Silicon nanowires grown on metal substrates via self-catalyst mechanism

•SiNW deposition was carried out without any seeds to promote SiNW growth.•Metal substrates did not require a special treatment or modification.•Possible growth mechanism was suggested and discussed.

Low Pressure Chemical Vapor Deposition (LPCVD) was applied to grow Silicon Nanowires (SiNWs) without any heteroatom catalyst or special pretreatment of substrates used. Silane (SiH4) as a precursor was pyrolyzed at 500 °C in an oven at molybdenum or iron substrates. NWs were several microns long, about 100 nm thick and possessed a core–jacket structure. The thin core was composed of crystalline silicon oriented in 〈110〉 direction whereas the jacket was formed by amorphous silicon. Unlike other approaches, this method avoids contamination caused by metal heteroatom seeds and/or applying special procedures for substrate pretreatment to initialize/support NW growth. The photocatalytical activity revealed that SiNW layers could be accredited with a relatively high rate of photocatalytical splitting of water into H2/O2.

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