Patent Publication Number: US-2019169496-A1

Title: Red phosphor and light emitting device comprising same

Description:
TECHNICAL FIELD 
     An embodiment relates to a red phosphor and a light emitting device including the same. 
     BACKGROUND ART 
     A light emitting device (LED) is a compound semiconductor element configured to convert electric energy into light energy, and may realize various colors by adjusting a composition ratio of the compound semiconductor. 
     A nitride semiconductor LED has advantages of low power consumption, semi-permanent lifetime, fast response speed, safety, and environmental friendliness compared to conventional light sources such as fluorescent lamps and incandescent lamps. Accordingly, it has been expanding applications such as a light-emitting diode backlight which replaces a cold cathode fluorescent lamp (CCFL) constituting a backlight of a liquid crystal display (LCD) device, white light-emitting diode lighting device which may replace the fluorescent lamp or the incandescent lamp, automotive headlights, and up to traffic lights. 
     A light emitting device may implement white light by combining an LED (light-emitting chip) and a phosphor. Nowadays, a K 2 SiF 6  phosphor as a red phosphor has been studied. However, such a fluoride phosphor has a problem that photoluminescence decreases or color coordinates change under a high temperature and high humidity environment. 
     DISCLOSURE 
     Technical Problem 
     An embodiment provides a red phosphor having excellent reliability and a light emitting device using the red phosphor. 
     Problems to be solved in embodiments are not limited thereto, and objects and effects which may be determined from solutions to the problems and embodiments described below are also included. 
     Technical Solution 
     One aspect of the present invention provides a red phosphor satisfies a following structural formula. 
       K 2 M 1-x Mn 4+   x F 6   [Structural Formula]
 
     Here, M is at least one element selected from the group consisting of a Group IV element and a Group XIV element, and the X satisfies 0.028≤X≤0.055. 
     The red phosphor may include a coating layer formed on a surface. 
     The coating layer may include a Group II or Group III element. 
     The coating layer may include at least one of MgO, In 2 O 3 , Al 2 O 3 , and B 2 O 3 . 
     Another aspect of the present invention provides a light emitting device, including a light emitting device (LED) configured to emit first light; and a wavelength conversion layer configured to convert a wavelength of the first light, wherein the wavelength conversion layer includes: a first phosphor configured to absorb the first light to emit light in a green wavelength range; and a second phosphor configured to absorb the first light to emit light in a red wavelength range, wherein the second phosphor satisfies a following structural formula. 
       K 2 M 1-x Mn 4+   X F 6   [Structural Formula]
 
     Here, M is at least one element selected from the group consisting of a Group IV element and a Group XIV element, and the X satisfies 0.028≤X≤0.055. 
     The wavelength conversion layer may include a light-transmissive resin in which the first wavelength converter and the second wavelength converter are dispersed. 
     A total amount of the first wavelength converter and the second wavelength converter may be 25 to 50 wt % based on 100 wt % of a composition of the wavelength conversion layer. 
     A total amount of the first wavelength converter and the second wavelength converter may be 25 to 45 wt % based on 100 wt % of a composition of the wavelength conversion layer. 
     A content ratio of the first wavelength converter may be 25 to 40%, and a content ratio of the second wavelength converter may be 60 to 75%. 
     A molar ratio of Mn of the second wavelength converter may be 0.04 to 0.055 mol. 
     A total amount of the first wavelength converter and the second wavelength converter may be 30 to 50 wt % based on 100 wt % of a composition of the wavelength conversion layer. 
     A content ratio of the first wavelength converter may be 15 to 30%, and a content ratio of the second wavelength converter may be 70 to 85%. 
     A molar ratio of Mn of the second wavelength converter may be 0.028 to 0.399 mol. 
     The second phosphor may include a coating layer formed on a surface. 
     The coating layer may include at least one of MgO, In 2 O 3 , Al 2 O 3 , and B 2 O 3 . 
     Advantageous Effects 
     According to an embodiment, a moisture resistance of a red phosphor may be improved. Accordingly, a decrease of photoluminescence can be controlled under a high temperature and high humidity environment. 
     In addition, a change of color coordinates can be controlled under a high temperature and high humidity environment. 
     Various and beneficial advantages and effects of the present invention are not limited to the above description, and can be more easily understood while describing a detailed embodiment of the present invention. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a conceptual diagram of a red phosphor according to an embodiment of the present invention, 
         FIG. 2  is a scanning electron microscope (SEM) photograph of a red phosphor coated with MgO using an ODE solution, 
         FIG. 3  is an SEM photograph of a red phosphor coated with In 2 O 3  using an ODE solution, 
         FIG. 4  is an SEM photograph of a red phosphor coated with Al 2 O 3  using an IPA solution, 
         FIG. 5  is an SEM photograph of a red phosphor coated with In 2 O 3  using a PEG solution, 
         FIG. 6  is an SEM photograph of a red phosphor coated with Al 2 O 3  using a PEG solution, 
         FIG. 7  is an SEM photograph of a red phosphor coated with B 2 O 3  using a PEG solution, 
         FIG. 8  is a conceptual diagram of a light emitting device according to an embodiment of the present invention, 
         FIG. 9  is a graph illustrating color coordinates of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 75%, 
         FIG. 10  is a graph illustrating luminous flux of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 75%, 
         FIG. 11  is a graph illustrating a spectrum of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 75%, 
         FIG. 12  is a graph illustrating color coordinates of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 50%, 
         FIG. 13  is a graph illustrating luminous flux of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 50%, 
         FIG. 14  is a graph illustrating a spectrum of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 50%, 
         FIG. 15  is a graph illustrating color coordinates of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 30%, 
         FIG. 16  is a graph illustrating luminous flux of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 30%, 
         FIG. 17  is a graph illustrating a spectrum of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 30%, 
         FIG. 18  is a graph illustrating a spectrum of a red phosphor in which a molar ratio of Mn is adjusted to 100%, 75% and 50%. 
         FIG. 19  is a graph illustrating a change of luminous flux of white light under a condition of 60° C. using a red phosphor having a molar ratio of Mn of 100%, 75% and 50%, 
         FIG. 20  is a graph illustrating a change of a Cx color coordinate of white light under a condition of 60° C. using a red phosphor having a molar ratio of Mn of 100%, 75% and 50%, 
         FIG. 21  is a graph illustrating a change of a Cy color coordinate of white light under a condition of 60° C. using a red phosphor having a molar ratio of Mn of 100%, 75% and 50%, 
         FIG. 22  is a graph illustrating a change of luminous flux of white light under a condition of 80° C. using a red phosphor having a molar ratio of Mn of 100%, 75% and 50%, 
         FIG. 23  is a graph illustrating a change of a Cx color coordinate of white light under a condition of 80° C. using a red phosphor having a molar ratio of Mn of 100%, 75% and 50%, 
         FIG. 24  is a graph illustrating a change of Cy color coordinate of white light under a condition of 80° C. using a red phosphor having a molar ratio of Mn of 100%, 75% and 50%, 
         FIG. 25  is a graph illustrating a change of luminous flux of white light under a condition of 80° C. and 85% using a red phosphor having a molar ratio of Mn of 100%, 75% and 50%, 
         FIG. 26  is a graph illustrating a change of Cx color coordinate of white light under a condition of 80° C. and 85% using a red phosphor having a molar ratio of Mn of 100%, 75% and 50%, 
         FIG. 27  is a graph illustrating a change of Cy color coordinate of white light under a condition of 80° C. and 85% using a red phosphor having a molar ratio of Mn of 100%, 75% and 50%, 
         FIG. 28  is a conceptual diagram of a light emitting device (LED) of  FIG. 8 , and 
         FIG. 29  is a conceptual diagram of an LED package according to an embodiment of the present invention. 
     
