Three New Lead Iodide Chain Compounds, APbI3, Templated by Molecular Cations

Abstract

The crystal structures of three new hybrid organic-inorganic lead halide compounds [IqH]PbI3, [4MiH]PbI3, and [BzH]PbI3 ([IqH+] = isoquinolinium, [4MiH+] = 4-methylimidazolium, [BzH+] = benzotriazolium) have been determined by single crystal x-ray diffraction. All three compounds have the same generic formula as perovskite, ABX3, but adopt a rare non-perovskite structure built from one dimensional (1D) edge-sharing octahedral chains. The bandgap of each compound was investigated by solid UV-Vis spectra. In comparison with previously reported hybrid compounds containing the same type of octahedral chains, [C10H7CH2NH3]Pbl3 and (C7H7N2)PbI3, all three new compounds have lower bandgaps (<2.4 ev), indicating that they may be promising for photovoltaic application.

Influence of Temperature, Pressure, and Humidity on the Stabilities and Transition Kinetics of the Various Polymorphs of FAPbI3

“…On the other hand, CsPbI 3 undergoes the δ → α transition at 560–600 K, but the cubic perovskite phase has a volume 6.9% larger than that of the δ phase, in spite of a 9% reduction of the volume of the octahedra, and CsSnI 3 behaves similarly . It must be noted, however, that those δ phases are not 2H but orthorhombic with double chains of edge-sharing octahedra, and among the hybrid halides, there are a variety of nonperovskite structures. , …”

“…52 It must be noted, however, that those δ phases are not 2H but orthorhombic with double chains of edge-sharing octahedra, and among the hybrid halides, there are a variety of nonperovskite structures. 53,54 Unfortunately, based on our diffraction data and the literature, it is not trivial to find solid information on the volumes per formula unit of the various polymorphs of FAPI. Most of our diffraction data were acquired during fast scans to minimize possible effects from degradation of the compacted powders during the scans in air, and were unsuitable for Rietveld refinement.…”

Structural diversity in hybrid lead halides templated by 4-methylimidazolium

“…3,[13][14][15] However, several other related structure-types featuring polyhedral connectivity other than cornerlinkages, such as edge-or face-sharing are known. These include the well-known facesharing hexagonal perovskites 16,17 and the relatively rare edge-sharing chains, [18][19][20][21][22] both of which are 1D frameworks. It is worth noting that variations of hexagonal perovskite can include both face-and corner-sharing polyhedra.…”

A spatiotemporal route to understanding metal halide perovskite crystallization

“…Each compound contains Pb (1), 5. The inorganic structures in compounds 1 -9 were analyzed using Bond Valence Sums 35,36 . Calculated ΣSi values for the Pb 2+ cations range between 1.75 and 1.88, corresponding well with the formal charge on these metal centers.…”