69276-13-7Relevant articles and documents
Properties of CH3NH3PbX3 (X = I, Br, Cl) powders as precursors for organic/inorganic solar cells
Dimesso,Dimamay,Hamburger,Jaegermann
, p. 6762 - 6770 (2014)
CH3NH3PbX3 (X = Cl, Br, I) perovskites were prepared by a self-organization processes using different precursor solutions. The XRD analysis indicates the formation, at room temperature, of a tetragonal structure (space group I4/mcm) for X = I, of a cubic structure (space group Pm3m) for X = Br, and of centro-symmetric cubic structure (space group Pm3m) for X = Cl, respectively. The structural analysis revealed the formation of CH3NH3Cl as secondary phase in the Cl-containing system. The morphological investigation revealed the formation of rhombo-hexagonal dodecahedra crystallite for X = I, Br, whereas cube-like aggregates were observed for X = Cl. The thermogravimetric analysis performed in air did not reveal any loss until 250 °C for X = I and 300 °C for X = Br, respectively, whereas the differential thermal analysis (DTA) detected two endothermic thermal events (at 336 and 409 °C) for X = I and one only (379 °C) for X = Br, respectively. The infrared spectra (IR) of the powders conformed to the 3-fold symmetry of the methylammonium ion which rotates around the C-N axis. Optical absorption measurements indicated that the CH3NH3PbX3 systems behave as direct-gap semiconductors with energy band gaps of 1.53 eV for X = I, 2.20 eV for X = Br, and 3.00 eV for X = Cl, respectively, at room temperature. The direct-gap semiconductivity for X = I and X = Br was confirmed by the photoluminescence emission measurements, whereas the compound for X = Cl is inactive. I-containing powders were dissolved in an organic solvent (dimethyl-formamide, DMF). The dispersion (100-300 μL) was dropped on glassy substrates on which thick films were obtained by spin-coating and thermal treatment at 120 °C for ca. 5 min. The preparation of the layers was performed in air at room temperature.
Structural Phase Transition and Electrical Conductivity of the Perovskite CH3NH3Sn1-xPbxBr3 and CsSnBr3
Yamada, Koji,Kawaguchi, Hiroshi,Matsui, Takashi,Okuda, Tsutomu,Ichiba, Sumio
, p. 2521 - 2525 (1990)
A series of solid solutions, CH3NH3Sn1-xPbxBr3 (X=0-1), having cubic perovskite structures was obtained by solid-state reactions.The 119Sn Moessbauer spectra for xa regular octahedron at 110 K.On the other hand, a single Lorentzian spectrum having a larger isomer shift was observed for x>0.7, suggesting the presence of a regular SnBr6 octahedra in the perovskite CH3NH3PbBr3 matrix.The high electrical conductivity of the perovskite CsSnBr3 drastically decreased upon the replacement of the cation by CH3NH3 and the central metal by Pb.This behavior suggests that both the infinite linear chain (-Br-Sn(Br)-Br-) and its bond length have significant importance regarding electrical conductivity.
Comparative study on the excitons in lead-halide-based perovskite-type crystals CH3NH3PbBr3 CH3NH 3PbI3
Tanaka, Kenichiro,Takahashi, Takayuki,Ban, Takuma,Kondo, Takashi,Uchida, Kazuhito,Miura, Noboru
, p. 619 - 623 (2003)
Optical absorption and magnetoabsorption spectra of the lead-halide-based perovskite-type crystals, CH3NH3PbX3 (X = Br, I) have been investigated. The lowest-energy excitons in these crystals are normal three-dimensional Wannier-type excitons. Bohr radii, binding energies, reduced masses, effective g factors, and oscillator strengths of the excitons have been determined with satisfactory accuracy. A larger bandgap and more tightly bound nature of the excitons in CH3NH3PbBr 3 compared to those in CH3NH3PbI3 are a natural consequence of the halogen substitution.
Dynamic disorder in methylammoniumtrihalogenoplumbates (II) observed by millimeter-wave spectroscopy
Poglitsch, A.,Weber, D.
, p. 6373 - 6378 (1987)
The temperature-dependent structure of crystalline methylammoniumtrihalogenoplumbates (II)-CH3NH+3 PbX-3 (X = Cl, Br, I)-as determined by x-ray diffraction, is compared with measurements of the temperature-dependent complex permittivity at frequencies of 50-150 GHz.The dielectric measurements reveal a picosecond relaxation process which corresponds to a dynamic disorder of the methylammonium group in the high-temperature phases of the trihalogenoplumbates.
In situ gas/solid reaction for the formation of luminescent quantum confined CH3NH3PbBr3 perovskite planar film
Zhang, Taiyang,Li, Ge,Xu, Feng,Wang, Yipeng,Guo, Nanjie,Qian, Xufang,Zhao, Yixin
supporting information, p. 11080 - 11083 (2016/09/19)
We demonstrate a new strategy for the in situ formation of highly luminescent CH3NH3PbBr3 perovskite planar film via the reaction between PbBr2 and methylamine gas. The obtained CH3NH3PbBr3 perovskite planar film exhibited similar quantum confinement to solution chemistry synthesized colloidal CH3NH3PbBr3 quantum dots. Such quantum confinement was realized by a PbOx/Pb(OH)2 framework, which is a by-product formed in situ from the reaction of PbBr2 and methylamine gas under ambient conditions.
