Lead-free perovskite using formamidinium iodide (FAI) and antimony trichloride (SbCl3) by inverse temperature crystallization method: Bandgap value UV/VIS spectroscopy

Out of concern over the harmful nature of lead, lead-free halide perovskites have attracted interest in the photovoltaic industry. One such substance suggested to replace lead-based perovskites is antimony-based perovskite, formamidinium antimony trichloride (FASbCl3), since it has a high coefficient of absorption, a nearly direct bandgap and a low effective density. Efficient use in photovoltaic applications will result in a clear explanation of the stability of this material. Here, the band gap energy is a factor that needs to be considered in the choice of solar cell material. The band distance energy is the minimal energy between the valence band ends and the conduction band. Manufacture of perovskite using FTO glass with a material composition FAI, SbCl3, solvent DMF and DMSO using the inverse crystallization temperature method. The UV/Vis spectroscopy difference test results resulted in a band gap value of 2.4 eV with the addition of 1 ml of solvent, a band gap value of 2.3 eV with the addition of 0.5 ml of solvent, and a band gap value of 2.6 eV with the addition of 0.8 ml of solvent. This illustrates that the greater the value of absorption, the smaller the bandgap that occurs. The low band gap distance is because the energy required to excite electrons is also getting smaller from the valence band to the conduction band.