On the ultraviolet B emissions of CaLaB7O13:Gd3+ phosphor

Abstract CaLaB7O13 doped with trivalent gadolinium (Gd3+) ions was prepared by the sol-gel technique with varying concentration of Gd3+. X-ray diffraction (XRD) analysis confirmed the formation of the prepared phosphors. The phosphors were characterized by the photoluminescence (PL) spectroscopy, where PL intensity increases by increasing the Gd3+ ions in the CaLaB7O13 matrix. Emission bands at 307 nm and 313 nm correspond to 6P5/2 → 8S7/2 and 6P7/2 → 8S7/2 transitions, respectively. Further, the phosphor with 0.09 mol of Gd3+ had the highest emission among different concentration of Gd3+ ions and decreased with further doping. Concentration quenching was owing to multipole-multipole interaction among the dopant ions. The Electron paramagnetic resonance (EPR) spectra confirmed the existence of Gd3+ ions in the prepared phosphors and exhibit the characteristic gadolinium U type spectrum.