Unravelling the photovoltaic response of butterfly-shaped fulvene based chromophores with the influence of double acceptor moieties: A DFT approach

Abstract

Herein, a series of butterfly-shaped fulvene based acceptor molecules ( and ) with A2-π-A1-π-A2 configuration was designed to explore their photovoltaic behavior. This designing strategy was carried out incorporating extended end-capped acceptors at the peripherals of conjugated tetraphenyl fulvene core (). Density functional theory (DFT) and time-dependent DFT (TD-DFT) approaches were conducted on the designed compounds to elucidate their structure–property relationships, photovoltaic and opto-electronic characteristics. Various analyses like HOMO-LUMO energy gaps, absorption maxima, density of states, binding energies of electrons and holes, transition density matrix, and open-circuit voltage, were employed to investigate photovoltaic behaviour of the entitled compounds. Interestingly, all the designed molecules ( and ) exhibited remarkable photovoltaic characteristics, such as minimal bandgap values in range of 2.275–2.310 , red-shifted absorption maxima (range 715–722 ) with good open-circuit voltage values. Moreover, all the derivatives exhibit lower binding energies with a decreasing order of Particularly, reveal the smallest exciton binding energy of 0.546 . These findings suggest that the entitled newly tetraphenyl fulvene based NFAs specifically hold significant potential as highly efficient candidates in the field of organic solar cells.