Facile all-dip-coating deposition of highly efficient (CH)NPbI Cl perovskite materials from aqueous non-halide lead precursor.

Sequential all-dip-coating deposition of (CH)NPbI Cl perovskite materials was conducted in an aqueous nonhalide lead precursor solution, which was followed by that in a (CH)NI and (CH)NCl mixed solution as part of a facile, cost-effective, and environmentally benign manufacturing process for high-efficiency perovskite solar cells. The (CH)NPbI Cl perovskite layers deposited the proposed process were constructed with a Cl/I ratio below ∼3%, indicating the partial insertion of Cl into the (CH)NPbI perovskite lattice. The amount of Cl inserted was readily modulated by varying the (CH)NCl concentration in the (CH)NI/(CH)NCl mixed solution. Incorporating a small amount of Cl led to significant improvements in the surface morphology and crystallinity of the perovskite layer as compared to (CH)NPbI fabricated under the same conditions. The perovskite solar cell devices with these (CH)NPbI Cl perovskite films exhibited superior device performances and stabilities, resulting in an outstanding power conversion efficiency of ∼15.3%. Results show that the fabrication of (CH)NPbI Cl perovskite material with an aqueous nonhalide lead precursor is more efficient than conventional spin-casting approach with detrimental organic solvents.