Abstract
In bulk single-crystal silicon, the semiconducting diamond-to-metallic ß-Sn phase transformation nucleates on defects, and is manifested by a sharp uptake in light absorption at a threshold of ∼11 Gpa, accompanied with the creation of nanosized (20-50 nm) fragmentation domains. We report on the observation of linear uptakes in the absorption and in the luminescence and with insignificant spectral change in ultrasmall 1-nm Si particles. We associate the gradual absorption uptake and luminescence yield with silicon-metal transformation on the surface. The insignificant change in the spectral content of the luminescence points to surface stability for particles, which are smaller than the bulk fragmentation domain. First-principles atomistic calculations yield absorption behavior that exhibits gradual uptake followed by sharp uptake at ∼9-11 Gpa. The results point to the conclusion that two-dimensional surface-like phase transformations are manifested by linear uptake in absorption and luminescence.
Original language | English (US) |
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Article number | 085417 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 85 |
Issue number | 8 |
DOIs | |
State | Published - Feb 10 2012 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics