A. Arakcheeva, D. Chernyshov, M. Spina, L. Forró and E. Horváth
The crystal structure of the pristine (I) and aged (II) crystals of CH3NH3PbI3 (hereafter MAPbI3) hybrid organic-inorganic lead iodide has been studied at 293 K with high-precision single-crystal X-ray diffraction using a synchrotron light source. We show that (I) and (II) are characterized by an identical tetragonal unit cell but different space groups: I422 for (I) and P42212 for (II). Both space groups are subgroups of I4/mcm, which is widely used for MAPbI3. The main difference between (I) and (II) comes from the difference in hydrogen bonds between the MA+ cation and the PbI3 framework which is the direct consequence of H2O insertion in the aged crystal (II).
New technologies launch novel materials; besides their performances in products, their health hazards must be tested. This applies to the lead halide perovskite CH3NH3PbI3 as well, which offers fulgurate applications in photovoltaic devices. We report the effects of CH3NH3PbI3 photovoltaic perovskites in human lung adenocarcinoma epithelial cells (A549), human dopaminergic neuroblastoma cells (SH-SY5Y) and murine primary hippocampal neurons by using multiple assays and electron microscopy studies. In cell culture media the major part of the dissolved CH3NH3PbI3 has a strong cell-type dependent effect. Hippocampal primary neurons and neuroblastoma cells suffer a massive apoptotic cell death, whereas exposure to lung epithelial cells dramatically alters the kinetics of proliferation, metabolic activity and cellular morphology without inducing noticeable cell death. Our findings underscore the critical importance of conducting further studies to investigate the effect of short and long-term exposure to CH3NH3PbI3 on health and environment.
We report the synthesis of Methylammonium Lead Iodide (CH3NH3PbI3) nanowires by a low temperature solution processed crystallization using a simple slip-coating method. The anisotropic particle shape exhibits advantages over nanoparticles in terms of charge transport under illumination. These results provide a basis for solvent-mediated tailoring of structural properties like the crystallite size and orientation in trihalide perovskite thin films, which, once implemented into a device, may ultimately result in an enhanced charge carrier extraction.