New compounds based on quaterthiophene and benzo[1,2,5] thiadiazole for solar cells application: correlation structure/electronic properties

Abstract

In this work, we report theoretical analysis on the geometries and optoelectronic properties of new small conjugated compounds based on quarterthiophene and benzo[1,2,5]thiadiazole as acceptor. These compounds were designed and characterized by using density functional theory (DFT) and time-dependent (TD) calculations. The study of the structural and optoelectronic properties (HOMO, LUMO, Gap energy, Voc) was realized by using DFT method at Becke’s three-parameter functional and Lee– Yang–Parr functional (B3LYP) level with 6-31G(d) basis set. The calculations were performed by Gaussian 09 program supported by Gauss View 5.0. The effects of the electron-donating and electron-withdrawing substituents on the geometries, electronic and photophysical properties of these molecules are discussed to investigate the relationship between structure and optoelectronic properties. These properties suggest these materials as good candidates for organic solar cells.