Preparation of Sr 1−x Ca x YSi 4 N 7 :Eu 2+ solid solutions and their luminescence properties

A series of quaternary nitride solid solutions with a general formula of Sr1−xCaxYSi4N7:Eu2+ (1 atom%) were synthesized by the carbothermal reduction and nitridation (CRN) method. The XRD patterns confirm the formation of a solid solution of Sr1−xCaxYSi4N7:Eu2+ (0 ≤ x ≤ 0.5). With an increase in x, the emission spectra shift from 540 nm to 564 nm under n-UV excitation. In addition, the temperature dependence of the PL intensity was investigated. The thermal stability is comparable to that of the commercial (Ba,Sr)2SiO4:Eu2+ phosphor. All the results indicate that the solid solution Sr1−xCaxYSi4N7:Eu2+ can be a good candidate of phosphor applicable to n-UV LEDs for solid-state lighting.