KR102113044B1 - Lithium-based garnet phosphor, preparing method of the same, and luminescent property of the same - Google Patents

Abstract

It relates to a lithium-based garnet phosphor, a method for manufacturing the lithium-based garnet phosphor, and light emission characteristics of the lithium-based garnet phosphor.

Description

Lithium-based garnet phosphor, its manufacturing method, and its luminescence properties {LITHIUM-BASED GARNET PHOSPHOR, PREPARING METHOD OF THE SAME, AND LUMINESCENT PROPERTY OF THE SAME}

The present application relates to a lithium-based garnet phosphor, a method for manufacturing the lithium-based garnet phosphor, and light emission characteristics of the lithium-based garnet phosphor.

Light emitting diodes are p-n junction diodes designed to operate under a forward bias to convert electricity into light through electroluminescence. Among them, GaP LEDs have been widely used in displays and the like.

1996, Nichia Chemical Co. The first commercial white LED device was manufactured using an InGaN blue LED chip coated with a yellow phosphor Y ₃ Al ₅ O ₁₂ : Ce ^{3 +} (YAG: Ce). The YAG: Ce phosphor absorbs a part of the emitted blue light to generate yellow light, and the yellow light combines with the remaining blue light to generate white light.

A white light emitting diode (WLED) is a next-generation light emitting device, and has less power consumption than conventional incandescent and fluorescent lamps, and has advantages such as high luminous efficiency, high brightness, and fast response speed. Therefore, it is a substitute for incandescent and fluorescent lamps. It is widely used.

Phosphor-converted white light emitting diodes (pc-WLEDs) are attracting attention as next generation solid state light sources due to their excellent properties such as low power consumption, high efficiency, long life, and environmental friendliness. The performance of the pc-WLED is highly dependent on the quality of the white light generated by the phosphor, and silicate, aluminate, alumino silicate, nitride, and borate, etc. are used as the phosphor host.

The technique of manufacturing a white light emitting diode can be roughly divided into two methods. The first method is a technique of manufacturing a white light emitting device using red, blue, and green light emitting diodes. The white light-emitting diode manufactured by the first method has a very good color rendering index (CRI) and optical characteristics, but is expensive for manufacturing and technical problems requiring driving each LED separately make it special for medical devices. It is used only for lighting. The second method, which is currently commercialized, is a technique for manufacturing a white light emitting device using a binary system that applies a yellow phosphor on a blue light emitting diode chip. The binary system has the advantage of being able to make a simple structure of a white light emitting diode having very good light characteristics, and thus has a low manufacturing cost, but has a disadvantage of low color rendering index (CRI) due to lack of light emission characteristics in the red region.

[Advanced technical literature]

Republic of Korea Patent Publication No. 2013-0128100.

The present application is intended to provide a lithium-based garnet phosphor, a method for manufacturing the lithium-based garnet phosphor, and light-emitting characteristics of the lithium-based garnet phosphor.

However, the problems to be solved by the present application are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

The first aspect of the present application provides a lithium-based garnet phosphor represented by Formula 1 below:

Li ₇ La _3-x Zr ₂ O ₁₂ : xLn ³⁺ ;

In Chemical Formula 1,

Ln is Ce, Tb, Dy, Sm, Ho, Pr, Er, or Yb,

0≤x≤0.5.

The second aspect of the present application provides a method for producing a lithium-based garnet phosphor represented by the following Chemical Formula 1 using a solid-state reaction method:

[Formula 1]

Li ₇ La _3-x Zr ₂ O ₁₂ : xLn ³⁺ ;

In Chemical Formula 1,

Ln is Ce, Tb, Dy, Sm, Ho, Pr, Er, or Yb,

0≤x≤0.5.

According to the embodiments herein, it has not been reported so far, expressed as Li ₇ La _3-x Zr ₂ O ₁₂ : xLn ³⁺ (Ln = Ce or Tb) using a solid-state reaction method. A new lithium-based garnet phosphor for white-emitting diodes can be produced.

The lithium-based garnet phosphor according to embodiments of the present application emits yellow, red, or green light, respectively, according to the type of the rare earth metal ion to be doped to control emission color, and has characteristics such as high brightness, high color purity, and high brightness. Therefore, it can be applied to white-light emitting diode devices.

