Method for Inkjet Printing an Organic-Inorganic Perovskite

A method for producing a printable ink solution, the method comprising providing an ink solution comprising a cation of formula (I):

• Anc-R1—W+ (I),
• wherein,
• Anc is selected from —COOH, —CONH2, —PO3H2, —PO2H2R2, —PO4H2, —SO3H2, —CONHOH, and salts thereof, R2 is an organic substituent comprising from 1-20 carbon atoms and 0-10 heteroatoms,
• W is a charged moiety comprising a positively charger quaternary ammonium group;
• selected from —NH3+, —NH—C(NH3+)═NH, —N═CH—NH3+;
• and,
• R1 is an optionally substituted organic moiety comprising 1-20 carbons,
• wherein R1 and R2 may be, independently, totally or partially halogenated.

An inkjet ink comprising a cation of formula (I):

• Anc-R1—W+ (I),
• wherein,
• Anc is selected from —COOH, —CONH2, —PO3H2, —PO2H2R2, —PO4H2, —SO3H2, —CONHOH, and salts thereof, R2 is an organic substituent comprising from 1-20 carbon atoms and 0-10 heteroatoms,
• W is a charged moiety comprising a positively charged quaternary ammonium group;
• selected from —NH3+, —NH—C(NH3+)═NH, —N═CH—NH3+;
• and,
• R1 is an optionally substituted organic moiety comprising 1-20 carbons,
• wherein R1 and R2 may be, independently, totally or partially halogenated,
• wherein said ink comprises further components required to form said perovskite layer.

A method for reducing and/or slowing down nucleation and/or precipitation of perovskite and/or perovskite intermediates in an inkjet ink comprising an organic-inorganic perovskite precursor solution, the method comprising adding a cation of formula (1) when preparing said inkjet ink:

• Anc-R1—W+ (I),
• wherein,
• Anc is selected from —COOH, —CONH2, —PO3H2, —PO2H2R2, —PO4H2, —SO3H2, —CONHOH, and salts thereof, R2 is an organic substituent comprising from 1-20 carbon atoms and 0-10 heteroatoms,
• W is a positively charged moiety comprising a positively charged nitrogen atom;
• R1 is an optionally substituted organic moiety comprising 1-20 carbons and 0-10 heteroatoms,
• wherein R1 and R2 may be, independently, totally or partially halogenated.