Long-Term Durability of Bromide-Incorporated Perovskite Solar Cells via a Modified Vapor-Assisted Solution Process

Organometallic halide perovskite materials as a potential light absorber have attracted much attention in the field of third-generation photovoltaics. The low stability and durability of perovskites have outstanding effects on their optoelectronic properties, which causes a big obstacle in scaling up these impressive solar cells. Here, we introduce the fabrication of efficient organometallic halide perovskite devices by a simple and low-temperature vapor-assisted solution process using methylammonium bromide (MABr) to construct pinhole-free and uniform perovskite thin films. The results show that using MABr as a second evaporated precursor in the fabrication of the perovskite layer loads the Br atoms into the final MAPbI(3-x)Br(x) structure in which higher open-circuit voltage, short-circuit current density, and fill factor are achieved compared to the pure MAPbI(3) perovskite structure. Perovskite solar cells based on the as-prepared films show a high power conversion efficiency of 15.34%, which presents an interesting 50 days of durability.