Strong yellow emission of polaronic magnetic exciton in Fe3+-doped CsCdCl3 perovskites

All-inorganic metal halide perovskite semiconductor materials have a wide range of potential applications for their excellent optoelectronic properties. Among those metal halides studied, cesium cadmium chloride has not been fully studied. Here, we report the simple synthesis and optical properties of Fe3+ doped CsCdCl3 perovskite powder by the hydrothermal technique; the products give a strong yellow photoluminescence quantum yield up to 63.22%. The powder x-ray diffraction pattern shows that the Fe3+ introduction does not change the hexagonal structure of the host lattice, magnetic characterization indicated direct Fe–Fe ferromagnetic coupling, and the photoluminescence enhancement is due to the overlapping of the self-trapped state and the d–d transition of the ferromagnetic Fe3+ pair, i.e., magnetic polarons.