An experimental and numerical study of particle nucleation and growth during low-pressure thermal decomposition of silane

Aerosol dynamics modeling of silicon nanoparticle formation during silane pyrolysis: a comparison of three solution methods

“…This critical nucleus size of ten silicon atoms is presently just a coarse estimate, but in the future can hopefully be obtained from kinetic Monte Carlo simulations of cluster formation, as presented in Li and Swihart (2001), or from the automated reaction mechanism generation approach (Broadbelt, Stark, & Klein, 1994;Broadbelt, Stark, & Klein, 1996) being applied to this system by Wong, Li, Swihart, and Broadbelt (2003). The observations of Nijhawan et al (2003) suggest that the present nucleation model overpredicted the nucleation rate for the conditions that they studied.…”

“…An e cient and reasonably accurate means of approximately solving the GDE is the MOM, which has been extensively used due to its relative ease of implementation and low computational cost (Lee, Chen, & Gieseke, 1984;Nijhawan et al, 2003;Pratsinis & Kim, 1989). The kth moment of the particle size distribution function n(v) is given by…”

“…In the SM, the ÿrst size bin was selected to have the same mean volume as the critical nucleus produced by the kinetic model. The nucleation rate was taken to be the formation rate of silicon-hydrogen clusters containing more than ten silicon atoms, as was done previously with this same reaction mechanism (Girshick et al, 2000;Nijhawan et al, 2003).…”

“…The chemical nucleation model has to be coupled with the aerosol general dynamic equation (GDE) to predict the evolution of the particle size distribution. In Girshick et al (2000) and Nijhawan et al (2003), a moment method assuming a lognormal distribution was used to solve the GDE in conjunction with this detailed nucleation model for simple one-dimensional geometries. Here we compare that approach to methods that provide greater detail without making a priori assumptions about the shape of the size distribution.…”

System for In Situ Characterization of Nanoparticles Synthesized in a Thermal Plasma Process

“…A variety of approaches have been used for such measurements, including laser light scattering, (1)(2)(3) sampling from the exhaust of turbomolecular pumps, (4,5) mobility analysis at low pressure, (6)(7)(8)(9) and particle beam mass spectrometry (PBMS). (10)(11)(12) There are limitations to each of these methods. While laser light scattering is fast and can provide information on aerosols throughout a reactor, the light scattering signals are complex convolutions of particle size, shape, concentration and refractive index.…”