Design, theoretical study and correlation of the electronic and optical properties of diethynylphenylthiophene as photovoltaic materials

Abstract

In this work the authors reported the design of molecules with low molecular weight, which can be used in environmental applications. The systems are derived of diethynylphenylthiophene (LMWOM) coupled to phenyldiamine as spacer, forming hyper conjugated macrocycles (p-PDT, m-PDT, o-PDT, p-ZnPDT, m -ZnPDT and o-ZnPDT). Similar structures are used as sensitized materials in photovoltaic cells. The optical, geometric, electronic and photovoltaic properties was estimate using DFT, base B3LYP 6–31g (d, 2p) in Gaussian 09, software of quantum chemistry. The experimental correlation was calculated thorough of electrochemical analyses for HOMO, LUMO and GAP parameters. The results obtained to allow a rationalization or explanation of the experimental data. On the other hand, the acid Lewis effect was considered incorporating zinc(II) to lineal and macrocycle structures. The best photovoltaic parameters were described for the p-PDT molecule with PCE 26.18%, Jsc = 14.79 mA cm2 and ΔE = 2.66 eV. Also, they were also observed electronic effects in the stabilization of macrocycle, influenced by the isomer spacer. The metal ion presented three effects between lineal and macrocycle structures: To improve the electronic distribution between donor and acceptor, provides rigidity to the system favoring the optical and electronic properties and decreases GAP value. Finally, the authors correlate experimentally the method used theoretically, and it are proposed molecules with competitive properties in relationship to organic systems used as photosensitized materials, currently.