Organic photovoltaics without p-n junctions: Computational study of ferroelectric columnar molecular clusters

TL;DR

This study uses computational methods to explore ferroelectric columnar molecular clusters, revealing their potential for photovoltaic applications by demonstrating charge separation driven by internal electric fields.

Contribution

It provides a detailed computational analysis of ferroelectric molecular clusters, highlighting their unique structural and electronic properties relevant to organic photovoltaics without p-n junctions.

Findings

B3CA stacks form helix-shaped molecular tubes stabilized by hydrogen bonds.

Uniaxial alignment generates electric fields that can split excitons.

Charge carriers can be driven to opposite ends of the tube, aiding photovoltaic function.

Abstract

Structural and electronic properties of ferroelectric columnar clusters constructed from benzene-1,3,5-tricarboxylic acid, (B3CA)n, were investigated at the Hartree-Fock level. It is shown that B3CA stacks form helix-shaped molecular tubes which are stabilized by intermolecular hydrogen bonds. It is furthermore shown that the strong electric field generated by the uniaxial alignment of the carboxyl groups can split an optically prepared exciton into an electron-hole pair and can drive the charge carriers to the opposite ends of the tube. Some consequences of the phenomenon for photovoltaic applications are discussed.