Theoretical investigation of efficient perovskite solar cells employing simple carbazole as hole transporting materials

• Modelling of simple Carbazole is carried out with the Gaussian 09 software. • Three Hole transporting materials employing carbazole as the center core units namely Cz-P, Cz-N and Cz-Pyr are reported. • Our systematic study highlights the effect of arene ring in 9 position of carbazole in enhancing the related performance of perovskite solar cells. • The resulting perovskite solar cell has been done by the SCAPS-1D simulator and shown a power conversion efficiency similar the spiroOMeTAD. The purpose of this research is to modelled molecule-based carbazole units as hole-transporting materials (HTMs) for perovskite solar cells using Density Functional Theory. We tried to shed light on the effect of grafting substituents onto the 9 positions of the carbazole unit with benzene (Cz-P), naphthalene (Cz-N), and pyrene (Cz-Pyr). The bandgap, HOMO, LUMO levels, and natural bond orbital (NBO) analysis, as well as the MEP and UV spectra, were predicted. The calculated results indicate that HOMO values of the HTMs examined range from −4.25 to −4.52 eV, which is suitable with the perovskite valence band. The NBO analysis demonstrates that the transitions in the selected compounds are dominated by bonding-antibonding interactions. In addition, the three studied materials were tested in perovskite based solar cell using Solar Cell Capacitance Simulator program (SCAPS-1D). These compounds had similar power conversion efficiencies to SpiroOMeTAD. Consequently, proving the potential of carbazole-based hole transporting materials in perovskite solar cells to achieve higher performance.