Research Article Synthesis of Nanocrystalline CdS by SILAR and Their Characterization Partha Protim Chandra, 1 Ayan Mukherjee, 2 and P. Mitra 2 1 Department of Physics, Banwarilal Bhalotia College, Asansol, Burdwan, West Bengal 713303, India 2 Department of Physics, he University of Burdwan, Golapbag, Burdwan, West Bengal 713104, India Correspondence should be addressed to P. Mitra; mitrapartha1@redifmail.com Received 7 January 2014; Accepted 15 May 2014; Published 17 June 2014 Academic Editor: Zainuriah Hassan Copyright © 2014 Partha Protim Chandra et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A simple and cost efective chemical technique has been utilized to prepare cadmium sulphide (CdS) nanoparticles at room temperature. he sample is characterized with XRD (X-ray difractometer), SEM (scanning electron microscope), TEM (transmission electron microscope), FTIR (Fourier transform infrared), EDX (energy dispersive X-rays), and UV-VIS (ultraviolet visible) spectrophotometer. he particle size estimated using X-ray line broadening method is ∼21.5 nm. While particle size estimation, both instrumental and strain broadening was taken into account. he lattice strain was evaluated using Williamson- Hall equation. SEM illustrates formation of submicron size crystallites and TEM image gives a particle size of ∼23.5 nm. he characteristic stretching vibration frequency of CdS was observed in the absorption band in FTIR spectrum. Optical absorption study exhibits a band gap energy value of about 2.44 eV. 1. Introduction Semiconductor nanoparticles are an important class of mate- rials with numerous applications in the fabrication of opto- electronic devices, photonic transducers, and photolumines- cent tags for biological studies [1]. Nanometer-sized semicon- ductors exhibit structural, electronic, optical, luminescence, and photoconducting properties very diferent from their bulk properties [2, 3]. Large-scale synthesis of semiconductor nanoparticles such as solid powder is critically important not only for the study of their physical properties but also for their industrial applications in the areas of catalysis, photocatalysis, and microelectronics. Cadmium sulphide is an important semiconductor and has many optoelectronic applications including solar cells, photodiodes, light emitting diodes, nonlinear optics, heterogeneous photocatalysis, high-density magnetic information storage, and many others in semicon- ductor industries [4, 5]. he characteristic absorption of light for CdS is in the visible range with a bulk band gap of ∼2.4 eV at room temperature [5]. Many of these nanoparticles can be prepared using simple wet-chemical methods of synthesis that allow one to manipulate the electronic properties of the particles [6–9]. In powder form, CdS has been syn- thesized using hydrothermal/solvothermal methods, thermal decomposition [10–12], single-molecule precursors approach [13], and chemical precipitation technique with or without capping agent [4]. In the presented work, a chemical dipping technique has been utilized to prepare nanopowders of CdS at room temperature. he technique involves successive dipping of a precleaned substrate in separately placed cationic and anionic precursor. Between every immersion it is rinsed in ion exchanged water. he technique, oten called SILAR (successive ionic layer adsorption and reaction), is generally reported for preparation of thin ilms of cadmium sulphide [14]. Normally under optimized deposition conditions, SILAR produces adherent thin ilms. he deposition parameters for getting adherent thin ilms include concentration and pH of the reacting baths, temperature of deposition, and speciic substrate treatment. In the present work, we have used SILAR technique to get nanoparticles of CdS. he SILAR deposition from aqueous solutions is a very promising method because of its simplicity and economy. he primary aim of the Hindawi Publishing Corporation Journal of Materials Volume 2014, Article ID 138163, 6 pages http://dx.doi.org/10.1155/2014/138163