Catalyst- and template-free direct electrodeposition of germanium and germanium-tin alloy nanowires from an ionic liquid

Ge and GeSn alloy nanowires exhibit a widely application potential in the fields of nanoscale electronic and optoelectronic devices, furthermore, they are important candidates for anode materials in the next-generation of lithium-ion batteries. Here, a simple catalyst-and template-free technique is proposed for electrodeposition of SnGe nanowires, Ge and GeSn nanowires from ionic liquid. The addition of 0.01 M GeCl4 to the SnCl2/ionic liquid electrolyte is found to inhibit the fractal growth of Sn and form hair-like nanowires with lengths more than 50 & mu;m, while tree-like fractal structures are formed in the absence of GeCl4. The concentration of GeCl4 in the solution greatly affects the morphology of the deposit. Taper and kinked Ge and GeSn nanowires can be directly electrodeposited from ionic liquid, interweaving of these twisted nanowires produces a microporous structure. This method may not only be limited to the preparation of Sn-and Ge-based nanowires, but also be used to prepare other group IV nanowires.

Automated summary

Ge and GeSn alloy nanowires have potential applications in nanoscale electronic and optoelectronic devices, and are important candidates for anode materials in the next-generation of lithium-ion batteries. A simple catalyst-and template-free technique is proposed for electrodeposition of SnGe nanowires, Ge nanowires, and GeSn nanowires from ionic liquid. The addition of 0.01 M GeCl4 to the SnCl2/ionic liquid electrolyte inhibits fractal growth of Sn and promotes the formation of hair-like nanowires with lengths over 50 μm, while the absence of GeCl4 leads to the formation of tree-like fractal structures. The concentration of GeCl4 in the solution significantly affects the morphology of the deposit. Taper and kinked Ge and GeSn nanowires can be directly electrodeposited from ionic liquid, and interweaving of these twisted nanowires produces a microporous structure. This method can be used for the preparation of not only Sn- and Ge-based nanowires, but also other group IV nanowires.