Abstract
Time-resolved photoluminescence (PL) spectra are reported for gas-suspended 1-10 nm diameter SiOx particles formed by laser ablation of Si into 1-10 Torr He and Ar. Three spectral bands (1.8, 2.5 and 3.2 eV) similar to PL from oxidized porous silicon were measured, but with a pronounced vibronic structure. Particle size and composition were determined with Z-contrast transmission electron microscopy imaging and high resolution electron energy loss spectroscopy linescans of individual nanoparticles. Maximized violet (3.2 eV) PL from the gas-suspended nanoparticles was correlated with an ex situ SiO1.4 overall particle stoichiometry. Cryogenically-collected gas-suspended nanoparticles produced web-like-aggregate films exhibiting very weak PL. Standard anneals restored strong PL bands without vibronic structure, but otherwise in agreement with the PL measured from the gas-suspended nanoparticles.
| Original language | English |
|---|---|
| Pages (from-to) | 438-440 |
| Number of pages | 3 |
| Journal | Applied Physics Letters |
| Volume | 73 |
| Issue number | 4 |
| DOIs | |
| State | Published - 1998 |