Figure 1 (a), in one embodiment of the present application, the observed Rietveld data of Li ₇ La ₃ Zr ₂ O ₁₂ (solid black line), calculated data (solid red line), and the difference profile (solid blue line) It is shown.
2, in one embodiment of the present application, Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Ce ^{3 +} (0 ≤ x ≤ 0.10) It shows the XRD pattern of the phosphor.
3 is, in one embodiment of the present application, Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Ce ³⁺ (0.02 ≤ x ≤ 0.10) monitored at 466 nm It shows the excitation spectrum of the phosphor.
4, in one embodiment of the present application, Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Ce ³⁺ (0.02≤ x ≤0.10) monitored at 260 nm It shows the emission spectrum of the phosphor.
5, in one embodiment of the present application, Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Tb ^{3 +} (0.02≤ x ≤0.10) It shows the XRD pattern of the phosphor.
FIG. 6 shows an excitation spectrum of Li ₇ La _{3 − x} Zr ₂ O ₁₂ : x Tb ³⁺ (0.02 ≦ x ≦ 0.10) phosphor monitored at 545 nm in one embodiment of the present application.
7 (a), in one embodiment of the present application, Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Tb ^{3 +} (0.02 ≤ x ≤ 0.10) shows the emission spectrum of the phosphor, and in Figure 7 ( b), in one embodiment of the present application, ⁵ D ₃ → ⁷ F ₆ and ⁵ D ₄ → ^It shows the luminescence intensity due to the ⁷ F ₅ transition.
8 is, in one embodiment of the present application, when x is 0.02 (●), 0.04 (■), 0.06 (◆), 0.08 (▲), and 0.10 (▼), respectively, Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Tb ^{3 +} (0.02≤ x ≤0.10) It shows the CIE coordinates of the phosphor.

Hereinafter, embodiments of the present application will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present application pertains may easily practice. However, the present application may be implemented in various different forms and is not limited to the embodiments described herein. In addition, in order to clearly describe the present application in the drawings, parts irrelevant to the description are omitted, and like reference numerals are assigned to similar parts throughout the specification.

Throughout this specification, “phosphor” refers to a material that absorbs various types of energy and emits visible light energy due to a unique energy difference of its own material. It is composed of an active agent (activator) incorporated in, the active body serves to determine the emission color by determining the energy level involved in the emission process.

Throughout the present specification, "garnet structure" generally refers to a structure that is configured as a structural formula of X ₃ Y ₂ Z ₃ O ₁₂ , where X is a dodecahedral site, Y is The octahedral site, Z is the tetrahedral site.

Throughout this specification, when a part is “connected” to another part, this includes not only “directly connected” but also “electrically connected” with another element in between. do.

Throughout this specification, when one member is positioned “on” another member, this includes not only the case where one member abuts another member, but also the case where another member exists between the two members.

Throughout the present specification, when a part “includes” a certain component, it means that the component may further include other components, not to exclude other components, unless specifically stated to the contrary. The terms “about”, “substantially”, etc., used to the extent of the present specification are used in or near the numerical values when manufacturing and substance tolerances unique to the stated meanings are presented, and To aid, accurate or absolute figures are used to prevent unscrupulous use of the disclosed disclosure by unscrupulous infringers. The term “~ (steps)” or “steps of” as used in the entire specification does not mean “steps for ~”.

Throughout the present specification, the term “combination (s)” included in the expression of the marki form means one or more mixtures or combinations selected from the group consisting of the components described in the expression of the marki form, It means to include one or more selected from the group consisting of the above components.

Throughout this specification, the description of “A and / or B” means “A or B, or A and B”.

Hereinafter, embodiments and examples of the present application will be described in detail with reference to the accompanying drawings. However, the present application may not be limited to these embodiments and examples and drawings.

The first aspect of the present application provides a lithium-based garnet phosphor represented by Formula 1 below:

Li ₇ La _3-x Zr ₂ O ₁₂ : xLn ³⁺ ;

In Chemical Formula 1,

Ln is Ce, Tb, Dy, Sm, Ho, Pr, Er, or Yb,

0≤x≤0.5.

In one embodiment of the present application, the lithium-based garnet phosphor may have a cubic crystal garnet crystal structure.

In one embodiment of the present application, the garnet structure generally refers to a structure configured as a structural formula of X ₃ Y ₂ Z ₃ O ₁₂ [where X is a dodecahedral site, Y is a regular octahedron Site (octahedral site, Z is tetrahedral site)], for example, Li ₇ La ₃ Zr ₂ O ₁₂ It may be a garnet structure.

