Le transistor est la brique élémentaire des circuits intégrés présents dans tous les appareils électroniques. Années après années l’industrie de la microélectronique a amélioré les performances des circuits intégrés (rapidité, consommation énergétique) en réduisant les dimensions du transistor. De nos jours, en plus de la réduction de la taille du transistor d’autres techniques permettent de soutenir cette croissance: ce sont les « booster » technologiques. Les contraintes mécaniques ou encore le remplacement du Silicium par d’autres matériaux tels que germanium (Ge) et les matériaux semi-conducteurs de type III-V sont des exemples de booster technologiques. Grâce à la modélisation numérique, cette thèse propose d’étudier les effets de booster technologiques sur les performances électriques de la future génération de transistors. / The transistor is the elementary brick of Integrated circuits found in all electronic devices. Years after years the microelectronic industry has enhanced the performances of integrated circuits (speed and energy consumption) by downscaling the transistor. Nowadays besides the transistor’s downscaling, other techniques have been considered to maintain this growth: they are called technological boosters. Mechanical strain or new material, such as germanium (Ge) and III-V semiconductors, to replace Silicon are example of technological boosters. By the means of numerical quantum simulations and modeling, this these work propose a study of the effect of technological boosters on the electric performances of the next generation of transistors.

<div> Challenges in the semiconductor industry have resulted in the discovery of a plethora of promising materials and devices such as the III-Vs (InGaAs, GaSb, GaN/InGaN) and 2D materials (Transition-metal dichalcogenides [TMDs]) with wide-ranging applications from logic devices, optoelectronics to biomedical devices. Performance of these devices suffer significantly from scattering processes such as polar-optical phonons (POP), charged impurities and remote phonon scattering. These scattering mechanisms are long-ranged, and a quantitative description of such devices require non-local scattering calculations that are computationally expensive. Though there have been extensive studies on coherent transport in these materials, simulations are scarce with scattering and virtually non-existent with non-local scattering. </div><div> </div><div>In this work, these scattering mechanisms with full non-locality are treated rigorously within the Non-Equilibrium Green's function (NEGF) formalism. Impact of non-locality on charge transport is assessed for GaSb/InAs nanowire TFETs highlighting the underestimation of scattering with local approximations. Phonon, impurity scattering, and structural disorders lead to exponentially decaying density of states known as Urbach tails/band tails. Impact of such scattering mechanisms on the band tail is studied in detail for several bulk and confined III-V devices (GaAs, InAs, GaSb and GaN) showing good agreement with existing experimental data. A systematic study of the dependence of Urbach tails with dielectric environment (oxides, charged impurities) is performed for single and multilayered 2D TMDs (MoS2, WS2 and WSe2) providing guideline values for researchers. </div><div><br></div><div>Often, empirical local approximations (ELA) are used in the literature to capture these non-local scattering processes. A comparison against ELA highlight the need for non-local scattering. A physics-based local approximation model is developed that captures the essential physics and is computationally feasible.</div>