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

sample peak 1
(eV)
peak 2
(eV)
peak 3
(eV)
as grown 1.41 1.62 1.88
1min 1.39 1.61 1.85
16min 1.41 1.57 1.80
31min 1.43 1.56 1.80
61min 1.33 1.55 1.80
Figure 4.29: PL spectra of 100(3.5/5) ML annealed at 700°C. The peak positions obtained
after gaussian tting are indicated in the table.
tel-00916300, version 1 - 10 Dec 2013
and 1min annealed spectra. This redshift may be attributed to the formation of
bigger Si-np. Following the Delerue law [Delerue 93], this shift is linked to a size
variation of 0.3 nm. Considering the maximum value of Si diusion coecient,
D Si = 10 −18 cm 2 s −1 at this temperature [Nesbit 85], the maximum diusion length
(l = D Si x t A ) after an annealing time of 16min is estimated to 0.3 nm. Consequently,
this PL shift can be attributed to the Si diusion favouring the growth of Si-np. The
quench of the PL intensity with further annealing time can be ascribed to this growth
of the Si-np as well as the detrimental contribution of the SRSN sublayer.
4.6.3 T A =900°C:
Figure 4.30 shows the PL spectra and the peak positions of 100(3.5/5) ML annealed
at 900°C.
sample peak 1
(eV)
peak 2
(eV)
peak 3
(eV)
as grown 1.41 1.62 1.88
1min 1.41 1.59 1.80
Figure 4.30: PL spectra of 100(3.5/5) ML annealed at 900°C. The peak positions obtained
after gaussian tting are indicated in the table.
The highest emission intensity is obtained after 1min when annealed at 900 °C
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