In one embodiment of the present application, the garnet structured oxide phosphor may include luminescence selected from the group consisting of yellow, red, green, and combinations thereof. For example, depending on the type of the rare earth metal ions Ce ^{3 +} , Tb ^{3 +,} Dy ^{3 +} , Sm ^{3 +} , Ho ^{3 +} , Pr ^{3 +} , Er ^{3 +} , or Yb ³⁺ , each yellow, It can emit red or green light, and a combination thereof can realize white light.

Lithium-based garnet phosphor according to one embodiment of the present application, because it has a high luminescence intensity, high color purity, and high brightness, can be suitably used as a variety of phosphors for LED, especially WLED display.

The second aspect of the present application provides a method for producing a lithium-based garnet phosphor represented by the following Chemical Formula 1 using a solid-state reaction method:

[Formula 1]

Li ₇ La _3-x Zr ₂ O ₁₂ : xLn ³⁺ ;

In Chemical Formula 1,

Ln is Ce, Tb, Dy, Sm, Ho, Pr, Er, or Yb,

0≤x≤0.5.

Regarding the method for manufacturing a lithium-based garnet phosphor according to the second aspect of the present application, detailed descriptions of parts overlapping with the first aspect of the present application have been omitted, but the description of the first aspect of the present application is omitted even if the description is omitted. The same can be applied to the second aspect.

In one embodiment of the present application, the solid-phase method may include an oxide or carbonate of a metal selected from the group consisting of Li, La, Zr, and combinations thereof; And an oxide or carbonate such as Ce, Tb, Dy, Sm, Ho, Pr, Er, or Yb, and calcined in a temperature range of about 100 ° C to about 1,000 ° C; And annealing the calcined powder in a temperature range of about 1,000 ° C to about 2,000 ° C to obtain a lithium-based garnet phosphor, but may not be limited thereto.

In one embodiment of the present application, the solid-phase method is the most common method among ceramic manufacturing methods, and the lithium-based garnet phosphor can be easily and economically mass-produced by the solid-phase method, but may not be limited thereto.

In one embodiment of the present application, the calcining step may be performed to remove impurities such as organic substances, and the calcining may be performed at a temperature range of about 100 ° C to about 1,000 ° C, but is not limited thereto. It may not. For example, the calcination is about 100 ° C to about 1,000 ° C, about 100 ° C to about 800 ° C, about 100 ° C to about 600 ° C, about 100 ° C to about 400 ° C, about 100 ° C to about 200 ° C, about 200 ° C To about 1,000 ° C, about 200 ° C to about 800 ° C, about 200 ° C to about 600 ° C, about 200 ° C to about 400 ° C, about 400 ° C to about 1,000 ° C, about 400 ° C to about 800 ° C, about 400 ° C to about 600 ° C, about 600 ° C to about 1,000 ° C, about 600 ° C to about 800 ° C, about 800 ° C to about 1,000 ° C, or about 500 ° C to about 700 ° C, about 100 ° C to about 800 ° C, about 100 ° C to about 800 ° C ℃, may be performed in a temperature range of about 100 ℃ to about 800 ℃, but may not be limited thereto.

In one embodiment of the present application, after the calcination, a flux may be added, but may not be limited thereto. For example, a small amount of flux may be added after the calcination, but may not be limited thereto.

In one embodiment of the present application, the flux may be in a liquid form having a melting point lower than the annealing temperature, and may be a role of a transporter between reactants, but may not be limited thereto.

In one embodiment of the present application, the flux does not remain in the final product, and may be to promote crystal growth of the product.

In one embodiment of the present application, the flux may be, for example, an alkali metal, an alkaline earth metal, or a halogen compound, for example, Li ₂ CO ₃ , but may not be limited thereto.

In one embodiment of the present application, the heat treatment temperature may be lowered due to the flux, and thus the cost of generating the phosphor may be reduced, but may not be limited thereto.

In one embodiment of the present application, the annealing may be performed at a temperature range of about 1,000 ° C to about 2,000 ° C, but may not be limited thereto. For example, when the annealing temperature exceeds about 2,000 ° C, aggregation becomes severe, and when the annealing temperature is less than about 1,000 ° C, it may have a monoclinic crystal structure, so the annealing is about 1,000 ° C to about 2,000 ° C. It is preferably carried out in the temperature range.

