The reduction of Eu~(3+) to Eu~(2+) in a new orange-red emission Sr_3P_4O_(13): Eu phosphor prepared in air and its photoluminescence properties

摘要

A new orange-red phosphor Sr_3P_4O_(13): Eu was synthesized by a high temperature solid-state reaction. X-ray powder diffraction (XRD) analysis confirms the formation of Sr_3P_4O_(13) in a triclinic system with space group P1. The photoluminescence spectra indicate that Sr_3P_4O_(13): Eu can be excited effectively by near ultraviolet (NUV) light and exhibit bright orange-red emission with excellent color stability. Interestingly, the emission bands of Eu~(2+) and Eu~(3+) were both observed in the photoluminescence spectra of air-sintered Sr_3P_4O_(13): Eu phosphor due to the self-reduction effect. This kind of abnormal reduction was explained by a charge compensation model.