| dc.description.abstract | We analyzed the amorphous–crystalline morphological transformation of a-Si:H films caused by applying an annealing treatment to
the Al/a-Si:H system at low temperature (250 C) during several hours. Optical micrographs show the growth of Si nuclei formed on the
amorphous matrix and also a t2 dependence of the average area of these crystalline grains, which suggest a bidimensional growth. Also
was investigated the growth kinetics in the lc-Si:H films considering the annealing time dependence of the crystalline fraction. The application
of the Avrami equation showed a good description of the experimental results during this morphological and structural transformation.
The low growth velocity measured Vg = 7.2 · 10 3 lm/min is a direct consequence of the low annealing temperature applied
(250 C), which reduces the silicon diffusion across the interface Al/a-Si:H. Infrared reflectance measurements show a relative diminishing
of the intensity for Si–H wagging mode with annealing time, suggesting effusion of hydrogen to the surface of the lc-Si:H films.
2005 Elsevier B.V. All rights reserved. | |
