Effect of Methylammonium Iodide on the All-solution Prepared Methylammonium Bismuth Iodide Perovskite Solar Cells Performance

Abstract

The methylammonium bismuth iodide (MBI), a promising lead (Pb)-free perovskite solar cells (PeSC’s) material, is suitable for photovoltaic applications due to less toxic and good stability. Herein, the effect of MAI (methylammonium iodide) on the structural, morphological, optical properties and solar cells performance of bismuth-perovskite solar cells (Bi-PeSC’s) by all-solution processed multi-step spin coating is investigated. The scanning electron microscope (SEM) morphology visually depicts that with the increase of methylammonium iodide (MAI) precursor molar ratio in bismuth (III) iodide (BiI3) x [= [MAI]/([MAI]+[BiI3])] from x=0 to x=0.8, the morphological phase changed significantly. Likewise, the x-ray diffraction (XRD) peak of BiI3 at 12.78o (003) is tremendously changed in the phase and intensity. At the same time, the solar cell performances exhibit gradual increment as increasing the content of MAI in BiI3 and the open circuit voltage (Voc) is exceeded four-times of the minimum MAI molar ratio. The maximum Voc obtained by multilayer Bi-PeSC’s is 0.34V and an efficiency shows an increment up to 0.0037% at MAI molar ratio, x=0.8. In brief, our findings suggested the improvement of Bi-perovskite absorber layer in the future.

Keywords

• mbi
• bismuth-perovskites
• perovskites solar cells
• mai ratios
• bi-pesc’s