Size and structural characterization of Si nanocrystal aggregates from a low pressure nonthermal plasma reactor

Xiaoshuang Chen, Takafumi Seto, Uwe R. Kortshagen, Christopher J. Hogan

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Si nanocrystals (NCs) are synthesizable in low-pressure plasmas with narrow diameter distributions because of unipolar negative charging in the plasma. However, NCs must pass into a spatial afterglow, where NCs may decharge and aggregate. We use both low-pressure differential mobility analysis and quantitative TEM image analysis to examine Si NCs sampled from a 2 Torr Ar-SiH4 plasma reactor. We find that Si NCs are incorporated into aggregates largely composed of 20 and fewer primary particles with nearly equal concentrations of negatively and positively charged NCs. The projected areas of aggregates scale with aggregate volume in similar manner to the scaling observed for aggregates from atmospheric pressure systems. Higher aggregate concentration is observed with increasing flow rate, while larger aggregate size is found with increasing precursor concentration. Measurements show that the spatial afterglow has a significant influence on the charge and extent of NC aggregation.

Original languageEnglish (US)
Pages (from-to)164-173
Number of pages10
JournalPowder Technology
Volume373
DOIs
StatePublished - Aug 2020

Keywords

  • Aggregation
  • Differential mobility analysis
  • Nanocrystal
  • Nonthermal plasma
  • Spatial afterglow

How much support was provided by MRSEC?

  • Primary

Reporting period for MRSEC

  • Period 7

Fingerprint Dive into the research topics of 'Size and structural characterization of Si nanocrystal aggregates from a low pressure nonthermal plasma reactor'. Together they form a unique fingerprint.

Cite this