2013/03/28 by Laura E. Ratcliff, Ratcliff, Laura E., Peter D. Haynes +1
Chemistry · Engineering · #Fullerene Chemistry and Applications #Organic Electronics and Photovoltaics #Molecular Junctions and Nanostructures
paper · pdf · doi:10.48550/arxiv.1303.7190
A recently developed linear-scaling density-functional theory (LS-DFT)\nformalism is used to calculate optical absorption spectra of hybrids of C60 and\nthe conjugated polymers poly(para-phenylene) (PPP) and poly(para-phenylene\nvinylene) (PPV). The use of a LS formalism allows calculations on large systems\nwith realistic proportions of C60, which has been of interest for the use of\nsuch materials in photovoltaics. Two different bonding structures are tested\nfor the hybrid PPP and for both systems additional peaks are present in the\nabsorption spectra below the original onset of absorption. By identifying the\neigenstates involved in the relevant transitions, a weighted density difference\nis formed, demonstrating the transfer of charge between the polymer chain and\nthe C60, in agreement with experiment. For the hybrid PPV, no additional peaks\nare observed in the absorption spectrum.\n