Structural, optical, electrical and positron annihilation studies of CdS:Fe system

Nanocrystals of Cd1−xFexS (x = 0–0.05) have been synthesized by aqueous solution precipitation method at room temperature. The effect of doping of Fe2+ ions (0–0.05) on CdS compound semiconductor has been studied, using X-ray diffraction (XRD), optical absorption (UV–vis), photoluminescence (PL), and positron annihilation spectroscopy (PAS). The structure of these nanocrystals is found to be single phase hexagonal. Optical absorption is found to be decreased on increasing the Fe2+ ions concentration. PL spectra are studied on most prominent excitation peaks within the wavelength range (586–731 nm). The emission intensities are found to be decreased on increasing Fe2+ ions concentration. DC electrical conductivity is found to be increased on increasing Fe2+ ions at room temperature. The Cd vacancy concentration decreases with increasing Fe concentration.