Simple wet chemical synthesis and photoluminescence characterization of SnO2:Eu3+ reddish-orange phosphor

SnO2:Eu3+ reddish-orange phosphor was synthesized by chemically etching metallic Sn shots and Eu2O3 powder in aqueous HNO3 solution. The synthesized phosphor was investigated by X-ray diffraction (XRD) analysis, photoluminescence (PL), PL excitation (PLE) spectroscopies, and PL decay time measurements. The Eu dopant concentration was found to be easily controlled by changing the quantity of the Eu2O3 addition. The structural and luminescence properties were optimized by measuring the XRD traces and characteristic Eu3+ emission intensities peaking at ~588-598 nm. The temperature dependence of the PL intensity was also measured from T=20 to 300 K. Interestingly, the multiple-peak structure in the PLE spectrum of SnO2:Eu3+ was observed and analyzed using the configurational-coordinate model. The proposed energy-level scheme for the Eu3+ ion in SnO2 may help in a better understanding of the PL properties of this and other Eu3+-activated phosphors.