Anchoring groups for dyes in p-DSSC application: insights from DFT.

Area of Science:

• Computational Materials Science
• Surface Chemistry
• Renewable Energy Technologies

Background:

• Antiferromagnetic nickel oxide (NiO) is a promising material for p-type dye-sensitized solar cells (p-DSSCs).
• Understanding organic ligand interactions with NiO surfaces is crucial for optimizing p-DSSC performance.
• Previous studies lack detailed computational insights into ligand binding and electronic effects on NiO surfaces.

Purpose of the Study:

• To computationally investigate the chemisorption of four organic ligands on an antiferromagnetic NiO (100) surface.
• To analyze the impact of ligand adsorption on the electronic properties (density of states) of the NiO substrate.
• To evaluate the implications of these findings for the operational principles of p-DSSCs.

Main Methods:

• Hybrid, periodic, spin-polarized density functional theory (DFT) calculations were employed.
• Calculations focused on bulk antiferromagnetic NiO and its clean (100) surface.
• The binding of four different organic ligands to the NiO (100) surface was simulated.

Main Results:

• Strong chemisorption of all investigated ligands onto the NiO surface was observed, evidenced by short interatomic distances and high binding energies.
• Ligand adsorption induced significant modifications to the density of states of the NiO substrate.
• Despite electronic modifications, the overall binding scenarios align with p-DSSC operational principles.

Conclusions:

• Organic ligands exhibit strong binding to NiO surfaces, essential for anchoring dyes in p-DSSCs.
• Some ligands significantly lower the NiO density of states, potentially requiring dyes with deeper HOMO levels.
• Careful ligand selection is necessary to optimize energy level alignment for efficient charge transfer in p-DSSCs.