Modified solvothermal synthesis and characterization of CdS/ZnS core/shell nanorods A.R. Baby Suganthi a , P. Sagayaraj b, * a Department of Physics, Saveetha School of Engineering, Saveetha University, Chennai 602 105, India b Department of Physics, Loyola College, Chennai 600 034, India highlights graphical abstract < CdS/ZnS core/shell nanorods were synthesized using two-step sol- vothermal approach. < The nanoparticles were character- ized by XRD, EDX, SEM, UVevis and TEM. < SEM images revealed the surface roughness after ZnS shell growth. < TEM microscopy offers evidence for the formation of core/shell nanostructures. article info Article history: Received 8 November 2012 Received in revised form 17 January 2013 Accepted 18 February 2013 Keywords: Semiconductors Nanostructures Electron microscopy Powder diffraction abstract Core/shell CdS/ZnS nanorods were synthesized using a two-step solvothermal approach. The first step is the formation of CdS nanoparticles initiated using nucleation followed by growth through coalescence- exchange and particle coagulation. The second step leads to the formation of ZnS and further coalescence-exchange leading to deposition and growth of a ZnS shell around CdS nanoparticles. The structural, morphological and chemical studies were performed using X-ray diffraction, Energy Disper- sive X-ray spectroscopy (EDX) Scanning electron Microscopy (SEM), UVevis absorption spectra and Transmission Electron Microscopy (TEM), provide direct evidence for shell growth. The present synthesis provides a rational approach to the design of novel core/shell nanomaterials with appealing applications in optoelectronic devices. Ó 2013 Elsevier B.V. All rights reserved. 1. Introduction One-dimensional (1D) semiconductor nanostructures are considered to be critical building blocks for nanoscale electronic and optoelectronic devices [1,2]. The performance of nanodevices using one dimensional semiconductor nanostructures depends on the efficiency of 1D semiconductor nanostructures used. In nano- structures the surface defects are prominent due to large surface to volume ratio, the efficiency of nanostructures and hence their performance in nanodevices could be improved by reducing surface defects [3]. Since large portion of atoms in nanocrystals is located at the surface, the codification of the surface has been recognized as one of the most advanced and intriguing methods to build tailored nanomaterials. It not only alters the charge, the functionality and the reactivity of the surface, but also enhances the thermal, mechanical and chemical stability of the material. Typi- cally, surface coating involves tailoring the surface properties of the nanomaterials, often accomplished by coating or encapsulating them within a shell of a preferred material [4]. To date, the best surface passivation approach is the creation of heterostructures such as core/shell nanostructures. In an effectively surface passivated core/shell nanostructure, the core is completely covered by an epitaxial shell with minimal lattice * Corresponding author. Tel.: þ91 44 28178200; fax: þ91 44 28175566. E-mail address: psagayaraj@hotmail.com (P. Sagayaraj). Contents lists available at SciVerse ScienceDirect Materials Chemistry and Physics journal homepage: www.elsevier.com/locate/matchemphys 0254-0584/$ e see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.matchemphys.2013.02.056 Materials Chemistry and Physics 139 (2013) 917e922