Predictive Simulations for Tuning Electronic and Optical Properties of SubPc Derivatives

TL;DR

This paper uses first-principles simulations to explore how substituting atoms in boron subphthalocyanine chloride can enhance its electronic and optical properties for better organic photovoltaic performance.

Contribution

It introduces a computational approach to predict and optimize the properties of SubPc derivatives by atom substitution and crystal structure modeling.

Findings

Substitution modifies molecular dipole moments significantly.

Predicted crystal structures show stable configurations after energy minimization.

Enhanced electronic and optical properties are achieved through specific atom substitutions.

Abstract

Boron subphthalocyanine chloride is an electron donor material used in small molecule organic photovoltaics with an unusually large molecular dipole moment. Using first-principles calculations, we investigate enhancing the electronic and optical properties of boron subphthalocyanine chloride, by substituting the boron and chlorine atoms with other trivalent and halogen atoms in order to modify the molecular dipole moment. Gas phase molecular structures and properties are predicted with hybrid functionals. Using positions and orientations of the known compounds as the starting coordinates for these molecules, stable crystalline structures are derived following a procedure that involves perturbation and accurate total energy minimization. Electronic structure and photonic properties of the predicted crystals are computed using the GW method and the Bethe-Salpeter equation, respectively. Finally, a simple transport model is use to demonstrate the importance of molecular dipole moments on device performance.