J. Appl. Cryst.の発刊に際して

A broad organic–inorganic series of hybrid metal iodide perovskites with the general formulation AMI3, where A is the methylammonium (CH3NH3+) or formamidinium (HC(NH2)2+) cation and M is Sn (1 and 2) or Pb (3 and 4) are reported. The compounds have been prepared through a variety of synthetic approaches, and the nature of the resulting materials is discussed in terms of their thermal stability and optical and electronic properties. We find that the chemical and physical properties of these materials strongly depend on the preparation method. Single crystal X-ray diffraction analysis of 1–4 classifies the compounds in the perovskite structural family. Structural phase transitions were observed and investigated by temperature-dependent single crystal X-ray diffraction in the 100–400 K range. The charge transport properties of the materials are discussed in conjunction with diffuse reflectance studies in the mid-IR region that display characteristic absorption features. Temperature-dependent studies show a ...

Semiconducting tin and lead iodide perovskites with organic cations: phase transitions, high mobilities, and near-infrared photoluminescent properties.

Although known since the late 19th century, organic–inorganic perovskites have recently received extraordinary research community attention because of their unique physical properties, which make them promising candidates for application in photovoltaic (PV) and related optoelectronic devices. This review will explore beyond the current focus on three-dimensional (3-D) lead(II) halide perovskites, to highlight the great chemical flexibility and outstanding potential of the broader class of 3-D and lower dimensional organic-based perovskite family for electronic, optical, and energy-based applications as well as fundamental research. The concept of a multifunctional organic–inorganic hybrid, in which the organic and inorganic structural components provide intentional, unique, and hopefully synergistic features to the compound, represents an important contemporary target.

Organic–Inorganic Perovskites: Structural Versatility for Functional Materials Design

The hybrid two-dimensional (2D) halide perovskites have recently drawn significant interest because they can serve as excellent photoabsorbers in perovskite solar cells. Here we present the large scale synthesis, crystal structure, and optical characterization of the 2D (CH3(CH2)3NH3)2(CH3NH3)n−1PbnI3n+1 (n = 1, 2, 3, 4, ∞) perovskites, a family of layered compounds with tunable semiconductor characteristics. These materials consist of well-defined inorganic perovskite layers intercalated with bulky butylammonium cations that act as spacers between these fragments, adopting the crystal structure of the Ruddlesden–Popper type. We find that the perovskite thickness (n) can be synthetically controlled by adjusting the ratio between the spacer cation and the small organic cation, thus allowing the isolation of compounds in pure form and large scale. The orthorhombic crystal structures of (CH3(CH2)3NH3)2(CH3NH3)Pb2I7 (n = 2, Cc2m; a = 8.9470(4), b = 39.347(2) A, c = 8.8589(6)), (CH3(CH2)3NH3)2(CH3NH3)2Pb3I10 (...

http://pubs.acs.org/doi/pdf/10.1021/acs.chemmater.6b00847

Ruddlesden-Popper Hybrid Lead Iodide Perovskite 2D Homologous Semiconductors

Recently, perovskite CH3NH3PbI3 sensitizer has attracted great attention due to its superb light-harvesting characteristics. Organometallic or organic materials were mostly used as sensitizers for solid-state dye-sensitized solar cells at early stages. Inorganic nanocrystals have lately received attention as light harvesters due to their high light-absorbing properties. Metal chalcogenides have been investigated with solid-state dye-sensitized solar cells; however, the best power conversion efficiency was reported to be around 6%. CH3NH3PbX3 (X = Cl, Br, or I) perovskite sensitizer made a breakthrough in solid-state mescoscopic solar cells, where the first record efficiency of around 10% was reported in 2012 using submicrometer-thick TiO2 film sensitized with CH3NH3PbI3. A rapid increase in efficiency approaching 14% followed shortly. In this Perspective, recent progress in perovskite-sensitized solid-state mesoscopic solar cells is reviewed. On the basis of the recent achievements, a power conversion eff...

/pdf/organometal-perovskite-light-absorbers-toward-a-20-tv5d5oar52.pdf

Organometal Perovskite Light Absorbers Toward a 20% Efficiency Low-Cost Solid-State Mesoscopic Solar Cell

Three inorganic–organic layered perovskite-type hybrids of the general formula [(CnH2n + 1NH3)2PbI4], n = 4, 5 and 6, display a number of reversible first-order phase transitions in the temperature range from 256 to 393 K. [(C4H9NH3)2PbI4] has a single phase transition, [(C5H11NH3)2PbI4] has two phase transitions and [(C6H13NH3)2PbI4] has three phase transitions. In all three cases, the lowest-temperature phase transition is thermochromic and the crystals change colour from yellow in their lowest-temperature phase to orange in their higher-temperature phase for [(C4H9NH3)2PbI4] and [(C6H13NH3)2PbI4], and from orange to red for [(C5H11NH3)2PbI4]. The structural details associated with this phase transition have been investigated via single-crystal X-ray diffraction, SC-XRD, for all three compounds.

