Patent Publication Number: US-2023159824-A1

Title: Green-Emitting Phosphors and Devices Thereof

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a non-provisional application and claims priority to U.S. Provisional Patent Application Ser. No. 63/009,800 filed Apr. 14, 2020 for “GREEN-EMITTING PHOSPHORS AND DEVICES THEREOF”; and to U.S. Provisional Patent Application Ser. No. 63/073,391 filed Sep. 1, 2020 for “GREEN-EMITTING PHOSPHORS AND DEVICES THEREOF”, each of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     The subject matter described herein relates generally to phosphors and devices, and more particularly, to green-emitting phosphors. 
     Current display device technology relies on liquid crystal displays (LCDs), which is one of the most widely used flat panel displays for industrial and residential applications. However, next-generation devices will have low energy consumption, compact size, and high brightness, requiring improved color gamut. 
     LED packages for use in displays are based on a combination of a blue LED, a green phosphor and a red phosphor. The color gamut is largely determined by the choice of phosphors. Red phosphor K 2 SiF 6 :Mn 4+  has a peak characterized by a full width at half maximum (FWHM) of 6 to 8 nm and yields high color reproducibility in correspondence with the relative intensity of the emission peak. Green phosphor, β-SiAlON: Eu 2+  has a full width at half maximum of 46 to 52 nm and has a peak wavelength of 534 to 540 nm, which is not a pure green but rather is greenish yellow in color. Accordingly, there is also a need for new green-emitting phosphors that efficiently absorb blue radiation, provide high quantum efficiency, and have improved color rendering. 
     BRIEF DESCRIPTION 
     Briefly, in one aspect, green-emitting phosphors are provided. The green-emitting phosphors are selected from [Ba 1−a−b Sr a Ca b ] x [Mg,Zn] y (UO 2 ) z ([P,V]O 4 ) 2(x+y+z)/3 , where 0≤a≤1, 0≤b≤1, 0.75≤x≤1.25, 0.75≤y≤1.25, and 0.75≤z≤1.25; and [Ba,Sr,Ca,Mg,Zn] p (UO 2 ) q [P,V] r O (2p+2q+5r)/2 , where 2.5≤p≤3.5, 1.75≤q≤2.25, and 3.5≤r≤4.5. 
     In another aspect, a phosphor composition is provided. The phosphor composition comprises a green-emitting phosphor and a red-emitting phosphor; wherein the green-emitting phosphor is selected from [Ba 1−a−b Sr a Ca b ] x [Mg,Zn] y (UO 2 ) z ([P,V]O 4 ) 2(x+y+z)/3 , where 0≤a≤1, 0≤b≤1, 0.75≤x≤1.25, 0.75≤y≤1.25, and 0.75≤z≤1.25; and [Ba,Sr,Ca,Mg,Zn] p (UO 2 ) q [P,V] r O (2p+2q+5r)/2 , where 2.5≤p≤3.5, 1.75≤q≤2.25, and 3.5≤r≤4.5; and the red-emitting phosphor is selected from [Ba,Sr,Ca] 2 Si 5 N 8 :Eu 2+ ; [Ca,Sr]AlSiN 3 :Eu 2+ ; [Ba,Sr,Ca]LiAl 3 N 4 :Eu 2+ ; [Sr,Ca,Mg]S:Eu 2+ ; and a phosphor of formula I: A x MF y :Mn 4+  (I), wherein A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is an absolute value of a charge of the MF y  ion; and y is 5, 6 or 7. 
     In yet another aspect, devices including an LED light source radiationally and/or optically coupled to a green-emitting phosphor are provided. The green-emitting phosphor is selected from [Ba 1−a−b Sr a Ca b ] x [Mg,Zn] y (UO 2 ) z ([P,V]O 4 ) 2(x+y+z)/3 , where 0≤a≤1, 0≤b≤1, 0.75≤x≤1.25, 0.75≤y≤1.25, 0.75≤z≤1.25; and [Ba,Sr,Ca,Mg,Zn] p (UO 2 ) q [P,V] r O (2p+2q+5r)/2 , where 2.5≤p≤3.5, 1.75≤q≤2.25, and 3.5≤r≤4.5. 
    
    
     
       DRAWINGS 
       These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: 
         FIG.  1    is a schematic cross-sectional view of a device, in accordance with one embodiment of the disclosure; 
         FIG.  2    is a schematic cross-sectional view of a lighting apparatus, in accordance with one embodiment of the disclosure; 
         FIG.  3    is a schematic cross-sectional view of a lighting apparatus, in accordance with another embodiment of the disclosure; 
         FIG.  4    is a cutaway side perspective view of a lighting apparatus, in accordance with one embodiment of the disclosure; 
         FIG.  5    is a schematic perspective view of a surface-mounted device (SMD), in accordance with one embodiment of the disclosure; 
         FIG.  6    shows the crystal structure of BaMgUO 2 (PO 4 ) 2  as determined by x-ray diffraction (XRD) analysis; 
         FIG.  7    shows the XRD powder pattern for BaMgUO 2 (PO 4 ) 2 ; 
         FIG.  8    shows an excitation spectrum (dotted) and an emission spectrum (solid) of a green emitting phosphor of formula BaMgUO 2 (PO 4 ) 2 ; 
         FIG.  9    shows the crystal structure of BaZnUO 2 (PO 4 ) 2  as determined by x-ray diffraction (XRD) analysis; 
         FIG.  10    shows the XRD powder pattern for BaZnUO 2 (PO 4 ) 2 ; 
         FIG.  11    shows an excitation spectrum (dotted) and an emission spectrum (solid) of a green emitting phosphor of formula BaZnUO 2 (PO 4 ) 2 ; 
         FIG.  12    shows the crystal structure of Ba 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7  as determined by x-ray diffraction (XRD) analysis; 
         FIG.  13    shows the XRD powder pattern for Ba 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7 ; 
         FIG.  14    shows an excitation spectrum (dotted) and an emission spectrum (solid) of a green emitting phosphor of formula Ba 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7 ; 
         FIG.  15    shows the crystal structure of γ-Ba 2 UO 2 (PO 4 ) 2  as determined by x-ray diffraction (XRD) analysis; 
         FIG.  16    shows the XRD powder pattern for γ-Ba 2 UO 2 (PO 4 ) 2 ; 
         FIG.  17    shows an excitation spectrum (dotted) and an emission spectrum (solid) of a green emitting phosphor of formula γ-Ba 2 UO 2 (PO 4 ) 2 ; 
         FIG.  18    shows an emission spectrum of a green-emitting phosphor of formula γ-Ba 2 UO 2 (PO 4 ) 2  at 30K; 
         FIG.  19    shows an emission spectrum of a green emitting phosphor of formula Ba 2 Sr(PO 4 ) 2 (UO 2 ) 2 P 2 O 7 ; 
         FIG.  20    shows an emission spectrum of a green emitting phosphor of formula BaSr 2 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7 ; 
         FIG.  21    shows an emission spectrum of a green emitting phosphor of formula Sr 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7 ; 
         FIG.  22    shows an emission spectrum of a green emitting phosphor of formula Ca 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7 ; 
         FIG.  23    shows an emission spectrum of a green emitting phosphor of formula BaMg 2 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7 ; 
         FIG.  24    shows an emission spectrum of a green emitting phosphor of formula Ba 2 Mg(PO 4 ) 2 (UO 2 ) 2 P 2 O 7 ; 
         FIG.  25    shows an emission spectrum of formula Ba 2 UO 2 (VO 4 ) 2 ; 
         FIG.  26    shows an emission spectrum of formula γ-Ba 2 UO 2 (PO 4 ) 2  co-doped with Eu 3+  at room temperature; 
     