    
    
     MODES OF THE INVENTION 
     Since the present invention may make various modifications and have several embodiments, specific embodiments are illustrated and described in the drawings. However, it should be understood that it is not intended to limit embodiments of the present invention to any specific embodiment, but includes all modifications, equivalents and substitutes within the spirit and scope of embodiments. 
     Terms including ordinal numbers such as first, second, etc. may be used to describe various components, but the components are not limited to the terms. However, the terms are only used for the purpose of distinguishing one component from another. For example, a second component may be named as a first component, and similarly, a first component may also be named as a second component without departing from the scope of embodiments. Terms of and/or includes a combination of a plurality of related described items or any items of a plurality of related described items. 
     Terms used herein is for the purpose of describing a specific embodiment only and is not intended to limit embodiments of the invention. The singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Also, it should be understood that terms such as “including” or “having” described herein are intended to specify the presence of feature, numbers, steps, operations, components, parts, or combinations thereof described on the specification but do not preclude the presence or addition possibility of one or more other features or numbers, steps, operations, components, parts, or combinations thereof. 
     In the description of embodiments, when an element is referred to as being “on or under” another element, the term “on or under” refers to either a direct connection between two elements or an indirect connection between two elements having one or more elements formed therebetween. In addition, when the term “on or under” is used, it may refer to a downward direction as well as an upward direction with respect to an element. 
     Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, the same or corresponding components are denoted by the same reference numerals, and redundant description thereof will be omitted. 
       FIG. 1  is a conceptual diagram of a red phosphor according to an embodiment of the present invention. 
     Referring to  FIG. 1 , a phosphor  202  according to an embodiment may be a structure in which a coating layer  202   b  is formed on a surface of a particle  202   a . The phosphor  202  may partially absorb excitation light and emit light in a red wavelength range. The light in the red wavelength range may have a peak at 630 to 635 nm, and a full width at half maximum (FWHM) may be 5 to 10 nm. The phosphor may be a fluoride phosphor satisfying a following structural formula. 
       K 2 M 1-x Mn 4+   X F 6   [Structural Formula]
 
