Étude de la formation d'agrégats de défauts ponctuels et d'impuretés de lithium dans le silicium cristallin par méthodes Monte-Carlo cinétique
This thesis, including three scientific articles, split in two parts: ``Theoretical, Methodology and Algorithmic'' and ``Simulations, Analysis and Results'', concerning our results on atomistic numerical methods as well as their application on systems based on crystalline silicon.  The first part consisting of three chapters introducing the problematic about activated process followed by the use of the transition state theory to address this thematic. Then we will discuss the key point of the kinetic Monte-Carlo method, with a review of advances that has been made so far. The second chapter presents the kinetic Activation-Relaxation Technique (kART), an off-lattice kinetic Monte-Carlo algorithm with on-the-fly catalogue building based on the Activation-Relaxation Technique nouveau (ARTn). ARTn is a powerful open-ended saddle search method, handling the long-range elastic effect completely. The first part ends with our first article, which addresses in detail the recent algorithmic additions, from the five past years, made to kART.   It is followed by the second part, consisting of three chapters, whose chapter four is a contextualization of: basic properties of silicon such as its crystalline phases; a definition of the various types of points defects existing in crystals; a presentation of interatomic potentials used; an introduction about the random telegraphic signals (RTS) noise; binary phases of c-LiSi; a discussion of the quick amorphisation of the c-Si anode during the first lithiation. Chapter 5 explains the aggregation and details pathways of diffusion of intrinsic defects in crystalline silicon. Jay \textit{et al.}~\cite{Jay2017} work, with our complete and precise preliminary results, led to a better understanding of random telegraphic signal (RTS) noise observed in highly damage semiconductors by correlating the oscillatory motion of vibrational states of small clusters of intrinsic defects present in these materials. Chapter 6 characterized energy states of the various configurations of systems with low concentration of lithium impurity in crystalline silicon. Thanks to kART, we show that impurities of lithium weakly interact, formed clusters shortly dissociate due to a non-negligible configuration entropy contribution.
Stability Aggregation Point defects Impurity Silicon Kinetic Monte Carlo