Synthesis and characterization of Cu2+ doped ZnS nanoparticles using TOPO and SHMP as capping agents

Undoped and Cu2+ doped (0.2–0.8%) ZnS nanoparticles have been synthesized through chemical precipitation method. Tri-n-octylphosphine oxide (TOPO) and sodium hexametaphosphate (SHMP) were used as capping agents. The synthesized nanoparticles have been analyzed using X-ray diffraction (XRD), transmission electron microscope (TEM), Fourier transform infrared spectrometer (FT-IR), UV–vis spectrometer, photoluminescence (PL) and thermo gravimetric-differential scanning calorimetry (TG-DTA) analysis. The size of the particles is found to be 4–6 nm range. Photoluminescence spectra were recorded for ZnS:Cu2+ under the excitation wavelength of 320 nm. The prepared Cu2+-doped sample shows efficient PL emission in 470–525 nm region. The capped ZnS:Cu emission intensity is enhanced than the uncapped particles. The doping ions were identified by electron spin resonance (ESR) spectrometer. The phase changes were observed in different temperatures.