In one embodiment of the present application, the annealing is about 1,000 ° C to about 2,000 ° C, about 1,000 ° C to about 1,800 ° C, about 1,000 ° C to about 1,600 ° C, about 1,000 ° C to about 1,400 ° C, about 1,000 ° C to about 1,200 ° C , About 1,200 ° C to about 2,000 ° C, about 1,200 ° C to about 1,800 ° C, about 1,200 ° C to about 1,600 ° C, about 1,200 ° C to about 1,400 ° C, about 1,400 ° C to about 2,000 ° C, about 1,400 ° C to about 1,800 ° C, about 1,400 ° C to about 1,600 ° C, about 1,600 ° C to about 2,000 ° C, about 1,600 ° C to about 1,800 ° C, about 1,800 ° C to about 2,000 ° C, or about 1,500 ° C to about 1,700 ° C may be performed in the temperature range, but It may not be limited.

In one embodiment of the present application, the annealing is a process of synthesizing ceramic crystals, and the active material may enter the matrix lattice through the annealing, but may not be limited thereto.

In one embodiment of the present application, the lithium-based garnet phosphor may have a cubic crystal structure through the annealing, but may not be limited thereto.

Hereinafter, the present invention will be described in more detail through the examples of the present application, but the following examples are only illustrative to aid understanding of the present application, and the contents of the present application are not limited to the following examples.

[Example]

Preparation of lithium-based garnet phosphor

Li ₇ La _{3 - x} Zr ₂ O ₁₂ : xLn (0≤x≤0.10, Ln = Ce ^{3 +} or Tb ^{3 +} ) phosphor was prepared through a solid-state process. The starting materials used in the above process are: La ₂ O ₃ (High Purity Chemical, 99.99%), ZrO (NO ₃ ) ₂ (High Purity Chemical, 98%), Li ₂ CO ₃ (High Purity Chemical, 99) %), CeO ₂ (High Purity Chemical, 99.99%), and Tb ₄ O ₇ (High Purity Chemical, 99%).

First, Li ₂ CO ₃ , La ₂ O ₃ , ZrO (NO ₃ ) ₂ , CeO ₂ , and Tb ₄ O ₇ were weighed, and the weighed powder was mixed with acetone (5 mL), and the mixture was blocked with pestle. Mix homogeneously for 30 minutes using mortar. To compensate for the loss of Li ₂ O during the subsequent annealing process, excess Li ₂ CO ₃ (10% by weight) was added to the starting material. Thereafter, the mixed powder was transferred to an alumina crucible and calcined at 900 ° C for 5 hours. The calcined powder of the Li ₇ La _{3 -x} Zr ₂ O ₁₂ : xCe ³⁺ (0≤x≤0.10) phosphor was annealed at 980 ° C for 5 hours, then pulverized and annealed at 980 ° C for 5 hours. For the Li ₇ La _{3 - x} Zr ₂ O ₁₂ : xTb ^{3 +} (0≤x≤0.10) phosphor, the calcined powder was annealed at 980 ° C for 5 hours in a reducing atmosphere (5% H ₂ + 95% N ₂ ). .

Characterization of lithium-based garnet phosphors

)을 이용한 X-선 회절분석기 (XRD; Rigaku RINT2000, Japan)를 사용하여 분석하였다. 상기 형광체의 PL (photoluminescence; 발광) 스펙트럼을 제논 램프가 장착된 분광 형광 측정기 (FS-2, Scinco Co., Korea)를 사용하여 수득하였다. 모든 발광 스펙트럼은 동일한 양의 제조된 형광체를 사용하여 얻었으며 동일한 조건 하에서 기록하였다. CIE 계산기를 사용하여 관찰된 발광 스펙트럼으로부터 CIE (Commission Internationale de l' Eclairage) 색도 좌표 (x, y)를 계산하였다. 또한, CIE 좌표 (x, y) 데이터를 사용하여 상관 색온도 (correlated color temperate; CCT)와 색 순도를 계산하였다.The crystal structure of the prepared lithium-based garnet phosphor is Cu Kα line (α = 1.5406

) Was analyzed using an X-ray diffractometer (XRD; Rigaku RINT2000, Japan). The PL (photoluminescence) spectrum of the phosphor was obtained using a spectrofluorimeter equipped with a xenon lamp (FS-2, Scinco Co., Korea). All emission spectra were obtained using the same amount of phosphor prepared and recorded under the same conditions. The CIE (Commission Internationale de l'Eclairage) chromaticity coordinates (x, y) were calculated from the observed emission spectrum using a CIE calculator. In addition, correlated color temperate (CCT) and color purity were calculated using CIE coordinate (x, y) data.

