Synthesis of Si nanoparticle chains and nanowhiskers by the monosilane decomposition in an adiabatic process during cyclic compression

A cyclic adiabatic compression reactor is used for the Si powder fabrication by the monosilane decomposition in a gas mixture with argon. Along with arbitrary agglomerations of Si nanoparticles, this method allows synthesizing nanoparticle chains and nanowhiskers, as an outlet gas pressure in the reactor increases from about 2.0 to 5.0 MPa. The increase in pressure corresponds to an increase in temperature from ~450 to 1050 °C, which leads to a change in the particle structure from amorphous to crystalline and reduces the particle size distribution. The particle chain and nanowhisker formation is associated with an increase in the duration of the synthesis process. The optical properties of the synthesized Si powders were determined by Si/SiO2 interfaces appeared by the oxidation in the air. The method is characterized by a relatively high production rate of Si powders of various morphologies, which may be of interest for various applications. [Display omitted] •Si powder was synthesized in adiabatic process using gas mixture of SiH4 and Ar.•Amorphous Si nanoparticles became crystalline as gas pressure increases.•Si particles are agglomerated into chains or nanowhiskers depending on gas pressure.•Effects of gas pressure are associated with an increase in temperature.•Si/SiO2 interface determines optical properties of Si powder after oxidation in air.