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

Several trials were made to simulate PL spectra similar to those obtained from PL
experiments. The typical case of 100(3.5/5) SRSO/SRSN ML was investigated by
varying the three emission cross-section parameters related to three emission peaks
- peak (1), (2) and (3). The three emission peak centers obtained from experiments
were given as input.
tel-00916300, version 1 - 10 Dec 2013
Figure 5.26: Experimental and simulated PL spectra of 100(3.5/5) SRSO/SRSN ML.
Figure 5.26 shows the experimental PL spectra and three selective trials (details
in Appendix III) each resulting in dierent shapes of the simulated PL spectra. All
the curves are normalized to unity to facilitate comparison.
It can be seen from the gure that the blue curve has all the three peaks, while
in pink and green curves only two peaks may be seen. Despite the presence of three
peaks, the simulated curve (blue curve) diers from the experimental PL shape. The
impossibility to reproduce the experimental PL shape with our initial assumptions,
suggests that the three kinds of emitters are not located within SRSO sublayer.
Moreover, the position of the peak maximum in all the curves are shifted from that
of experimental curve, though the input peak positions are the same as experiments.
This shift clearly indicates the eect of optical cavity on the peak intensity, and
emission width.
Previous results of simulations on SRSO/SiO 2 MLs show the presence of two
peaks centered around 1.4 and 1.5 eV respectively (Sec. 5.5). These positions
coincide with peak (1) and (2) of SRSO/SRSN MLs. Thus, we may say that the
unattributed low energy peak (peak 1), in SRSO/SRSN MLs arises from second kind
of emitters in SRSO sublayers. Further investigations are in progress considering
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