Methoxy triphenylamine hexaazatrinaphthylene based small molecules as donor material for photovoltaic applications

Organic solar cells (OSCs) are capturing huge interest because of their numerous benefits, which include transparency, flexibility, and solution processability. In current project, five new donor molecules (J1-J5) were designed by employing the strategy of end capped alteration of the acceptor moieties on the two sides of the reference molecule. The Methoxy Triphenylamine hexaazatrinaphthylene (MeO-TPA-HATNA) have been used as a reference molecule in this study. DFT and TD-DFT methods employing B3LYP/6-31G (d, p) functional has been applied to perform different analysis. Geometrical, and opto-electronic features of all tailored chromophores were investigated, and comparison was made with the reference J. Among all tailored molecules, J5 shows highest λ_max (862 nm) with the least band gap of 1.28 eV. TDM and DOS analysis revealed the high rate of charge transfer. Further, reorganization energy calculations are also executed to examine the charge transfer features of the designed molecules. The results shows that J5 among all these molecules has the highest rate of charge carrier (electron and hole) mobility with least RE values and this molecule can be used as a promising donor material for OSCs with remarkable charge transferring properties. Furthermore, the designed materials showed a suitable HOMO along with higher LUMO energy levels with respect to PC61BM molecule and coupling the PC₆₁BM acceptor with investigated donor molecules gives highly increased V_oc (0.66-0.76 V) than reference molecule (0.49 V) and also the power conversion efficiency (PCE) is elevated to 15.09%. The outcomes of current theoretical research have demonstrated that the end capped alteration of different acceptor groups is an excellent strategy to get OSCs with desirable photovoltaic performance. As, all the newly created molecules (J1-J5) have exhibited outstanding electronic and optical properties therefore, these can be expectedly prove excellent material for creating high efficiency future organic photovoltaic devices.