Performance Enhancement of NH3(CH2)4NH3CoCl4-Based Perovskite Solar Cell via DFT-Guided SCAPS-1D Simulations

Abstract

This work provides an investigation into enhancing the performance of solar cells based $N{H}_3{\left(C{H}_2\right)}_{4}N{H}_3\mathrm{CoC}{l}_4$, using a unique combination of density functional theory (DFT) calculations and SCAPS-1D device modeling. Through DFT, we determine that $N{H}_3{\left(C{H}_2\right)}_{4}N{H}_3\mathrm{CoC}{l}_4$ has an indirect bandgap of 1.84 eV, closely matching the experimental value of 1.80 eV. The material's electronic structure is largely influenced by cobalt and chlorine atoms, while nitrogen and hydrogen contribute to lattice stability. Optical analysis reveals an initial absorption peak at 5.11 eV, along with effective absorption in the visible spectrum (1.6–3.2 eV). To ensure that SCAPS simulations produce realistic results, we benchmarked SCAPS against a reference device (FTO/$\mathrm{Ti}{O}_2$/$\left[N{H}_3{\left(C{H}_2\right)}_{2}N{H}_3\right]\mathrm{MnC}{l}_4$/Spiro-OMeTAD/Au) and found close agreement with experimental data. With confidence in SCAPS, we utilized DFT-derived parameters for $N{H}_3{\left(C{H}_2\right)}_{4}N{H}_3\mathrm{CoC}{l}_4$, including bandgap, effective masses, density of states, mobilities, and permittivity, as inputs for further simulation. In the optimization phase, parameters such as the thicknesses of the hole and electron transport layers, defect densities, doping concentrations, and temperature effects are systematically adjusted. These optimizations result in a notable power conversion efficiency (PCE) of 19.71% at room temperature.