Combined nanoscale strain and halide composition mapping in perovskite layers deposited on silicon for tandem solar cells.

This proposal concerns halide perovskites used as upper active layer on top of silicon for tandem solar cells. Our aim is to simultaneously map, using the ID13 nano-beam, the microstructural properties of perovskite layers, as well as the halide composition by combining XRD and XRF. The objective is to gain fundamental insights into the processes governing the microstructure of pristine and aged perovskite layers, which is of the outmost importance for further improvement of the performances of tandem cells. State-of-the-art perovskite layers deposited on flat silicon and silicon with pyramid-textured surfaces, will be studied. The influence of the deposition technique on the microstructure of pristine layers will be investigated (slot die coating vs. physical vapor deposition), as well as the effect of aging by probing slot die deposited layers exposed to controlled illumination. Finally, cross-section samples obtained by cryo-FIB will be used to probe along the layer’s depth.