Luminescence Properties of Sm3+ doped Bi2ZnB2O7

The phosphors of （Bi 1-x Smx）2ZnB2O7 （x=0.01, 0.03, 0.05, 0.07, and 0.09） were synthesized by conventional solid state reaction. The purity of all samples was checked by X-ray powder diffraction （XRD）. XRD analysis shows that all these compounds are of a single phase of Bi2ZnB2O7, indicating that the Bi 3+ in Bi2ZnB2O7 can be partly replaced by the Sm 3+ without the change of crystal structure. The excitation and emission spectra at room temperature show the typical 4f-4f transitions of Sm 3+ . The dominant excitation line is around 404 nm due to 6H 5/2 →4K 11/2 and the emission spectrum consists of a series of lines at 563, 599, 646, and 704 nm due to 4G 5/2 →6H 5/2 , 6H 7/2 , 6H 9/2 , and 6H 11/2 , respectively. The optimal concentration of Sm 3+ in Bi2ZnB2O7 is about 3mol% （relative to 1mol Bi 3+ ） and the critical distance Rc was calculated as 2.1 nm. The temperature dependence of the emission intensity of Bi 1.94 Sm 0.06 ZnB2O7 was examined in the temperature range between 100 and 450 K. The quenching temperature where the intensity has dropped to half of the initial intensity is 280 K. The lifetime for Sm 3+ in Bi 1.94 Sm 0.06 ZnB2O7 is fitted as a value of 0.29 and 1.03 ms.