Synthesis, characterization and phase transitions in the inorganic–organic layered perovskite‐type hybrids [(CnH2n + 1NH3)2PbI4], n = 4, 5 and 6

In this paper we report the synthesis and the crystal structure of inorganic–organic hybrids containing various lead halides as the inorganic motif and a primary amine as the organic constituent. The organic molecule investigated is (C6H5C*H(CH3)NH2) and both the R and S as well as the racemic (±) forms were used. Within the structures obtained, three different inorganic motifs are displayed by the lead halide octahedra: 1-D polymeric face-sharing chains of formula PbCl3((R)–C6H5CH(CH3)NH3), PbBr3((R)–C6H5CH(CH3)NH3), PbI3((R)–C6H5CH(CH3)NH3) and PbI3((S)–C6H5CH(CH3)NH3); 1-D polymeric corner-sharing chains of formula PbCl5((±)–C6H5CH(CH3)NH3)3 and PbBr5((±)–C6H5CH(CH3)NH3)3; and 2-D corner-sharing layers of formula PbI4((S)–C6H5CH(CH3)NH3)2 and PbI4((R)–C6H5CH(CH3)NH3)2. The changes in geometry and intermolecular interactions such as hydrogen bonding and pi stacking are discussed and compared between the eight structures.

Synthesis and crystal structures of inorganic–organic hybrids incorporating an aromatic amine with a chiral functional group

Four inorganic-organic hybrid materials that consist of 2-D layers of corner-sharing lead(II) iodide octahedra separated by alkylammonium chains have been crystallized and characterized via single-crystal XRD (SCXRD). The four hybrids, represented by the general formula [(C(n)H(2n+1)NH(3))(2)PbI(4)] and abbreviated C(n)PbI, exhibit multiple reversible phase transitions for a narrow temperature range. The transition temperatures were determined with differential scanning calorimetry experiments. The number of transitions and the transition temperatures are dependant on the chain length; for n = 7 and 10, there are three transitions, and for n = 8 and 9, there are two transitions. Regardless of the number of transitions, all four compounds have identical lowest temperature phases, which have inorganic layers that are eclipsed, non-planar conformations of the alkyl ammonium chains and yellow-coloured crystals. The next highest temperature phase for three of the compounds (C(10)PbI goes through an intermediate phase first), has staggered inorganic layers, all-trans planar conformations of the chains and orange coloured crystals. The highest temperature phase for n = 8 and 10 has red-coloured crystals and shows a disordering of the alkylammonium chains over two positions and staggered inorganic layers. The high temperature phase of C(7)PbI retains its orange colour and has only increased thermal motion of its alkylammonium chain. The structure of the high temperature phase of C(9)PbI was not determined. The SCXRD structures of the various phases give clues to the structural changes that the compounds undergo at the phase transitions, which will now enable future studies of their optical and electronic properties to be better understood.

Synthesis, characterization and phase transitions of the inorganic-organic layered perovskite-type hybrids [(C(n)H(2n+1)NH3)2PbI4], n = 7, 8, 9 and 10.

The room temperature single-crystal structures of the inorganic–organic layered perovskite-type hybrids of general formula [(CnH2n+1NH3)2PbI4] (n = 12, 14, 16 and 18) have been determined. The four compounds each display two reversible phase transitions above room temperature, with phases labelled III, II and I. The single-crystal structures of phase II have also been determined. The phase transition from phase III to phase II is a first-order transition and corresponds to a change in the conformation of the alkylammonium chains and a shift of the inorganic layers relative to each other. The phase change from III to II is thermochromic for all compounds, going from a yellow to an orange colour.

Synthesis, characterization and phase transitions of the inorganic–organic layered perovskite-type hybrids [(CnH2n+1NH3)2PbI4] (n = 12, 14, 16 and 18)

Diammonium cations of general formula (H3N–R–NH3) have been used as templating moieties on lead(II) halide motifs, forming a variety of inorganic–organic nanocomposites. The R group can have simple, straight alkyl chains, which if even-membered and greater than ethane, form 2-D layers based on the RbAlF4 structure type, as found in [(H3N(CH2)4NH3)PbBr4] (1), [(H3N(CH2)4NH3)PbI4] (2), [(H3N(CH2)8NH3)PbI4] (4), [(H3N(CH2)10NH3)PbBr4] (5), and [(H3N(CH2)12NH3)PbI4] (6). If the R group has fused aromatic rings like naphthalene, the 2-D layered perovskite-type motif is still adopted, as in [(H3NC10H6NH3)PbI4] (7). If the chain is odd-membered, a 0-D inorganic motif, consisting of isolated blocks of face-sharing PbI6 octahedra and isolated iodide anions is seen, as in [(H3N(CH2)7NH3)4Pb3I12·2I−] (3). 1-D motifs, which have edge-sharing twin-anionic chains of corner-sharing ribbons are also observed in the compounds [(H3NC2H4NH3)4PbBr4] (8) and [(H3NC6H4CH2C6H4NH3)PbI6] (9) respectively.

David G. Billing

Papers

Synthesis, characterization and phase transitions in the inorganic–organic layered perovskite‐type hybrids [(CnH2n + 1NH3)2PbI4], n = 4, 5 and 6

Synthesis and crystal structures of inorganic–organic hybrids incorporating an aromatic amine with a chiral functional group

Synthesis, characterization and phase transitions of the inorganic-organic layered perovskite-type hybrids [(C(n)H(2n+1)NH3)2PbI4], n = 7, 8, 9 and 10.

Synthesis, characterization and phase transitions of the inorganic–organic layered perovskite-type hybrids [(CnH2n+1NH3)2PbI4] (n = 12, 14, 16 and 18)

Lead halide inorganic–organic hybrids incorporating diammonium cations