Theoretical Study of Some Cyclopentene and Cyclohexene Derivatives of C60 and C20 Nano Fullerenes as Electron Receptors for Polyhexyl Thiophene (P3HT) Polymer in Organic Photovoltaic

Organic photovoltaic cells (OPV) have an active part that is inclusive two parts; electron donor and electron receptor. In this work, Polyhexyl thiophene (P3HT) polymer is considered as an electron donor and some cyclopentene and cyclohexene derivatives of C60 and C20 nanofullerens as electron receptors, that using Gaussian 09 software and density functional theory (DFT) at B3LYP/6-31G (d, p) level are evaluated. After optimization of the structures, the contribution of s and p orbitals and also, energy resonance  π→π* in molecules, some of quantum descriptors such as HOMO and LUMO energy, energy gap (Eg), chemical potential (μ), chemical hardness (η), electrophilicity index (ω) and maximum charge transfer (∆Nmax) were performed. The value of the open circuit voltage (Voc), which is one of the most important parameters indicating efficiency of a solar cell (η), was obtained for the studied molecules with Gaussian outputs. Results show that cyclopentene and cyclohexane derivatives of C60 and C20 nanofullerens can have be desired efficiency as receptors in photovoltaic cells. However, the cyclopentene derivatives will be more effective than cyclohexene derivatives in solar cells.