Synthesis and photoluminescence properties of oxynitride phosphors M0.98Si2O2N2: [formula omitted] (M=Ba, Sr, Ca) using the cellulose assisted liquid phase precursor process

Abstract

Oxynitride phosphors M0.98Si2O2N2: Eu0.022+ (M=Ba, Sr, Ca) for white LEDs were synthesized at 1300, 1400, and 1500°C by using the partially cellulose assisted liquid phase precursor (PLPP) process and compared with solid state reaction (SSR) process. MSi2O2N2 (M=Ba, Sr, Ca) crystal structure was obtained from M0.98Si2O2N2: Eu0.022+ phosphor fired at 1400°C using the PLPP process. However these phosphors were not synthesized through the SSR process at same temperature. M0.98Si2O2N2: Eu0.022+ (M=Ba, Sr, Ca) phosphors from PLPP produced a blue color emission at 487nm (380nm excitation), a green color emission at 528nm (374nm excitation), and a yellow color emission at 538nm (371nm excitation). M0.98Si2O2N2: Eu0.022+ phosphors from PLPP had higher luminescence and crystallinity compared with those obtained from the SSR process. The prepared phosphors were analyzed by X-ray diffraction (XRD), photoluminescence (PL) and field-emission scanning electron microscopy (FE-SEM).