A Computational Study on A Series of Phenanthrene and Phenanthroline Based Potential Organic Photovoltaics

Abstract

A series of phenanthrene and phenanthroline derivatives were considered computationally by the application of Density Functional Theory at the B3LYP/6-31++G(d,p) level to investigate their potential usage as organic solar cell components, thermally activated delayed fluorescence and nonlinear optic compounds. The structures were constructed as a D-pi-A motif in order to increase the ability to achieve intramolecular charge transfer enabling them to act as organic semiconductors. The inter-frontier energy gap of all compounds was found to be in the range of semiconductors. The thermally activated delayed fluorescence (TADF) properties of the compounds were also discussed in relation to the results obtained by TD-DFT calculations. Some of them possessed very narrow triplet-singlet transition energy leading to future TADF applications. Moreover, the nonlinear optic characteristics of all compounds were investigated through calculations of the total molecular dipole moment (mu(tot)), linear polarizability (alpha(tot)) and hyperpolarizability (beta(tot)). The results indicate the potential nonlinear optic property of all of the systems.