    
    
     Unless otherwise indicated, the drawings provided herein are meant to illustrate features of embodiments of the disclosure. These features are believed to be applicable in a wide variety of systems comprising one or more embodiments of the disclosure. As such, the drawings are not meant to include all conventional features known by those of ordinary skill in the art to be required for the practice of the embodiments disclosed herein. 
     DETAILED DESCRIPTION 
     In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings. 
     The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. 
     Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about,” “substantially,” and “approximately,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and/or interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. All references are incorporated herein by reference. 
     Square brackets in the formulas indicate that at least one of the elements within the brackets is present in the phosphor material, and any combination of two or more thereof may be present, as limited by the stoichiometry of the composition. For example, the formula [Ca,Sr,Ba] 3 MgSi 2 O 8 :Eu 2+ ,Mn 2+  encompasses at least one of Ca, Sr or Ba or any combination of two or more of Ca, Sr or Ba. Examples include Ca 3 MgSi 2 O 8 :Eu 2+ ,Mn 2+ ; Sr 3 MgSi 2 O 8 :Eu 2+ ,Mn 2+ ; or Ba 3 MgSi 2 O 8 :Eu 2+ ,Mn 2+ . Formula with an activator after a colon “:” indicates that the phosphor composition is doped with the activator. Formula showing more than one activator separated by a “,” after a colon “:” indicates that the phosphor composition is doped with either activator or both activators. For example, the formula [Ca,Sr,Ba] 3 MgSi 2 O 8 :Eu 2+ ,Mn 2+  encompasses [Ca,Sr,Ba] 3 MgSi 2 O 8 :Eu 2+ , [Ca,Sr,Ba] 3 MgSi 2 O 8 :Mn 2+  or [Ca,Sr,Ba] 3 MgSi 2 O 8 :Eu 2+  and Mn 2+ . 
     The green-emitting phosphors of the present disclosure absorb radiation in the near-UV or blue region (a wavelength range between about 400 nm and 470 nm) and emit in a narrow band with a main emission peak centered at a wavelength range between 500 nm and 550 nm, particularly from about 510 nm to about 530 nm, and more particularly from about 515 nm to about 525 nm. These phosphors are useful in display applications. Gamut of a display incorporating the narrow band green-emitting phosphors, which may be measured according to NTSC, DCI-P3, Adobe, or BT2020 standards, may be significantly improved relative to phosphors that have a relatively wide-band emission. 
     In some embodiments, the phosphors contain phosphate/vanadate groups, and are of formula [Ba 1−a−b Sr a Ca b ] x [Mg,Zn] y (UO 2 ) z ([P,V]O 4 ) 2(x+y+z)/3 , where 0≤a≤1, 0≤b≤1, 0.75≤x≤1.25, 0.75≤y≤1.25, 0.75≤z≤1.25. In some embodiments, one or more additional activator ions may be present, such as Mn 2+ , Mn 4+ , Ce 3+ , Cr 3+ , Eu 2+  or Eu 3+ . In particular, the phosphors contain phosphate groups, and are of formula [Ba x [Mg,Zn] y (UO 2 ) z [PO 4 ] 2(x+y+z)/3 . Particular examples include Ba[Mg,Zn]UO 2 (PO 4 ) 2 , and more particularly BaMgUO 2 (PO 4 ) 2  and BaZnUO 2 (PO 4 ) 2 . 
     In other embodiments, the phosphors contain [P,V] 2 O 7  groups in addition to phosphate/vanadate groups, and are of formula [Ba,Sr,Ca,Mg,Zn] p (UO 2 ) q [P,V] r O (2p+2q+5r)/2 , where 2.5≤p≤3.5, 1.75≤q≤2.25, 3.5≤r≤4.5. In some embodiments, one or more additional activator ions may be present, such as Mn 2+ , Mn 4+ , Ce 3+ , Cr 3+ , Eu 2+  or Eu 3+ . In particular, the phosphors contain phosphate and pyrophosphate groups, and are of formula Ba p (UO 2 ) q P r O (2p+2q+5r)/2 . Particular examples include Ba 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7  and gamma-Ba 2 UO 2 (PO 4 ) 2 (γ-Ba 2 UO 2 (PO 4 ) 2 ). 
     In one embodiment, the phosphors may be Ba 2 Sr(PO 4 ) 2 (UO 2 ) 2 P 2 O 7 , BaMgUO 2 (PO 4 ) 2 , BaZnUO 2 (PO 4 ) 2 , Ba 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7 , gamma-Ba 2 UO 2 (PO 4 ) 2 , BaSr 2 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7 , Sr 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7 , Ca 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7 , BaMg 2 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7 , Ba 2 Mg(PO 4 ) 2 (UO 2 ) 2 P 2 O 7 , Ba 2 UO 2 (VO 4 ) 2 , or γ-Ba 2 UO 2 (PO 4 ) 2 :Eu 3+ . 
     The phosphors of the present disclosure may be characterized as uranium-doped or U-doped because the U 6+  ions are part of the emitting species. The term ‘U-doped’ typically indicates that a relatively small number of uranium atoms is substituted in the host lattice. In many compounds the uranium is present in the host lattice as the uranyl ion (UO 2 ) 2+ . Because the uranyl ion is characterized by linear O—U—O bonding, there is typically an upper limit to the substitution that can be achieved, on the order of a few mole percent with respect to the site on which it is substituted. When substituting for a M 2+  ion there are size constraints between the M 2+  and the (UO 2 ) 2+  center that may create host lattice strain and/or compensating defects in the host lattice. As a result, concentration quenching of the U 6+  emission usually occurs before full substitution is achieved. In contrast, the phosphors of the present disclosure contain the UO 2  species as part of the host lattice and comprise uranyl ions at a concentration as high as about 40 mole % relative to the total number of moles of M 2+  cations present. 
