Modelling, synthesis, fabrication, and characterization of a novel lead-free organo-inorganic iodide perovskite for photovoltaic application

Abstract

This work is aimed at modelling, synthesizing, and characterizing of a novel lead-free organo-inorganic halide perovskite for photovoltaic application. A planar solar cell device architecture was employed in the fabrication with graphite anode. Thermo-gravimetry analyzer (TGA) was used to determine the thermal stability under nitrogen flow from 20 ^oC to 870 ^oC. The TGA result exhibits thermal stability above 200 ^oC. X-Ray Diffraction (XRD) was used to confirm the crystallinity formation, several peaks were observed with the most prominent peaks at 2Ө = 19.0^o, 29.5^o, and 33.3^o with average crystalline size of 42 nm calculated using Scherrer’s equation. The Field Emission Scan Electron Microscope/Energy Dispersion Spectroscope (FESEM/EDS) results showed a plate-like/cubic structure of hexagonal crystal shapes. These shapes are agglomerated in nature with fine and coarse grains, which might improve the photo-excited electrons diffusion through aggregating the light scattering properties and effective mean path of light of perovskite solar cell. Differential Scanning Calorimetry (DSC) results showed that gradual decomposition of the material can only be visible between 200 ^oC and 240 ^oC with the peak at 223.9 ^oC. The photoluminescence properties of the synthesized perovskites light absorbing layers exhibit a broad band spectrum emission within the range of 340 to 588nm, which is within visible spectrum. The UV-vis spectrum exhibits a strong optical absorption band in the visible region, which extends from 360 nm to 725 nm. The band gap energy was calculated from the plotted Tauc fit and estimated to be 1.99 eV. The J-V of the synthesized material recorded the highest PCE of 4.6 % with a fill factor of 19.56.