*2.1.1.2. Laser beam parameters*

('washed') nanoparticles at the same time from the substrate because the separation distance,

**Figure 4.** SEM micrographs of ZnO nanoparticles deposited in a 13 Pa O2 flux on a Si substrate. Target‐substrate sepa‐ ration distance was of 3 cm (a), 4 cm (b) or 5 cm (c). Inset: water droplet in static mode and the measured CA.

For target‐substrate separation distances longer than plasma length, the species in plasma lost their kinetic energy by collisions with other species and gas molecules from the ambient and

A very low number of pulses (generally under 100) generate a deposition of nano/micro‐ particles on the substrate surface. Slightly increasing the number of pulses produces islands of material. Upon increasing the number of pulses, the substrate is covered by a continuous

**Figure 5.** Typical transmission spectra recorded in the case of PLD simple ZnO films (solid curve), and films covered with Au nanoclusters after ablation by 100 pulses from a Au target (dashed curve). (Reproduced with permission from

in this case, was too small (in any case, smaller than the plasma length).

8 Applications of Laser Ablation - Thin Film Deposition, Nanomaterial Synthesis and Surface Modification

therefore the ablation rate was significantly lower than for 4 cm.

*2.1.1.1.3. Influence of number of pulses*

thin film [15].

Ref. [15]).
