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The single-component BiOCl:Dy3+ white-light-emitting phosphor was successfully prepared. The luminescence performance with excellent thermal stability indicated that this as-prepared product could act as a high-performance phosphor candidate for n-UV w-LED application. • The single-component BiOCl:Dy3+ phosphor was prepared successfully. • The phosphor emitted white light under the excitation in n-UV light region. • The PL properties obtained excellent thermal stability at higher temperatures. • The phosphor could have great potential for n-UV w-LED application. The advantages of single-component white-light-emitting phosphor make it more important for n-UV-light emitting diodes with excellent properties and efficiency. Herein, the BiOCl:Dy3+ white-light-emitting phosphor was firstly prepared by high temperature solid-state reaction. And the crystal structure, luminescence properties, lifetime, and thermal quenching behavior were carried out in detail. The results revealed that the BiOCl:Dy3+ phosphor could be excited efficiently in a broad near ultraviolet (n-UV) light region, which matched well with the n-UV chips for w-LEDs. Under the excitation at 390 nm, the BiOCl:Dy3+ phosphor exhibited white light with three emission peaks centered at 481, 575, and 664 nm, respectively. The optimal doping concentration of Dy3+ ions was found to be x = 0.03, and exchange interaction was confirmed to result in the concentration quenching. Furthermore, when the test temperature turned up to 150 °C, the intensity of emission peaks at 481 and 575 nm could still remain 77.96% and 77.93% of the initial intensity at room temperature. With the their activation energy of 0.33 eV and 0.27 eV, the excellent thermal stability of the BiOCl:Dy3+ phosphor were confirmed. All these results indicated that this as-prepared product could act as a high-performance phosphor candidate for n-UV w-LED application. [ABSTRACT FROM AUTHOR]

Graphical abstract Na 3 GdP 2 O 8 : Sm3+ and Na 3 GdP 2 O 8 : Dy3+ phosphors were successfully prepared and emitted orange-red and white light under UV/NUV excitation, respectively. The excellent thermal stability further indicated that these phosphors have great potential for applications in UV/NUV excited w-LEDs. Highlights • The novel Sm3+ and Dy3+ ions doped Na 3 GdP 2 O 8 phosphors were prepared. • Both orange-red and white lights could obtain with excellent thermal stability. • These phosphors are potential for application in UV/NUV based w-LEDs. Abstract With the rapid demand of white light emitting diodes (w-LEDs), studies on the ultraviolet/near-ultraviolet (UV/NUV) light excited phosphors are becoming more and more important. Herein the novel Na 3 GdP 2 O 8 : Re3+ (Re = Sm, Dy) phosphors were synthesized through a high-temperature solid-state reaction method. The Sm3+-doped Na 3 GdP 2 O 8 phosphors emitted orange-red light centered at 600 nm, under the NUV excitation at 403 nm. When excited at 350 nm, the Na 3 GdP 2 O 8 : Dy3+ phosphors presented a white light emission, including three peaks at 483, 578, and 670 nm, respectively. In addition, both of the Na 3 GdP 2 O 8 : Sm3+ and Na 3 GdP 2 O 8 : Dy3+ phosphors showed excellent thermal stability at different temperatures, of which the emission intensities at 150 °C could maintain about 75% and 79% of those at room temperature, respectively. These results indicate that the as-prepared phosphors can be considered as potential candidates for applications in UV/NUV excited w-LEDs. [ABSTRACT FROM AUTHOR]

A series of apatite-type phosphors Ba 4.97− x Sr x (PO 4 ) 3 Cl:Eu 2+ ( x = 0, 0.5, 1.0, 1.5, 2.0) were synthesized by the high temperature solid-state reaction method, and its luminescence properties were investigated in detail. It can be found that a red shift of the emission peak wavelength emerged from 439 to 462 nm with the continuous introduction of Sr 2+ into the crystal lattice which has been simulated by a crystal-field model. The red shift is explained by the distortion in the crystal structure through X-ray diffraction and the Rietveld refinement analysis. According to a recently raised structural model, Eu 2+ ions are surrounded by O atoms, PO 4 tetrahedrons and Ba/Sr ions. After introducing Sr 2+ into the lattice, the interatomic distance between Ba/Sr atoms and Eu 2+ was expected to become shorter, resulting in a distortion of the inner EuO n polyhedrons. Then the crystal field strength surrounding Eu 2+ was increased, finally resulting in the red shift. [ABSTRACT FROM AUTHOR]

Cyan-emitting LiBaBO 3 :Eu 2+ phosphor was synthesized by solid-state reaction at 800 °C. Structure refinement by Rietveld method reveals that LiBaBO 3 crystallizes in a monoclinic cell, space groups P 2 1 / c or P 2 1 / n . Upon 365 nm excitation, LiBaBO 3 :Eu 2+ shows a symmetric emission band peaking at 496 nm with full-width at half-maximum of 80 nm; when monitoring at 496 nm, a broad excitation band in the UV region (250–420 nm) is observed. The luminescence property of LiBaBO 3 :Eu 2+ is considerably different from LiSrBO 3 :Eu 2+ which holds the same space group. The local structures of the two hosts are compared to explain the different behaviors of Eu 2+ . [ABSTRACT FROM AUTHOR]