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

Background of this thesis: A new method of depositing SRSO/SiO 2 MLs by
using hydrogen instead of the usually used oxygen was demonstrated in our laboratory
by reactive magnetron sputtering approach [Gourbilleau 00, Gourbilleau 01].
The inuence of various parameters like deposition temperature, hydrogen rate,
annealing temperatures [Portier 03, Chausserie 05] etc. on the formation of Sinanoparticles
(Si-np) and their emission,absorption and electrical properties were
investigated [Gourbilleau 09, Maestre 10]. A high density of Si-nanoparticles (10 18
np/cm 3 ) was achieved as can be seen from the EFTEM image (Fig. 1.15) and optoelectronical
investigations were performed on such layers for solar cell applications.
High values of resistance obtained till now on these kind of layers, require further
investigations and optimizations before their incorporation in a device.
tel-00916300, version 1 - 10 Dec 2013
Figure 1.15: Microstructural images of SRSO/SiO 2 superlattice showing the formation
of Si-nanoparticles [Gourbilleau 09].
In this context, the four major objectives of this thesis are:
1. Enhancing the already reported [Maestre 10] Si-np density by (i) varying the
deposition parameters and the sputtering approaches, and (ii) investigating
post fabrication processes on Si-rich Silicon oxide and silicon nitride layers in
mono- and multilayered congurations
2. Decreasing the thermal budget for the formation of Si-np.
3. Demonstrating the advantages of SRSO/SRSN MLs over SRSO/SiO 2 MLs,
with more emphasis on the absorption and emission properties.
4. Gaining insight on photoluminescence properties with experimental and theoretical
analyses, for further developments towards device integrations.
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