Tailoring of the thieno [3,2-b] thiophene-based molecule towards promising hole transporting materials for perovskite solar cells

[Display omitted] •Computational Study of M3-R and five tailored molecules (M3A1-M3A5) through DFT calculations (MPW1PW91/6-31G/d,p).•Absorption profile, FMOs, DOS, MEPS, TDM, NCI, IS and CDD maps analyzed for assessing the better PCE of designed molecules as compared to M3-R.•Voc of reference (M3-R) and tailored HTMs (M3A1-M3A5) calculated by blending with acceptor PC61BM.•Superior chemical reactivity, increased stability, improved charge mobility and good solubility in THF, addressing reduced charge recombination leading to better-performing PSCs. Perovskite solar cells (PSCs) garnered the interest of researchers owing to their affordable fabrication and higher efficiency. Solution-processing hole transporting materials (HTMs) having remarkable charge mobility are highly appreciated for acquiring improved efficiency of PSCs. In this project, we designed five new HTMs (M3A1-M3A5) based on thieno (3,2-b) thiophene by introducing thiophene linkers and terminal acceptors. Our basic purpose was to enhance photovoltaic and opto-electronic attributes for highly efficient PSCs. We employed MPW1PW91/6-31G for computationally investigating tailored HTMs in terms of geometrical, opto-electronic, charge transferal, and photovoltaic parameters. Outcomes demonstrated a bathochromic shift in both gaseous and THF phases. Our tailored HTMs exhibited deeper HOMO levels (−4.81 → -4.64) along with reduced band gaps (0.94–2.13 eV) as compared to M3-R and Spiro-OMeTAD, referring to improved hole-extraction and solution processing. Lower excitation energies of tailored HTMs lead to minimized energy loss. The reorganization energy of hole (λh) and electron (λe) are quite lower than M3-R suggesting higher charge mobility. Greater hole transfer integral (0.14 eV) points toward better hole transportation along with reduced λe and λh. Considerably greater open-circuit voltage (VOC) ensures the conspicuous efficiency of PSCs. All the findings validated the effectiveness of the applied strategy for the fabrication of HTMs for future PSCs.