Solution-processed mixed halide CH3NH3PbI3−xClx thin films prepared by repeated dip coating

• Published in: Journal of materials science Vol. 54; no. 18; pp. 11818 - 11826
• Main Authors: Karim, A. M. M. Tanveer, Hossain, M. S., Khan, M. K. R., Kamruzzaman, M., Rahman, M. Azizar, Rahman, M. Mozibur
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2019; Springer Nature B.V
• Subjects: absorbance; Absorption spectra; Absorptivity; ambient temperature; Cathodoluminescence; Characterization and Evaluation of Materials; chemical bonding; Chemical Routes to Materials; Chemistry and Materials Science; Classical Mechanics; coatings; Crystallography and Scattering Methods; crystals; emissions; energy; Energy gap; Hydrogen bonds; Immersion coating; Light emission; Materials Science; Metal halides; Optoelectronics; Perovskites; Photoluminescence; Polymer Sciences; Scanning electron microscopy; Solid Mechanics; Temperature dependence; Thin films; X-ray diffraction
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-019-03740-0

The mixed halide CH 3 NH 3 PbI 3−x Cl x crystalline thin film has been prepared by two-step solution-processed repeated dip coating method at an ambient atmosphere. X-ray diffraction study reveals the presence of tetragonal and cubic phases in deposited film. Raman study confirms the metal halide bond in the inorganic framework and organic CH 3 stretching/bending of C–H bond in CH 3 NH 3 PbI 3−x Cl x perovskite. Scanning electron microscopy shows that cuboid and polyhedral-like crystal grains of 100 nm to 2 μm may find applications in optoelectronics. The perovskite CH 3 NH 3 PbI 3−x Cl x thin film shows high spectral absorption coefficient of the order of 10 6  m −1 . In optical band gap study, we found the coexistence of cubic and tetragonal perovskite phases. The energy band gap is dominated by cubic phase having E g  = 2.50 eV over tetragonal phase with band gap E g  = 1.67 eV. The room-temperature photoluminescence study confirms band edge, shallow and deep-level emissions. The temperature-dependent cathodoluminescence study shows red, green and ultraviolet emissions. The dominating green luminescence evolved for cubic phase at 2.51 eV. The red and ultraviolet emissions are also found for mixed-phase CH 3 NH 3 PbI 3−x Cl x thin film, suitable for preparation of light-emitting devices.