[18p-PA5-1~22] 6.4 Thin films and New materials

▲ [18p-PA5-16] One-pot solvent free synthesis of BiOI films via oxidation of BiI₃ in air

〇Anissa Adiwena Putri^1,2, Amr Attia Abuelwafa^1,3, Shinya Kato¹, Naoki Kishi¹, Tetsuo Soga¹ (1.Nagoya Inst. of Tech., 2.Walisongo State Islamic Univ., 3.South Valley Univ.)

Keywords:BiOI, direct annealing, air oxidation

Bismuth oxyiodide (BiOI) is the promising bismuth-based materials which has been applied as photocatalyst in waste treatment. Since it has good absorption under visible spectral range, BiOI can be used as the component in photovoltaic devices. While BiOI powder could be obtained from direct annealing of BiI₃, it is also possible to prepare the BiOI films by this BiI₃ powder oxidation. The direct annealing of BiI₃ is preferable for our BiOI preparation since it does need the solvent usage. From the vapor deposition, the deposited BiI₃ in glass substrates could be obtained. Then, the deposited BiI₃ was annealed at 350 ^oC for 1 h to result in the BiOI layer. To study the structural property, all films were characterized by X-Ray diffraction (XRD) and Raman spectrophotometer. To evaluate the optical character and its morphology, the analysis using UV-Visible spectrophotometer and FESEM were also required. The crystal planes (001); (002); (102); (110); (004); (200); and (122) were confirmed by its XRD patterns. However, only three basic crystal planes appeared in the annealed BiI₃ for 45 min, namely (001); (102); and (110). We did not find the BiI₃ residue and BiOI derivations peaks in our diffractogram. By the difference in the thickness and crystal planes composition, those BiOI films may show the different optical and photovoltaic properties. To sum up, the deposition time of BiI₃ had the effect on the amount of the deposited BiOI onto glass substrates. Due to the different amount of the deposited material, the film thickness changed. It may also change other characters, like its optical and other behaviors.