End-group modification in a fluorene-terminated efficient hole transport materials for organic and perovskite solar cells

Perovskite solar cells having straightforward design, affordable manufacturing process, and good photovoltaic performance are hot topics nowadays. In this study the designing of four small donor molecules (DM-1–DM-4) by replacing the four-sided methoxy groups of DM-R with different thiophene spacer acceptor moieties. The selected DFT basis set B3LYP/6–31 G** (d,p) method has been used for computational analysis to examine developed HTMs. Lower bandgaps (1.74–2.19 eV) were observed for all of the architecture molecules (DM-1-DM-4), compared to the DM-R (3.40 eV) indicating enhanced electron density transfer. When electron pull-out acceptor moieties are selected, all designed molecules (DM-1–DM-4) have high open-circuit voltage (1.84–1.91 V) and deeper HOMO energies (− 5.31– − 4.98 eV). The architecture molecules (DM-1–DM-4) are extremely soluble, as indicated by their large dipole moments (16.42 D–27.97 D), which are projected to make the fabrication of multilayered films. The reorganization energy of the electron shown by DM-3 was 0.0034 eV, While the reorganization energy of the hole examined in DM-2 was 0.0031 it concluded that maximum electron and hole transfer is achieved in the mentioned molecules as compared to other studied molecules. All HTMs (DM-1–DM-4) show better PCEs (21.39–29.38%) and higher FF (0.8803–0.9043) than R (6.72%). This research shows that DM-1–DM-4 molecules are useful building blocks that are proposed as a theoretical method for creating high-performance PSCs.