Emission band shift of the cathodoluminescence of Y2SiO5 : Ce phosphor affected by its activator concentration

Abstract

The high-temperature phase (X2-phase) and the low-temperature phase (X1 phase) of a potential low-voltage blue phosphor Y2SiO5:Ce have been studied. It is observed that as the concentration of Ce increased, the emission band of the X2 phase was shifted to the longer wavelength, toward the emission band of the X1 phase, when the phosphor synthesis was performed under reduction atmosphere. This phenomenon seems to be related to a preferential site of Ce in Y2SiO5 as the Ce concentration is increased. It appears that when the number of a large-size ions, Ce3+, is increased under reduction atmosphere, their coordination number is affected. One of the cation sites (B1 site) in its high-temperature phase (X2 phase) is preferentially occupied, and shows emission ssimiliar to that of the low-temperature phase (X1 phase).