Journal of Alloys and Compounds 486 (2009) 702–705 Contents lists available at ScienceDirect Journal of Alloys and Compounds journal homepage: www.elsevier.com/locate/jallcom Influence of Mn doping on the microstructure and optical properties of CdS C. Wang a,∗ , H.M. Wang b , Z.Y. Fang a a School of Physics, State Key Laboratory for Mesoscopic Physics, Peking University, 5 Yiheyuan Road, Beijing 100871, China b Department of Biological and Chemical Engineering, Jiaxing University, Jiaxing 314001, China article info Article history: Received 24 December 2008 Received in revised form 7 July 2009 Accepted 7 July 2009 Available online 15 July 2009 Keywords: Mn 2+ -doped Structure Optical absorption Photoluminescence abstract High quality Cd 1-x Mn x S(x = 0–0.05) nanorods have been synthesized by a simple chemical route. The nanorods have a uniform single-crystal hexagonal structure and preferentially grow along [0 0 1] direc- tion. The influence of doping Mn 2+ ions on CdS compound semiconductor has been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM). Also, investigations about the optical properties of the Mn 2+ doped CdS nanorods were conducted with UV–vis absorption spectroscopy and photoluminescence emission spectroscopy. The luminescence due to Mn 2+ intra-3d transition is clearly observed near 590 nm in Mn-doped CdS nanorods. And the emission intensity is found to enhance with increasing Mn 2+ ion concentration. © 2009 Elsevier B.V. All rights reserved. 1. Introduction One-dimensional (1D) semiconductor nanomaterials have attracted considerable research activities due to their great poten- tial for fundamental studies of the roles of dimensionality and size in their physical properties as well as for application in optoelec- tronic nanodevices and functional materials [1–4]. As a direct band gap material with E g of 2.42 eV at room temperature, cadmium sulfide (CdS) is one of the most important groups II–VI semi- conductors, which has potential application of lighting–emitting diodes, solar cell, or other electronic devices [5–7]. Over the past few years, various approaches have been applied to achieve one- dimensional CdS nanocrystals [8–19]. In particular, modifying the properties of semiconductor nanomaterials can be made by tai- loring their energy band structure [14,15], with ion implantation, ion doping [20], chemical vapor ion doping [16]. The ion doping of nanocrystalline semiconductors results in new optical prop- erties [21]. Since the first report on luminescence properties of Mn-doped ZnS nanocrystals [17], many research groups have stud- ied the optical, magnetic and fluorescent properties of Mn-doped CdS nanocrystals [20,18,22–26]. However, most studies focus on doped CdS nanoparticles. The synthesis of one-dimensional doped CdS nanocrystalline semicon- ductors is needed for the best understanding of their physical properties and especially much more important for their poten- tial application in nano-scale optoelectrical devices. In this paper, ∗ Corresponding author. Tel.: +86 010 62768571. E-mail address: chenwang0315@126.com (C. Wang). we report a simple chemical route to synthesize Mn 2+ -doped CdS nanorods. UV–vis absorption spectroscopy and photoluminescence emission spectroscopy have been used to study the influence of the Mn 2+ doping on the optical properties of CdS nanorods. 2. Experimental 2.1. Sample preparation Here, carbon disulfide was used as the sulfur source and ethylenediamine was used as the nucleophilic attack regents to release H2S. Carbon disulfide can react with ethylenediamine as described by reaction (1) [27–29]: H2NCH2CH2NH2 + CS2 → H2NCH2CH2NHCSSH (1) The product will undergo polymerization accompanied by release of gaseous H2S as described by reaction (2): n(H2NCH2CH2NHCSSH) → [–HNCH2CH2NHCS–]n + nH2S ↑ (2) Based on this strategy, the reaction route was designed to prepare CdS nanorods as follows. A 60 cm 3 aqueous solution of final pH 7, which contains ethylenediamine (3 mmol), cadmium chloride (1 mmol) and manganese chloride was heated to 70 ◦ C, carbon disulfide (3 mmol) was rapidly injected into the warm solution. For changing the manganese concentration in the host material, the concentration of manganese chloride (0–5at.%) is changed. All the reagents are commercially available and ana- lytical grades used without further purification. The mixture was maintained at this temperature under magnetic stirring for 4 h. Finally, the mixture became bright yel- low. The precipitate was filtered off, washed with distilled water and absolute alcohol several times to remove the impurities, and then dried in vacuum at 70 ◦ C for 8 h before further characterization. 2.2. Characterization The Cd1-xMnxS (x = 0, 0.03, 0.05) nanorods were characterized by a D8 ADVANCE X-ray diffraction (XRD), using graphite-monochromatized Cu K radi- ation ( = 1.54178 Å). A scanning rate of 4 ◦ /min was applied to record the patterns in the 2 range between 20 ◦ and 75 ◦ . Transmission electron microscopy (TEM) and 0925-8388/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.jallcom.2009.07.043