     The phosphors of the present disclosure may be produced by firing a mixture of precursors under an oxidizing atmosphere. Non-limiting examples of suitable precursors include the appropriate metal oxides, hydroxides, alkoxides, carbonates, nitrates, aluminates, silicates, citrates, oxalates, carboxylates, tartarates, stearates, nitrites, peroxides, phosphates, pyrophosphates and combinations thereof. Suitable materials for use as precursors include, but are not limited to, BaCO 3 , BaHPO 4 , Ba 3 (PO 4 ) 2 , Ba 2 P 2 O 7 , Ba 2 Zn(PO 4 ) 2 , BaZnP 2 O 7 , Ba(OH) 2 , Ba(C 2 O 4 ), Ba(C 2 H 3 O 2 ) 2 , Ba 3 (C 6 H 5 O 7 ) 2 , Ba(NO 3 ) 2 , CaCO 3 , Eu 2 O 3 , Mg(C 2 O 4 ), Mg(C 2 H 3 O 2 ) 2 , Mg(C 6 H 6 O 7 ), MgCO 3 , MgO, Mg(OH) 2 , Mg 3 (PO 4 ) 2 , Mg 2 P 2 O 7 , Mg 2 Ba(PO 4 ) 2 , MgHPO 4 , Mg(NO 3 ) 2 , NH 4 MgPO 4 , (NH 4 ) 2 HPO 4 , NH 4 VO 3 , SrCO 3 , Zn(C 2 O 4 ), Zn(C 2 H 3 O 2 ) 2 , Zn 3 (C 6 H 5 O 7 ) 2 , ZnCO 3 , ZnO, Zn(OH) 2 , Zn 3 (PO 4 ) 2 , Zn 2 P 2 O 7 , Zn 2 Ba(PO 4 ) 2 , ZnHPO 4 , Zn(NO 3 ) 2 , NH 4 ZnPO 4 , UO 2 , UO 2 (NO 3 ) 2 , (UO 2 ) 2 P 2 O 7 , (UO 2 ) 3 (PO 4 ) 2 , NH 4 (UO 2 )PO 4 , UO 2 CO 3 , UO 2 (C 2 H 3 O 2 ) 2 , UO 2 (C 2 O 4 ), H(UO 2 )PO 4 , UO 2 (OH) 2 , and ZnUO 2 (C 2 H 3 O 2 ) 4 , and various hydrates. For example, the exemplary phosphor BaMgUO 2 (PO 4 ) 2  may be produced by mixing the appropriate amounts of BaCO 3 , MgO, and UO 2  with the appropriate amount of (NH 4 ) 2 HPO 4  and then firing the mixture under an air atmosphere. In another example, the exemplary gamma barium uranyl phosphate or gamma barium uranyl orthophosphate (γ-Ba 2 UO 2 (PO 4 ) 2 ) may be produced by mixing stochiometric amounts of BaHPO 4  and UO 2  with an excess of (NH 4 ) 2 HPO 4  (DAP) and then firing the mixture under an air atmosphere. The precursors may be in solid form or in solution. Non-limiting examples of solvents include water, ethanol, acetone, and isopropanol, and suitability depends chiefly on solubility of the precursors in the solvent. After firing, the phosphor may be milled to break up any agglomerates that may have formed during the firing procedure. 
     The mixture of starting materials for producing the phosphor may also include one or more low melting temperature flux materials, such as boric acid, borate compounds such as lithium tetraborate, alkali phosphates, and combinations thereof. Non-limiting examples include (NH 4 ) 2 HPO 4  (DAP). Li 3 PO 4 , Na 3 PO 4 , NaBO 3 -H 2 O, Li 2 B 4 O 7 , K 4 P 2 O 7 , Na 4 P 2 O 7 , H 3 BO 3 , and B 2 O 3 . The flux may lower the firing temperature and/or firing time for the phosphor. If a flux is used, it may be desirable to wash the final phosphor product with a suitable solvent to remove any residual soluble impurities that may have originated from the flux. 
     The firing of the samples is generally done in air, but since the uranium is in its highest oxidation state (U 6+ ) it can also be fired in O 2  or other wet or dry oxidizing atmospheres, including at oxygen partial pressures above one atmosphere, at a temperature between about 900° C. and about 1300° C., particularly between about 1000° C. and about 1200° C., for a time sufficient to convert the mixture to the phosphor. The firing time required may range from about one to twenty hours, depending on the amount of the mixture being fired, the extent of contact between the solid and the gas of the atmosphere, and the degree of mixing while the mixture is fired or heated. The mixture may rapidly be brought to and held at the final temperature, or the mixture may be heated to the final temperature at a lower rate such as from about 2° C./minute to about 200° C./minute. 
     The phosphor compositions according to the present disclosure may include, in addition to the green-emitting phosphor, a red emitting phosphor of formula I: A x MF y :Mn 4+  (I), wherein A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is an absolute value of a charge of the MF y  ion; and y is 5, 6 or 7. In one embodiment, the red emitting phosphor for formula I is A 2 (MF 6 ):Mn 4+ , where A is Li, Na, K, Rb, Cs, or a combination thereof; and M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof. In particular, the red emitting phosphor may be K 2 SiF 6 :Mn 4+ . The red emitting phosphor of formula is radiationally and/or optically coupled to the LED light source. The phosphors of formula I are described in U.S. Pat. Nos.  7 , 497 , 973 , and  8 , 906 , 724 , and related patents assigned to the General Electric Company. Examples of the red emitting phosphors of formula I include, K 2 (TiF 6 ):Mn 4+ , K 2 (SnF 6 ):Mn 4+ , Cs 2 (TiF 6 ):Mn 4+ , Rb 2 (TiF 6 ):Mn 4+ , Cs 2 (SiF 6 ):Mn 4+ , Rb 2 (SiF 6 ):Mn 4+ , Na 2 (SiF 6 ):Mn 4+ , Na 2 (TiF 6 ):Mn 4+ , Na 2 (ZrF 6 ):Mn 4+ , K 3 (ZrF 7 ):Mn 4+ , K 3 (BiF 7 ):Mn 4+ , K 3 (YF 7 ):Mn 4+ , K 3 (LaF 7 ):Mn 4+ , K 3 (GdF 7 ):Mn 4+ , K 3 (NbF 7 ):Mn 4+  or K 3 (TaF 7 ):Mn 4+ . In certain embodiments, the phosphor of formula I is K 2 SiF 6 :Mn 4+ . 
     In addition to the green-emitting phosphor and, optionally, the red-emitting Mn 4+  doped phosphor of formula I, a phosphor composition according to the present disclosure may include one or more other luminescent materials. Additional luminescent materials such as blue, yellow, red, orange, or other color phosphors may be used in the phosphor composition to customize the white color of the resulting light and produce specific spectral power distributions. 
