid and 1-octadecene to the first complex solution and heating to form a first reaction solution; And
And a core forming step of adding an alcohol solution containing a lithium precursor and a fluorine precursor to the first reaction solution and heating to form core nanoparticles.

The method of claim 8, wherein the gadolinium precursor is selected from the group consisting of gadolinium acetate (Gd (CH ₃ COO) ₃ ), gadolinium chloride (GdCl ₃ ), gadolinium chloride hydrate (GdCl ₃ .6H ₂ O) One,
The yttrium precursor is any one selected from the group consisting of yttrium acetate (Y (CH ₃ COO) ₃ ), yttrium chloride (YCl ₃ ), yttrium chloride hydrate (YCl ₃ .6H ₂ O)
The ytterbium acetate precursor ytterbium _{(Yb (CH 3 COO) 3} ), ytterbium chloride (YbCl _3), ytterbium chloride hydrate (YbCl ₃ .6H ₂ O), and one selected from the group consisting of one and the ,
Wherein the erbium precursor is any one selected from the group consisting of erbium acetate (Er (CH ₃ COO) ₃ ), erbium chloride (ErCl ₃ ), erbium chloride (ErCl ₃ .6H ₂ O), and combinations thereof.

The method according to claim 8, wherein the heat treatment in the core forming step is performed at 200 to 370 캜 for 10 minutes to 4 hours.

7. The method of claim 6, wherein step (ii)
Preparing a second mixed solution containing an yttrium precursor, a cerium precursor, a terbium precursor and an oleic acid salt, and heating the second mixed solution to form a second complex solution;
Adding oleic acid and 1-octadecene to the second complex solution and heating to form a second reaction solution; And
Adding core nanoparticles to be contained in the light emitting shell nanoparticles to the second reaction solution, adding an alcohol solution containing a lithium precursor and a fluorine precursor, and then heating to form a light emitting shell on the surface of the core nanoparticles Luminescent shell forming step.

12. The method of claim 11,
The yttrium precursor is any one selected from the group consisting of yttrium acetate (Y (CH ₃ COO) ₃ ), yttrium chloride (YCl ₃ ), yttrium chloride hydrate (YCl ₃ .6H ₂ O)
The cerium precursor is any one selected from the group consisting of cerium acetate (Ce (CH ₃ COO) ₃ ), cerium chloride (CeCl ₃ ), cerium chloride hydrate (CeCl ₃ .7H ₂ O)
Wherein the terbium precursor is any one selected from the group consisting of terbium acetate (Tb (CH ₃ COO) ₃ ), terbium chloride (TbCl ₃ ), terbium chloride (TbCl ₃ .6H ₂ O), and combinations thereof.

The method according to claim 11, wherein the heat treatment in the light-emitting shell forming step is performed at 200 to 370 ° C for 10 minutes to 4 hours.

7. The method of claim 6, wherein step (iii)
Preparing a third mixed solution containing an yttrium precursor and an oleic acid salt and heating the third mixed solution to form a third complex solution;
Adding oleic acid and 1-octadecene to the third complex solution and heating to form a third reaction solution; And
Adding an alcohol solution containing a lithium precursor and a fluorine precursor to the third reaction solution, adding a light-emitting shell nanoparticle to be contained in the crystalline shell nanoparticle, and heating the resultant to heat a crystalline shell And forming a crystalline shell.

15. The method of claim 14,
Wherein the yttrium precursor is any one selected from the group consisting of yttrium acetate (Y (CH ₃ COO) ₃ ), yttrium chloride (YCl ₃ ), yttrium chloride hydrate (YCl ₃ .6H ₂ O), and combinations thereof.

15. The method of claim 14, wherein the heat treatment in the crystalline shell forming step is performed at 200 to 370 DEG C for 10 minutes to 4 hours.

8. The method of claim 7, wherein step (iv)
Preparing a fourth mixed solution containing a gadolinium precursor and an oleic acid salt, and heating the fourth mixed solution to form a fourth complex solution;
Adding oleic acid and 1-octadecene to the fourth complex solution and heating to form a fourth reaction solution; And
Crystalline shell nanoparticles to be contained in the paramagnetic shell nanoparticles are added to the fourth reaction solution and an alcohol solution containing a lithium precursor and a fluorine precursor is added and heated to form a paramagnetic shell on the surface of the crystalline shell nanoparticle Forming a shell-forming shell-forming step.

18. The method of claim 17,
Wherein the gadolinium precursor is any one selected from the group consisting of gadolinium acetate (Gd (CH ₃ COO) ₃ ), gadolinium chloride (GdCl ₃ ), gadolinium chloride hydrate (GdCl ₃ .6H ₂ O), and combinations thereof.

18. The method of claim 17, wherein the heat treatment in the paramagnetic shell forming step is performed at 200 to 370 DEG C for 10 minutes to 4 hours.

A polymer composite comprising the nanophosphor according to any one of claims 1 to 5.

A contrast agent comprising the nanophosphor according to any one of claims 1 to 5.

An anti-fake cord comprising the nanophosphor according to any one of claims 1 to 5.