Molecular engineering strategy of naphthalimide based small donor molecules for high-performance organic solar cells

Abstract

In current study, four novel (A2-Л-A1-D-A1-Л-A2) type molecules namely NIDCS1, NIDCS2, NIDCS3, and NIDCS4 having central donor core (1,4-dimethoxybenzene) and end-capped bis(2-(5-(4-(N-(2-ethylhexyl)1,8-naphthalimide)yl) acceptors linked via thiophene spacer have been designed. Frontier molecular orbitals, UV–vis spectrum, density of states, transition density matrix, and reorganizational energies (RE) have been evaluated through density functional theory via CAM-B3LYP/6-31G** level of theory to find best candidate for photovoltaic applications. Among all designed molecules NIDCS3 is superior because of high maximum absorption value (454 nm), low energy gap (2.56 eV), high hole mobility (0.007408), and comparable open-circuit voltage as compared to reference molecule. Moreover, the combination of PC61BM/NIDCS3 molecule has been examined for efficient charge transfer which indicates that our investigated molecules act as donor material for high-performance organic solar cell. All designed molecules have shown the enhanced afore-said parameters that is plausible reason for their potential use in contriving the future proficient OSCs.