Environmental-friendly lead-free chiral Mn-based metal halides with efficient circularly polarized photoluminescence at room temperature

In recent years, chiral organic-inorganic hybrid metal halides have attracted more and more attention from researchers. However, most chiral metal halides are based on toxic Pb elements. In this work, we first successfully prepared a pair of lead-free manganese-based metal halide enantiomers (R/S-1-PPA) 2 MnBr 4 (R/S-1-PPA=R/S-1-Phenylpropan-1-amine). Under the excitation of 365 nm UV light, (R/S-1-PPA) 2 MnBr 4 exhibited bright green emission, which can be attributed to the spin-forbidden d-d transition of Mn 2+ . In addition, the decay lifetimes were as high as 32.57 μs and 33.60 μs for (R-1-PPA) 2 MnBr 4 and (S-1-PPA) 2 MnBr 4 , respectively. (R/S-1-PPA) 2 MnBr 4 showed notable circular dichroism (CD) signals and displayed highly efficient circularly polarized photoluminescence (CPPL) at room temperature with the large g lum of − 0.01 and 0.008, respectively. The high g lum enables them to be a series of very promising materials for the development of chiral optoelectronic devices based on chiral hybrid metal halides. Finally, the white LED device constructed with (R-1-PPA) 2 MnBr 4 also showed a wide color gamut, as high as 107% of NTSC, and a "warm" white light-correlated color temperature of 6883 K, which indicated it has good competitiveness in the application of white light LED devices. • We synthesized a pair of Pb-free Mn-based chiral metal halides (R/S-1-PPA) 2 MnBr 4 . • The halides emitted green CPPL, with g lum of − 0.01 and 0.008 at room temperature. • The g lum represent the maximum of the reported Mn-based metal halides.