▎ 摘　　要

NOVELTY - Perovskite precursor composition comprises perovskite precursors and a salt of a cationic imidazole derivative in which at least one of two nitrogen atoms in the imidazole ring is linked to a carbon chain bearing a cyano (-Ce=N) group, where the cationic imidazole derivative has (I) or (II). USE - Perovskite precursor composition (all claimed). ADVANTAGE - The composition has exhibited a suitable band gap, high absorption coefficients, long charge mobility, and long diffusion length, combined with easy and low-cost processing methodologies, and can improve the efficiency and stability of PSCs, has been utilized as an effective large cation additive to stabilize the PSCs with high PCE, enhancing the stability owing to formation the of additional hydrogen bonds, has improved the quality of the perovskite film, increase the hydrophobicity of the film surface protect the hydrolysis when exposed to moisture, and thus increase the stability, has effectively added a protection layer to the perovskite film, allowing the perovskite solar cells to be manufactured in air, and ionic liquids (ILs) are non-volatile salts with high thermal stability and electrochemical stability due to their strong electrostatic forces between their molecular ions. DETAILED DESCRIPTION - Perovskite precursor composition comprises perovskite precursors and a salt of a cationic imidazole derivative in which at least one of two nitrogen atoms in the imidazole ring is linked to a carbon chain bearing a cyano (-Ce=N) group, where the cationic imidazole derivative has the formula (I) or (II), where the formula (I) and (II) R1=1-4 C alkyl, R2= -(CH2)n-; and R2a=-(CH2)a-, R2b=-(CH2)b-, where b is 1-6, n is 2-6, and a is 1-6. INDEPENDENT CLAIMS are included for: 1. a method for preparing a perovskite film, which involves: a. preparing the perovskite precursor composition; b. providing a substrate; and c. formatting a perovskite film on the surface of the substrate; 2. a perovskite solar cell, which comprises a transparent conductive layer, a perovskite film comprising the perovskite precursor composition, and an electrode, optionally further comprising an electron transport layer, an electron blocking layer, a hole transport layer, and a hole blocking layer, where phenylamine-9,9-spirobifluorene.