     Here, M may be at least one element selected from the group consisting of a Group IV element and a Group XIV element. In one example, M may be Si or Ti. X may satisfy 0≤X≤0.2. However, the present invention is not limited thereto, and X may satisfy 0.028≤X≤0.055. A range of X may be appropriately adjusted within the above range depending on desired luminescence characteristics or the like. 
     An active element, Mn, may react with air and be easily oxidized. Therefore, there is a problem that photoluminescence decreases when Mn is exposed to air for a long period of time. Accordingly, in the present embodiment, reliability can be improved by coating a surface of the phosphor. 
     According to an embodiment, the coating layer  202   b  may be formed on the surface of the particle  202   a.    
     The coating layer  202   b  may include a Group III or Group IV element. The coating layer  202   b  may include a metal oxide such as MgO, In 2 O 3 , Al 2 O 3 , and B 2 O 3 . The coating layer  202   b  may be formed of a single layer or a plurality of layers using a metal oxide. When the plurality of layers are formed, a metal included in each layer may be different. 
     The coating layer  202   b  may be prepared by adding and mixing a phosphor powder, a coating agent, and a reaction catalyst to and with a dispersion solution, and then cleaning and drying the mixture. Hereinafter, it will be described in more detail in the following non-limiting experimental examples. 
     First Experimental Example 
     An MgO-coated red phosphor was prepared by reacting 3.0 g of KsiF phosphor, 0.5 g of Mg(C 2 H 3 O 2 ) 2 , and 1 ml of a reaction catalyst (CH(CH 2 ) 7 COOH) at 40° C. for 3 hours in 20 ml of a dispersion solution of ODE (CH 3 (CH 2 ) 15 CH═CH 2 ). Thereafter, the MgO-coated red phosphor was cleaned two times with 20 ml of IPA, and then dried at 90° C. for 1 hour. An SEM photograph of the prepared phosphor is shown in  FIG. 2 , and a measured photoluminescence is shown in Table 1. 
     Second Experimental Example 
     An In 2 O 3 -coated red phosphor was prepared by reacting 3.0 g of KsiF phosphor, 0.5 g of In(C 2 H 3 O 2 ) 2 , and 1 ml of a reaction catalyst (CH(CH 2 ) 7 COOH) at 40° C. for 3 hours in 20 ml of a dispersion solution (CH 3 (CH 2 ) 15 CH═CH 2 ). Thereafter, the In 2 O 3 -coated red phosphor was cleaned two times with 20 ml of IPA, and then dried at 90° C. for 1 hour. An SEM photograph of the prepared phosphor is shown in  FIG. 3 , and a measured photoluminescence is shown in Table 1. 
     Third Experimental Example 
     An Al 2 O 3 -coated red phosphor was prepared by reacting 4.0 g of KsiF phosphor, 0.5 g of Al(NO 3 ) 3 , and 0.5 g of a reaction catalyst (Urea CO(NH 2 ) 2 ) at 40° C. for 3 hours in 50 ml of a dispersion solution of isopropyl alcohol (IPA). Thereafter, the Al 2 O 3 -coated red phosphor was cleaned two times with 20 ml of IPA, and then dried at 90° C. for 1 hour. An SEM photograph of the prepared phosphor is shown in  FIG. 4 , and a measured photoluminescence is shown in Table 1. 
     Fourth Experimental Example 
     An In 2 O 3 -coated red phosphor was prepared by reacting 5.0 g of KsiF phosphor, 1.25 g of InCl 3 , and 2.5 g of a reaction catalyst (Citric acid) at 40° C. for 3 hours in 20 ml of a dispersion solution of polyethylene glycol (PEG). Thereafter, the In 2 O 3 -coated red phosphor was cleaned three times with 20 ml of IPA, and then dried at 90° C. for 2 hours. An SEM photograph of the prepared phosphor is shown in  FIG. 5 , and a measured photoluminescence is shown in Table 1. 
     Fifth Experimental Example 
     An Al 2 O 3 -coated red phosphor was prepared by reacting 5.0 g of KsiF phosphor, 1.25 g of Al(NO 3 ) 3 , and 2.5 g of a reaction catalyst (Citric acid) at 40° C. for 3 hours in 20 ml of a dispersion solution of polyethylene glycol (PEG). Thereafter, the Al 2 O 3 -coated red phosphor was cleaned three times with 20 ml of IPA, and then dried at 90° C. for 2 hours. An SEM photograph of the prepared phosphor is shown in  FIG. 6 , and a measured photoluminescence is shown in Table 1. 
     Sixth Experimental Example 
     A B 2 O 3 -coated red phosphor was prepared by reacting 5.0 g of KsiF phosphor, 1.25 g of Boric acid, and 2.5 g of a reaction catalyst (Citric acid) at 40° C. for 3 hours in 20 ml of a dispersion solution of polyethylene glycol (PEG). Thereafter, the B 2 O 3 -coated red phosphor was cleaned three times with 20 ml of IPA, and then dried at 90° C. for 2 hours. An SEM photograph of the prepared phosphor is shown in  FIG. 7 , and a measured photoluminescence is shown in Table 1. 
     
       
         
           
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Photoluminescence (PL %) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 Comparative Example 
                 100 
               
               
                   
                 First Experimental Example 
                 93.4 
               
               
                   
                 Second Experimental Example 
                 98.2 
               
               
                   
                 Third Experimental Example 
                 97.8 
               
               
                   
                 Fourth Experimental Example 
                 101.1 
               
               
                   
                 Fifth Experimental Example 
                 98.6 
               
               
                   
                 Sixth Experimental Example 
                 93.0 
               
               
                   
                   
               
            
           
         
       
     
     Referring to Table 1, when photoluminescence of a red phosphor (the comparative example) without coating a surface thereof is defined as 100, it can be seen that the photoluminescence of an experimental example is relatively lower. However, in the case of the fourth experimental example, it can be confirmed that the photoluminescence is higher than that of the comparative example. The second experimental example and the fourth experimental example are both coated with In, but a dispersion solution is different. Therefore, it can be seen that when the coating is performed using the PEG solution, the photoluminescence can be further increased. 
     Table 2 below is a table illustrating measurement of Comparative Example and Experimental Examples 4, 5, and 6, in which an intensity of luminescence decreases as a time elapses at 150° C. 
     
