The initial stages of particle formation are important in several industrial and environmental systems; however, the phenomenon is not completely understood due to the inability to measure cluster size distributions. A high resolution differential mobility analyzer with an electrometer was used to map out the early stages of Si particle formation from pyrolysis of SiH4 in a furnace aerosol reactor. We detected for the first time subnanometer stable clusters from silane pyrolysis, and the diameter was measured to be about 0.7 nm. This diameter is within the range of probable sizes that the reported families of critical silane clusters could have based on their actual molecular structure. The size distributions of negative clusters are also mapped out. In addition, gas chromatography mass spectrometry, and transmission electron microscopy characterizations of the clusters and primary particles are used to assess their mechanistic roles in aerosol dynamics of the initial stages of particle formation.


Civil, Architectural and Environmental Engineering

Research Center/Lab(s)

Center for Research in Energy and Environment (CREE)


This work was partially supported by the Solar Energy Research Institute for India and the United States (SERIIUS), funded jointly by the U.S. Department of Energy (Office of Science, Office of Basic Energy Sciences, and Energy Efficiency and Renewable Energy, Solar Energy Technology Program, under Subcontract No. DE-AC36-08GO28308 to the National Renewable Energy Laboratory, Golden, Colorado) and the Government of India through the Department of Science and Technology under Subcontract No. IUSSTF/JCERDC-SERIIUS/2012.

Keywords and Phrases

Aerosols; High resolution transmission electron microscopy; Mass spectrometry; Pyrolysis; Size distribution, Aerosol dynamics; Cluster-size distribution; Differential mobility analyzers; Environmental systems; Gas chromatography-mass spectrometry; High resolution; Particle formations; Primary particles, Gas chromatography

International Standard Serial Number (ISSN)

0021-9606; 1089-7690

Document Type

Article - Journal

Document Version

Final Version

File Type





© 2020 The Authors, All rights reserved.

Publication Date

01 Jan 2020