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 US 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. (C) 2007 Elsevier B.V. All rights reserved.