Deep Red Color Emission in an Sm[sup 2+]-Doped SrB[sub 4]O[sub 7] Phosphor

Abstract

The main objective of the present investigation was to increase the photoluminescence and color chromaticity of Sm2+Sm2+ -doped Sr-borate phosphors by adding co-dopants. Among the co-dopants used, which included Ce, Mn, Eu, Mg, Zn, Ca, and Ba, the co-doping of europium and samarium was effective in improving the luminescence and color chromaticity of Sr1−xSmxB4O7Sr1−xSmxB4O7 under excitation at 254nm254nm . The photoluminescence spectrum of the Sr1−xSmxB4O7Sr1−xSmxB4O7 phosphor showed a peak corresponding to Sm3+Sm3+ ions at 595nm595nm , and another for Sm2+Sm2+ ions at 686nm686nm under 254nm254nm excitation even after a strong reduction process. Eu2+Eu2+ ion co-doping increased the intensity of the Sm2+Sm2+ peak and eliminated the Sm3+Sm3+ peak. Thus, the europium co-doping shifted the luminescence to a deep red region. In addition, energy transfer between Eu2+Eu2+ and Sm2+Sm2+ was also investigated in detail.