Multidimensional modelling and designing of efficient small molecule acceptors for organic solar cells

Chemical structural engineering is a helpful method to design the semi-conductors for organic solar cells (OSCs). The understanding of structural and electronic properties of materials is essential for designing and calibration of materials. By making structural adjustments at the terminal position, new small molecule acceptors can be created. Electronic properties are studied in detail. Electrostatic potential both in qualitative and quantitative way is studied to explore the electron density distribution. The electron density is significantly changed on the change of terminal groups. The excited state behaviour has also undergone a noticeable alteration. The increase in electron-deficient character at the terminal location causes the absorption spectra to shift to the red. The structural changes have an important effect on non-covalent interactions also. Through molecular dynamics (MD) simulations, the bulk behaviour of pure small molecule acceptors and their blend with polymer donor PM6 is examined. Radial distribution function is attained from MD simulations. The alteration in terminal groups has significantly changed the packing behavior of pristine acceptors and their blend with polymer donor.