A Model for the Growth of Silicon Particles from Laser-Heated Gases

Abstract

Abstract Laser-synthesized silicon powder is spherical and nonagglomerated when produced under proper conditions. Otherwise it consists of agglomerates of very small particles or fused aggregates of larger particles. A synthesis model has been developed that includes silane decomposition kinetics, interdiffusion of reactant and annular gases, particle growth by collision coalescence of Si droplets, and a measured temperature distribution. Predicted particle size distributions agree closely with a measured distribution. Variation in the growth time for different flow streams primarily broadens the mass distribution, whereas intermixing of the silane flow with the annular gas primarily broadens the number distribution.