Study of perovskite materials for direct detection of ionizing radiation

The hybrid organic-inorganic perovskite MAPbBr₃ is a promising semiconductor for X-ray detection applications. Photodetection in the energy range used in medical radiography requires a high material thickness (> 500 μm). The main objective of this work was to study the impact of solution growth conditions of millimeter thick crystals on crystal defects (strains, dislocations, inclusions, and impurities). In this context, we set up an original methodology for the rapid optimization of growth conditions based on growth mechanisms and growth kinetics monitoring. The growth conditions used enabled us to produce crystals covering a wide range of crystal defects. The impact of these defects on the electronic properties of MAPbBr₃ single crystal X-ray detector devices was studied. It appears that strains, dislocations, impurities, and nanoscopic solvent inclusions have little impact on the resistivity and sensitivity of the detectors. On the other hand, a high density of micrometric inclusions tends to significantly degrade the electronic properties of the devices. (author)