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

The PL spectra is composed of two peaks.
ˆ The absence of emission in ML with 8 nm thick SRSO sublayer is related to
the loss of quantum connement eect.
ˆ All the emission properties investigated above are expected to be inuenced
by optical/geometrical phenomena which will be analyzed in chapter 5.
3.10 Conclusions
tel-00916300, version 1 - 10 Dec 2013
A vast analysis of SRSO monolayer and SRSO/SiO 2 multilayer congurations have
been discussed in this chapter. High refractive index in SRSO layer were obtained
by developing a new deposition approach: Reactive co-sputtering. A deep insight
on the deposition process, and the structural changes associated with each growth
method is analyzed in the rst part of this chapter. One of the major goals of this
thesis is achieved by attaining a higher density of Si-np (2.6 ± 0.5 x 10 19 np/cm 3 )
in SRSO/SiO 2 MLs than the earlier reported value of 9 x 10 18 np/cm 3 using the
reactive co-sputtering approach. It is demonstrated that the SiO 2 barrier thickness
plays an important role in the formation of size controlled Si-np. For t SiO2 lower
than or equal to 3 nm, there is no eective prevention of Si diusion. Considering
a balance between diusion barrier and carrier transport, it is estimated that the
optimal barrier thickness is around 3-3.5 nm.
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