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Abstract :
[en] Chalcogenides exhibit a wide range of physical properties making them very at-
tractive for future electronic and thermoelectric applications. Their layered nature
allows them to be easily isolated in layers just few atoms thick. The new exciting
properties arising when reducing the dimensionality of materials have motivated
the scientific community to investigate these materials. In this thesis, we theoret-
ically investigate the structural, electronic and vibrational properties of two fam-
ilies of chalcogenides : mono-chalcogenides and Transition Metal Dichalcogenides
(TMDs). This theoretical investigation was conducted with the powerful predictive
capacities of Density Functional Theory and the Temperature Dependent Effec-
tive Potential method. We investigate the excellent thermoelectric properties of
SnSe, the nature of the phase transition occurring with temperature and highlight
the link between the two. We study the structural transformation in few-layer
SnSe and SnS, and its effect on vibrational properties. The finite temperature
behavior of the vibrational properties of a selection of TMDs in their bulk form
is presented, and their thermal conductivity is compared. We study the effects of
heterostructuring by alternatively stacking different TMDs. We show a contrac-
tion of the Van der Waals gap when TMDs with different chalcogens are combined.
We also explain the suppression of the charge density wave instability in certain
heterostructures. Finally we investigate the transfer of charge and the electronic
properties of heterostructures of mono and di-chalcogenides called ferecrystals.