Preparation and characterization of chemically deposited (Cd0.7-Zn0.3)S:CdCl2,Gd nanocrystalline films

Nanocrystalline films of (Cd-0.7-Zn-0.3)S:CdCl2,Gd are prepared by chemical deposition technique on microscopic glass substrates with varied concentrations of capping agents thiophenol and methanol. The deposition is based on the principle of precipitation followed by condensation. Results of XRD, SEM, optical absorption spectra and photoluminescence emission spectra are presented. The crystalline nature of (Cd-0.7-Zn-0.3)S:CdCl2,Gd was found by XRD studies in which different diffraction peaks of CdS and ZnS are observed. The SEM micrographs show long tubes and irregular distributions of particles in presence of capping agents. The blue shift observed from optical absorption spectra in the present case indicates a quantization effect. Band gaps are also found to increase due to particle size reduction. The photoluminescence emission spectra show shift of peaks in the lower wavelength side due to reduction in particle size. The particle sizes are determined from optical absorption and XRD studies. (C) 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim.