scholarly journals Final report submitted to the US Department of Energy (8/15/96 to 8/14/00). [Experimental and theoretical investigation of dual laser ablation for stoichiometric large-area multi-component film growth]

2000 ◽  
Author(s):  
Sarath Witanachchi ◽  
Pritish Mukherjee
Keyword(s):  
Laser Ablation ◽  
Theoretical Investigation ◽  
Film Growth ◽  
Department Of Energy ◽  
Final Report ◽  
Large Area ◽  
The Us ◽  
Dual Laser

Evidence for the physical basis and universality of the elimination of particulates using dual-laser ablation. I. Dynamic time-resolved target melt studies, and film growth of Y2O3 and ZnO

2002 ◽  
Vol 91 (4) ◽  
pp. 1828-1836 ◽  
Author(s):  
Pritish Mukherjee ◽  
Shudong Chen ◽  
John B. Cuff ◽  
Palanikumaran Sakthivel ◽  
Sarath Witanachchi
Keyword(s):  
Laser Ablation ◽  
Film Growth ◽  
Physical Basis ◽  
Time Resolved ◽  
Dynamic Time ◽  
Dual Laser

scholarly journals Highly Ionized Carbon Plasma Generation by Dual-Laser Ablation for Diamond-Like Carbon Film Growth

2000 ◽  
Vol 617 ◽  
Author(s):  
S. Witanachchi ◽  
A. M. Miyawa ◽  
P. Mukherjee
Keyword(s):  
Laser Ablation ◽  
Film Growth ◽  
Carbon Film ◽  
Plasma Temperature ◽  
Optical Emission ◽  
Carbon Films ◽  
Rapid Expansion ◽  
Laser Ablation Process ◽  
Carbon Plasma ◽  
Dual Laser

AbstractCarbon plasmas produced by excimer laser ablation show a low ionization yield of about 8-10%. The coupling of a second CO2laser pulse into the plasma in the dual-laser ablation process significantly increases the plasma temperature and the ionization. The resulting rapid expansion of the plasma gives rise to high ion kinetic energies and broader ion expansion profiles [1]. Optical emission spectroscopy and an ion probe have been used to investigate the dynamics of the carbon plasma. Single and dual-laser ablated carbon plumes have been deposited on DC-biased silicon substrates to form amorphous carbon films. The diamond-like behavior of these films was studied by Raman spectroscopy. The Raman spectra were deconvolved to gauge the effect of the density and the energy of ions on the formation of diamond-like sp3 -bonded carbon (DLC) films. The advantage offered by the dual-laser process for the growth of DLC films is discussed.

Dual‐laser ablation for particulate‐free film growth

1995 ◽  
Vol 66 (12) ◽  
pp. 1469-1471 ◽  
Author(s):  
S. Witanachchi ◽  
K. Ahmed ◽  
P. Sakthivel ◽  
P. Mukherjee
Keyword(s):  
Laser Ablation ◽  
Film Growth ◽  
Free Film ◽  
Dual Laser

Room Temperature Growth of Conducting ZnO Films

1997 ◽  
Vol 485 ◽  
Author(s):  
S. Witanachchi ◽  
Y. Ying ◽  
A. M. Miyawa ◽  
P. Mukherjee
Keyword(s):  
Laser Ablation ◽  
Room Temperature ◽  
Zno Films ◽  
Large Area ◽  
Temperature Growth ◽  
Glass Substrates ◽  
Laser Ablation Process ◽  
Ambient Oxygen ◽  
Zn Ions ◽  
Dual Laser

AbstractSingle and dual-laser ablation techniques have been used to grow conductive ZnO films at room temperature by ablating a Zn metal target in oxygen ambient. The emission spectroscopy of the material plumes shows a significant presence of oxygen ions and Zn ions in the dual-laser ablated plume. Furthermore, dual-laser ablated plumes expanded rapidly in the radial direction resulting in large-area uniform films. The electrical properties of the films deposited on glass substrates depend critically on the ambient oxygen pressure. Conductivities of the order of 103 (ω.cm)-1 have been obtained for films deposited at room temperature by the dual-laser ablation process.

Preparation of Large Area Cross-Sectional Tem Specimen of Semiconducting Heteroepitaxial Materials

1991 ◽  
Vol 254 ◽  
Author(s):  
M. Tamura ◽  
S. Aoki
Keyword(s):  
Sample Preparation ◽  
Film Growth ◽  
General Information ◽  
One Dimension ◽  
Main Principle ◽  
Large Area ◽  
Cross Sectional ◽  
Growth Modes ◽  
Present Technique ◽  
Grinding And Polishing

AbstractThe sample preparation procedures which enable us to observe large areas over a few tens of microns in one-dimension of semiconducting heteroepitaxial materials are described. The main principle involves the careful grinding and polishing of samples. In these procedures, another side thinning of the specimen after finishing initial side polishing is carried out using a sample platform by hand throughout all of the following steps. It is shown that for some typical examples of heteroepitaxial films general information concerning the film growth modes and structures, as well as the defect morphologies and natures introduced during growth can be effectively obtained by using the present technique.

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.

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