Electrochemical preparation of silver selenide films and nanowires from aqueous solutions

Both thin films and nanowires of silver selenide were synthesized by electrodeposition from an aqueous acid electrolyte containing silver ion complexed with SCN and selenium dioxide at room temperature. Orthorhombic Ag2Se films with Ag slightly in excess were obtained. After annealing in argon atmosphere, the films are highly (002) oriented. A positive transverse magnetoresistance of about 20-25% at T=5 K, and 10-13% at T =300 K, in fields of H=50 kOe were observed in the electrodeposited films. Furthermore, silver selenide nanowires were synthesized from the same aqueous system by electrodeposition in porous anodic alumina templates. X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Energy dispersive absorption X-ray (EDAX) characterization results showed that the nanowires are highly crystalline with (002) growth direction after annealing. In addition, the atomic ratio of Ag/Se in the films and the nanowire samples can be controlled from about 3.0 to 2.1 by adjusting the concentration of Ag-I and Se-IV source and the deposition potential.