High-Efficiency Inorganic Perovskite Solar Cell in a Wide Additive-Processing Window

The crystallization quality of a perovskite thin film determines the photovoltaic performance of its devices to a certain extent, so the deposition of a high-quality perovskite thin film becomes the key to preparing high-performance perovskite solar cells. Herein, we provide a wide additive-processing window to obtain high-quality perovskite films, thus achieving significant photovoltaic performance. We imported dimethylammonium iodide (DMAI), which serves as a crystal growth additive by optimizing the crystallization process, which extended the aging time of the precursor solution. By optimizing the content of the additive and the aging time of the precursor solution to control the crystal growth and final grain morphology, we achieved a wide additive-processing window with a concentration of 0.3–0.9 M and an aging time of 2–16 h. The results show that the introduction of additive dimethylammonium iodide improves the film quality of perovskites by forming an intermediate, reducing the surface defects, and increasing the carrier lifetime of the CsPbI2+xBr1–x film. CsPbI2+xBr1–x-based inorganic perovskite solar cells (IPSCs) exhibits a high PCE of up to 14.9% and a high Voc of up to 1.28 V. More importantly, the performance has possessed such a region with high fill factor (FF) and PCE in all Cs-based IPSCs, providing a wide range of additive-processing window and facilitating industrial applications.