DFT study of Si/Ge conjugated systems

Abstract

Though significant efforts have been extended to improve material/material design, the organic luminescent molecule containing n-conjugated aromatic system opens a new avenue for understanding the molecular modelling strategies. The molecular electronics components largely depend on n-conjugation as for charge transportation. An n-nconjugated small molecule, formamide was primarily studied within density functional theory (DFT) framework to investigate the Si/Ge substitution effect on its inherent geometric and electronic properties. The nature of hydrogen bond in these types of molecules both at ground state and at low-lying states was also extensively explored based on electronegativity as a part of investigation ofn-conjugated system.Several n-conjugated systems including Si/Ge heteroatoms were then investigated substantially to get deep insight into their geometric and electronic properties, as for example, planarity, dihedral angles, potential energy surface, aromaticity, stability, hyperconjugation, and so on.lt enables someone to modify the structure or composition in search of more active molecules. We continued our OFT studies along with TD-DFT (Time-dependent density functional theory) on n-<:onjugated cyclic structures to know how heteroatoms (like Si, S or N) within conjugated backbone and extension of nconjugation length by incorporation of donor/acceptor fragments under different architectures influence electron delocalization and bring change into their inherent electronic and optical properties. This detailed study is expected to be helpful for effective design of molecular systems for optoelectronic applications.