| abstract |
The present invention relates to a composition comprising a compound having a perovskite crystal structure, wherein A, B, X and M are constituent components, and the number of moles of M is divided by the total number of M and B moles. The molar ratio of [M/(M+B)] is 0.7 or less. (A is a cerium ion, an organic ammonium ion or a cerium ion located at each vertex of a hexahedron centering on B in the perovskite crystal structure. B is a lead ion. M is selected from the group consisting of cesium ions. One or more kinds of cations of a group of cations of a valence metal element. X represents a component located at each vertex of an octahedron centered on B in the perovskite crystal structure, and is selected from Cl - and Br. - , F - , I - and SCN - one or more anions of the group formed). |