Crystalline quality control in sequential vapor deposited perovskite film toward high efficiency and large scale solar cells

Pure vapor method shows particular advantages in preparing large-area uniform and conformal perovskite film, which can be applied to manufacture perovskite modules and fully textured perovskite/silicon tandem solar cells (TSCs). Here, we provide details on controlling the vapor-solid reaction to acquire high-quality perovskite films, including precisely adjusting vapor pressure and organic salts component, vapor-solid reaction, and post-annealing perovskite film. By employing the optimized conditions, we obtained high-quality perovskite films. Power conversion efficiency (PCE) of the inverted structure device can reach as high as 18.1% with an absorber bandgap of 1.62 eV, among the highest PCE using the vapor technique (Table S1). Significantly, the large-area perovskite film has uniform crystallinity and coverage on textured silicon. Thus, the pure vapor fabrication method of perovskite films shed light on the application of perovskite solar cells because of the potential in module and tandem solar cells.