Non-linear Optical (NLO) Properties of Conjugated Thiophene and Ethylene Dioxy Thiophene (EDOT) Oligomers: A Density Functional Theory (DFT) Study
Neranga Abeyasinghe
Department of Chemistry, University of Colombo, Colombo 03, Sri Lanka
Rohini M. de Silva
Department of Chemistry, University of Colombo, Colombo 03, Sri Lanka
K. M. Nalin de Silva *
Department of Chemistry, University of Colombo, Colombo 03, Sri Lanka and Sri Lanka Institute of Nanotechnology, Nanotechnology and Science Park, Mahenwatta, Pitipana, Homagama, Sri Lanka
*Author to whom correspondence should be addressed.
Abstract
We report accurate nonlinear optical (NLO) properties of mixed thiophene and ethylene dioxythiophene oligomers using Density Functional Theory at the B3LYP and B3PW91 levels of theory using 6-31G basis set using Gaussian98 software package. The geometry optimizations of all molecules were performed using the same level of theory. The first static hyperpolarizabilities (β) of these molecules were calculated using B3LYP and B3PW91/6-31G using the same software package. The HOMO-LUMO gaps of these molecules were also calculated using the same level of theory. The calculation of hyperpolarizabilities of these molecules could prove useful owing to the recent reports of the synthesis of these molecules for optoelectronic applications.
Keywords: Ethylene dioxythiophene, thiophene, hyperpolarizability, density functional theory, non linear optics