A Blue Light-Emitting Cu2+-Doped SrZn2(PO4)2 Nanophosphor: Synthesis, Characterization, Structure, Site Symmetry, and Optical Properties

SrZn 2 (PO 4 ) 2 :Cu 2+ nanophosphor was synthesized via a solution combustion route utilizing nitrate-based precursors. Comprehensive analysis was conducted to determine the phase identification, crystal structure, crystallite size, sample morphology, vibrational bands, bonding nature, dopant site environment, and emission properties. X-ray diffraction analysis revealed a monoclinic crystal structure with average crystallite size of 72 nm, while morphological characterization indicated an anisotropic stone-like structure with particle size in the nano range. The infrared (IR) spectrum highlighted different vibrating modes corresponding to functional groups including PO 4 3− and P–O–P in the phosphor compound. Electron paramagnetic resonance (EPR) and absorption studies revealed characteristic d–d transitions, confirming tetragonal distortion in the octahedral symmetry of Cu ions with the host lattice and indicating covalent bonding. The photoluminescence spectrum exhibited enhanced emission in the blue region, and the CIE chromatic coordinates and color correlation temperature (CCT) indicated that the prepared material has application potential in blue light-emitting devices and display devices.