Quantum-chemical calculations of structure, electronic properties, and spectra of PBDB-T:ITIC hetero-junctions

We modelled PBDB-T:ITIC heterojunctions by applying DFT on dimers built of various conformersof a PBDB-T segment and the ITIC molecule. These variations represented the non-uniformity ofthe interface between the donor and the acceptor in the organic solar cell. Based on this model,we calculated electronic and optical properties most relevant for charge separation at the interfaceusing DFT and TD-DFT, respectively. For almost half of our modelled dimers, we found that theband offsets between them and the pristine donor and acceptor materials resulted in charge carriertrapping leading to inefficient charge separation as well as non-geminate recombination. When wecalculated the exciton binding energy by TD-DFT using either the B3LYP or the HSE06 functional,we obtained very different qualitative and quantitative results. This dataset contains the GAUSSIAN .log and .cub files for all calculations used in the publication.