This proposal concerns the very promising technology of tandem solar cells where hybrid halide perovskites (HHP) are used as an active layer on top of a silicon cell. Our aim is to simultaneously map, using the ID13 nano-beam, the strain, lattice orientation and halide distribution by combining XRD and XRF in pristine and aged samples. This will allow to gain fundamental insights into aging mechanisms of HHP films. After a first successful experiment in June 2023, we apply for a follow-up experiment. Samples obtained from two different deposition methods as well as films deposited on different substrates will be studied and compared. The microstructure of all above samples will be investigated in the sample plane. A second focus concerns the study of cross section samples of solar cells prepared in different conditions, in the perspective of depth-resolved studies of the HHP microstructure and halide composition.