The Effect of Sr on Luminescence of Ce-Doped (Ca,Sr)AlSiO.

A series of Ce-doped (Ca,Sr)AlSiO phosphors with different Ce and Ca/Sr concentrations were prepared by a high temperature solid-state reaction technique. To get insight into the structure-luminescence relationship, the impact of incorporation of Sr on structure of (Ca,Sr)AlSiO was first investigated via Rietveld refinement of high quality X-ray diffraction (XRD) data, and then the VUV-UV excitation and UV-vis emission spectra of (Ca,Sr)AlSiO:Ce were collected at low temperature. The results reveal that the crystal structure evolution of (Ca,Sr)AlSiO:Ce has influences on band gaps and Ce luminescence properties including 4f-5d (i = 1-5) transition energies, radiative lifetime, emission intensity, quantum efficiency, and thermal stability. Moreover, the influence of Sr content on the energy of Eu-O charge-transfer states (CTS) in (Ca,Sr)AlSiO:Eu was studied in order to construct vacuum referred binding energy (VRBE) schemes with the aim to further understand the luminescence properties of (Ca,Sr)AlSiO:Ce. Finally, X-ray excited luminescence (XEL) spectra were measured to evaluate the possibility of (Ca,Sr)AlSiO:Ce as a scintillation material.