Poster: Stability enhancement in FAPbI₃ perovskite absorbers via Guanidinium doping for photovoltaic applications

Hybrid halide perovskite (HHP) materials present a flexible version of the next-generation photovoltaic technology. Formamidinium lead iodide (FAPbI₃) perovskite has recently gained immense interest as a possible absorber of hybrid halide perovskite (HHP) based solar cells and is extensively investigated both on experimental and theoretical fronts. However, it is unstable against the moisture, making this material domain inappropriate for long run. In the present work, we deal with the synthesis of GA-doped FAPbI₃ (GA_xFA_1-xPbI₃) perovskite material via spin-coating method. The structural and optical properties have been investigated via X-ray Diffraction and UV-Vis/PL spectroscopy, respectively. From XRD, it is found that the GA content plays a vital role in the formation of α-phase and its stabilization over δ-phase. The optical investigation shows the optimum band gap of GA-doped FAPbI₃ perovskite for the photovoltaic application. Also, we have developed theoretical understanding of structural, electronic and optical properties of GA-doped FAPbI₃ using density functional theory (DFT) approach with good matching with experimental results. Our calculations revealed that GA-doped FAPbI₃ can be a suitable candidate for absorber layer in HHP based solar cells.