LAUSR

Low-dimensional hybrid lead halides have recently been reported to be efficient white light emitters. However, unlike lead halide 3D perovskites, most of the reported low-dimensional materials with broad-band emission crystallize in different structure types according to their halogen com-position (i.e. Cl, Br, I) for a selected organic molecule. Be-cause of the absence of isostructural halide series, the role of the chemistry on the self-trapping of the excitons at the origin of the broad-band emission remains unclear. Among the most efficient white phosphors, the hybrid lead bromide (TDMP)PbBr4 (TDMP = Trans-2,5-dimethylpiperazinium) built of post-perovskite type chains exhibits the record pho-toluminescence quantum yield for hybrid lead halides. In this communication, the two new isostructural (TDMP)PbX4 chloride and iodide analogues could be synthesized and structurally characterized. Comparison of the optical prop-erties of the lead halide series reveals a strong dependence of the nature of the halogen (Cl, Br, I) on the trap-ping/detrapping of the excitons and the resulting emission intensities, wavelengths as well as band broadness.