Exploaration of the influence of end-capped structural modification on photovoltaic properties of selenopheno-thiophene core based non-fullerene chromophores: A DFT study

Abstract

In current study, six novel selenopheno-thiophene (ST) core-based chromophores (SePTD1- SePTD6) with A-D-A configuration were designed via structural tailoring with terminal acceptors of SePTR. The optoelectronic and photovoltaic properties of SePTD1-SePTD6 were explored through TDDFT/DFT approaches. The B3LYP/6–31 G(d,p) level was chose through benchmarked study with the help of DFT and experimental UV-Vis values of SePTR. All tailored chromophores exhibited a comparatively smaller band gap (2.144–2.003 eV), along with a significant bathochromic shift (676.8–724.2 nm) and an increased rate of charge transference then reference chromophore (2.119 eV and 686.6 nm). Among all derivatives, SePTD2 exhibited some unique characteristics such as, least HOMO/LUMO energy gap (2.003 eV), highest absorption values (665.4 nm in gas and 724.2 nm in solvent), least binding energy (0.291 eV) and also significant value of open circuit voltage (1.860 V). The aforementioned findings suggest that employing molecular engineering with extended acceptors enhances the photovoltaic performance of non-fullerene materials, thereby encouraging experimentalists to develop highly efficient photovoltaic devices.