Spiro based hole transporting materials improving optical and photoelectric properties for perovskite solar cells

The geometrical, optoelectronic, and photovoltaic characteristics of the spiro-based molecules were studied using density functional theory (DFT) with the B3LYP/6–31 G (d,p) level of theory. The computed results for all the designed molecules (SP1-SP10) based on spiro core using different acceptors through thiophene bridging showed that they are more promising for perovskite solar cells. The newly incorporated moieties in the hole-transporting materials exhibit more negative HOMO energies (−4.70 to − 4.89 eV) and smaller band gaps (1.34–2.12 eV) than the reference compound (HOMO = − 4.65 eV; band gap = 3.51 eV), indicating improved charge-transport characteristics. The designed molecules have higher V_OC (1.23 V to 1.42 V) than the reference molecule (1.18 V). Overall, spiro-based hole-transporting materials enhance the optoelectronic properties of perovskite solar cells and will build on ideas about their applications and enhance the performance of spiro-based molecules in photovoltaic solar cells.