     Suitable phosphors for use in the phosphor composition, in addition to the green and red-emitting phosphors, include, but are not limited to: ((Sr 1−z [Ca,Ba,Mg,Zn] z ) 1−(x+w) [Li,Na,K,Rb] w Ce x ) 3 (Al 1−y Si y )O 4+y+3(x−w) F 1−y−3(x−w) , 0≤x≤0.10, 0≤y≤0.5, 0≤z≤0.5, 0≤w≤x; [Ca,Ce] 3 Sc 2 Si 3 O 12  (CaSiG); [Sr,Ca,Ba] 3 Al 1−x Si x O 4+x F 1−x :Ce 3+  (SASOF)); [Ba,Sr,Ca] 5 (PO 4 ) 3 [Cl,F,Br,OH]:Eu 2+ ,Mn 2+ ; [Ba,Sr,Ca]BPO 5 :Eu 2+ ,Mn 2+ ; [Sr,Ca] 10 (PO 4 ) 6 *vB 2 O 3 :Eu 2+  (wherein 0≤v≤1); Sr 2 Si 3 O 8 *2SrCl 2 :Eu 2+ ; [Ca,Sr,Ba] 3 MgSi 2 O 8 :Eu 2+ ,Mn 2+ ; BaAl 8 O 13 :Eu 2+ ; 2SrO*0.84P 2 O 5 *0.16B 2 O 3 :Eu 2+ ; [Ba,Sr,Ca]MgAl 10 O 17 :Eu 2+ ,Mn 2+ ; [Ba,Sr,Ca]Al 2 O 4 :Eu 2+ ; [Y,Gd,Lu,Sc,La]BO 3 :Ce 3+ ,Tb 3+ ; ZnS:Cu + ,Cl − ; ZnS:Cu + ,Al 3+ ; ZnS:Ag + ,Cl − ; ZnS:Ag + ,Al 3+ ; [Ba,Sr,Ca] 2 Si 1−n O 4−2n :Eu 2+  (wherein 0≤n≤0.2); [Ba,Sr,Ca] 2 [Mg,Zn]Si 2 O 7 :Eu 2+ ; [Sr,Ca,Ba][Al,Ga,In] 2 S 4 :Eu 2+ ; [Y,Gd,Tb,La,Sm,Pr,Lu] 3 [Al,Ga] 5−a O 12−3/2a :Ce 3+  (wherein 0≤a≤0.5); [Ca,Sr] 8 [Mg,Zn](SiO 4 ) 4 Cl 2 :Eu 2+ ,Mn 2+ ; Na 2 Gd 2 B 2 O 7 :Ce 3+ ,Tb 3+ ; [Sr,Ca,Ba,Mg,Zn] 2 P 2 O 7 :Eu 2+ ,Mn 2+ ; [Gd,Y,Lu,La] 2 O 3 :Eu 3+ ,Bi 3+ ; [Gd,Y,Lu,La] 2 O 2 S:Eu 3+ ,Bi 3+ ; [Gd,Y,Lu,La]VO 4 :Eu 3+ ,Bi 3+ ; [Ca,Sr,Mg]S:Eu 2+ ,Ce 3+ ; SrY 2 S 4 :Eu 2+ ; CaLa 2 S 4 :Ce 3+ ; [Ba,Sr,Ca]MgP 2 O 7 :Eu 2+ ,Mn 2+ ; [Y,Lu] 2 WO 6 :Eu 3+ ,Mo 6+ ; [Ba,Sr,Ca] b Si g N m :Eu 2+  (wherein 2b+4g=3m); Ca 3 (SiO 4 )Cl 2 :Eu 2+ ; [Lu,Sc,Y,Tb] 2−u−v Ce v Ca 1+u Li w Mg 2−w P w [Si,Ge] 3−w O 12−u/2  (where 0.5≤u≤1, 0≤v≤0.1, and 0≤w≤0.2); [Y,Lu,Gd] 2−m  [Y,Lu,Gd]Ca m Si 4 N 6+m C 1−m :Ce 3+ , (wherein 0≤m≤0.5); [Lu,Ca,Li,Mg,Y], alpha-SiAlON doped with Eu 2+  and/or Ce 3+ ; Sr(LiAl 3 N 4 ):Eu 2+ , [Ca, Sr,Ba]SiO 2 N 2 :Eu 2+ ,Ce 3+ ; beta-SiAlON:Eu 2+ ; 3.5MgO*0.5MgF 2 *GeO 2 :Mn 4+ ; Ca 1−c−f Ce c Eu f Al 1+c Si 1−c N 3 , (where 0≤c≤0.2, 0≤f≤0.2); Ca 1−h−r Ce h Eu r Al 1−h (Mg,Zn) h SiN 3 , (where 0≤h≤0.2, 0≤r≤0.2); Ca 1−2s−t Ce s [Li,Na] s Eu t AlSiN 3 , (where 0≤s≤0.2, 0≤t≤0.2, s+t&gt;0); [Sr,Ca]AlSiN 3 : Eu 2+ ,Ce 3+ , and Li 2 CaSiO 4 :Eu 2+ . 
     In particular embodiments, additional phosphors include: [Y,Gd,Lu,Tb] 3 [Al,Ga] 5 O 12 :Ce 3+ , β-SiAlON:Eu 2+ , [Sr,Ca,Ba][Ga,Al] 2 S 4 :Eu 2+ , [Li,Ca]α-SiAlON:Eu 2+ , [Ba,Sr,Ca] 2 Si 5 N 8 :Eu 2+ , [Ca,Sr]AlSiN 3 :Eu 2+ , [Ba,Sr,Ca]LiAl 3 N 4 :Eu 2+  and [Sr,Ca,Mg]S:Eu 2+ . 
     The ratio of each of the individual phosphors in the phosphor composition may vary depending on the characteristics of the desired light output. The relative proportions of the individual phosphors in the various phosphor compositions may be adjusted such that when their emissions are blended and employed in a device, for example a lighting apparatus, there is produced visible light of predetermined x and y values on the CIE chromaticity diagram. 
     Other additional luminescent materials suitable for use in the phosphor composition may include electroluminescent polymers such as polyfluorenes, preferably poly(9,9-dioctyl fluorene) and copolymers thereof, such as poly(9,9′-dioctylfluorene-co-bis-N,N′-(4-butylphenyl)diphenylamine) (F8-TFB); poly(vinylcarbazole) and polyphenylenevinylene and their derivatives. In addition, the light emitting layer may include a blue, yellow, orange, green or red phosphorescent dye or metal complex, a quantum dot material, or a combination thereof. Materials suitable for use as the phosphorescent dye include, but are not limited to, tris(1-phenylisoquinoline) iridium (III) (red dye), tris(2-phenylpyridine) iridium (green dye) and iridium (III) bis(2-(4,6-difluorephenyl)pyridinato-N,C2) (blue dye). Commercially available fluorescent and phosphorescent metal complexes from ADS (American Dyes Source, Inc.) may also be used. ADS green dyes include ADS060GE, ADS061GE, ADS063GE, and ADS066GE, ADS078GE, and ADS090GE. ADS blue dyes include ADS064BE, ADS065BE, and ADS070BE. ADS red dyes include ADS067RE, ADS068RE, ADS069RE, ADS075RE, ADS076RE, ADS067RE, and ADS077RE. Exemplary quantum dot materials are based on CdSe, ZnS or InP, including, but not limited to, core/shell luminescent nanocrystals such as CdSe/ZnS, InP/ZnS, PbSe/PbS, CdSe/CdS, CdTe/CdS or CdTe/ZnS. Other examples of the quantum dot materials include halide perovskite quantum dots such as CsPbX 3 , where X is Cl, Br, I or a combination thereof. All of these semiconductor quantum dots may also have appropriate shells or coatings for passivation and/or environmental protection. 
     Devices according to the present disclosure include an LED light source radiationally coupled and/or optically coupled to one or more of the green-emitting phosphors.  FIG.  1    shows a device  10 , according to one embodiment of the present disclosure. The device  10  includes a LED light source  12  and a phosphor composition  14  including a green-emitting phosphor of the present disclosure. The LED light source  12  may be a UV or blue emitting LED. In some embodiments, the LED light source  12  produces blue light in a wavelength range from about 440 nm to about 460 nm. In the device  10 , the phosphor composition  14  including the green-emitting phosphor as described herein, is radiationally coupled and/or optically coupled to the LED light source  12 . Radiationally coupled or optically coupled means that radiation from the LED light source  12  is able to excite the phosphor composition  14 , and the phosphor composition  14  is able to emit light in response to the excitation by the radiation. The phosphor composition  14  may be disposed on a part or portion of the LED light source  12  or located remotely at a distance from the LED light source  12 . 
