Simulation et optimisation des cellules solaires des structures Metalisolant-semiconducteur MIS a differents materiaux semiconducteurs en couche mince

Abstract

At present, silicon-based solar cells hold a dominant position in the solar cell market due to silicon's appropriate band gap matching the solar spectrum and its abundance on Earth. However, the efficiency of silicon-based solar cells has limitations, leading researchers and developers to focus on alternative approaches for further advancements in solar cell technology. Advancements in technology pave the way for cutting-edge research in the development of highly efficient and cost-effective MIS solar cells, offering promising prospects for diverse and widespread applications. The device was subjected to precise analyses using the Silvaco Atlas software, enabling a comprehensive numerical investigation into the correlation between various effects and the device's performance and reliability. In this thesis, the electrical performance of a metal-insulator-semiconductor (MIS) solar cell is evaluated. The focus is on its design with various high-k dielectrics, the objective of the study is to optimize the device's geometrical dimensions while enhancing quantum mechanical tunneling mechanisms, The thesis also provides a comprehensive comparison between the suggested solar cell structures using crystalline silicon (c-Si) and thin film silicon (hydrogenated amorphous silicon, a-Si:H).It explains the physics underlying both thin-film silicon solar cells and c-Si, emphasizing the use of diverse material selections involving high-k insulator layers. These layers play a pivotal role in overcoming the limitations of conventional SiO2, such as Al2O3, HfO2, Si3N4, TiO2, and Ta2O5. The evaluation focuses on comparing performance parameters, with a primary emphasis on conversion efficiency. Additionally, the study assesses the impact of interface state density, doping density, oxide thickness, and oxide fixed charge on the electrical outputs of the proposed MIS solar cell. As observed from the responses of the devices, MIS diodes utilizing HfO2 and Ta2O5 as the insulating layers exhibit the highest efficiency under visible light. This is attributed to the fact that these diodes enable more efficient tunneling of hot electrons due to the asymmetry of the thin energy barrier. Consequently, the insulating layer plays a crucial role in determining the tunneling probability of electrons and optimizing the conversion efficiency, as evidenced by the findings of this study.