Organic-inorganic hybrid perovskites

An organic-inorganic hybrid perovskite of formula (I) below:

• [(A)1−2.48p−b(B)3.48p+b](1+2p−y)/(1+p)(Pb)1−p−m(M)m(X1)3−y−q(X2)q (I)
• in which:
• A represents a cation chosen from Cs, Rb and a monovalent organic cation comprising an ammonium or carboxamidamidium group,
• B represents a monovalent organic cation of formula (II) below:
• R1—(CH2)2—R2 (II)
• in which:
• R2 represents an ammonium or carboxamidamidium group,
• z represents 1, 2 or 3, and
• R1 represents —H, —OH, —SH, —CN or a halogen, with the proviso that B is other than A,
• X1 and X2 represent a halide, with the proviso that X1 and X2 are different from each other,
• p is a number from 0.05 to 0.23,
• b is a number greater than or equal to −0.30 and less than or equal to 0.30, with the proviso that b is greater than −3.48p and is less than (1−2.48p),
• y represents a number greater than 0 and less than or equal to p,
• q represents a number greater than or equal to 0 and less than or equal to (3−y),
• M represents a divalent metal cation, and
• m represents a number greater than or equal to 0 and less than or equal to (1−p).