Organic-inorganic hybrid metal halides are extensively studied since they have excellent photoelectric properties, diverse constituents, and tunable band gaps. However, most of the discoveries are random and lack of new...

In order to meet the needs of social development, more and more research attention has been paid to multifunctional molecular-based phase transition materials. The traditional phase transition materials with single...

With vigorous development of the photovoltaic hot topic, the organic-inorganic hybrid perovskite (OIHP) have become the focus in the search for functional materials. Among them, layered 2D OIHPs provide the...

The tunable structure, abundant raw materials, and ease of preparation have made molecular dielectric crystals popular for use in device design. In spite of this, some known molecular switching materials have a low phase transition temperature and a low dielectric constant, which limit their applications. Therefore, designing and synthesizing molecular-based phase transition compounds with high phase transition temperature and superior properties is especially important. In this work, we use 3-chloropropan-1-ammonium hydrochloride and SbCl 3 / SbBr 3 inorganic salts as building blocks to synthesize com-pounds (CPA) 2 (BPA) 2 Sb 2 Br 10 (1) (CPA = 3-chloropropan-1ammonium, BPA = 3-bromopropan-1-ammonium) and (CPA) 2 Sb 2 Cl 8 (2). Compound 1 has a high phase transition temperature (407.45 K). Dielectric measurements and differential scanning calorimetry (DSC) confirm the structural phase transition in compound 1, and no fatigue decay is observed after several dielectric cycles. In addition, compounds 1 and 2 possess semiconductor properties. The findings of this study provide new directions for the design and application of multifunctional molecular dielectric materials.

Hybrid lead halide perovskites have received extensive scientific attention owing to their great potential in the field of fluorescent displays and light-emitting diodes. Currently, most luminescent materials contain functional molecular and rareearth metal ion parts. However, the mechanism of photoluminescence property in two-dimensional hybrid lead halide perovskites with different layered inorganic skeletons has been reported rarely. To better understand the effect of an inorganic skeleton on the fluorescence property, here, we report three organic−inorganic hybrid materials with different layered inorganic frameworks: (MACH) 2 •PbBr 4 (Prv-1, MACH = cyclohexylmethylammonium), (2-MPQ)•PbBr 4 (Prv-2, 2-MPQ = 2-methylpiperazinium), and (TMBA) 4 •Pb 3 Br 10 (Prv-3, TMBA = N′N′N′trimethylbenzylammonium). Among them, Prv-1 is a (100)-oriented perovskite, Prv-2 belongs to the (110)-oriented perovskite, and the inorganic framework of Prv-3 possesses [Pb 3 Br 10 ] units. Interestingly, Prv-1 has a strong blue-violet fluorescence emission, while the luminescence effect of Prv-2 is very weak; notably, Prv-3 emits a charming bright-orange light. Meanwhile, results of theoretical computational studies also reveal that the electronic structure of all three compounds is highly dependent on structurally distorted [PbBr 6 ] octahedra, and the frontier molecular orbital (FMO) analysis further suggests that HOMO and LUMO of Prv-3 are contributed by inorganic and organic components, respectively. In addition, all three materials belong to direct band gap semiconductors, and the band gaps are 2.79, 2.97, and 2.76 eV, respectively. Significantly, there are obvious differences in conduction bands. Based on the above analysis, the photoluminescence mechanism of three hybrid materials is explained from the electronic levels. Consequentially, this work might provide practical strategies and perspectives for exploring novel structure-related properties.