Synthesis of novel Dy3+ activated phosphate phosphors for NUV excited LED

The new trivalent dysprosium activated X6AlP5O20 (where X=Sr, Ba, Ca and Mg) phosphors were prepared by the combustion method. The prepared phosphors are characterized by XRD, photoluminescence and SEM techniques. Excited by 350 nm near-ultraviolet (NUV) light, the phosphors show an efficient blue and yellow band emissions, which originates from the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions of Dy3+ ion, respectively. The excitation spectra of the phosphors are broadband extending from 340 to 400 nm, which are characteristics of NUV excited LED. The effect of the Dy3+ concentration on the luminescence properties of X6AlP5O20:Dy3+ (where X=Sr, Ba, Ca and Mg) phosphors is studied. Ca6AlP5O20 phosphors show strong PL emission intensity around 25 times more as compared to Ba6AlP5O20, Sr6AlP5O20 and Mg6AlP5O20 phosphors. The investigated prepared phosphors are suitable for a NUV excited LED.