PhD thesis : Shallow defects passivation of perovskite solar cells for long term stability

Perovskite solar cells (PSC) have been developed 10 years ago with a great

success in enhancing the power conversion efficiencies to the level of silicon

technology. However, the lack of stability is one important bottleneck. At LRCS,

recent works using in situ characterization techniques underlined the involvement

of the surface point defects on the perovskite stability under humidity. Passivation

of these surface defects is therefore a key not only to enhance the power

conversion efficiency but also the stability.

This Ph-D thesis targets the development of a new device architecture including

bi-functional materials with a specific design for faster hole extraction while also

passivating surface defects, in particular iodide vacancies. The first part is

devoted to the optimization of the PSC device performances, including the new

materials developed in this project, and stability assessment of materials and

devices using ISOS protocol. Secondly, studies on in situ characterization

techniques and time-resolved spectroscopies will enable to provide direct

assessment on materials stability, degradation pathways and finally proving the

working principle of the aforementioned bifunctional layer.