**2.2. Characterization**

The morphology of the product was analysed by field emission scanning electron microscope (FESEM-SUPRA 55). Using atomic force microscopy (NTEGRA PRIMA-NTMDT, USA), the surface topography of the thin phosphor films was studied. The crystal structure and phase purity of as-synthesized phosphor were recognized and confirmed by PANalytical's X'Pert PRO Materials Research X-ray Diffractometer (Almelo, USA) equipped with a CuKα radiation (λ = 0.154060 Å) at a scanning rate of 0.02°s−1 in a 2*θ* range of 15°–60°. Further, down-conversion PL excitation and emission studies and fluorescence decay time measurements were performed at room temperature using a Cary bench-top spectrophotometer (AGILENT Instruments, USA).