     The general discussion of the example LED light source discussed herein is directed toward an inorganic LED based light source. However, as used herein, the term is meant to encompass all LED light sources such as semiconductor laser diodes (LD), organic light emitting diodes (OLED) or a hybrid of LED and LD. In addition, the LED light source may be a miniLED or microLED, which may be used in self-emissive displays. Further, it should be understood that the LED light source may be replaced, supplemented or augmented by another radiation source unless otherwise noted and that any reference to semiconductor, semiconductor LED, or LED chip is merely representative of any appropriate radiation source, including, but not limited to, LDs and OLEDs. In some embodiments, the phosphor composition  14  further includes a red emitting phosphor of formula I, particularly K 2 SiF 6 :Mn 4+ . 
     The phosphor composition  14  may be present in any form such as powder, glass, or composite e.g., phosphor-polymer composite or phosphor-glass composite. Further, the phosphor composition  14  may be used as a layer, sheet, strip, dispersed particulates, or a combination thereof. In some embodiments, the phosphor composition  14  includes the green-emitting phosphor in glass form. In some of these embodiments, the device  10  may include the phosphor composition  14  in form of a phosphor wheel (not shown). The phosphor wheel may include the green-emitting phosphor embedded in a glass. A phosphor wheel and related devices are described in WO 2017/196779. 
       FIG.  2    illustrates a lighting apparatus or lamp  20 , in accordance with some embodiments. The lighting apparatus  20  includes an LED chip  22 , and leads  24  electrically attached to the LED chip  22 . The leads  24  may comprise thin wires supported by a thicker lead frame(s)  26  or the leads  24  may comprise self-supported electrodes and the lead frame may be omitted. The leads  24  provide current to LED chip  22  and thus cause it to emit radiation. 
     A layer  30  of a phosphor composition including the green-emitting phosphor is disposed on a surface of the LED chip  22 . The phosphor layer  30  may be disposed by any appropriate method, for example, using a slurry prepared by mixing silicone and the phosphor composition. In one such method, a silicone slurry in which the phosphor composition particles are randomly suspended is placed around the LED chip  22 . This method is merely exemplary of possible positions of the phosphor layer  30  and LED chip  22 . The phosphor layer  30  may be coated over or directly on the light emitting surface of the LED chip  22  by coating and drying the slurry over the LED chip  22 . The light emitted by the LED chip  22  mixes with the light emitted by the phosphor composition to produce desired emission. 
     With continued reference to  FIG.  2   , the LED chip  22  may be encapsulated within an envelope  28 . The envelope  28  may be formed of, for example glass or plastic. The LED chip  22  may be enclosed by an encapsulant material  32 . The encapsulant material  32  may be a low temperature glass, or a polymer or resin known in the art, for example, an epoxy, silicone, epoxy-silicone, acrylate or a combination thereof. In an alternative embodiment, the lighting apparatus  20  may only include the encapsulant material  32  without the envelope  28 . Both the envelope  28  and the encapsulant material  32  should be transparent to allow light to be transmitted through those elements. 
     In some embodiments as illustrated in  FIG.  3   , a phosphor composition  33  green-emitting phosphor is interspersed within the encapsulant material  32 , instead of being formed directly on the LED chip  22 , as shown in  FIG.  2   . The phosphor composition  33  may be interspersed within a portion of the encapsulant material  32  or throughout the entire volume of the encapsulant material  32 . Blue light emitted by the LED chip  22  mixes with the light emitted by phosphor composition  33 , and the mixed light transmits out from the lighting apparatus  20 . 
     In yet another embodiment, a layer  34  of the phosphor composition including the green-emitting phosphor, is coated onto a surface of the envelope  28 , instead of being formed over the LED chip  22 , as illustrated in  FIG.  4   . As shown, the phosphor layer  34  is coated on an inside surface  29  of the envelope  28 , although the phosphor layer  34  may be coated on an outside surface of the envelope  28 , if desired. The phosphor layer  34  may be coated on the entire surface of the envelope  28  or only a top portion of the inside surface  29  of the envelope  28 . The UV/blue light emitted by the LED chip  22  mixes with the light emitted by the phosphor layer  34 , and the mixed light transmits out. Of course, the phosphor composition may be located in any two or all three locations (as shown in  FIGS.  2 - 4   ) or in any other suitable location, such as separately from the envelope  28  or integrated into the LED chip  22 . 
     In any of the above structures, the lighting apparatus  20  ( FIGS.  2 - 4   ) may also include a plurality of scattering particles (not shown), which are embedded in the encapsulant material  32 . The scattering particles may comprise, for example, alumina, silica, zirconia, or titania. The scattering particles effectively scatter the directional light emitted from the LED chip  22 , preferably with a negligible amount of absorption. 
     Some embodiments include a surface mounted device (SMD) type light emitting diode  50 , e.g. as illustrated in  FIG.  5   , for backlight applications. This SMD is a “side-emitting type” and has a light-emitting window  52  on a protruding portion of a light guiding member  54 . An SMD package may comprise an LED chip as defined above, and a phosphor composition including the green-emitting phosphor as described herein. 
