Abstract
The dynamics of nanoparticle formation by laser ablation into background gases are revealed by gated-ICCD photography of photoluminescence (PL) and Rayleigh-scattering (RS) from gas suspended nanoparticles. These techniques, along with gated-spectroscopy of PL from isolated, gas-suspended nanoparticles, permit fundamental investigations of nanomaterial growth, doping, and luminescence properties prior to deposition for thin films. Using the time-resolved diagnostics, particles unambiguously formed in the gas phase were collected on TEM grids. Silicon nanoparticles, 1-10 nm in diameter, were deposited following laser ablation into 1-10 Torr Ar or He. Three in situ PL bands (1.8, 2.6, 3.2 eV) similar to oxidized porous silicon were measured, but with a pronounced vibronic structure. Structureless photoluminescence bands were reproduced in the films (2.1, 2.7, 3.2 eV) only after standard annealing. The ablation of metal zinc into Ar/O2 is also reported for the preparation of < 10 nm diameter hexagonal zincite nanocrystals. The particles were analyzed by bright field and Z-contrast TEM and high resolution EELS.
| Original language | English |
|---|---|
| Pages (from-to) | 359-364 |
| Number of pages | 6 |
| Journal | Materials Research Society Symposium - Proceedings |
| Volume | 536 |
| State | Published - 1999 |
| Event | Proceedings of the 1998 MRS Fall Meeting - The Symposium 'Advanced Catalytic Materials-1998' - Boston, MA, USA Duration: Nov 30 1998 → Dec 3 1998 |