Design of High Performance Graphene Thin Films Perovskite Solar Cells by Numerical Modeling Based on Coupled Differential Equations

In this study, graphene a two dimensional nanomaterial was prepared by modified Hummer’s method and the optical properties were explored using UV-visible spectroscopy to determine absorption coefficients at different wavelengths based on Beer-Lambert’s law. Graphene based lead-free methyl ammonium germanium halide solar cell was designed in the second stage using graphene oxide (GO) as carrier absorbers and transporters. Numerical modelling of the device in solar capacitance stimulating (SCAPS 1D) program based on second order differential equation was done. A photovoltaic parameters of 0.6227 V, 38.58 mAcm-2, 83.07 %, 19.95 % were recorded as the open-circuit voltage, current density, fill factor and power conversion efficiency (PCE) for FTO/GO/Perovskite/Cu2O/Au. Using the same settings for the second design, the Au/spiro-ometad/FASnI3/TiO2/FTO, the current density increases sharply from 0.50 V and with valence and conduction band at -0.35 eV and 1.78 eV respectively. The light transmittance and heat distribution across the device determine by origin pro-version 9.8.0200 indicated uniform transmission and absorption. The study showed that the presence of graphene, improved the optical transparency and enhanced carrier generation and interaction between other layers which optimized the electrical conductivity and efficiency of the solar cells when compared to previous studies in the literature. The results emphasized a viable approach in the design of efficient and stable solar cells at a reduced cost and optical losses. If mass produced can be deployed commercially due to enhanced solar energy absorption potential ahead of the Si based PVCs.