This work aims to provide theoretical guidance about fabricating high-efficiency electroluminescent materials by means of smart molecular design. 

Density functional theory is utilized to investigate the geometric structures of the two heterocyclic thiophene and silicon pentadiene dithienosiloles (DTS) derivatives. 

It is shown that different substituents in the side chain have minor influences on the geometric properties of rigid molecules, whereas the electronic structure and charge transport performance can be tuned effectively. 

5-flurophenyl DTS can be regarded as a promising bipolar charge transport material with equilibrated hole and charge transfer performance.