Structural characterization and photoluminescence in the rare earth-free oxy-fluoride anti-perovskites Sr3−xBi2x/3AlO4F and Sr3−xBi2x/3GaO4F
The activator Bi3+ has been successfully incorporated into the anti-perovskite oxy-fluoride host lattice Sr3MO4F (M = Al, Ga) to form rare earth-free phosphors of the composition Sr3−xBi2x/3AlO4F, 0 ≤ x ≤ 0.1, and Sr3−xBi2x/3GaO4F, 0 ≤ x ≤ 0.048. These phases absorb in the UV region (λex = 240–326 nm) and exhibit broad emission in the blue region of the visible spectrum (λem = 446.5–455 nm). The optimum compositions for maximum photoluminescent intensity were determined to be Sr2.976Bi0.016AlO4F and Sr2.976Bi0.016GaO4F before concentration quenching occurs. Full structural characterization based upon PXRD and NPD data were performed with DFT calculations suggesting that Bi3+ ions are preferentially incorporated on the ten coordinate Sr(1) site.