Synthesis and Structural, Crystallographic, Electronic, Chemical and Optical characterizations of Alpha-Diisopropylammonium Bromide (α-DIPAB) Thin Films*

Thin films of the molecular organic ferroelectric diisopropylammonium bromide (DIPAB) have been grown by the slow evaporation technique. We report on the synthesis and characterization of as-grown Alpha-Diisopropylammonium Bromide (α-DIPAB) thin films. In particular, structural, crystallographic, electronic, chemical, and optical properties are measured and interpreted. To elucidate structural and crystallographic properties, X-ray diffraction (XRD) measurements are conducted to reveal that α-DIPAB thin film is polycrystalline and exhibits monoclinic structure. Generalized Gradient Approximation (GGA) and HSE06 hybrid functional methods are employed to calculate band structure and density of states of thin films. Taking into account the Van der Waals forces, HSE06 method yields an optical band gap (≈ 6 eV). Scanning Electronic Microscopy (SEM) micrographs demonstrate that thin-film surface cracks appear dividing the surface into ice land-like regions.