RESUMO
Layered double perovskites have the potential to further expand the vast space of optoelectronic properties and applications of halide perovskites. Among the â¼60 known members, to date only the ⟨111⟩-oriented layered double perovskites, Cs4Cd1-xMnxBi2Cl12, have shown efficient photoluminescence (PL). The replacement of Bi with Sb in these materials was investigated, resulting in two new families of layered inorganic perovskite alloys with full solubility. The first, Cs4Cd1-xMnxSb2Cl12, exhibits a PL emission at 605 nm ascribed to Mn2+ centers, with a maximum quantum yield of 28.5%. The second, Cs4Cd0.8Mn0.2(Sb1-yBiy)2Cl12, contains a fixed amount of Mn2+ and Cd2+ but variable Sb3+ and Bi3+ concentrations. We observed a decreased efficiency of the Cs4Cd1-xMnxSb2Cl12 family compared to that of Cs4Cd1-xMnxBi2Cl12, which was attributed to a decreased spin-orbit and Jahn-Teller couplings in Sb and the subsequent increased electronic delocalization. The present work lays out a roadmap to achieve high photoluminescence efficiencies in layered double perovskites.