A Hybrid Density Functional Study of Oligothiophene/ZnO Interface for Photovoltaics

TL;DR

This study uses hybrid-density functional theory to analyze how molecular orientations at the sexithiophene/ZnO interface affect electronic properties and photovoltaic efficiency, highlighting the importance of interfacial design.

Contribution

It provides new insights into how molecular orientation influences electronic structure and photovoltaic performance at organic/inorganic interfaces.

Findings

Interfacial molecular orientations significantly affect adsorption energy.

Orientation impacts energy level alignment and open circuit voltage.

Electronic coupling strength varies with molecular orientation.

Abstract

Organic/inorganic donor-acceptor interfaces are gaining growing attention in organic photovoltaic applications as each component of the interface offers unique attributes. Here we use hybrid-density functional theory to examine the electronic structure of sexithiophene/ZnO interfaces. We find that interfacial molecular orientations strongly influence the adsorption energy, the energy level alignment, and the open circuit voltage. We attribute the orientation dependence to the varied strength of electronic coupling between the molecule and the substrate. Our study suggests that photovoltaic performance can be optimized by controlling the interfacial design of molecular orientations.