Influence of Molecular Polarizability on the Active Layer of Organic Photovoltaic Cells: A case study of Poly(3-hexylthiophene)

Abstract

The complexity of the microstructure of the active layer in organic photo- voltaics (OPVs) poses a unique challenge in improving the efficiency of OPV devices. Molecular dynamics (MD) simulation provides a direct route to determining this microstructure. However, for a donor material like poly (3- hexylthiophene), (P 3HT ) n , approximations made in all previous force field for MD simulation has been the neglect of explicit polarization. We looked at the morphology of (P 3HT ) n using MD simulations at different temperatures where we confirmed the semi-crystalline behavior of P3HT between temper- atures of 300 K and 400 K. In line with this, we developed force fields from ab initio data with and without inclusion of explicit molecular polarizability for dimers of (P 3HT ) 1 with monomers optimized at the MP2/cc-pvtz level.