Electrochemical synthesis of metal chalogenide nanorods, nanotubes, segmented nanorods, and coaxial nanorods

Abstract

Electrodeposition is a key technique to create nanostructures of metals and inorganic semiconductors. Unlike the electrodeposition of metals, the fabrication of nanostructures of binary semiconductors with desired crystallinity and stoichiometry is not straightforward. Herein, we describe the optimization of conditions for the electrodeposition of stoichiometry and crystalline cadmium selenide (CdSe), cadmium telluride (CdTe), and CdSe/CdTe nanostructures. We first identified the optimal conditions for the electrodeposition of CdSe and CdTe with 1:1 stoichiometry by varying the concentrations of Cd2+ and SeO2 (or TeO2) and optimizing the electrodeposition potential. We then optimized the pH of the electrolysis solution for increasing the crystallinity of the deposited structures. We then tested the efficacy of our electrodeposition conditions on substrates such as gold, nickel, and indium tin oxide. We used the optimized conditions to electrodeposit semiconductors within anodic aluminum oxide (AAO) membranes to create oriented CdSe and CdTe nanorods, CdSe/CdTe segmented nanorods, and CdSe/CdTe coaxial nanorods. These optimized electrodeposition conditions add a valuable tool in the synthetic toolbox for the synthesis of crystalline semiconductor nanostructures for solar cell applications.