Abstract: The invention relates to an optoelectronic material comprising a compound, wherein the compound comprises: (i) one or more cations, A; (ii) one or more first B cations, Bn+; (iii) one or more second B cations, Bm+; and (iv) one or more chalcogen anions, X; wherein the one or more first B cations, Bn+ are different from the one or more second B cations, Bm+; n represents the oxidation state of the first B cation and is a positive integer of from 1 to 7 inclusive; m represents the oxidation state of the second B cation and is a positive integer of from 1 to 7 inclusive; and n+m is equal to 8.