Method for synthesis of organic iodides, a perovskite-forming composition comprising an organic iodide and a photovoltaic cell with a perovskite layer obtained therefrom

A method for obtaining a salt having a general formula:

• RxNI, wherein:
• RxN is an organic cation (RxN+),
• wherein R represents substituents (R—) independently selected from a group consisting of organic substituents:
• R1—, R2—, R3— and hydrogen (H—), wherein the donor of organic cation RxN+ contains as organic substituents:
• R1—, R2— and optionally R3— moieties independently selected from a group consisting of:
• straight chain or branched chain alkyl substituents containing 1 to 8 carbon atoms in a substituent molecule,
• x is a number of the substituents R— directly linked with the nitrogen (N) atom in the organic cation RxN+, wherein x is 3 or 4,
• I is an iodide anion (I−),
• the method comprising the steps of:
• preparing a reaction mixture by:
• synthesizing hydrogen iodide (HI) in situ by mixing molecular iodine (I2) with formic acid (COOH) in a molar ratio of molecular iodine (I2):
• formic acid (COOH) of no less than 1.01:1, in a solvent medium,
• introducing into the solvent medium a compound being a donor of an organic cation RxN+ in an amount providing the molar ratio of the donor of the organic cation RxN+:
• molecular iodine (I2) of no less than 1.01:1, and
• maintaining the reaction mixture at a temperature of not less than 20° C. for a time necessary to obtain a reaction product being the salt having the general formula RxNI.