Perovskite film, method of preparing thereof, and optoelectronic device

A method of preparing a perovskite film, comprising following steps:

• step S10, adding a first monomer and a second monomer into a perovskite precursor solution at a predetermined ratio, and stirring uniformly to form a first mixed solution, wherein the first mixed solution is prepared on a substrate;
• step S20, annealing the substrate having the first mixed solution prepared on a surface of the substrate, wherein the first monomer and the second monomer are reacted in situ to form a first polymer, the perovskite precursor solution forms perovskite crystal grains, and the first polymer is combined with the perovskite crystal grains and concentrated at a crystal grain boundary of the perovskite crystal grains;
• and
• step S30, curing the first mixed solution to form the perovskite film;
• wherein the first monomer and the second monomer are respectively represented by following structural formulas (I) and (II):
• and
• wherein R1 and R3 are one of same or different branched alkyl groups having 3 to 20 carbon atoms, a branched amine group having 3 to 30 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms or a fused aromatic hydrocarbon group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaromatic hydrocarbon group having 5 to 30 carbon atoms or a fused heterocyclic aromatic hydrocarbon group having 6 to 30 carbon atoms;
• and
• wherein R2 is a group containing at least one of O, N, and S atoms, Fx is a fluorine atom bonded to a phenyl ring, x is a number of the fluorine atoms, and x is an integer of 2 to 4.