Picosecond dynamics of photoexcited carriers in silicon nanocrystal/Si3N4 superlattices: Presence of K-0 centers
2015
Abstrakt
We report in detail on the picosecond dynamics of photoexcited charge carriers in size-controlled silicon nanocrystals in silicon nanocrystal/Si3N4 superlattices. The samples were prepared using plasma enhanced chemical vapor deposition and subsequent thermally induced phase separation.
The pump and probe transmission technique was used to monitor directly the initial (picosecond) carrier dynamics. The transient transmission signal (decay time about 2 ps) was found to be independent of the nanocrystal size, pump pulse intensity and wavelength from the interval 400 to 700 nm.
The signal is attributed to the dynamics of photoexcited carriers captured on the K-0 centers in Si3N4. (C) 2015 AIP Publishing LLC.