       
         
           
               
               
               
               
               
               
               
             
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 0 h 
                 24 h 
                 48 h 
                 72 h 
                 96 h 
                 120 h 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Comparative 
                 100 (PL %) 
                 50.8 
                 49.8 
                 44.3 
                 42.7 
                 42.0 
               
               
                 Example 
               
               
                 Fourth 
                 100 (PL %) 
                 94.8 
                 93.3 
                 85.7 
                 81.1 
                 80.9 
               
               
                 Experimental 
               
               
                 Example 
               
               
                 Fifth 
                 100 (PL %) 
                 96.5 
                 90.2 
                 86.5 
                 81.7 
                 81.6 
               
               
                 Experimental 
               
               
                 Example 
               
               
                 Sixth 
                 100 (PL %) 
                 94.8 
                 88.9 
                 82.1 
                 76.2 
                 73.0 
               
               
                 Experimental 
               
               
                 Example 
               
               
                   
               
            
           
         
       
     
     In the case of the comparative example in which a surface is not coated, it can be seen that the photoluminescence (PL) is decreased by about 50% when the red phosphor is exposed for 24 hours in an environment at 150° C. It can be seen that the decrease of the photoluminescence is relatively small even after a time further elapses. 
     However, when referring to the fourth to sixth experimental examples, it can be seen that the decrease of the photoluminescence is smaller than that of the comparative example. In particular, in the case of the fourth and fifth experimental examples, it can be seen that the luminance may be maintained at about 80% or more of an initial intensity of luminescence even after about 120 hours have elapsed. 
       FIG. 8  is a conceptual diagram of a light emitting device according to an embodiment of the present invention. 
     Referring to  FIG. 8 , the light emitting device of an embodiment includes an LED  100  configured to emit first light L 1  and a wavelength conversion layer  200  configured to absorb and emit a part of the first light L 1 . 
     The LED  100  may be a blue LED configured to emit light of 420 to 470 nm or an ultra-violate (UV) emitting element configured to emit light of an ultraviolet wavelength range. A structure of the LED  100  is not particularly limited thereto. 
     The wavelength conversion layer  200  includes a first phosphor  201 , a second phosphor  202 , and a light-transmissive resin  204  in which the first phosphor  201  and the second phosphor  202  are dispersed. A structure of the wavelength conversion layer  200  is not limited thereto. 
     The wavelength conversion layer  200  may be disposed only on an upper surface of the LED  100 , or may be disposed on the upper surface and a side surface thereof. Alternatively, the LED  100  may be entirely molded by filling a cavity of a package. 
     The light-transmissive resin  204  may be selected from any one or more of the group consisting of epoxy resin, silicone resin, polyimide resin, urea resin, and acrylic resin, but is not limited thereto. 
     The first light L 1  emitted from the LED  100  and the light converted by the wavelength conversion layer  200  may be mixed to implement white light L 2  on the CIE color coordinates. 
     The first phosphor  201  may partially absorb the first light L 1  and emit light in a green wavelength range. The light in the green wavelength range may have a peak at 525 to 545 nm, and a full width at half maximum (FWHM) may be 45 to 55 nm. 
     The first phosphor  201  may include at least one of β-type SiAlON:Eu, B aYSi 4 N 7 :Eu, Ba 3 Si 6 O 12 N 2 :Eu, CaSi 2 O 2 N 2 :Eu, SrYSi 4 N 7 :Eu, and LuAG. 
     As described above, the second phosphor  202  may be a fluoride phosphor satisfying the following structural formula. 
       K 2 M 1-x Mn 4+   X F 6   [Structural Formula]
 
