In this work we present the formation process of crystalline and amorphous nanostructured silicon made from a continuously operating hot-wall reactor synthesis process. In this reactor, silicon particles are synthesized at variable operating conditions varying the pressure range between 15 and 100 kPa, the temperature between 800 and 1000°C and the precursor concentration. The defined variation of process parameters leads to a controllable particle size and morphology at productions of up to 1 kg/h. The resulting materials are analyzed with several techniques to investigate the relation between particle size, crystallinity, morphology and synthesis conditions. X-ray diffraction analysis (XRD) is used to analyze the crystallinity of the materials. While the position of the Bragg reflexes of the crystalline material can be assigned to those of bulk silicon, the XRD analysis of the amorpous samples confirms the absence of crystalline material. To proof the long-term stability of the production process, both, the crystalline and the amorphous materials are analyzed using BET. The results reveal a specific surface area of ~17 m2/g for the crystalline material and ~68 m2/g for the amorphous material and a deviation of the specific surface area smaller than 5%.
Journal: TechConnect Briefs
Volume: 1, Nanotechnology 2012: Advanced Materials, CNTs, Particles, Films and Composites (Volume 1)
Published: June 18, 2012
Pages: 361 - 364
Industry sector: Advanced Materials & Manufacturing
Topics: Nanoparticle Synthesis & Applications