| Autor: |
Abia, Carmen, López, Carlos A., Gainza, Javier, Rodrigues, João Elias F. S., Ferrer, Mateus M., Dalenogare, Gustavo, Nemes, Norbert M., Dura, Oscar J., Martínez, José L., Fernández-Díaz, María T., Álvarez-Galván, Consuelo, Alonso, José A. |
| Zdroj: |
Inorganic Chemistry; 20220101, Issue: Preprints |
| Abstrakt: |
All-inorganic lead halide perovskites like CsPbBr3, CsPbI3, or RbPbI3are good replacements for the classical hybrid organic–inorganic perovskites like CH3NH3PbI3, susceptible to fast degradation in the presence of humid air. They also exhibit outstanding light absorption properties suitable for solar energy applications. Here, we describe the synthesis of RbPbI3by mechanochemical procedures with green credentials, avoiding toxic or expensive organic solvents; this specimen exhibits excellent crystallinity. We report neutron powder diffraction data, essential to revisit some subtle structural features around room temperature (200–400 K). In all these regimes, the orthorhombic Pnmacrystal structure is characterized by the presence along the bdirection of the crystal of double rows of edge-sharing PbI6octahedra. The lone electron pairs of Pb2+ions have a strong stereochemical effect on the PbI6octahedral distortion. The relative covalency of Rb–I versus Pb–I bonds shows that the Pb–I-related motions are more rigid than Rb–I-related vibrations, as seen in the Debye temperatures from the evolution of the anisotropic displacements. The optical gap, measured by diffuse reflectance UV–vis spectroscopy, is ∼2.51 eV and agrees well with abinitiocalculations. The thermoelectric Seebeck coefficient is 3 orders of magnitude larger than that of other halide perovskites, with a value of ∼117,000 μV·K–1at 460 K. |
| Databáze: |
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