     Here, M may be at least one element selected from the group consisting of a Group IV element and a Group XIV element. In one example, M may be Si or Ti. X may satisfy 0≤X≤0.2 or 0.028≤X≤0.055. Hereinafter, for convenience of explanation, the second phosphor is described as a red phosphor represented by K 2 SiF 6 :Mn 4+ . 
     A molar ratio x of the active element, Mn may be 0.028 to 0.055 mol. When the molar ratio of Mn is 0.04 to 0.055 mol, a total amount of the first phosphor  201  and the second phosphor  202  may be 25 to 45 wt % based on 100 wt % of a composition of the wavelength conversion layer. For example, when a total amount of the first and second phosphors is 40 wt %, a content of the light-transmissive resin  204  may be 60 wt %. 
     At this point, a content ratio of the first phosphor  201  may be 25 to 40%, and a content ratio of the second phosphor  202  may be 60 to 75%. When such a condition is satisfied, white light may be implemented on the CIE coordinate system. In addition, as described later, a Cx color coordinate deviation may be improved. 
     When the molar ratio of Mn is 0.028 to 0.399 mol, the total amount of the first phosphor  201  and the second phosphor  202  may be 30 to 50 wt % based on 100 wt % of the composition of the wavelength conversion layer. At this point, the content ratio of the first phosphor  201  may be 15 to 30%, and the content ratio of the second phosphor  202  may be 70 to 85%. When such a condition is satisfied, white light may be mixed with the light of the LED and be implemented on the CIE coordinate system. In addition, the Cx color coordinate deviation may be improved. 
     Hereinafter, the case where the molar ratio of Mn is 0.07 mol is defined as Mn:100%, 0.525 mol is defined as Mn:75%, 0.035 mol is defined as Mn:50%, and 0.021 mol is defined as Mn:30%. 
       FIG. 9  is a graph illustrating color coordinates of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 75%,  FIG. 10  is a graph illustrating luminous flux of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 75%, and  FIG. 11  is a graph illustrating a spectrum of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 75%. 
     In the comparative example, white light was implemented using a blue LED, a beta SiAlON green phosphor, and a red phosphor of Mn:100%. In the first experimental example, white light was implemented using a blue LED, a beta SiAlON green phosphor, and a red phosphor of Mn:75%. 
     Table 3 below is a table illustrating measurement of luminous flux, the CIE color coordinates, color reproducibility (NTSC), and wavelength peak (WP) of the white light implemented by the comparative example and the first experimental example, and Table 4 illustrates a mixing ratio of phosphor. 
     
       
         
           
               
               
               
               
               
               
               
             
               
                   
                 TABLE 3 
               
             
            
               
                   
                   
               
               
                   
                 Phosphor 
                 Flux 
                 Flux 
                   
                 NTSC 
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Division 
                 Green 
                 Red 
                 (lm) 
                 (%) 
                 Cx 
                 Cy 
                 (%) 
                 W · P (nm) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Comparative 
                 Beta 
                 KSF 
                 13.7 
                 100.0 
                 0.268 
                 0.265 
                 89.8 
                 447.4 
               
               
                 Example 
                 SiAlON 
                 Mn: 100% 
               
               
                 First 
                   
                 KSF 
                 13.5 
                 98.6 
                 0.268 
                 0.265 
                 88.8 
                 446.4 
               
               
                 Experimental 
                   
                 Mn: 75% 
               
               
                 Example 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
             
               
                   
                 TABLE 4 
               
             
            
               
                   
                   
               
               
                   
                 Light 
                 Phosphor Mixing Ratio 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Transmissive 
                   
                 GreenBeta- 
                   
                   
               
               
                 Division 
                 Resin 
                 Total (wt %) 
                 SiAlON 
                 KSFMn:100 
                 KSFMn:75% 
               
               
                   
               
               
                 Comparative 
                 Silicone 
                 20.9 
                 33.5 
                 66.5 
                 — 
               
               
                 Example 
               
               
                 First 
                   
                 25.2 
                 31.2 
                 — 
                 68.8 
               
               
                 Experimental 
               
               
                 Example 
               
               
                   
               
            
           
         
       
     
     As shown in  FIG. 9 , it can be seen that both the white light of the comparative example and that of the first experimental example are white light on the CIE coordinate system. In addition, as shown in  FIG. 10  and Table 3, the luminous flux of the first experimental example is almost the same as that of the comparative example. 
     Referring to Table 4, it can be seen that in the comparative example, the total amount of the phosphor was 20.9 wt % based on 100 wt % of the total composition, whereas in the case of the first experimental example, the total amount increased to 25.2 wt %. In addition, in the case of the first experimental example, it can be seen that the content ratio of the red phosphor is 68.8%, which is slightly higher than that of the comparative example. 
     That is, when a molar ratio of Mn of the red phosphor is lowered, it can be seen that the total amount of the phosphor is relatively increased and the content of the red phosphor is increased in order to maintain the white light on the CIE coordinate system. 
       FIG. 12  is a graph illustrating color coordinates of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 50%,  FIG. 13  is a graph illustrating luminous flux of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 50%, and  FIG. 14  is a graph illustrating a spectrum of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 50%. 
     In the comparative example, white light was implemented using a blue LED, a beta SiAlON green phosphor, and a red phosphor of Mn:100%. In the second experimental example, white light was implemented using a blue LED, a beta SiAlON green phosphor, and a red phosphor of Mn:50%. 
     Table 5 below is a table illustrating measurement of luminous flux, the CIE color coordinates, color reproducibility (NTSC), and wavelength peak (WP) of the white light implemented by the comparative example and the second experimental example, and Table 6 illustrates a mixing ratio of phosphor. 
     
       
         
           
               
               
               
               
               
               
               
             
               
                   
                 TABLE 5 
               
             
            
               
                   
                   
               
               
                   
                 Phosphor 
                   
                 Flux 
                   
                 NTSC 
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Division 
                 Green 
                 Red 
                 Flux (lm) 
                 (%) 
                 Cx 
                 Cy 
                 (%) 
                 W · P (nm) 
               
               
                   
               
               
                 Comparative 
                 Beta 
                 KSF 
                 11.96 
                 100.0 
                 0.245 
                 0.220 
                 91.0 
                 446.7 
               
               
                 Example 
                 SiAlON 
                 Mn: 100% 
               
               
                 Second 
                   
                 KSF 
                 12.07 
                 100.9 
                 0.244 
                 0.220 
                 90.7 
                 446.5 
               
