The electrodeposition of tellurium and zinc telluride was investigated on a nickel electrode in the 40-60 mol % zinc chloride-1-ethyl-3-methylimidazolium chloride molten salt containing propylene carbonate as a cosolvent at 40°C. Tellurium(IV) can be electrochemically reduced to tellurium in this solution. Addition of 8-quinolinol (oxine) to the solution shifts the reduction of Te(IV) to more negative potential. Deposits of Zn-Te can be obtained through the underpotential deposition of zinc on tellurium which occurs at a potential near -0.1 V. At potentials more negative than ca. -0.5 V, tellurium can be further reduced to tellurium(-II) species which may react with zinc(II) to form Zn-Te. Energy-dispersive spcctroscopy data indicate that the composition of the Zn-Te deposits is dependent upon the deposition potential and the Te(IV) concentration in the plating solution. Characteristic X-ray diffraction patterns of cubic ZnTe are observed for the electrodeposited Zn-Te samples that have been annealed at temperatures ranging from 250 to 400°C. The flatband potential of the Zn-Te electrodeposits was determined by photocurrent and impedance (Mott-Schottky plot) experiments. The optical handgap of the ZnTe deposits determined by optical absorption spectrometry is 2.3 V, which agrees well with the literature values.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry