Analysis on nanoparticle growth by coagulation in silane plasma reactor

초록

The particle growth in a silane plasma reactor by coagulation between particles was analyzed by using a discrete-sectional model, considering effects of a particle charge distribution based on the Gaussian distribution function. At the start of the plasma discharge, there is the high concentration of small-size particles, and later large-size particles appear and grow by coagulation between small-size particles. Some fractions of small-size particles are in a neutral state or even charged positively. The positively charged small-size particles coagulate faster and more selectively with large-size particles, which are charged more negatively than with medium-size particles. Also, the particle-size distribution in a plasma reactor becomes bimodal and large-size particles become quite monodisperse. As the mass generation rate of monomers increase or as the monomer diameter decreases, large-size particles grow more quickly and the particle-size distribution becomes bimodal earlier. The plasma reactor can be a good candidate to produce monodisperse, nanosized particles.