ORIGINAL PAPER Characterization of Bi 2 Se 3 prepared by electrodeposition M. Khadiri 1 & M. Elyaagoubi 2 & R. Idouhli 1 & M. Mabrouki 3 & A. Abouelfida 1 & A. Outzourhit 2 Received: 13 June 2020 /Revised: 25 July 2020 /Accepted: 13 August 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Bi 2 Se 3 compound was deposited catholically under potential control, from a mixture solution composed from equi- molar SeO 2 and BiCl 3 . The concentration of selenium and bismuth precursors was about 5 ∙ 10 −3 M. The electro- deposited films were grown on FTO substrates (Transparent Conductive Glass Fluorine-Doped Tin Oxide (FTO)– Coated Glass). Deposition potential was determined from cyclic voltammetry (CV) where the platinum mesh was taken as working electrode. The growth kinetics depends on the applied potential. It was found, using EDS tech- nique, that suitable ratio of Se/Bi corresponding to Bi 2 Se 3 was reached at − 250 mV vs. SCE (saturated calomel electrode). X-ray and grazing X-ray diffraction revealed that the obtained film at − 250 and − 200 mV/SCE consisted a rhombohedral Bi 2 Se 3 structure. Raman shift was employed to corroborate the X-ray results with the possibility of formation of a rhombohedral Bi 2 Se 3 when the applied potential was − 200 mV (vs. SCE). The Bi 2 Se 3 -obtained films were an n-type semiconductor with a carrier charge concentration which depends on the applied potential. Keywords Bi 2 Se 3 . Cyclic voltammetry . Electrodeposition . Nucleation . Thin films Introduction Groups V–VI thin-film semiconductors based on sul- fides, selenides, and tellurides have a narrow band gap. Among them, the bismuth selenide (Bi 2 Se 3 ) is a direct gap semiconductor, and the gap energy noted E g ranges from 0.16 to 0.35 eV [1]. Bismuth selenide has been widely studied because of its non-toxicity [2] and its potential applications in medical [3], photovoltaic [4], infrared, and gas detection [5], and in thermoelec- tric and optoelectronic devices applications fields [6–8]. Bismuth selenide (Bi 2 Se 3 ) has a rhombohedral crystal structure, integrated in a hexagonal lattice which allows to highlight the stacking of atomic layers, corresponding to the basic quintet of the structure: Se(1)-Bi-Se(2)-Bi- Se(1) [9]. The different atomic layers of the sequence are arranged perpendicularly to the ternary axis of the rhombohedral mesh, which is also the c axis of the hexagonal mesh. However, under particular preparation conditions, the orthorhombic phase may appear [10, 11]. Several techniques can be used to obtain Bi 2 Se 3 thin films, namely exfoliation [8], radio frequency sputtering [12, 13], hydrothermal method [14, 15], co-reduction [ 16], successive ionic layer adsorption and reaction (SILAR) technique [ 17], potentiostatically controlled electroplating in HNO 3 medium at different voltages and on different substrates [10, 18–20], and electroplating under gal- vanostatic control [21]. In this work, we prepared thin films of Bi 2 Se 3 by potentiostatic electrodeposition on an FTO-coated glass substrate in an acidic medium (HCl 1 M). The voltammetric study allowed us to determine the range of applied potential to obtain Bi 2 Se 3 films. Several tech- niques are used for the characterization of the obtained films such as X-ray diffraction, scanning electron mi- croscopy coupled with the energy dispersive X-ray (EDX) microanalysis. Vibration modes relative to the Bi 2 Se 3 structure are determined by Raman spectroscopy. * M. Khadiri Khadiri_m@gmx.fr 1 Applied Chemistry and Biomass Laboratory Department of Chemistry, Faculty of Science Semlalia, University Cadi Ayyad, BP 2390, Morocco, Morocco 2 Laboratory of Nanomaterials for Energy and the Environment (LN2E), Faculty of Sciences Semlalia Marrakech, Cadi Ayyad University, BP 2390, Marrakech, Morocco 3 Laboratory of Industrial Engineering Beni-Mellal TSF, BP 523, 23000 Marrakech, Morocco Journal of Solid State Electrochemistry https://doi.org/10.1007/s10008-020-04807-8