Structure And Photophysical Properties Fullerenes Deirvatives: Molecule Design For Novel Solar Cell Acceptor Mateirals

In the recent years, it is one of the most important methods to improve and explore newmateriel by introducing functional groups to fullerenes molecule in order to adjust thestructure and charge transfer property and improve the material electronic transport capability.However, it is not so clear for the relationship between luminescent mechanism, structure andspectrum properties, and the theory study still is few. In our paper we study and explore therelation between structure and luminescence behavior, structure and carrier transport propertyof a series of fullerenes derivates molecule by using density functional theory(DFT) and timedependent density functional theory (TDDFT).The result shows,1) TD-O3LYP/6-31G*is the most appropriate in describing theelectronic spectroscopic properties of PCBM analogs. The calculations for excitation states ofPCBM indicates that only the shoulder peak of electronic transitions of excitation states at430nm is contributed by charge transport (CT) from the benzene ring to C60cage, others areall identified to Ï€â†'Ï€*like transition. This makes it attractive for future possible photovoltaicapplications. The absorption characteristics of the PCBM derivatives are governed by the Ï€system of the fullerenes.2) B-PC70BM (BP7) can improve the efficiency by increasing theopen-circuit voltage and charge transfer mobility while using as a good candidate for acceptormaterial in bulk heterojunction solar cell.