Synthesis,Structure And Optical Properties Of Low-Dimensional Organic-Inorganic Metal Halide Hybrids

Organic-inorganic hybrid metal halides are a class of materials with very excellent optoelectronic properties,which formed by self-assembly of organic cations and inorganic anions.Recently,organic-inorganic metal halide hybrids have become a research hotspot.Organic-inorganic hybrid metal halides provide the possibility of integrating useful organic and inorganic characteristics within a single crystalline molecular-scale composite,which have broad application prospects in optics such as photovoltaic devices,light-emitting diodes,and optical pump lasers.Three-dimensional?3D?and two-dimensional?2D?structures of metal halides have narrow-band emission in small Stokes shift.One-dimensional?1D?structures existed trapped excited-state emission and zero-dimensional?0D?structures possess emission from recombined excited-state.Compared to well-developed 3D and 2D structure,1D and0D structures of hybrid metal halides remained underdeveloped so far.Based on the above analysis,a series of low-dimensional metal halides were prepared by solution evaporation method,and their optical properties were studied.The specific work content was as follows:?1?The non-photoluminescence 1D chain compound(C₄NOH₁₀)₂BiBr₅?1?was synthesized,and then changed the solvent system to obtain the 0D compound(C₄NOH₁₀)₃BiBr₆·CH₃CN?2?with blue-green photoluminescence at a low temperature.By replacing organic cation,the OD compound[(C₆NH₁₄)₄BiBr₆]Br·CH₃CN?3?with blue photoluminescence at a low temperature was synthesized.By changing the configuration of the BiBr₆ octahedron,the band gap structure of the metal halide was adjusted to control its optical properties.?2?Two 0D organic cadmium halide metal halides(C₄NOH₁₀)₆Cd₃Cl₁₂·2H₂O?4?and(C₄NOH₁₀)₂CdBr₄?5?with phosphorescence emission were synthesized.It was speculated that the luminescence mechanism was:fluorescence emission in the inorganic part with recombination of recombination excitons as a luminescence mechanism.At the same time,there was also a phosphorescence emission from the triplet state to the ground state in the organic part.?3?Two 0D organic-inorganic hybrid metal halides(C₄NOH₁₀)₅MnCl₉·C₂H₅OH?6?and(C₄NOH₁₀)₂MnCl₄?7?were synthesized.When thermal treatment of the compound 6,the structure of compound 6 was converted into the compound 7 with the departure of ethanol molecules.This paper speculated the process of structural transformation and characterizes its structural transformation and thermochromic luminescence.