     Devices of the present disclosure include lighting and display apparatuses for general illumination and display applications. Examples of display apparatuses include liquid crystal display (LCD) backlight units, televisions, computer monitors, laptops, mobile phones, smartphone, tablet computers and other handheld devices. Where the display is a backlight unit, the green-emitting phosphor may be incorporated in a sheet or strip that is radiationally coupled and/or optically coupled to the LED light source, as described in US Patent Application Publication No. 2017/0254943. Examples of other devices include chromatic lamps, plasma screens, xenon excitation lamps, UV excitation marking systems, automotive headlamps, home and theatre projectors, laser pumped devices, and point sensors. 
     By use of the phosphor compositions described herein, devices can be provided producing white light for display applications, for example, LCD backlight units, having high color gamut and high luminosity. Alternately, devices can be provided producing white light for general illumination having high luminosity and high CRT values for a wide range of color temperatures of interest (2500 K to 10000 K). The list of these applications is meant to be merely exemplary and not exhaustive. 
     Although specific features of various embodiments of the disclosure may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the disclosure, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing. 
     EXAMPLES 
     Example 1: Preparation of BaMgUO 2 (PO 4 ) 2    
     Stoichiometric amounts of BaCO 3 , MgO, UO 2  and (NH 4 ) 2 HPO 4  (DAP) were weighed out into a Nalgene bottle and ball milled for two hours. After the mixture was thoroughly blended the powder was transferred into an alumina crucible and fired at 500° C. to decompose the DAP. The fired blend was then transferred back into the Nalgene bottle and milled for another two hours. After the second milling the powder was transferred back into the alumina crucible for firing at 1000-1100° C. After firing, a yellow colored powder of composition BaMgUO 2 (PO 4 ) 2  was obtained. 
     The crystal structure of this material was solved and is shown in  FIG.  6   . The XRD powder pattern is shown in  FIG.  7   , and crystallographic data is shown in Table 1. The emission (solid line) and excitation (dotted line) spectra of BaMgUO 2 (PO 4 ) 2  are shown in  FIG.  8   . 
     Example 2: Preparation of BaZnUO 2 (PO 4 ) 2    
     Stoichiometric amounts of BaCO 3 , ZnO, UO 2  and (NH 4 ) 2 HPO 4  (DAP) were weighed out into a Nalgene bottle and ball milled for two hours. After the mixture was thoroughly blended the powder was transferred into an alumina crucible and fired at 500° C. to decompose the DAP. The fired blend was then transferred back into the Nalgene bottle and milled for another two hours. After the second milling the powder was transferred back into the alumina crucible for firing at 1000-1100° C. After firing a yellow colored powder of composition BaZnUO 2 (PO 4 ) 2  was obtained. 
     The crystal structure of this material was solved and is shown in  FIG.  9   . The XRD powder pattern is shown in  FIG.  10   , and crystallographic data is shown in Table 1. Emission (solid line) and excitation spectra (dotted line) of BaZnUO 2 (PO 4 ) 2  are shown in  FIG.  11   . 
     Example 3: Preparation of Ba 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7    
     Stoichiometric amounts of BaCO 3 , UO 2  and (NH 4 ) 2 HPO 4  (DAP) were weighed out into a Nalgene bottle and ball milled for two hours. After the mixture was thoroughly blended the powder was transferred into an alumina crucible and fired at 500° C. to decompose the DAP. The fired blend was then transferred back into the Nalgene bottle and milled for another two hours. After the second milling the powder was transferred back into the alumina crucible for firing at 1000-1100° C. After firing a yellow body colored powder was obtained. 
     The crystal structure of this material was solved and is shown in  FIG.  12   . The XRD powder pattern is shown in  FIG.  13   , and crystallographic data is shown in Table 1. Emission (solid line) and excitation (dotted line) spectra of Ba 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7  are shown in  FIG.  14   . 
     Example 4: Preparation of γ-Ba 2 UO 2 (PO 4 ) 
     Stoichiometric amounts of BaHPO 4 , UO 2  and 5% excess (NH 4 ) 2 HPO 4  (DAP) were weighed out into a Nalgene bottle and ball milled for two hours. After the mixture was thoroughly blended the powder was transferred into an alumina crucible and fired at 1100° C. to decompose the DAP. The fired blend was then transferred back into the Nalgene bottle and milled for another two hours. After the second milling the powder was transferred back into the alumina crucible for firing at 1200° C. After firing a yellow body colored powder was obtained. 
     The crystal structure of this material was solved and is shown in  FIG.  15   . The XRD powder pattern is shown in  FIG.  16   , and crystallographic data is shown in Table 1. Emission (solid line) and excitation (dotted line) spectra of γ-Ba 2 UO 2 (PO 4 ) 2  are shown in  FIG.  17   . An emission spectrum of γ-Ba 2 UO 2 (PO 4 ) 2  at 30K is shown in  FIG.  18   . 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Crystallographic Data 
               
