The invention belongs to the technical field of photoelectric materials and devices, and particularly relates to a
perovskite thin film and a preparation method and application thereof. A
fluorine-containing
phosphazene compound is used as a ligand and is mixed with a
perovskite precursor solution composed of
lead iodide, formamidine
iodine and
cesium iodide,
spin coating is performed, the
fluorine-containing
phosphazene compound and part of formamidine cations form
hydrogen bonds, part of formamidine cations are anchored at the bottom of a
perovskite film, Cs-formamidine cations are uniformly distributed, and the perovskite film is prepared. Meanwhile, the
fluorine-containing
phosphazene compound and Pb < 2 + > form a coordinate bond, Pb < 2 + > defects are passivated, and the perovskite thin film is obtained through anti-
solvent treatment and annealing treatment. The fluorine-containing phosphazene compound interacts with the components in the perovskite precursor solution, so that the
nucleation rate of perovskite can be increased, the
crystallization rate can be slowed down, the tensile stress can be eliminated, the perovskite does not enter
crystal lattices, and the stability and
crystallinity of the film are guaranteed. The perovskite thin film can be used for an inverted
perovskite solar cell, and the performance and the stability of a device are improved.