Effect of 3,5‐Substitutions in Benzannulated Boron‐Dipyrromethene‐Based Organic Dyes on the Photovoltaic Performance of Solar Cells through Quantum Chemical Analysis

This theoretical investigation focuses on 12 benzannulated boron‐dipyrromethene (BODIPY) based dyes (R‐BABDP) as potential new electron donors in organic photovoltaics (OPVs). The present study examines the effect of 3,5‐substitutions of the BODIPY core on their optoelectronic and photovoltaic properties. The ground state geometric and electronic properties are calculated using B3LYP/6‐31G(d,p) method, and the UV‐Vis spectra using TD‐PBE0/6‐311++G(d,p). The designed materials exhibit energy gaps (Δ E HL ) of 2.162–2.539 eV, which are optimal for efficient PV devices. The photovoltaic parameters of dyes are computed in conjunction with the commonly used PC 61 BM electron acceptor. The light harvesting efficiency values range from 0.6577 to 0.8654, open‐circuit voltage ( V oc ) from −0.014 to 1.787 eV, and fill factor (FF) from 0.324 to 0.926. The maximum absorption ( λ max ) range of 541–721 nm demonstrates a significant redshift behavior. The global chemical reactivity indices are as follows: electron affinity ( A , 0.316–2.865 eV), ionization potential ( I , 5.169–7.499 eV), chemical hardness ( η , 2.317–2.595 eV), electrophilicity index ( ω , 1.549–5.794 eV), and electron‐accepting power ( ω + , 0.482–3.493 eV). The correlational analysis reveals a strong correlation between open‐circuit voltage and electron‐accepting power, electrophilicity index, and maximum absorbance. These findings suggest that the designed donors with potential electron‐withdrawing units ( R = NO 2 and R = SO 2 CN), robust stability, and longer λ max can be promising candidates for photovoltaics.