Lead halide perovskites, and particularly hybrid organic-inorganic materials based on formamidinium, possess exceptional optoelectronic properties that have been intensively exploited for photovoltaic (PV) applications. Within this family of materials, FAPbBr3 is also particularly promising for X-ray detection in medical applications. However, this technology requires the ability to deposit thick layers (>100 µm) over large areas. CEA-LITEN has developed an innovative approach for depositing inorganic perovskites using close-space sublimation (CSS), which meets these criteria. Very recently, it has been shown that it is possible to deposit FAPbBr3 using this method, marking a world first.

However, the growth mechanisms of FAPbBr3 and hybrid perovskites via CSS are largely misunderstood, and the possibilities offered by this deposition method are yet to be fully explored. Furthermore, these results are also extremely promising for PV applications, as similar growth is expected by substituting Br to form FAPbI3.

This thesis aims to (i) determine and optimize the growth conditions via CSS for FAPbBr3 layers, (ii) understand the growth mechanisms of FAPbBr3 through advanced characterizations (in-situ and ex-situ), and (iii) optimize devices for X-ray detection. The extension of this work to FAPbI3 for PV applications is also anticipated. The novelty of this approach and the potential to address multiple applications offer prospects for publications and patents.