Structural and photoluminescence study of Mn2+-activated CaYAl3 O7 blue phosphors.

The structural and photoluminescence properties of CaYAl3 O7 phosphor material doped with varying concentration of Mn(2+) have been studied. The phosphor material was synthesized by the combustion method at 500 °C and was characterized using X-ray diffraction, Fourier transform infrared spectroscopy and photoluminescence spectroscopy (PL). X-ray diffraction showed that the crystallites have average sizes in the range of ~58-70 nm. Corresponding Fourier transform infrared spectroscopy investigations confirm the phase formation and the presence of aluminate group (Al-O bands) in CaYAl3 O7 :Mn(2+) phosphor. Under the excitation at 356 nm wavelength, the PL spectra show the occurrence of two emission peaks obtained in the blue region at 389 nm and 412 nm, which is attributed to the 4 T1(G) → 6A1 transition of Mn(2+) ion. Upon increasing Mn(2+) concentration, the relative PL intensity shows an initial decrement followed by an increase displaying the effect of concentration quenching. Overall the results suggest the possibility of using this material in white lighting devices and plasma display panels.