Method of preparing single crystal perovskite and method of manufacturing solar cell using single crystal perovskite

A method of forming single crystal perovskite, the method comprising:

• forming a preliminary thin film by applying a perovskite precursor solution containing an additive on a substrate;
• exposing the preliminary thin film to a vacuum state by transferring the preliminary thin film to a vacuum chamber, wherein the exposing of the preliminary thin film to the vacuum state is performed for 1 second to 10 minutes, wherein an internal pressure of the vacuum chamber is 1−1 to 3−3 torr;
• and
• switching the internal pressure of the vacuum chamber to an atmospheric pressure,
• an inert gas is heated at 25° C. to 300° C. and injected into the vacuum chamber,
• wherein the additive includes a substituted or unsubstituted C1 to C30 aliphatic ammonium salt, a substituted or unsubstituted C6 to C30 aromatic ammonium salt, a substituted or unsubstituted C1 to C30 aliphatic amine salt, a substituted or unsubstituted C6 to C30 aromatic amine salt, or a combination thereof,
• wherein:
• the substituted or unsubstituted C1 to C30 aliphatic ammonium salt or the substituted or unsubstituted C6 to C30 aromatic ammonium salt is any one of
• 2-chloroethylammonium (CIEA+), ethane-1,2-diammonium (EDA2+), 2-(methylthio)-ethylammonium (MTEA+), n-propylammonium (n-PA+), n-butylammonium (n-BA+), iso-butylammonium (i-BA+), tert-butylammonium (tBA+), tetra-butylammonium (TBA+), 5-ammonium valeric acid (5-AVA+), n-hexyl trimethyl ammonium (HTAB+), n-octylammonium (n-OA+), n-dodecylammonium (n-DA+), pentafluorophenylethylammonium (FEA+), 4-tert-butyl-benzylammonium (tBBA+), and 1-napthylmethylammonium (NMA+),
• wherein:
• the perovskite precursor solution further contains a passivation additive, and
• the passivation additive has at least one functional group of a metal cation, —CN, —NH2, —N3, —Cl, —Br, —I, —F, —COOH, —POOH, —OH, —CF3, —OCH3—C═O, —S═O—SH, —NH, a benzyl group, an alkoxy group, and —CH3, thereby forming a single crystal perovskite with a single crystal plane in a vertical direction.