Efficient Emission in Halide Layered Double Perovskites: The Role of Sb <sup>3+</sup> Substitution in Cs <sub>4</sub> Cd <sub> 1– <i>x</i> </sub> Mn <sub> <i>x</i> </sub> Bi <sub>2</sub> Cl <sub>12</sub> Phosphors
Brenda Vargas, Eduardo Coutiño‐González, Oscar Ovalle-Encinia, C. Sánchez-Aké, Diego Solís-Ibarra
Abstract
Layered double perovskites have the potential to further expand the vast space of optoelectronic properties and applications of halide perovskites. Among the ∼60 known members, to date only the ⟨111⟩-oriented layered double perovskites, Cs 4 Cd 1– x Mn x Bi 2 Cl 12, 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, Cs 4 Cd 1– x Mn x Sb 2 Cl 12, exhibits a PL emission at 605 nm ascribed to Mn 2+ centers, with a maximum quantum yield of 28.5%. The second, Cs 4 Cd 0.8 Mn 0.2 (Sb 1– y Bi y ) 2 Cl 12, contains a fixed amount of Mn 2+ and Cd 2+ but variable Sb 3+ and Bi 3+ concentrations. We observed a decreased efficiency of the Cs 4 Cd 1– x Mn x Sb 2 Cl 12 family compared to that of Cs 4 Cd 1– x Mn x Bi 2 Cl 12, 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.