Hydrogen-bonded supramolecular assembly of dyes at nanostructured solar cell interfaces

TL;DR

This study uses first-principles calculations to analyze the TiO2/N3 dye interface in solar cells, revealing hydrogen bonding as key to dye arrangement and suggesting supramolecular assemblies influence device efficiency.

Contribution

It introduces a novel modeling approach for semiconductor/dye interfaces, emphasizing hydrogen bonding and supramolecular assembly in dye-sensitized solar cells.

Findings

Hydrogen bonding is essential for accurate interface modeling.

Dyes form supramolecular assemblies at the TiO2 interface.

Modeling insights can guide the design of more efficient solar cells.

Abstract

We calculate from first principles the O1s core-level shifts for a variety of atomistic models of the interface between TiO2 and the dye N3 found in dye-sensitized solar cells. A systematic comparison between our calculations and published photoemission data shows that only interface models incorporating hydrogen bonding between the dyes are compatible with experiment. Based on our analysis we propose that at the TiO2/N3 interface the dyes are arranged in supramolecular assemblies. Our work opens a new direction in the modeling of semiconductor/dye interfaces and bears on the design of more efficient nanostructured solar cells.