               
                 Experimental 
                   
                 Mn: 50% 
               
               
                 Example 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
             
               
                   
                 TABLE 6 
               
             
            
               
                   
                   
               
               
                   
                 Light 
                 Phosphor Mixing Ratio 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Transmissive 
                   
                 GreenBeta- 
                   
                   
               
               
                 Division 
                 Resin 
                 Total (wt %) 
                 SiAlON 
                 KSFMn:100 
                 KSFMn:50% 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Comparative 
                 Silicone 
                 20.0 
                 32 
                 68 
                 — 
               
               
                 Example 
               
               
                 Second 
                   
                 33.0 
                 18.5 
                 — 
                 81.5 
               
               
                 Experimental 
               
               
                 Example 
               
               
                   
               
            
           
         
       
     
     As shown in  FIG. 12 , it can be seen that both the white light of the comparative example and that of the second experimental example are white light on the CIE coordinate system. In addition, as shown in  FIG. 13  and Table 5, the luminous flux of the second experimental example is almost the same as that of the comparative example. 
     Referring to Table 6, it can be seen that in the comparative example, the total amount of the phosphor was 20.0 wt % based on 100 wt % of the total composition, whereas in the case of the second experimental example, the total amount increased to 33.0 wt %. In addition, in the case of the second experimental example, it can be seen that the content ratio of the red phosphor is 81.5%, which is higher than that of the comparative example. 
     It can be seen that the total amount of the total phosphors and the content of the red phosphor were increased in the second experimental example using Mn:50% as compared with the first experimental example. 
       FIG. 15  is a graph illustrating color coordinates of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 30%,  FIG. 16  is a graph illustrating luminous flux of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 30%, and  FIG. 17  is a graph illustrating a spectrum of white light implemented using a red phosphor having a molar ratio of Mn of 100% and 30%. 
     In the comparative example, white light was implemented using a blue LED, a beta SiAlON green phosphor, and a red phosphor of Mn:100%. In the third experimental example, white light was implemented using a blue LED, a beta SiAlON green phosphor, and a red phosphor of Mn:30%. 
     Table 7 below is a table illustrating measurement of luminous flux, the CIE color coordinates, color reproducibility (NTSC), and wavelength peak (WP) of the white light implemented by the comparative example and the third experimental example, and Table 8 illustrates a mixing ratio of phosphor. 
     
       
         
           
               
               
               
               
               
               
               
             
               
                   
                 TABLE 7 
               
             
            
               
                   
                   
               
               
                   
                 Phosphor 
                   
                 Flux 
                   
                 NTSC 
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Division 
                 Green 
                 Red 
                 Flux (lm) 
                 (%) 
                 Cx 
                 Cy 
                 (%) 
                 W · P (nm) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Comparative 
                 Beta 
                 KSF 
                 15.92 
                 100.0 
                 0.259 
                 0.248 
                 87.0 
                 447.9 
               
               
                 Example 
                 SiAlON 
                 Mn: 100% 
               
               
                 Third 
                   
                 KSF 
                 15.55 
                 97.4 
                 0.259 
                 0.248 
                 86.6 
                 447.9 
               
               
                 Experimental 
                   
                 Mn: 30% 
               
               
                 Example 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
             
               
                   
                 TABLE 8 
               
             
            
               
                   
                   
               
               
                   
                 Light 
                 Phosphor Mixing Ratio 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Transmissive 
                   
                 GreenBeta- 
                   
                   
               
               
                 Division 
                 Resin 
                 Total (wt %) 
                 SiAlON 
                 KSFMn:100 
                 KSFMn:30% 
               
               
                   
               
               
                 Comparative 
                 Silicone 
                 28.5 
                 31.5 
                 68.5 
                 — 
               
               
                 Example 
               
               
                 Third 
                   
                 91.0 
                 10.5 
                 — 
                 89.5 
               
               
                 Experimental 
               
               
                 Example 
               
               
                   
               
            
           
         
       
     
     As shown in  FIG. 15 , it can be seen that both the first white light and the second white light are white light on the CIE coordinate system. However, referring to  FIG. 16  and Table 7, it can be seen that the luminous flux of the third experimental example is decreased by about 2.3% as compared with that of the comparative example. 
     It can be seen that in the comparative example, the total amount of the phosphor was 28.0 wt % based on 100 wt % of the total composition, whereas in the case of the third experimental example, the total amount is 91.0 wt %, which is very high. In addition, in the case of the third experimental example, it can be seen that the content ratio of the red phosphor is 89.5%, which is much higher than that of the comparative exam*. 
     Therefore, when a molar ratio of Mn is lowered to 30% or less, luminous flux is lowered and a total amount of the phosphor may be excessively increased. In this case, reliability problems may occur. 
       FIG. 18  is a graph illustrating a spectrum of a red phosphor in which a molar ratio of Mn is adjusted to 100%, 75% and 50%. 
     Table 9 below is a table illustrating measurement of wavelength peak (WP), relative luminance, full width at half maximum (FWHM), and a particle size according to a molar ratio of Mn. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 9 
               
             
            
               
                   
                   
               
               
                   
                 Wave- 
                   
                   
                   
               
               
                   
                 length 
                 Relative 
                   
                 Particle Size [μm] 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Peak 
                 luminance 
                 FWHM 
                   
