Luminescent-center tuning for Ba6Ca3YAlSi6O24:Ce3+, Na+ orthosilicate phosphors

Abstract

Ce3+ ion-doped Ba6Ca3YAlSi6O24 phosphors with a charge-compensating Na+ ion were prepared using a solid-state reaction. Ba6Ca3YAlSi6O24 was structurally characterized using synchrotron X-ray powder diffraction. The emission wavelengths of Ce3+ in different Ba2+ and Ca2+ sites with the distortion index of polyhedrons in the host lattice were calculated. The photoluminescence excitation and emission spectra of the Ce3+-activated phosphors were site-selectively monitored; furthermore, the emission quenching as a function of Ce3+ content in the Ba6-2xCexNaxCa3YAlSi6O24 and Ba6Ca3-2xCexNaxYAlSi6O24 (x = 0.01-0.4) was clearly distinguished at relatively high concentrations of the activator. The Gaussian components of the phosphors were exploited by using the Ce3+ ion sites in the host lattice; in addition, the one and two luminescent centers for the Ba6-2xCexNaxCa3YAlSi6O24 and Ba6Ca3-2xCexNaxYAlSi6O24 phosphors, respectively, were identified. The sites of the luminescent centers for the calculated Ba6Ca3-2xCexNaxYAlSi6O24 composition was selectively tuned as the (BaCa)9-2xCexNaxYAlSi6O24 lattice structure.