Synthesis and spectroscopic analysis of LiCaLa(MoO ₄ ) ₃ :Ln ³⁺ (Ln = Tb, Dy, Eu, Sm) phosphors for opto-electronic applications

In search of versatile phosphors to cater to the opto-electronic applications, a series of Ln3+ (Ln = Eu, Dy, Tb, Sm) singly doped LiCaLa(MoO4)3 phosphors were successfully prepared by adopting the solid-state reaction synthesis method. Structural information, including the formation of the phase, crystal structure and the space group, was recorded using the XRD pattern. The structure of LiCaLa(MoO4)3 closely aligns with the tetragonal structure having I41/a space group. Elemental composition and surface morphology were recorded using FE-SEM and EDS techniques. Irregular shape with particle sizes ranging from 5 to 20 µm were obtained, and elemental composition was also confirmed using EDS spectra. Photoluminescence spectra recorded with the excitation of host and dopant ions reveal the dominant emission in the visible region at 616, 575, 545 and 600 nm, and the decay lifetime obtained was 0.42, 0.19, 0.66 and 0.57 ms for trivalent Eu-, Dy-, Tb- and Sm-doped LiCaLa(MoO4)3 phosphors, respectively. Under the host and typical excitation of dopant ions, PL spectra were recorded and found that, only for Tb3+ ions, intensity is more in comparison with other dopants. Obtained results suggest that this phosphor has potential applications in human-centric lighting, display technology, security, anti-counterfeiting, etc.