Influence of calcination temperature on the photoluminescence spectral response of Sm-doped YAG nanocrystals as red-emitting phosphor

Abstract

This work reports on the synthesis of samarium-doped yttrium aluminum garnet nanocrystals via co-precipitation method. The effect of calcination temperature on the formation of the crystalline phase of the prepared powder has been studied. The as-prepared powder was transformed from the amorphous to crystalline phase at calcination temperature around 900 °C, and the crystallite size enhanced at higher calcination temperature, 1000 °C. The crystallization temperature of the prepared YAG powder was measured using differential thermal analysis technique and confirmed by X-ray diffraction. Moreover, the correlation between this phase transformation and the photoluminescence (PL) spectral response of Sm ions has been established. The effect of the crystal field of the environment around Sm ions on its PL spectral response is also discussed. Furthermore, the excitation levels of Sm3+-doped YAG nanocrystals have been measured. These findings attempt to highlight on the role of PL in probing the local environment of such phosphor.