Nucleation and morphology control for efficient perovskite solar cells via hot-air quenching process

Despite of promising aspects of planar perovskite solar cells, there are several problems limiting their high power conversion efficiency (PCE). This device structure without meso-scaffold simplify a fabrication process, however, it has proven to be challenging due to the complex crystal-growth behavior of perovskite films. Various sizes of nuclei can form different grain sizes and sometimes form pinholes between them. Thus, it is important to control the nucleation of perovskite layer carefully. We introduced swift nucleation in planar CH3NH3PbI3-xClx perovskite devices to control morphology of perovskites. The champion device showed 19.0% of power conversion efficiency with the average power conversion efficiency of 17.6%.