Comparative study of structural and optical behavior of Er3+ doped Y2SiO5 phosphor prepared by different methods

Erbium doped yttrium silicate (Y2SiO5:Er3+) (YSO:Er) crystal with dual optical behavior were fabricated by combustion synthesis method and solid state reaction method. The phosphor was characterized for various structural behaviors by using powder X-ray diffraction, electron microscopy techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM). Prepared phosphor has monoclinic structure with different phases called X-1 and X-2 as per the synthesis temperature involved. Obtained crystals were further characterized for surface morphology and crystal size confirmation by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) respectively. Spectral behavior of the crystal was determined by recording the emission spectra under two different excitations belonging to the UV region at 380 nm and in NIR region at 980 nm. The crystal shows emission in the green region and red region for both the excitations but follows two different energy transfer mechanism called down shifting and upconversion respectively for the phosphors synthesized by combustion as well as solid state reaction method. Correlation between crystal size and luminescence behavior like emission intensity and life time of emission were investigated in detail.