Halide perovskite (HaP) solar cells have reached ~23% conversion efficiency in the 6 years since serious research began in the field. In spite of the enormous research being carried out on these cells, there are still many outstanding questions. One of these is: What is the operating mechanism that dominates in HaP cells? By careful choice of experimental conditions and procedures, necessary because of the electron beam sensitivity of the materials to the electron beam, we succeeded to use electron beam-induced current (EBIC) to understand the photovoltaic operating mechanisms of the cells. The mechanisms are found to be dependent on the specific HaP used, while also the metal contact can affect the nature of the cell. As part of these studies we demonstrate effects of both the electron beam and of light on both the HaP itself and on cells made using the HaPs.
