Modifying Optoelectronic Properties of Molecular Halide Perovskite Cs4PbBr6 via Organic Ligands: A First-Principles Investigation

Abstract Molecular halide perovskites offer interesting optoelectronic properties that are rarely observed in the three-dimensional counterpart, which suffers from poor stability and phase transformation. In this manuscript, we examine the modification of the prototypical molecular halide perovskite Cs4PbBr6 via the incorporation of the organic ligands, employing the first principles calculations. We propose that the inclusion of the organic ligands that interact with the Cs4PbBr6 unit is effective to modify the structural, electronic and optical properties of the molecular halide perovskite. In addition, the polaronic states of Cs4PbBr6 in the presence of the ligand modification are analyzed, demonstrating the large impacts of the organic ligands on the halide perovskite polaronic states. This study highlights a feasible design strategy that could potentially offer superior optoelectronic properties of the molecular halide perovskite-based materials.