                   
                   
                 D90 − 
               
               
                 Division 
                 [nm] 
                 (%) 
                 [nm] 
                 D10 
                 D50 
                 D90 
                 D10 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 KSF-Mn 
                 632 
                 100 
                 7 
                 18 
                 26 
                 40 
                 22 
               
               
                 100% 
               
               
                 KSF-Mn 
                 632 
                 91 
                 7 
                 18 
                 26 
                 40 
                 22 
               
               
                 75% 
               
               
                 KSF-Mn 
                 632 
                 77 
                 7 
                 18 
                 26 
                 40 
                 22 
               
               
                 50% 
               
               
                   
               
            
           
         
       
     
     Referring to Table 9 and  FIG. 18 , when the luminance of the red phosphor of which Mn is 100% is 100, it can be seen that the relative luminance of the red phosphor of Mn:75% is decreased to 91%, and the relative luminance of the red phosphor of Mn:50% is decreased to 77%. However, it can be seen that the FWHM, wavelength peak and particle size are substantially the same. 
       FIG. 19  is a graph illustrating a change of luminous flux of white light under a condition of 60° C. using a red phosphor having a molar ratio of Mn of 100%, 75% and 50%,  FIG. 20  is a graph illustrating a change of a Cx color coordinate of white light under a condition of 60° C. using a red phosphor having a molar ratio of Mn of 100%, 75% and 50%, and  FIG. 21  is a graph illustrating a change of a Cy color coordinate of white light under a condition of 60° C. using a red phosphor having a molar ratio of Mn of 100%, 75% and 50%. 
     Referring to  FIG. 19 , in the case of the third experimental example using a red phosphor having Mn of 50%, it can be seen that the variation width of the luminous flux of white light is relatively low. On the other hand, in the case of the comparative example using a red phosphor of Mn:100% and the first experimental example using a red phosphor of Mn:75%, it can be seen that a degree of decrease in the luminous flux increases as a time elapses. At this point, when the phosphor is coated with a metal oxide as described above, the decrease of the luminous flux may be more effectively reduced. 
     Referring to  FIG. 20 , in the case of the third experimental example, it can be seen that the variation width of the Cx coordinate of the white light is the lowest. In the case of the comparative example, it can be seen that the variation width of the Cx coordinate is the highest as a time elapses. 
     Therefore, when the molar ratio of Mn of the red phosphor is lowered, it can be seen that the reliability of the package may be improved. 
     However, the molar ratio of Mn of the red phosphor may be inversely proportional to the total amount of the phosphor. That is, the lower the molar ratio of Mn, the lower the Cx change rate, but an amount of the phosphor used may be increased. 
     However, referring to  FIG. 21 , it can be seen that the variation width of the Cy coordinate is relatively similar even after times elapse in the comparative example, the first experimental example, and the second experimental example. 
     As shown in  FIGS. 22 to 24 , even when a temperature is further raised to 80° C., similar result values could be obtained in the deviation of such luminous flux, Cx color coordinate, and Cy color coordinate. In addition, as shown in  FIGS. 25 to 27 , similar result values could be obtained even under the condition of high temperature/high humidity (80° C./85%). 
       FIG. 28  is a conceptual diagram of LED of  FIG. 8 , and  FIG. 29  is a conceptual diagram of an LED package according to an embodiment of the present invention. 
     Referring to  FIG. 28 , a substrate  110  of the LED  100  includes a conductive substrate or an insulating substrate. The substrate  110  may be a material suitable for growing a semiconductor material or a carrier wafer. The substrate  110  may be formed of a material selected from sapphire (Al 2 O 3 ), SiC, GaAs, GaN, ZnO, Si, GaP, InP, and Ge, but is not limited thereto. 
     Buffer layers  111  and  112  may mitigate lattice mismatch between a light-emitting structure provided on the substrate  110  and the substrate  110 . The buffer layers  111  and  112  may be grown as a single crystal on the substrate  110 , and the buffer layers  111  and  112  grown as the single crystal may improve the crystallinity of a first semiconductor layer  130 . 
     The light-emitting structure provided on the substrate  110  includes the first semiconductor layer  130 , an active layer  140 , and a second semiconductor layer  160 . In general, the above-described light-emitting structure may be divided into a plurality of pieces by cutting the substrate  110 . 
     The first semiconductor layer  130  may be a compound semiconductor such as a group III-V or a group II-VI, and the first semiconductor layer  130  may be doped with a first dopant. The first semiconductor layer  130  may be a semiconductor material having a composition formula of Inx1Aly1Ga1-x1-y1N (0≤x1≤1, 0≤y1≤1, 0≤x1+y1≤1), for example, may be selected from GaN, AlGaN, InGaN, InAlGaN, or the like. The first dopant may be an n-type dopant such as Si, Ge, Sn, Se or Te. When the first dopant is an n-type dopant, the first semiconductor layer  130  doped with the first dopant may be an n-type semiconductor layer. 
     The active layer  140  is a layer where electrons (or holes) injected through the first semiconductor layer  130  and holes (or electrons) injected through the second semiconductor layer  160  meet. As the electrons and the holes recombine, the active layer  140  may transit to a low energy level and may generate light having a wavelength corresponding thereto. There is no limitation on a light-emitting wavelength in the present embodiment. 
