Device for preparing pure silicon nanowires by electrodeposition at ambient temperature in enclosure in isolation from atmosphere, includes depositing solution to be electrolyzed, solvent ion, substrate comprising membrane, and metal layer

摘要

The device comprises a depositing solution to be electrolyzed, which is the source of pure silicon to be deposited by electrodeposition, a purified solvent ion of very high stability, which is able to dissolve the depositing solution to obtain a homogenized mixture (1) of the depositing solution and the ionic solvent and which is chosen based on their high silicon reduction potential, a substrate (2) comprising a nanoporous membrane of which the thickness and the diameter of pores are chosen depending on the desired length and diameter of silicon nanowires respectively, and a metal layer. The device comprises a depositing solution to be electrolyzed, which is the source of pure silicon to be deposited by electrodeposition, a purified solvent ion of very high stability, which is able to dissolve the depositing solution to obtain a homogenized mixture (1) of the depositing solution and the ionic solvent and which is chosen based on their high silicon reduction potential, a substrate (2) comprising a nanoporous membrane of which the thickness and the diameter of pores are chosen depending on the desired length and diameter of silicon nanowires respectively, and a metal layer of a minimum thickness of 50 nm deposited on the nanoporous membrane and forming a working electrode, a container (5) of electrolysis electrically insulated and resistant to chemical products used in the device, a platinum counter-electrode (4), a device (6) for applying a controlled potential difference corresponding to the silicon reduction potential depending on working conditions between the working electrode and a platinum-reference electrode (3). The pore diameter of the nanoporous membrane is chosen depending on the desired diameter of silicon nanowires, and the thickness of the metal layer is twice the diameter of used pores. The quantity of homogenized mixture of the depositing solution and ionic solvent is for wetting completely the substrate. The nanoporous membrane depositing on the metal layer is arranged at the bottom of the electrolysis container. The counter electrode is maintained by fastening the above substrate. The potential difference applying device serves as a working electrode and reference electrode, and a potentiostat, where the potential difference is -2700 mV. The deposition time depends on thickness and length of desired nanowires. The maximum length and diameter of nanowires are limited by the thickness of the used nanoporous membrane and the diameter of pores respectively. The rate of oxygen and water in the enclosure in isolation from the atmosphere are maintained and controlled below 1 ppm.