First example of vinylbenzene based small photovoltaic molecules: Towards the development of efficient D-π-A configured optoelectronic materials for bulk heterojunction solar cells.

Making contribution to the development of novel photovoltaic materials for solar cell applications, we rationally developed six novel vinylbenzene based planar donor-π-acceptor (D-π-A) compounds. Optoelectronic properties of developed molecules are determined using frontier molecular orbital (FMO), UV–Visible, density of state (DOS), transition density matrix (TDM) heat map, open circuit voltage (Voc), binding energies (E b), reorganization energy of electron (λ e), hole (λ h), charge transfer analysis and compared with reference DVB-T-ID. Donor group modifications effectively contributed to augment photovoltaic features in all developed compounds. Developed molecules are found with reduced energy gap (2.566–1.805 eV), broaden absorption wavelength (548.09–800.36 nm) and small transition energy (2.262–1.549 eV) as compared to reference DVB-T-ID values 2.819 eV, 492.84 nm and 2.515 eV respectively. The developed molecules have proficient hole and electron transfer mobilities and can serve as best candidate when blended with PC 61 BM film. Optoelectronic features of all developed molecules especially D5 is ascertained eye-catching as compared to DVB-T-ID , hence recommended for future solar cell applications. [Display omitted] • Six vinylbenzene based planar D-π-A photovoltaic compounds are designed by donor group modifications. • The optoelectronic properties were studied in detail using DFT and TDDFT calculations. • FMO, UV–Visible, DOS, ODOS, TDM, Voc, reorganization energy of electron and hole, binding energy and charge transfer analysis are performed. • All vinylbenzene based investigated molecules exhibited remarkable optoelectronic properties. • Investigated molecules are recommended for future solar cell applications. [ABSTRACT FROM AUTHOR]