NUV excited luminescence of Eu3+ doped inorganic NaCa0.5Al2B2O7 phosphor via slow evaporation technique

Tetrahedrally coordinated rigid crystal structure enables partial self-reduction of mixed-valence europium for optical thermometric application

“…57 The absorption peaks at 973 cm −1 , 905 cm −1 , and 751 cm −1 were attributed to the asymmetric and symmetric stretching vibration modes of BO 4 . 56,58 The absorption peak at 562 cm −1 was ascribed to the P-O-B bending vibration mode between PO 4 and BO 4 . 59,60 The phase purity of the CaBPO 5 :x% Eu (x = 0-0.7) phosphors with different Eu doping concentrations were checked by powder X-ray diffraction (XRD) measurements, which exhibited intense peaks that were consistent with the simulation pattern of CaBPO 5 (ICSD-77518) without any observed impurity (Fig.…”