Ferroelectric phase transition in Cs3Bi2I9

Melnikova, S. V.; Зайцев, А. И.

doi:10.1134/1.1129882

Cited by 28 publications

(22 citation statements)

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“…24,27,28 Two main structure types of A 3 M 2 X 9 can be distinguished, the ones with hexagonal close packing and the ones with cubic close packing of A and X. For the bismuth iodides of the former group, isolated Bi 2 I 3− 9 ions result as pairs of face-sharing Bi-I octahedra (e.g.…”

Section: Introductionmentioning

confidence: 99%

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Crystal and Electronic Structures of Complex Bismuth Iodides A₃Bi₂I₉ (A = K, Rb, Cs) Related to Perovskite: Aiding the Rational Design of Photovoltaics

et al. 2015

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Ternary bismuth halides form an interesting functional materials class in the context of the closely related Pb halide perovskite photovoltaics, especially given the significantly reduced toxicity of Bi when compared with Pb. The compounds A 3 Bi 2 I 9 (A = K, Rb, Cs) examined here crystallize in two different structure types: the layered defectperovskite K 3 Bi 2 I 9 type, and the Cs 3 Cr 2 Cl 9 type. The latter structure type features isolated Bi 2 I 9 3− anions. Here, the crystal structures of the ternary iodides are redetermined and a corrected structural model for Rb 3 Bi 2 I 9 , as established by single crystal X-ray diffraction and solid state 87 Rb NMR spectroscopy and supported by density functional theory (DFT) calculations is presented. A variety of facile preparation techniques for single crystals, bulk materials, as well as solution-processed thin films are described. The optical properties and electronic structures are investigated experimentally by optical absorption and ultraviolet photoemission spectroscopy and computationally by DFT calculations. Absolute band positions of the valence and conduction bands of these semiconductors, with excellent agreement of experimental and calculated values, are reported, constituting a useful input for the rational interface design of efficient electronic and optoelectronic devices. The different structural connectivity in the two different structure types, somewhat surprisingly, appears to not impact band positions or band gaps in a significant manner. Computed dielectric properties, including the finding of anomalously large Born effective charge tensors on Bi 3+ , suggest proximal structural instabilities arising from the Bi 3+ 6s 2 lone pair. These anomalous Born effective charges are promising for defect screening and effective charge carrier transport. The structural, electronic, and optical properties of the complex bismuth iodides are to some extent similar to the related lead iodide perovskites. The deeper valence band positions in the complex bismuth iodides point to the need for different choices of hole transport materials for Bi-iodide based solar cell architectures.

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Section: Introductionmentioning

confidence: 99%

“…Here we focus on the heavy alkali metal bismuth iodides A 3 Bi 2 I 9 for which the crystal structures have been reported: A = K, 20 Rb, 21 and Cs. 22 While the phase transitions in the Cs compound have been wellstudied, [23][24][25][26] only one report each for the K and Rb salt are to be found.…”

Section: Introductionmentioning

confidence: 99%

Crystal and Electronic Structures of Complex Bismuth Iodides A₃Bi₂I₉ (A = K, Rb, Cs) Related to Perovskite: Aiding the Rational Design of Photovoltaics

et al. 2015

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“…With decreasing T, the lattice constants of the LT phase vary significantly: a m decreases from 8.385(4) to 8.358(8) A; b m decreases from 14.537 (7) to 14.51(1) A; whereas c m ¼ 21.11(1) A remains practically constant; b increases from 90 to 90.71(7) [4]. Below 220 K, optical studies of a single crystal revealed small striated twins along the c-axis [1]. The small deviation of the optical indicatrix [1] seems to result from the deviation of the c maxis from the normal to the (ab) m plane for each monoclinic domain [4].…”

Section: Introductionmentioning

confidence: 96%

“…The interest in the study of Cs 3 Bi 2 I 9 is associated to a phase transition which has been observed at temperatures below 220 K [1,2]. The hexagonal room temperature (RT) modification (space group P6 3 /mmc; a h ¼ 8.…”

Section: Introductionmentioning

confidence: 99%

“…The hexagonal room temperature (RT) modification (space group P6 3 /mmc; a h ¼ 8. 409(1) and c h ¼ 21.243(5) A [3,4]) transforms reversibly to the monoclinic low temperature (LT) phase (C-centered unit cell with the monoclinic axis b: [1,4]). On the basis of 127 I NQR spectra, it was postulated that the monoclinic LT modification was incommensurate in the temperature range 220-205 K [2].…”

