Zero-Dimensional Organic–Inorganic Hybrid Zinc Halides for Multiple Applications in Anti-Counterfeiting, X-Ray Imaging and White LEDs

Zinc halides have been less explored even though they are a promising lead-free family with the merits of environmental friendliness and low cost. Here, the organic–inorganic hybrid zinc halides are screened with aromatic molecules containing amino groups (MXDA: m-Xylylenediamine, ABI: 2-Aminobenzimidazole, pipda: 2-piperidylmethylamine, p-MPEA: p-Methylphenethylamine), and six new compounds are discovered: (MXDA)ZnCl 4 ( 1 ), (ABI) 2 ZnCl 4 ( 2 ), (pipda) 2 H 2 OZnCl 2 ( 3 ), [(pipda) 4 Zn 2 Br 4 ]·H 2 O ( 4 ), (p-MPEA) 2 ZnCl 4 ( 5 ), and (p-MPEA) 2 ZnBr 4 ( 6 ). The discovered compounds exhibit diverse efficient light emissions (blue, green, yellow, and ultraviolet) under ultraviolet light irradiation. By doping Sb and Mn at the Zn site, (MXDA)ZnCl 4 exhibits different colors of light under excitation light of different wavelengths, so it is successfully used for anti-counterfeiting. (MXDA)Zn 0.91 Mn 0.09 Cl 4 is also found to be an efficient X-ray scintillator for X-ray imaging. Among the as-explored new phases, a maximum photoluminescent quantum yield of 82.60% is realized, enabling the utilization for white light-emitting diodes. The results suggest that the zinc halides are a new lead-free family with superior optoelectronic properties, which can be used for multiple applications.