Novel red color emitting Ca 0.995 Mg 2 (SO 4 ) 3 :0.5Eu 2+ phosphor under UV, blue and green excitation for plant growth LEDs

In the recent few years, Eu2+ and Mn4+ activated phosphors are widely used as potential color converters for indoor plant cultivation lighting application due to their marvellous luminescence characteristics as well as low cost. In this investigation, we are synthesized novel red color emitting Ca(2-x)Mg2(SO4)3: xmol% Eu2+ (x = 0-1.0 mol%) phosphors via solid-state reaction method in reducing atmosphere. The PL excitation spectra of synthesized phosphors exhibited a broad excitation band with three excitation bands peaking at 349 nm, 494 nm and 554 nm. Under these excitations, emission spectra exhibits broad band in the red color region around 634 nm. The PL emission intensity were measured for different concentration of Eu2+. The maximum Eu2+ doping concentration in Ca2Mg2(SO4)3 host was observed for 0.5 mol%. According to Dexter theory, it was determined that dipole-dipole interaction is responsible for concentration quenching. The luminous red color emission of the sample was confirmed by CIE color coordinate. The results of PL excitation and emission spectrum of prepared phosphors are well-matched with excitation and emission wavelengths of phytochrome PR. Therefore, as per the entire investigation and obtained results it was concluded that the synthesized Ca0.995Mg2(SO4)3:0.5mol%Eu2+ phosphor has huge potential for plant cultivation application.