Optical, structural and morphological characterization of CdS-doped sol-gel silico-phosphate films

The paper presents the synthesis as well as optical, structural and morphological characterization of CdS nanoparticles embedded in silico-phosphate thin films, as a promising luminescence temperature sensing material. The films were synthesized by sol-gel method, spin coating technique. UV-Vis (Ultraviolet-Visible) ellipsometric absorption is specific to CdS semiconductor nanoparticles with a cut-off correlated with the band gap of the dopant. Luminescence spectroscopy shows in evidence a large emission band centered at about 470 nm, provided by 340 nm excitation. SEM-EDX (Scanning Electron Microscopy-Energy Dispersive X-ray) analysis of the annealed films reveal different areas with ordered structural units attributted to CdS dopant nanoparticles. AFM (Atomic Force Microscopy) relieves a relative uniform structure taking into consideration the complex composition of the film.