Emap

Realizing photovoltaic devices that achieve the full potential of the active materials will require a better knowledge of their working mechanism, in particular it is of paramount importance to understand which physical and chemical process govern not only their power conversion efficiency (PCE) but also their long-term stability. The interfaces between the active film and the charge transport layers (CTLs) are among the most important factor in determining both the PCE and the stability of the active materials. In particular a better study of these interfaces during the device operation is needed. For this reason, the aim of this project is to develop a new strategy to probe in operando the electronic properties of device relevant for photovoltaic application. The objective is to set up a method enabling a sub µm resolution mapping of the energy landscape using X-ray photoemission spectroscopy while the device is under operation. Via the XPS mapping of the device in operando we will access the chemical and electronic information of the active materials interfaces and their mutual interactions. This new approach relies on the nano X-ray beam available at ANTARES beamline at the synchrotron SOLEIL that will be used to perform scanning electron photoemission microscopy (SPEM). To demonstrate the generality of the developed method two types of active material relevant for solar cells, Metal halide perovskite thin film and PbS nanocrystals, will be studied. Through the direct measure of the energy landscape of these devices across the different interfaces during operation, we target to identify the bottle neck of the current performances. The consortium is made of three partners. Synchrotron Soleil will lead the project and drive the in operando SPEM part, while IPVF and INSP will bring their material and device expertise