Design of fused bithiophene systems containing silole and five-membered heterocycles for optoelectronic materials

Abstract The influence of various substituents of six fused-ring systems designed on the basis of the bithiophene moiety on the geometric and electronic structures , their injection, transport and optical properties, was investigated using quantum chemical computations with the DFT and TD-DFT methods, and the wavefunction CASPT2 method. Compared to the parent compounds, most of modified molecules with substituents at α-position of fused-ring bithiophene get smaller band gaps and are better in the electron injection and transport properties.