title: Electrodeposition of germanium from the ionic liquid 1-butyl-1-methylpyrrolidinium dicyanamide.
abstract: The electrodeposition of germanium from the ionic liquid 1-butyl-1-methylpyrrolidinium dicyanamide ([BMP][DCA]) and a mixture of [BMP][DCA] and 1-butyl-1-methylpyrrolidinium chloride ([BMP]Cl) was studied using cyclic voltammetry and using an electrochemical quartz crystal microbalance (EQCM). [GeCl4(BuIm)2] (BuIm = N-butylimidazole) was used as germanium source as it has a solubility of 0.47 M, up to 13 times the solubility of GeCl4 in [BMP][DCA]. Cyclic voltammograms show an irreversible electrochemical behavior and two reduction waves were observed. The wave at the more positive potential was assigned to the reduction of Ge(4+) to Ge(2+). The wave at the more negative potential was attributed to the formation of Ge(0). The diffusion coefficient of Ge(4+) in [BMP][DCA] containing 0.1 M [GeCl4(BuIm)2] is 1.1 × 10(-12) m(2) s(-1), and the exchange current density is 2 × 10(-4) A m(-2) at 50 °C. Polymerization of dicyanamide anions took place at the anode in the solution of [BMP][DCA]. The polymerization reaction could be avoided by using an equimolar [BMP]Cl-[BMP][DCA] mixture as electrolyte. Smooth, porous germanium films were electrodeposited on both copper and silicon substrates.
authors: KU Leuven-University of Leuven, Department of Metallurgy and Materials Engineering, Leuven, Belgium.
authors: Minxian
authors: M
authors: Wu
authors: Neil R
authors: NR
authors: Brooks
authors: Stijn
authors: S
authors: Schaltin
authors: Koen
authors: K
authors: Binnemans
authors: Jan
authors: J
authors: Fransaer
mesh_terms: D004595:Electroplating; D005857:Germanium / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D009570:Nitriles / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D011759:Pyrrolidines / Q000737:chemistry*
chemical_list: D052578:Ionic Liquids; D009570:Nitriles; D009942:Organometallic Compounds; D011759:Pyrrolidines; D005857:Germanium; C583114:1-butyl-1-methylpyrrolidinium dicyanamide