TITLE:
Determination of the Nucleation Region Location of Si Nano-Crystal Grains Prepared by Pulsed Laser Ablation through Changing Position of Substrates
AUTHORS:
Zechao Deng, Qingshan Luo, Ziqiang Hu, Xiaolong Zhang, Xuecheng Ding, Lizhi Chu, Yinglong Wang
KEYWORDS:
Nucleation Region Location; Si Nano-Crystal Grains; Pulsed Laser Ablation
JOURNAL NAME:
Journal of Surface Engineered Materials and Advanced Technology,
Vol.3 No.2,
April
30,
2013
ABSTRACT: To determine the nucleation region
location of Si nano-crystal grains, pulsed laser ablation of Si target is performed in Ar gas of 10 Pa at room temperature with laser fluence of 4 J/cm2,
the substrates are located horizontal under ablation spot with different
vertical distance. Characteristics of deposited grains are described by scanning
electron microscopy, Raman scattering and X-ray diffraction spectra, the
results indicate that deposition position on substrates in a certain range is relative
to target surface, which changes according to different vertical distance of
substrates to ablation spot. Grain size increasedat first and then decreased with
addition of lateral distances to target in the range, but the integral
distribution rule was independent of position of substrates. Combining with
hydrodynamics model, nucleation division model, thermokinetic equation and flat
parabolic motion, spatial nucleation region location of grains is obtained
through numerical calculations, which is 2.7 mm-43.2 mm to target surface along the plume
axis.