Structural phase transition, electronic and optical properties of the 2D hybrid organic-inorganic perovskite-type 2C6MnCl4

Abstract

We have synthesized the hybrid material 1, 6-diaminhexane tetrachloro manganate (2C₆MnCl₄) by slow evaporation at room temperature. The compound 2C₆MnCl₄ was characterized by X-ray Powder Diffraction, Scanning Electron Microscopy, Energy Dispersive X-ray and UV-Visible spectroscopies. Single-crystal X-ray diffraction analysis performed at various temperatures (290, 250, 200, 160, and 150 K) reveals a structural phase transition occurring between 250 and 200 K. The optical measurements show that this hybrid material undergoes an indirect optical transition and presents an energy gap value of about 2.78 eV. The optical reflectance spectrum shows three absorption bands at 361, 422, and 507 nm. The computed band gap electronic was found to be about 2.75 eV which is in good agreement with the experimental value. The electronic total and partial density of states were calculated using density functional theory (DFT) to assess the various orbitals' contributions at the minimum conduction band and maximal valence band.