Yellowish green-emitting KSrPO4:Tb3+ phosphors with various doping concentrations prepared by using microwave assisted sintering

Abstract KSr 1− x PO 4 : x Tb 3+ phosphors with various concentrations ( x = 0.05, 0.06, 0.07, 0.08) of Tb 3+ ions were synthesized in succession by using microwave assisted sintering. The sintering condition was set at 1200 °C for 1 h in air. The microstructural and luminescent characteristics of KSrPO 4 :Tb 3+ phosphors were investigated and are discussed here. The XRD result shows that the prepared KSr 1− x PO 4 : x Tb 3+ phosphors would have an impure phase as the Tb 3+ ion increases to more than x = 0.06. The photoluminescence measurement shows that the series of the emission-state 5 D 4 → 7 F 6 , 5 D 4 → 7 F 4 , and 5 D 4 → 7 F 3 , corresponding to the typical 4f → 4f intra-configuration forbidden transitions of Tb 3+ , are appeared and the major emission peak is around at 542 nm. Moreover, the maximum photoluminescence intensity is appeared when the molar concentration of Tb 3+ is 0.06. The decay time value of the KSr 1− x PO 4 : x Tb 3+ phosphors with x = 0.06 is about 0.27 ms.