Films minces à base de Si nanostructuré pour des cellules ...

initiated in this thesis, for the growth of SRSO layers. From the parameters analyzed
above, T d was chosen as 500°C, and r H as 26% for this set of studies.
3.4.1 Eect of power density applied on Si cathode, (P Si )
The eect of varying the P Si during the reactive co-sputtering is investigated. The
same range of power densities and time of deposition as used in method 2 were
employed.
(a) Deposition rates (r d ) and Refractive index (n 1.95eV )
tel-00916300, version 1 - 10 Dec 2013
The inuence of P Si on r d and n 1.95eV is shown in gure 3.9 with the values of sample
thicknesses at each P Si , in the inset. The time of deposition was xed to be 3600s.
There is an increase of r d with P Si , similar to the trend observed in method 2.
The deposition rate obtained by method 3 is higher than that obtained by method
1 (at T d = 500°C) and lower than that obtained by method 2.
The comparison between thicknesses
obtained from method 2 and
3 shows this decrease in r d more
evidently. For the same deposition
conditions, the addition of hydrogen
in the plasma decreases the thickness
by about 70%.
The variation of refractive index
shown in the right axis of the gure
3.9 shows a steady increase with
P Si . Besides it can be noticed that
the refractive index values have increased
signicantly as compared to
the other two methods. This can be
attributed to the combination of deposition
methods 1 and 2 that allows in achieving higher Si incorporation in the lm.
Figure 3.9: Eect of P Si on deposition rate (left
axis), refractive index (right axis), and thickness
(Inset).
(b) Fourier transform infrared spectroscopy
Figure 3.10 shows the eect of P Si as seen from Brewster and normal incidence FTIR
spectra. In all the spectra, TO 3 peak is normalized to unity for comparison.
It can be seen from the Brewster incidence spectra (Fig. 3.10a), that the LO 3
peak intensity is very low as compared to the other two methods of SRSO growth,
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