Correlative Imaging of Ageing Processes of Photovoltaic Materials – CLEOPATRA

Halide perovskites have attracted a strong interest in the photovoltaic community as a result of their high power conversion efficiency and the solid opportunity to realize low-cost and industry-scalable technology. One of the main drawbacks preventing the commercialisation of such technologies is the long term stability of the cells. Researchers nowadays are focusing on improving the device architecture where interface properties play a crucial role on both final performances and durability. However, questions regarding the physics behind the modified interfaces such as the completeness of the coverage of the passivating layers, the effects on carrier extraction and the influence on cells stability are still open. Due to the complexity of the system and the high range of open issues, often traditional macroscopic characterisation tools are not able to elucidate the physical and chemical processes underlying the working principles of solar cells. This project aims at understanding the fundamental properties of the interfaces of emerging photovoltaic technologies by the use of a characterisation approach based on imaging methods. A multi-technique and multi-scale characterisation platform will be employed to investigate and locally cross-link chemical, electrical and optical interfacial properties of photovoltaic materials. A systematic and quantitative study of physical properties and chemical compositions will be performed via operando experiments. The large number of experimental techniques used to characterise the materials will lead to the acquisition of big multi-dimensional datasets that will be then treated and correlated by employing artificial intelligence and machine learning methods. Thanks to machine learning methods, I will correlate the evolution of several physical and chemical parameters to different stresses conditions and build detailed physical models of the dynamics of the optical and compositional properties of photovoltaic materials and devices