On the True Band Gap of the (CH₃NH₃)₂Pb(SCN)₂I₂ Hybrid Perovskite: An Interesting Solar‐Cell Material

The hybrid halide perovskite methyl ammonium lead iodide thiocyanate – (CH₃NH₃)Pb(SCN)₂I₂ – is synthesized both as a powder and as a thin film. The crystal structure and key optical properties (band gap) are determined by diffuse reflectance spectra and X‐ray diffraction (Rietveld refinement) measurements and compared to density functional theory (DFT) state‐of‐the‐art calculations. It is found that the refined orthorhombic crystal structure presents 2D‐layer confinement, and that the optical band gap presented in this work does confirm some previous reports and rebuts other results, too.