Photoluminescence and Refractive Index Dispersion Properties of Zn3−xMx(PO4)2 (M=Co, Ni; x = 1) Nanoparticles

This study investigated the structural, optical, and photoluminescence properties of Zn 3-x M x (PO 4 ) 2 (M=Co, Ni; x = 1) nanoparticles, synthesized via the solid-state method.The optical constants and dispersion energy parameters were determined using UV-visible spectroscopy.The optical band gaps were found to be 2.48 eV for Zn 3 (PO 4 ) 2 , 3.05 eV for Zn 2 Ni(PO 4 ) 2 , and 3.12 eV for Zn 2 Co(PO 4 ) 2 .The optical dielectric constant of Zn 3-x M x (PO 4 ) 2 (M=Co, Ni; x = 1) was also determined.Photoluminescence spectra revealed peaks at 2.56 eV for Zn 3 (PO 4 ) 2 , 3.26 eV for Zn 2 Co(PO 4 ) 2 , and 2.47 eV for Zn 2 Ni(PO 4 ) 2 .These peaks correspond to the recombination of excitons and/or shallowly trapped electron-hole pairs, indicating band-edge emission.