Synthesis of silicon nanoparticles using a novel reactor with an elongated reaction zone created by coaxially aligned SiH4 gas and a CO2 laser beam

We demonstrated silicon nanoparticle synthesis using a novel CO2 laser pyrolysis reactor. The reactor was designed to have an elongated reaction zone more than 10 times longer than conventional laser pyrolysis systems by aligning the laser beam and precursor gas stream in the same direction within the simple tubular reactor. Experimental results showed that the elongated reaction zone contributed to production of silicon nanoparticles using SiH4 gas and influenced the size distribution of nanoparticles. Since the proposed reactor utilized the laser beam more efficiently without focusing the laser beam, it would be beneficial to large-scale production tolerating higher power CO2 lasers. Silicon nanoparticle synthesis mechanisms using a proposed reactor and synthesized nanoparticles were discussed in detail based on X-ray diffraction and transmission electron microscopy measurements.