Li as a parent material ₇ La _3-x Zr ₂ O ₁₂ Choice of

In this example, Li ₇ La ₃ Zr ₂ O ₁₂ was selected as the host material and the structure and PL characteristics of the Li ₇ La ₃ Zr ₂ O ₁₂ phosphor doped with Ce ^{3 +} or Tb ^{3 +} were studied.

Example  One: Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Ce ^{3 +} (0≤ x ≤0.10) phosphor

Structural parameters for confirming the crystal structure of Li ₇ La ₃ Zr ₂ O ₁₂ were obtained from conventional literature. Since the JCPDS data for the Li ₇ La ₃ Zr ₂ O ₁₂ could not be used, the XRD pattern of the Li ₇ La _{3- x} Zr ₂ O ₁₂ : x Ce ³⁺ phosphor was reported in the literature Li ₇ La ₃ Zr ₂ It was compared with the XRD pattern of O ₁₂ . The XRD pattern of the Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Ce ^{3 +} phosphor was consistent with the XRD pattern of the previously reported Li ₇ La ₃ Zr ₂ O ₁₂ (FIG. 1). Analysis results and structural parameters are summarized in Table 1 and Table 2, respectively. The Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Ce ^{3 +} (0≤x≤0.10) phosphor has a cubic crystal structure and an I4 ₁ acd space group. No impurity peaks associated with the dopant were observed. The XRD pattern of the Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Ce ^{3 +} (0≤x≤0.10) phosphor is shown in FIG. 2.

The excitation spectrum of the Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Ce ^{3 +} (0.02≤x≤0.10) phosphor monitored at 466 nm is shown in FIG. 3. The excitation spectrum shows two broad bands at 260 nm and 415 nm. The bands 4f ^{1 (2} F _5/2) of the Ce ^{+ 3-ion} is ^{due> 4f 0 5d 1 (2 D} 5/2 and _² D ^_3/2) transition. Broad band at 415 nm is consistent with the emission of the blue LED chip, so that the _{Li 7 La 3 - x Zr 2} O 12: x Ce 3 + represents the availability of a phosphor on a blue LED chip of the white LED.

The emission spectrum of the Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Ce ^{3 +} (0.02≤x≤0.10) phosphor obtained under 260 nm excitation is shown in FIG. 4. The emission spectrum is due to 5d where 4f ground state ⁽² F _5/2 and ² F _7/2) Ce ^{3 +} ions to the transition from the state, showing a broad asymmetric shape centered at 427 nm and 466 nm.

Example  2: Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Tb ^{3 +} (0≤ x ≤0.10) phosphor

In order to investigate the crystal structure of the Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Tb ^{3 +} (0≤x≤0.10) phosphor, an XRD pattern as shown in FIG. 5 was obtained. The XRD pattern of the Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Tb ^{3 +} (0≤x≤0.10) phosphor was in good agreement with the pattern reported for Li ₇ La ₃ Zr ₂ O ₁₂ , and the cubic structure and It can be seen that I4 has ₁ acd space group. No significant difference was observed between the undoped Li ₇ La ₃ Zr ₂ O ₁₂ and the T ₇ ^{3 +} doped Li ₇ La _{3 - x} Zr ₂ O ₁₂ (0.02≤x≤0.10) phosphor, It means that the doped Tb ^{3 +} ion does not affect the crystal structure of Li ₇ La ₃ Zr ₂ O ₁₂ .

The excitation spectrum of the Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Tb ^{3 +} (0.02≤x≤0.10) phosphor monitored at 545 nm is shown in FIG. 6. The band observed at 262 nm and 298 nm is due to the spin-allowed and the spin forbidden transition derives from the 4f ⁸ → 4f ⁷ 5d ¹ transition of Tb ^{3 +} ions. The weak peaks observed at 355 nm, 373 nm, 380 nm and 489 nm are ⁷ F ₆ → ⁵ D ₂ , ⁷ F ₆ → ⁵ L ₁₀ , ⁷ F ₆ → ⁵ D ₃ and ⁷ F ₆ of Tb ^{3 +} ions, respectively. → due to the ⁵ D ₄ transition, which corresponds to the 4f ⁸ -4f ⁸ forbidden transition of the Tb ^{3 +} ion. The intensity of the peak observed at 262 nm increases as the Tb ^{+ 3} concentration is increased up to 6 mol%, which was reduced at higher Tb ^{+ 3} concentration.

