Cellules solaires pérovskite hybrides à base de formamidinium-césium (FA-Cs) : Simulation et analyse expérimentale

In a short period, the hybrid organic-inorganic perovskite solar cells demonstrated a higher power conversion efficiency (PCE) than other solar cells. However, the stability and toxicity issues restrict from entering into commercialization. Therefore, this thesis aims to tackle both mentioned issues to enhance the solar cell photovoltaic (PV) performance from a laboratory perspective. Especially, doping with cesium and bromide into formamidinium lead iodide (FAPbI3) perovskite to improve the phase stability. Also, using Copper and Bismuth is particularly relevant to diminish the lead content in the active layer while reducing the intrinsic limitations of FAPbI3 devices in terms of stability and defect states. Additionally, the FAPbI3 perovskite structure was modeled using Materials Studio software, and the numerical simulation of various solar cell models developed using SCAPS-1D software, which provides a physics insight into its operation. Both experimental and theoretical analyses allow us to understand the charge generation mechanism and the limitations of device current-voltage characteristics based on different doping/interlayer strategies over the perovskite composition to improve the device performance. The structural and mechanical stability behavior of the α-phase FAPbI3 unit cell was systematically investigated based on all the twelve possible orientations of organic FA cation inside the inorganic cubic cage. The lattice parameters, iodine shift, elastic-constant values, electron density difference (EDD), and Mulliken charge analysis provide factual justifications to understand the mechanism.