Two-Dimensional Halide Perovskite Materials

A two-dimensional halide perovskite material, comprising:

• a first halide perovskite component of formula L2An−1MnX3n+1 and a second halide perovskite component of formula L′2A′n′−1M′n′X′3n′+1, wherein:
• L represents a conjugated organic ligand cation of a conjugated and optionally substituted aryl and/or hetero aryl system, wherein each aryl and/or hetero aryl ring in the conjugated and optionally substituted aryl or hetero aryl system may be same or different;
• L′ represents a conjugated or a non-conjugated organic ligand cation;
• A and A′ each independently represents a cation Cs+, Rb+, CH3NH3+, CH3CH2NH3+, or
• M and M′ each independently represents a divalent metal cation Pb2+, Sn2+, Ge2+, Cu2+, Zn2+, Cd2+, Hg2+, Ni2+, Co2+, Fe2+, Mn2+, Cr2+, V2+, pd2+, Pt2+;
• X and X′ each independently represents F−, Cl−, Br− or I−;
• n and n′ each independently is 1-6;
• and
• wherein the first halide perovskite component and the second halide perovskite component are not the same perovskite, and the first halide perovskite is first formed as a lateral core and the second halide perovskite is formed surrounding the lateral core of the first halide perovskite.