Perovskite layer, fabrication method and use the same

A perovskite layer for use in a solar cell comprising a mixture of a mixed-halide perovskite and a sulfonyl naphthoquinone-based compound with a structure of any one of Formula (II), (III), (IV), (V), (VI), or (VII):

• wherein:
• R1 is independently selected from one of OM, OR4, and NR5R6, with M being a cation selected from the group consisting of H+, Na+, K+, Cs+, Rb+, Sr2+, Ca2+, Ni2+, Cu2+, Co2+, Zn2+, Mg2+, Ba2+, Li+, ammonium ion, and aminum ion;
• R4, R5 and R6 are independently selected from the group consisting of hydrogen, substituted or unsubstituted C1 to C4 alkyl, substituted or unsubstituted C2 to C6 alkenyl, substituted or unsubstituted C2 to C6 alkynyl, halogen, unsubstituted C6 to C10 aryl, —CN, —C(═O)OH, —C(═O)H, —C(═O)R7, —OR7, —SH, —SR7, —NH2, —NHR6, —N(R7)2, —Si(R7)3, —OSi(R7)3, —S(O)OH and —P(O)(OH)2 where R7 is an alkyl or a phenyl, and n being 1-1000;
• wherein the sulfonyl naphthoquinone-based compound does not include a porphyrin, and is arranged to suppress halide segregation in the mixed-halide perovskite.