     The active layer  140  may have any one of a single-well structure, a multi-well structure, a single-quantum-well structure, a multi-quantum-well (MQW) structure, a quantum-dot structure, and a quantum-wire structure, but the structure of the active layer  140  is not limited thereto. 
     The active layer  140  may have a structure in which a plurality of well layers and barrier layers are alternately arranged. The well layer and the barrier layer may have a composition formula of InxAlyGa1-x-yN (0≤x≤1, 0≤y≤1, 0≤x+y≤1), and an energy band gap of the barrier layer may be greater than that of the well layer. 
     The second semiconductor layer  160  may be formed on the active layer  140  and may be implemented as a compound semiconductor such as a group III-V or a group II-VI, and the second semiconductor layer  160  may be doped with a second dopant. The second semiconductor layer  160  may be formed of a semiconductor material having a composition formula of In x5 Al y2 Ga 1-x5-y2 N (0≤x5≤1, 0≤y2≤1, 0≤x5+y2≤1) or may be formed of a material selected from AlInN, AlGaAs, GaP, GaAs, GaAsP, AlGaInP, or the like. When the second dopant is a p-type dopant such as Mg, Zn, Ca, Sr, or Ba, the second semiconductor layer  160  doped with the second dopant may be a p-type semiconductor layer. 
     An electron blocking layer (EBL)  150  may be disposed between the active layer  140  and the second semiconductor layer  160 . The EBL  150  may block a flow of electrons supplied from the first semiconductor layer  130  to the second semiconductor layer  160  and may increase probability that electrons and holes recombine in the active layer  140 . An energy band gap of the EBL  150  may be greater than that of the active layer  140  and/or the second semiconductor layer  160 . 
     The EBL  150  may be formed of a semiconductor material having a composition formula of In x1 Al y1 Ga 1-x1-y1 N (0≤x1≤1, 0≤y1≤1, 0≤x1+y1≤1), for example, may be selected from AlGaN, InGaN, InAlGaN, or the like. 
     A first electrode  180  may be formed on an exposed part of the first semiconductor layer  130 . In addition, a second electrode  170  may be formed on the second semiconductor layer  160 . Various metal and transparent electrodes may be applied to the first electrode  180  and the second electrode  190 . 
     The first electrode  180  and the second electrode  170  may include any one of metals selected from In, Co, Si, Ge, Au, Pd, Pt, Ru, Re, Mg, Zn, Hf, Ta, Rh, Ir, Cr, Mo, Nb, Al, Ni, Cu, and WTi. The first electrode  180  and the second electrode  170  may further include an ohmic electrode layer as necessary. 
     Referring to  FIG. 29 , an LED package  10  according to an embodiment includes a first lead frame  11 , a second lead frame  12 , an LED  100 , a wavelength conversion layer  200 , and a body  13 . 
     An LED having various structures that emit light in a blue or an ultraviolet wavelength range may be applied to the LED  100 . In addition, the configuration described in  FIG. 28  may be applied to the LED  100  as it is. 
     The LED  100  may be electrically connected to the first lead frame  11  and the second lead frame  12 . An electrical connection between the LED  100  and the first and second lead frames  11  and  12  may be determined by an electrode structure (vertical or, horizontal) of the LED. 
     The body  13  includes a cavity  13   a  to which the first lead frame  11  and the second lead frame  12  are fixed and the LED  100  is exposed. The body  13  may include a polymer resin such as polyphthalamide (PPA). 
     The wavelength conversion layer  200  is disposed in the cavity  13   a  and includes first and second phosphors  201  and  202 . The first and second phosphors  201  and  202  may be dispersed in the light-transmissive resin  204 . The wavelength conversion layer  200  may include the above-described characteristics as it is. 
     The light emitting device or the LED package of an embodiment may further include an optical member such as a light guide plate, a prism sheet, and a diffusion sheet to function as a backlight unit. In addition, the LED of an embodiment may be further applied to a display device, a lighting device, and an indicating device. 
     At this point, the display device may include a bottom cover, a reflection plate, a light-emitting module, a light guide plate, an optical sheet, a display panel, an image signal output circuit, and a color filter. The bottom cover, the reflective plate, the light-emitting module, the light guide plate, and the optical sheet may form a backlight unit. 
     The reflection plate is disposed on the bottom cover, and the light-emitting module emits light. The light guide plate is disposed in front of the reflection plate to guide light emitted from the light-emitting module forward, and the optical sheet includes a prism sheet or the like and is disposed in front of the light guide plate. The display panel is disposed in front of the optical sheet, the image signal output circuit supplies an image signal to the display panel, and the color filter is disposed in front of the display panel. 
     In addition, the lighting device may include a substrate, a light source module including the LED of an embodiment, a heat dissipating unit configured to dissipate heat of the light source module, and a power supply unit configured to process or convert an electrical signal provided from the outside and provide the processed or converted electrical signal to the light source module. Further, the lighting device may include a lamp, a headlamp, or a street lamp or the like. 
     Embodiments of the present invention described above are not limited to the above-described embodiments and the accompanying drawings. It will be apparent to those skilled in the art to which the present embodiment of the present invention belongs that multiple substitutions, modifications and changes are possible without departing from the technical idea of embodiments.