Abstract
Time-resolved terahertz spectroscopy is used to probe ultrafast carrier dynamics and terahertz conductivity
in photoexcited thin films of silicon nanocrystals, polynanocrystalline silicon, and epitaxial silicon-on-sapphire.
We show that a Drude-Smith model provides an excellent fit to the observed transient terahertz conductivity in
all of our samples, revealing a transition from a Drude-like response with low carrier backscatter in bulk
silicon-on-sapphire to a non-Drude-like, localized behavior with high carrier backscatter in the silicon nanocrystal
films. Evidence for long-range conduction between nanocrystals is observed, and we show that the
photoconductive lifetime of the silicon nanocrystals is dominated by trapping at Si/SiO2 interface states.
Original language | English |
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Journal | Physical Review B Condensed Matter |
Volume | 73 |
Issue number | 19 |
Pages (from-to) | 193311 |
ISSN | 0163-1829 |
DOIs | |
Publication status | Published - 2006 |
Externally published | Yes |