Planar Laser-Induced Fluorescence Diagnostics of Pulsed Laser Ablation of Silicon

1995 ◽  
Vol 388 ◽  
Author(s):  
D. G. Goodwin ◽  
D. L. Capewell ◽  
P. H. Paul
Keyword(s):  
Laser Ablation ◽  
Ground State ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Laser Induced Fluorescence ◽  
Time Sequence ◽  
Planar Laser Induced Fluorescence ◽  
Fluorescence Diagnostics ◽  
Planar Laser ◽  
Background Gas

AbstractPlanar laser-induced fluorescence has been used to acquire time sequence images of ground-state, neutral Si and SiO during laser ablation of an Si target in vacuum and in the presence of a background gas at a fluence of 3-4 J/cm2. the SiO images, taken in air, strongly suggest that the observed SiO is created through reaction of silicon with oxygen at the contact front as the plume expands.

Effect of Non-equilibrium Pulsed Ejection of Si Species into Background Gas on the Formation of Si Nanocrystallite and Nanocrystal-film

2011 ◽  
Vol 1305 ◽  
Author(s):  
Ikurou Umezu ◽  
Shunto Okubo ◽  
Akira Sugimura
Keyword(s):  
Laser Ablation ◽  
Film Growth ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Hydrogen Gas ◽  
Gas Pressure ◽  
Spatial Confinement ◽  
The Individual ◽  
Background Gas ◽  
Non Equilibrium

ABSTRACTThe Si nanocrystal-films are prepared by pulsed laser ablation of Si target in a mixture of helium and hydrogen gas. The total gas pressure and hydrogen partial gas pressure were varied to control structure of nanocrystal-film. The surface of Si nanocrystallite was hydrogenated and degree of hydrogenation increased with increasing hydrogen partial gas pressure. The aggregate structure of nanocrystal-film depended on both the total gas pressure and the hydrogen partial gas pressure. The former and the latter alter spatial confinement of Si species during deposition and the surface hydrogenation of individual nanocrystal, respectively. Spatial confinement increases probability of collision between nanocrystals in the plume. While, surface hydrogenation prevents coalescence of nanocrystals. The individual or aggregated nanocrystals formed in the plume reach the substrate and the nanocrystal-film is deposited on the substrate. The non-equilibrium growth processes during pulsed laser ablation are essential for the formation of the surface structure and the subsequent nanocrystal-film growth. Our results indicate that the structure of nanocrystal-film depends on the probabilities of collision and coalescence between nanocrystals in the plume. These probabilities can be varied by controlling the total gas pressure and the hydrogen partial gas pressure.

Size classification of Si nanoparticles formed by pulsed laser ablation in helium background gas

1999 ◽  
Vol 69 (S1) ◽  
pp. S243-S247 ◽  
Author(s):  
T. Makino ◽  
N. Suzuki ◽  
Y. Yamada ◽  
T. Yoshida ◽  
T. Seto ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Size Classification ◽  
Si Nanoparticles ◽  
Background Gas

Non-equilibrium Growth Processes of Porous TiO2 Nanocrystal-films during Pulsed Laser Ablation

2013 ◽  
Vol 1497 ◽  
Author(s):  
Ikurou Umezu ◽  
Nobuyasu Yagi ◽  
Akira Sugimura ◽  
Takehito Yoshida
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Hierarchical Structures ◽  
Pulsed Laser Ablation ◽  
Rutile Phase ◽  
Gas Pressure ◽  
Target Distance ◽  
Structural Formation ◽  
Background Gas ◽  
Non Equilibrium

ABSTRACTWe performed pulsed laser ablation of titanium dioxide (TiO2) target in O2 background gas. Effects of background gas pressure and substrate target distance on the structure of deposited films are clarified. The hierarchical structures are observed when we change scale of observation. The film deposited on the substrate is composed of primary nanocrystal and secondary porous-aggregated-nanostructures. The primary nanocrystal changes from anatase to rutile phase with increasing background gas pressure or substrate target distance. The porosity of secondary aggregated structure increases with increasing background gas pressure or substrate target distance. The similarity between the effects of background gas and substrate target distance indicates that confinement of the plume between target and substrate is important for structural formation. The non-equilibrium aggregation processes of nanocrystals in the plume and on the substrate are essential for the hierarchical structure of the nanocrystal film.

Annealing effects on structures and optical properties of silicon nanostructured films prepared by pulsed-laser ablation in inert background gas

2001 ◽  
Vol 90 (10) ◽  
pp. 5075-5080 ◽  
Author(s):  
Toshiharu Makino ◽  
Yuka Yamada ◽  
Nobuyasu Suzuki ◽  
Takehito Yoshida ◽  
Seinosuke Onari
Keyword(s):  
Optical Properties ◽  
Laser Ablation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Nanostructured Films ◽  
Annealing Effects ◽  
Background Gas
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