RESEARCH ARTICLE Copyright © 2012 American Scientific Publishers All rights reserved Printed in the United States of America Journal of Nanoscience and Nanotechnology Vol. 12, 1–7, 2012 ZnSe/ZnSe:Ag Nanoparticles: Synthesis, Characterizations, Optical and Raman Studies Pushpendra Kumar 1 2 3 ∗ , Jai Singh 3 , Koduri Ramam 1 , and Avinash C. Pandey 2 1 Faculty of Engineering, Department of Materials Engineering, University of Concepcion, Concepcion, Chile 2 Nanotechnology Application Centre, University of Allahabad, Allahabad 211002, India 3 Faculty of Science, Department of Physics, Banaras Hindu University, Varanasi 221005, India Nanoparticles (NPs), grown in liquid media, stand out over other classes of inorganic nanomaterials due to the high degree of control with which their crystal structure, size, shape, and surface func- tionalities can be engineered in the synthesis stage and to the versatility with which they can be processed and implemented into a large spectrum of devices and processes. In present work pure and Ag-doped ZnSe NPs were successfully synthesized from the solution phase chemistry and investigated with respect to their structural and optical properties. The resulting powder consists of nanocrystalline particles were characterized by X-ray diffraction (XRD), UV-Visible spectroscopy, photoluminescence spectroscopy, transmission electron microscopy (TEM), high resolution trans- mission electron microscopy (HRTEM), energy dispersive X-ray analysis (EDX) techniques and Raman spectroscopy. A UV emission peak was observed from the excitons transition at 380 nm in the room temperature photo luminescent (PL) spectra. The blue emission band was assigned to the Zn interstitial and vacancy level transition. Even though Ag ions known to act as an efficient non-radiative loss center for near band gap emission (NBE), a decreased NBE is obtained at room temperature even for a nominal Ag concentration. XRD data analysis shows that the Ag dopant atoms are incorporated into the cubic ZnSe host lattice. Keywords: 1. INTRODUCTION Revolutionary improvement of chemistry to nanoscale individuals adept to establish superior or even alterna- tive physical-chemical possessions as well as diversified capabilities for multi assignment applications envisages production of breed-new nanoparticulates with a spa- tially controlled distribution of their composition. Nano- structures are of vital debate owing to their exceptional dimension dependent properties and favourable applica- tions as building blocks in electronics, optoelectronics, sensors and actuators and in bioimaging. 1–22 To consid- erate the size dependent functionalities of nanomaterials has yielded to the revolting theoretical explanations and experimental dimensions. This consents one to foretell size dependent properties and interchange collaborations for a wide range of semiconductors regardless of their size, shape, composition and synthetic protocol. Recently, wide ranges of techniques have been developed to syn- thesize metals/oxides/chalcogenides/nitrides with control of their microstructure. ZnSe an important II–VI, n-type ∗ Author to whom correspondence should be addressed. direct band gap semiconductor has attracted considerable attention due to its applications in light-emitting diodes, photo-detectors and full colour display. 23–26 The wide band gap (bulk band gap 2.7 eV) and significantly large bind- ing energy (21 meV), 27 makes this semiconductor an ideal choice as inorganic passivation shell for a variety of semi- conductor core/shell nanocrystals and also an attractive host for the formation of doped nanocrystals. 28–35 The improvement of new luminescent constituents with com- plex composition is of curiosity for sympathetic electronic excitation and relaxation phenomenon with participation of one and more active centers. Considerable efforts have been devoted to develop an understanding of the cor- relation between structure and electronic properties of the nano-variants and the growth parameters of nano- structures. However, precise control for the yield of desired nanostructures still remains a big challenge. It is now well known that the doping of nanocrystals can be achieved at all. 30–35 By systematically tuning the host lat- tice composition, the dopant concentration and the nano- crystals size; one can efficiently tune the band parameters and interactions within these systems to probe the exis- tence of carriers. The incorporation of donor atoms into J. Nanosci. Nanotechnol. 2012, Vol. 12, No. xx 1533-4880/2012/12/001/007 doi:10.1166/jnn.2012.6736 1