A Bismuth-HalideDouble Perovskite with Long CarrierRecombination Lifetime for Photovoltaic Applications

Despite the remarkable rise in efficiencies\nof solar cells containing\nthe lead-halide perovskite absorbers RPbX<sub>3</sub> (R = organic\ncation; X = Br<sup>–</sup> or I<sup>–</sup>), the toxicity\nof lead remains a concern for the large-scale implementation of this\ntechnology. This has spurred the search for lead-free materials with\nsimilar optoelectronic properties. Here, we use the double-perovskite\nstructure to incorporate nontoxic Bi<sup>3+</sup> into the perovskite\nlattice in Cs<sub>2</sub>AgBiBr<sub>6</sub> (<b>1</b>). The\nsolid shows a long room-temperature fundamental photoluminescence\n(PL) lifetime of ca. 660…