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

(a) PL spectra vs. FG annealing. (b) PL peak maximum vs. t A .
tel-00916300, version 1 - 10 Dec 2013
Figure 4.39: (a) Eect of annealing time under forming gas on the PL spectra of
50(3.5/5) SRSO/SRSN ML and, (b) PL peak maximum with regard to time of annealing
in SRSO/SRSN MLs with dierent t SRSN . (Inset) Recalling the inuence of t SRSN on PL
from STA (1min-1000°C/N 2 ) samples.
the control over emission peak position.
Figure 4.39b shows the PL peak maximum of FG annealed 50(3.5/t SRSN ) MLs
where t SRSN varies between 1.5-10 nm. The samples were annealed sequentially
between 0.5-5h. It can be observed that the time of annealing shows minimal in-
uence on the PL intensity. Thus, 0.5h is a sucient annealing time for achieving
considerable emission.
Since T A =500°C favours exodiusion
of hydrogen, further investigations under
forming gas annealing were performed
by reducing T A , to understand
the role of hydrogen in passivation of
dangling bonds. Similar intensities were
obtained even by reducing the T A further
down to 380°C (not shown here).
It was observed in both the cases, that
the intensities for a given time increase
with t SRSN till 8 nm and decreases with
further increase in t SRSN as observed in
STA (Inset of Fig. 4.39b). Figure 4.40
shows a comparison of PL spectra between
50 and 100 patterned MLs after STA and 4.75h-FG. The emission intensity
Figure 4.40: Comparing the PL spectra
obtained after STA and 4.75h-FG annealing
processes in 50 and 100 patterned
SRSO/SRSN MLs.
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