            
           
           
               
               
               
               
               
            
               
                   
                   
                   
                   
                 γ- 
               
               
                   
                 BaZnUO 2 (PO 4 ) 2   
                 BaMgUO 2 (PO 4 ) 2   
                 Ba 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7   
                 Ba 2 UO 2 (PO 4 ) 2   
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                 Mol. Wt. 
                 662.69 
                 621.61 
                 1315.94 
                 734.63 
               
               
                 Crystal System 
                 Monoclinic 
                 Monoclinic 
                 Monoclinic 
                 Triclinic 
               
               
                 Space Group 
                 P2 1   
                 P2 1   
                 C2/c 
                 P-1 
               
               
                 a (Å) 
                 5.438 
                 5.469 
                 19.052 
                 6.772 
               
               
                 b (Å) 
                 8.310 
                 8.331 
                 9.169 
                 8.643 
               
               
                 c (Å) 
                 9.811 
                 9.802 
                 9.477 
                 9.07 
               
               
                 α (deg) 
                 90 
                 90 
                 90 
                 105.03 
               
               
                 β (deg) 
                 96.02 
                 96.57 
                 96.89 
                 93.93 
               
               
                 γ (deg) 
                 90 
                 90 
                 90 
                 111.40 
               
               
                 Vol. (Å 3 ) 
                 440.9 
                 443.7 
                 1643.6 
                 469.5 
               
               
                 Z 
                 2 
                 2 
                 4 
                 2 
               
               
                 Den (g/cm 3 ) 
                 4.990 
                 4.652 
                 5.317 
                 5.196 
               
               
                   
               
            
           
         
       
     
