Group 16 substitution effects on the electronic and optical properties of 1-dimensional conjugated heterocycle oligomers: a relativistic self-interaction corrected real-space TDDFT study.

First-principles calculations employing real-space self-interaction corrected (time-dependent) density functional theory with incorporation of scalar and spin-orbit relativistic corrections have been used to elucidate the electronic characteristics and optical response of linear heterocycle-based oligomers as a function of Group 16 atom substitution. Analysis reveals intense substitution-dependent ultraviolet π-π* transitions in all oligomeric systems investigated. Upon p-type doping via single-hole introduction, these materials exhibit characteristic polaron absorptions in the near-infrared region. In the neutral species, absorption in the visible region is seen only for the heaviest Group 16 substitutions. However, upon oxidation all of the oligomers display significant visible light absorption. The systematic modulation of both optical and band gap properties through chalcogen substitution and charge-carrier doping provides a framework for the engineering of organic materials with applications in multiple technological domains.