Section: Introductionmentioning

confidence: 99%

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The LT phase of Cs₃Bi₂I₉

Arakcheeva¹,

Chapuis²,

Meyer³

2001

Zeitschrift Für Kristallographie - Crystalline Materials

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The low temperature (LT) modification of Cs 3 Bi 2 I 9 has been refined to R(F) ¼ 0.055 on the basis of X-ray diffraction measurements at T ¼ 130 K from a twin crystal with six fractions connected by 3-fold axis and m-planes symmetry operations. Data were collected on a KM4CCD diffractometer; MoK a -radiation; 1769 independent reflections with F > 4s(F) were obtained. Below the LT phase transition each reflection were split. The absorption correction was accounted for by the Gaussian integration method. The parameters of the monoclinic unit cell are: (7) ; space group C2/c. The structure of the monoclinic LT phase is slightly distorted in comparison to the hexagonal RT phase (a m ¼ a. The phase transition at T ¼ 218 K between the RT and LT modifications is reversible. The additional maxima observed in the Fourier-syntheses are associated with coherent parts in domains belonging to various twin fractions. The nature, the probable structure and the temperature variations of the domain boundaries are considered and discussed. It is suggested that the specific effect observed on 127 I NQR spectra for the LT modification between 205 < T K < 218 may be due to the incommensurate nature of the domain boundaries. Low-temperature structural studiesThe small ($ 0.05 mm) single crystal of Cs 3 Sb 2 I 9 used for the room temperature study [4] was also used for the low temperature experiment. The X-ray diffraction measurements were obtained at 130 K from a KM4CCD diffract-

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Bismuth Based Hybrid Perovskites A₃Bi₂I₉ (A: Methylammonium or Cesium) for Solar Cell Application

et al. 2015

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Low-toxic bismuth-based perovskites are prepared for the possible replacement of lead perovskite in solar cells. The perovskites have a hexagonal crystalline phase and light absorption in the visible region. A power conversion efficiency of over 1% is obtained for a solar cell with Cs3 Bi2 I9 perovskite, and it is concluded that bismuth perovskites have very promising properties for further development in solar cells.

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Ferroelectric phase transition in Cs3Bi2I9

Cited by 28 publications

References 3 publications

Crystal and Electronic Structures of Complex Bismuth Iodides A₃Bi₂I₉ (A = K, Rb, Cs) Related to Perovskite: Aiding the Rational Design of Photovoltaics

Crystal and Electronic Structures of Complex Bismuth Iodides A₃Bi₂I₉ (A = K, Rb, Cs) Related to Perovskite: Aiding the Rational Design of Photovoltaics

The LT phase of Cs₃Bi₂I₉

Bismuth Based Hybrid Perovskites A₃Bi₂I₉ (A: Methylammonium or Cesium) for Solar Cell Application

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Ferroelectric phase transition in Cs3Bi2I9

Cited by 28 publications

References 3 publications

Crystal and Electronic Structures of Complex Bismuth Iodides A3Bi2I9 (A = K, Rb, Cs) Related to Perovskite: Aiding the Rational Design of Photovoltaics

Crystal and Electronic Structures of Complex Bismuth Iodides A3Bi2I9 (A = K, Rb, Cs) Related to Perovskite: Aiding the Rational Design of Photovoltaics

The LT phase of Cs3Bi2I9

Bismuth Based Hybrid Perovskites A3Bi2I9 (A: Methylammonium or Cesium) for Solar Cell Application

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Crystal and Electronic Structures of Complex Bismuth Iodides A₃Bi₂I₉ (A = K, Rb, Cs) Related to Perovskite: Aiding the Rational Design of Photovoltaics

Crystal and Electronic Structures of Complex Bismuth Iodides A₃Bi₂I₉ (A = K, Rb, Cs) Related to Perovskite: Aiding the Rational Design of Photovoltaics

The LT phase of Cs₃Bi₂I₉

Bismuth Based Hybrid Perovskites A₃Bi₂I₉ (A: Methylammonium or Cesium) for Solar Cell Application