# Optoelectronic properties of one-dimensional molecular chains simulated by a tight-binding model

## TL;DR

This study uses a tight-binding model combined with first-principles calculations to analyze the optical properties of a one-dimensional zinc-phthalocyanine molecular chain, successfully interpreting experimental spectra and highlighting exciton coupling effects.

## Contribution

First application of tight-binding calculations combined with first-principles methods to study optical properties of a molecular chain, emphasizing exciton interactions.

## Key findings

- Successfully interpreted experimental UV-Vis spectra.
- Highlighted the importance of exciton coupling.
- Compared with ab initio results showing similar absorption features.

## Abstract

Studying optical properties of organic materials is important due to the rapid development of organic light-emitting diodes, solar cells, and photon detectors. Here for the first time we have performed tight-binding calculations for singlet excitons, in combination with first-principles calculations of the excited states in molecular dimers, to describe the optical properties of a zinc-phthalocyanine one-dimensional molecular chain. We have included the intra-molecule and charge-transfer excitations and the coupling between them. Our calculations have successfully interpreted a body of experimental UV-Vis optical spectra of transition-metal phthalocyanines. Compared with the previous ab initio calculations for a molecular dimer, the optical absorptions at the split peaks of the Q-bands can be comparable, which indicates the importance of the coupling between the intra-molecular and charge-transfer excitons.

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Source: https://tomesphere.com/paper/1904.01881