Analyse et optimisation des paramètres photovoltaïques dans les cellules solaires à simple jonction, tandem et triple-jonction en technologie couches minces de silicium.

Abstract

Thin-film silicon solar cells are a low-cost technology and an alternative to traditional wafer-based crystalline solar cells. This work focused on the analysis and optimization of photovoltaic parameters of thin-film silicon solar cells in order to obtain higher efficiency. One of the approaches to improve efficiency is to develop solutions for enhancing the open circuit voltage Voc. For our numerical simulations, AMPS-1D software, which was developed by the group of Prof. Fonash from Penn state University and, wxAMPS2 and wxAMPS3, which were designed at the University of Illinois at Urbana Champaign, in collaboration with Nankai University of China, were used. Firstly, optical and electrical properties of the layers, p-i interface (larger band gap of p-doped window layer, inserting buffer layer) and the active layer (i-layer) thickness in amorphous hydrogenated silicon (a-Si:H) and microcrystalline hydrogenated silicon (μc-Si:H) p-i-n single-junction solar cells have been optimized. Their efficiency, however, remains low and limited. In order to achieve higher and stabilized efficiency for a-Si:H solar cells, multijunction approach is used. We simulated and optimized a tandem micromorph solar cell (a-Si:H/μc-Si:H) and a triple-junction solar cell (a-Si:H/μc-Si:H/μc-Si:H). In multijunction structure, an optimized tunnel recombination junction (TRJ) between subcells and a carefull current matching are required. Simulation results show that the structures achieved higher efficiency thanks to an improvement of Voc due to a better use of the solar spectrum.