     Example 5: Preparation of Ba 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7    
     BaCl 2 .2H 2 O (8.2001 g, 33.5686 mmol) and UO 2 (NO 3 ) 2 .6H 2 O (2.9746 g, 5.9239 mmol) were added to a 250 mL beaker containing a large stir bar followed by 137 mL of deionized water. The starting mixture represents an 85/15 mole ratio of Ba and UO 2 . The mixture was stirred at room temperature until it was homogeneous. A deionized water solution of ammonium hydrogen phosphate (11.12 mL, 3.5516 M, 39.4938 mmol) was added to the stirring solution over 15 minutes by syringe pump at room temperature. The mixture was stirred an additional 5 minutes and then filtered on a Buchner funnel. The light yellow powder was washed with deionized water (3×75 mL) with churning of the product before each wash. The Ba/UO 2  hydrogen phosphate intermediate (9.1059 g) was dried at room temperature. 
     The hydrogen phosphate intermediate (2.23 g) was fired in an alumina crucible at 1050° C. Single crystal x-ray diffraction analysis indicated that the heat-treated product comprises Ba 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7 . 
     Example 6: Preparation of Ba 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7    
     Stoichiometric amounts of Ba 3 (PO 4 ) 2 , UO 2 (NO 3 ) 2 -6H 2 O and DAP were blended in a Nalgene bottle with 20 mL of deionized (DI) H 2 O and ball milled (with yttria stabilized zirconia, YSZ media) for two hours. After blending the mixture was then filtered and dried to eliminate the excess water. Once dry the powder was crushed and placed in an alumina crucible for firing at 1000° C.-1100° C. in air for 5 hours. After firing a yellow body colored powder was obtained. 
     Example 7: Preparation of Ba 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7    
     γ-Ba 2 UO 2 (PO 4 ) 2 , (UO 2 ) 3 (PO 4 ) 2 -4H 2 O and DAP were blended in a Nalgene bottle and ball milled (with YSZ media) for two hours. After the mixture was thoroughly blended the powder was transferred into an alumina crucible and fired at 1100° C. for 5 hours. After firing a yellow body colored powder was obtained. The phosphor material produced the same emission spectrum after excitation at 450 nm as shown in  FIG.  14   . 
     Example 8: Preparation of Ba 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7    
     γ-Ba 2 UO 2 (PO 4 ) 2 , UO 2  and DAP were blended in a Nalgene bottle and ball milled (with YSZ media) for two hours. After the mixture was thoroughly blended the powder was transferred into an alumina crucible and fired at 1100° C. for 5 hours. After firing a yellow body colored powder was obtained. The phosphor material produced the same emission spectrum after excitation at 450 nm as shown in  FIG.  14   . 
     Example 9: Preparation of Ba 2 Sr(PO 4 ) 2 (UO 2 ) 2 P 2 O 7    
     Stoichiometric amounts of BaCO 3 , SrCO 3  and UO 2 , were blended with (NH 4 ) 2 HPO 4  (DAP) (5% excess) in a Nalgene bottle and ball milled (with YSZ media) for two hours. After the mixture was thoroughly blended the powder was transferred into an alumina crucible and fired at 500° C. for 5 hours. After firing the powder was again blended for 2 hrs and fired at 1000° C.-1100° C. in air for 5 hours. After firing a yellow body colored powder was obtained. The emission spectrum after excitation at 450 nm is shown in  FIG.  19   . 
     Example 10: Preparation of BaSr 2 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7    
     Stoichiometric amounts of BaCO 3 , SrCO 3  and UO 2 , were blended with (NH 4 ) 2 HPO 4  (DAP) (5% excess) in a Nalgene bottle and ball milled (with YSZ media) for two hours. After the mixture was thoroughly blended the powder was transferred into an alumina crucible and fired at 500° C. for 5 hours. After firing the powder was again blended for 2 hours and fired at 1000° C.-1100° C. in air for 5 hours. After firing a yellow body colored powder was obtained. The emission spectrum after excitation at 450 nm is shown in  FIG.  20   . 
     Example 11: Preparation of Sr 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7    
     Stoichiometric amounts of SrCO 3  and UO 2 , were blended with (NH 4 ) 2 HPO 4  (DAP) (5% excess) in a Nalgene bottle and ball milled (with YSZ media) for two hours. After the mixture was thoroughly blended the powder was transferred into an alumina crucible and fired at 500° C. for 5 hours. After firing the powder was again blended for 2 hours and fired at 1000° C.-1100° C. in air for 5 hours. After firing a yellow body colored powder was obtained. The emission spectrum after excitation at 450 nm is shown in  FIG.  21   . 
     Example 12: Preparation of Ca 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7    
     Stoichiometric amounts of CaCO 3  and UO 2 , were blended with (NH 4 ) 2 HPO 4  (DAP) (5% excess) in a Nalgene bottle and ball milled (with YSZ media) for two hours. After the mixture was thoroughly blended the powder was transferred into an alumina crucible and fired at 500° C. for 5 hrs. After firing the powder was again blended for 2 hrs and fired at 1000° C.-1100° C. in air for 5 hrs. After firing a yellow body colored powder was obtained. The emission spectrum after excitation at 450 nm is shown in  FIG.  22   . 
     Example 13: Preparation of BaMg 2 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7    
     Stoichiometric amounts of BaCO 3 , MgO and UO 2  were blended with (NH 4 ) 2 HPO 4  (DAP) (5% excess) in a Nalgene bottle and ball milled (with YSZ media) for two hours. After the mixture was thoroughly blended the powder was transferred into an alumina crucible and fired at 500° C. for 5 hours. After firing the powder was again blended for 2 hours and fired at 1000° C.-1100° C. in air for 5 hours. After firing a yellow body colored powder was obtained. The emission spectrum after excitation at 450 nm is shown in  FIG.  23   . 
     Example 14: Preparation of Ba 2 Mg(PO 4 ) 2 (UO 2 ) 2 P 2 O 7    
     Stoichiometric amounts of BaCO 3 , MgO and UO 2 , were blended with (NH 4 ) 2 HPO 4  (DAP) (5% excess) in a Nalgene bottle and ball milled (with YSZ media) for two hours. After the mixture was thoroughly blended the powder was transferred into an alumina crucible and fired at 500° C. for 5 hours. After firing the powder was again blended for 2 hours and fired at 1000° C.-1100° C. in air for 5 hours. After firing a yellow body colored powder was obtained. The emission spectrum after excitation at 450 nm is shown in  FIG.  24   . 
     Example 15: Preparation of Ba 2 UO 2 (VO 4 ) 2    
     Stoichiometric amounts of BaCO 3 , NH 4 VO 3  and UO 2 , were blended in a Nalgene bottle and ball milled (with YSZ media) for two hours. After the mixture was thoroughly blended the powder was transferred into an alumina crucible and fired at 500° C. for 5 hours. After firing the powder was again blended for 2 hours and fired at 1000° C.-1100° C. in air for 5 hours. After firing a yellow body colored powder was obtained. The emission spectrum after excitation at 450 nm is shown in  FIG.  25   . 
     Example 16: Preparation of γ-Ba 2 UO 2 (PO 4 ) 2 :Eu 3+   
     Stoichiometric amounts of BaCO 3 , UO 2 , Eu 2 O 3  and (NH 4 ) 2 HPO 4  (DAP) (5% excess) were blended in a Nalgene bottle and ball milled (with YSZ media) for two hours. After the mixture was thoroughly blended the powder was transferred into an alumina crucible and fired at 500° C. for 5 hours. After firing the powder was again blended for 2 hours and fired at 1100° C.-1200° C. in air for 5 hours. After firing a yellow body colored powder was obtained. The emission spectrum after excitation at 450 nm at room temperature is shown in  FIG.  26   . 
     Example 17: Gamut Coverage of Phosphor Blends 
     Blend simulations using (u,v) or (x,y) color space were calculated using the spectra of a 450 nm blue LED and PFS (K 2 SiF 6 :Mn 4+ ) passing through standard LCD color filters. The color filter (CF) set and optical density of the CF set were kept constant, so that the results of the modeling only showed the effect of changing the green phosphor. The blend ratios of the LED and green and red phosphors were varied so that the output of the emission after going through the optical stack and color filter set were at the same D65 color point and then gamut area coverages were calculated. Results are shown in Table 2. 
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                   
                 Adobe 
                 DCI 
                 BT2020 
                 NTSC 
               
               
                 Green Phosphor 
                 (%) 
                 (%) 
                 (%) 
                 (%) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 (u, v) 
                   
               
            
           
           
               
               
               
               
               
            
               
                 β-SiAlON:Eu 2+   
                 87 
                 93 
                 80 
                 84 
               
               
                 BaZnUO 2 (PO 4 ) 2   
                 100 
                 98 
                 88 
                 97 
               
               
                 BaMgUO 2 (PO 4 ) 2   
                 100 
                 98 
                 88 
                 97 
               
               
                 Ba 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7   
                 98 
                 99 
                 87 
                 95 
               
               
                 γ-Ba 2 UO 2 (PO 4 ) 2   
                 94 
                 99 
                 85 
                 91 
               
            
           
           
               
               
               
            
               
                   
                 (x, y) 
                   
               
            
           
           
               
               
               
               
               
            
               
                 β-SiAlON:Eu 2+   
                 82 
                 90 
                 70 
                 80 
               
               
                 BaZnUO 2 (PO 4 ) 2   
                 100 
                 95 
                 83 
                 97 
               
               
                 BaMgUO 2 (PO 4 ) 2   
                 100 
                 95 
                 83 
                 97 
               
               
                 Ba 3 (PO 4 ) 2 (UO 2 ) 2 P 2 O 7   
                 97 
                 98 
                 81 
                 95 
               
               
                 γ-Ba 2 UO 2 (PO 4 ) 2   
                 91 
                 100 
                 80 
                 90 
               
               
                   
               
            
           
         
       
     
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.