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

(a) Emission spectra
(b) I P Lmax vs. total thickness.
Figure 5.19:
index.
Inuence of total thickness on the emission spectra, for a xed refractive
tel-00916300, version 1 - 10 Dec 2013
(b) Inuence of emission cross-section and emission width on the shape
of the PL spectra
Figure 5.20: Simulating the width and intensity
of PL spectra similar to experimental
curve using single emitter. σ emis.max = 8.78
x 10 −19 m 2 .
It can be seen in all the gures above,
that the PL peak intensity and width of
the simulated curves are dierent from
the experimentally obtained one. As
mentioned earlier, the initial parameters
are obtained from tting k(λ) and
for SRSO/SiO 2 ML under discussion,
the parameters are as follows: σ abs.max =
8.78 x 10 19 m 2 , with center at 3.21 eV
and width 0.02 eV. Using similar parameters
for emission in the case of 300 nm
thick 50(3/3) ML, further simulations
were made to obtain a PL shape similar
to that of experimentally obtained
one (Fig. 5.20). It can be seen from the
gure that the PL peak is not well resolved
with such conditions, despite varying the widths of the emission peak in the
input. In order to increase the intensity and width (about 0.3 eV) to that of experimental
curve, further simulations were made by varying the emission cross-sections
and changing the theoretical width in the program (Fig. 5.21).
It can be seen from gure 5.21 that signicant PL intensity is witnessed either
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