3D imaging compositional map in one-step growth of CH 3 NH 3 PbI 3

In this report, we use atom probe tomography (APT) to produce 3D compositional maps of one-step growth of perovskite films (CH 3 NH 3 PbI 3 , MAPbI 3 . Initial studies indicate that further grain size enhancement and improved crystallinity can be achieved with the addition of Cd to these films. For MAPbI 3 films, perovskite specimens for APT were prepared and analyzed, which highlighted several challenges in the development of an APT procedure that reduces the effects of sample preparation and data collection on the fundamental morphology of the perovskite being analyzed. This optimization of the APT process, specifically for perovskite films, must be achieved before meaningful comparisons can be drawn between baseline films and those with Cd additives. We present some of the observed changes in morphology of the perovskite due to the APT process, which will enable future process optimization.