Thin layers of new salt, BET-TTF[Ni(dmit) 2 ] 2 , electrodeposited on silicon wafers Aneta Aniela Kowalska a,b, * , Jean-Philippe Savy c , Dominique de Caro c , Lydie Valade c , Laure Vendier c , Elena Laukhina d,e , Concepcio Rovira d , Jacek Ulanski a a Department of Molecular Physics, Technical University of Lodz, ul. Zeromskiego 116, 90-924 Lodz, Poland b Department of Materials Molecular Science, Institute for Molecular Science, Myodaiji, Okazaki, Aichi 444-8585, Japan c Laboratoire de Chimie de Coordination du CNRS, 205 route de Narbonne, 31077 Toulouse Cedex 4, France d Institut de Ciencia de Materials de Barcelona (CSIC), Campus UAB, E-08193 Bellaterra, Spain e CIBER-BBN, C/Marı ´a de Luna, 11 (CEEI-Modulo 3), 50018, Zaragoza, Spain Received 26 November 2007; received in revised form 13 February 2008; accepted 15 February 2008 Available online 29 February 2008 Abstract The new charge transfer salt, BET-TTF[Ni(dmit) 2 ] 2 , was obtained using the electrodeposition method. Thin layers of this new salt were grown on (001)-oriented silicon wafers as anode. The stoichiometry of the new salt was evaluated by infrared and Raman spectroscopy and the unit cell parameters of its structure were determined by powder X-ray diffraction. It was found that, by using different current density during the electrodeposition, layers of different morphologies can be obtained, but the stoichiometry of the formed salt remains the same. Ó 2008 Elsevier Masson SAS. All rights reserved. Keywords: Thin films; Organic conductors; Electrodeposition 1. Introduction Charge transfer complexes and salts based on derivatives of tetrathiafulvalene (TTF) donor attract, since many years, a lot of interest due to a broad range of properties of these materials, within which one can find organic insulators, semiconductors, metals and superconductors. In particular, many interesting re- sults have been obtained within the family based on bis(ethy- lenedithio)tetrathiafulvalene (BEDT-TTF) [1]. By modifying the substituents in the TTF core, it is possible to obtain a wide range of structures and physical properties [2]. Within them, the bis(ethylenethio)tetrathiafulvalene (BET-TTF) donor (see Fig. 1a) has attracted a special attention [3e5]. In spite of several interesting and unique properties ex- hibited by charge transfer complexes and salts, they cannot find practical application in a form of single crystals. For this reason, many efforts are devoted to elaborate efficient methods of producing thin films and layers consisting of charge transfer complexes. One family of originally developed methods, the so-called reticulate doping technique, allows one to produce isotropic and highly oriented thin layers of organic conductors and semiconductors, as well as thin films of com- posites and nanocomposites [6,7]. In this work, we have em- ployed an electrolytic process to form thin films of organic charge transfer salts on silicon wafers substrates [8]. Taking into account that the number of sulphur atoms influences the contacts between the stacks in molecular crystals, we have chosen to study the association of the BET-TTF donor with the nickel bis(1,3-dithio-2-thione-4,5-dithiolate) (Ni(dmit) 2  ) [9e11] acceptor (Fig. 1b). 2. Experimental BET-TTF [12] and (n-Bu 4 N)[Ni(dmit) 2 ] [13] were synthe- sized according to published procedures. * Corresponding author. Department of Materials Molecular Science, Insti- tute for Molecular Science, Myodaiji, Okazaki, Aichi 444-8585, Japan. Tel.: þ81 564 55 7420. E-mail address: kowalska@ims.ac.jp (A.A. Kowalska). 1293-2558/$ - see front matter Ó 2008 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.solidstatesciences.2008.02.018 Available online at www.sciencedirect.com Solid State Sciences 10 (2008) 1777e1779 www.elsevier.com/locate/ssscie