Laser ablation deposition of silicon nanostructures

Pulsed laser deposition with an off-axis geometry in a low-pressure argon a mbient was used to produce films of nanosized silicon clusters or crystalli tes. Size selection was achieved by the distance of the deposit from the ta rget. The local film structure and the crystallite size of the films were s tudied as a function of the distance from the target using micro-Raman spec troscopy. The nanocrystal size on the off-axis placed substrate varied in t he range 1...5 nm, increasing with increasing distance from the target; thi s made it possible to achieve size selection of the nanocrystals. The surfa ce morphology of the deposits was studied using scanning electron microscop y. Room temperature photoluminescence of the samples with 514.5 nm excitati on was rather weak. Silicon 2p core photoelectron spectra showed the existe nce of a silicon dioxide layer on the surface of the nanoparticles.