As shown in Figure 7 (a), the Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Tb ^{3 +} (0.02≤x≤0.10) phosphor emission spectrum of 383 nm, 417 nm, 438 nm, and 470 nm Showed four peaks at ⁵ D ₃ → ⁷ F ₆ and ⁵ D ₃ of Tb ^{3 +} ions, respectively. → ⁷ F ₅ , ⁵ D ₃ → ⁷ F ₄ , and ⁵ D ₃ → ⁷ F ₃ because of the transition. In addition, the peaks of 488 nm, 545 nm, 592 nm, and 662 nm are ⁵ D ₄ → ⁷ F ₆ , ⁵ D ₄ → ⁷ F ₅ , ⁵ D ₄ → ⁷ F ₄ and ⁵ D ₄ → ⁷ of Tb ^{3 +} , respectively. Due to the F ₃ transition. Among them, the strongest peak at 545 nm ( ⁵ D ₄ → ⁷ F ₅ ) corresponds to green emission. As the concentration of Tb ^{3 +} ion increased from 2 mol% to 10 mol%, ⁵ D ₃ → intensity of the light emission caused by the ⁷ F ₆ transitions are somewhat reduced, but, ⁵ D ₄ → caused by the ⁷ F ₅ transition The intensity of emitted light increased due to the cross relaxation process [Fig. 7 (b)].

The CIE chromaticity coordinates (x, y) of the Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Tb ^{3 +} (0.02≤x≤0.10) phosphor are shown in FIG. 8. As the concentration of Tb ^{3 +} ion increased, the emission color changed from white to green. Table 3 shows the calculated CIE coordinates (x, y), CCT, ( ⁵ D ₀ → ⁷ F ₂ ) / ( ⁵ D ₀ → ⁷ F ₁ ) and color purity. Calculated CCT decreased as the Tb ^{+ 3} concentration. In addition, the color purity of the Li ₇ La _{3 - x} Zr ₂ O ₁₂ : x Tb ^{3 +} (0.02≤x≤0.10) phosphor was in the range of 14.9% to 28.8%.

In this example, a novel lithium-based garnet Li ₇ La _3-x Zr ₂ O ₁₂ phosphor doped with rare earth metal ions (Ce ^{3 +} or Tb ^{3 +} ) was prepared by a solid-phase method. The crystal structure and PL properties of the Li ₇ La _3-x Zr ₂ O ₁₂ phosphor doped with Ce ^{3 +} or Tb ^{3 +} were first studied by the present application. The new lithium-based garnet phosphor is a promising phosphors that respectively emit yellow or green by the addition of Ce ^{+ 3} or Tb ^{3 +} ion, and therefore can be applied to the white LED.

The foregoing description of the present application is for illustration, and a person having ordinary knowledge in the technical field to which the present application belongs will understand that it is possible to easily change to other specific forms without changing the technical spirit or essential characteristics of the present application. Therefore, it should be understood that the above-described embodiments are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present application is indicated by the claims, which will be described later, rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be interpreted to be included in the scope of the present application.

Claims (5)

A lithium-based garnet phosphor represented by the following Chemical Formula 1,
Lithium-based garnet phosphors in which light emission color changes from light green to green as the concentration of Tb ³⁺ ions increases upon irradiation with light:
[Formula 1]
Li ₇ La _3-x Zr ₂ O ₁₂ : xLn ³⁺ ;
In Chemical Formula 1,
Ln is Tb,
0 <x≤0.5.
According to claim 1,
The lithium-based garnet phosphor has a cubic crystal garnet crystal structure, a lithium-based garnet phosphor.
According to claim 1,
The lithium-based garnet phosphor is to include green light emission, lithium-based garnet phosphor.
Method for preparing a lithium-based garnet phosphor represented by the following formula (1) using a solid-state reaction method:
[Formula 1]
Li ₇ La _3-x Zr ₂ O ₁₂ : xLn ³⁺ ;
In Chemical Formula 1,
Ln is Tb,
0 <x≤0.5.
The method of claim 4,
The solid phase method,
An oxide or carbonate of a metal selected from the group consisting of Li, La, Zr, and combinations thereof; And mixing the oxide or carbonate of Tb and calcining in a temperature range of 100 ° C to 1,000 ° C; And
It comprises annealing the calcined powder in a temperature range of 1,000 ℃ to 2,000 ℃ to obtain a lithium-based garnet phosphor,
Method for producing lithium-based garnet phosphor.

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