Non-Covalent Postfunctionalization of Dye Layers on TiO₂ - A Tool for Enhancing Injection in Dye-Sensitized Solar...

Area of Science:

• Materials Science
• Photovoltaics
• Nanotechnology

Background:

• Titanium dioxide (TiO2) nanoparticle films are crucial components in dye-sensitized solar cells (DSSCs).
• Tailoring dye layers is essential for optimizing light harvesting and charge transfer efficiency in DSSCs.
• Developing advanced functionalization strategies can improve the stability and performance of DSSC devices.

Purpose of the Study:

• To report on newly tailored dye layers for covalent and non-covalent functionalization of TiO2 nanoparticle films.
• To investigate a functionalization concept combining stable covalent attachment with reversible hydrogen bonding.
• To integrate porphyrin and BODIPY dyes for enhanced photophysical properties and DSSC performance.

Main Methods:

• Employing tailored dye layers for both covalent deposition and non-covalent post-functionalization of TiO2 nanoparticle films.
• Utilizing a functionalization concept involving Hamilton receptor-cyanuric acid binding motif for reversible hydrogen bonding.
• Step-by-step integration of a first porphyrin layer and a second porphyrin/BODIPY layer.
• Probing photophysical properties of individual dye components and their combinations.

Main Results:

• Successful implementation of a dual-layer functionalization strategy on TiO2 nanoparticle films.
• Demonstration of intermixing stable covalent attachment with versatile reversible hydrogen bonding.
• Identification of promising dye combinations with enhanced photophysical properties.
• Achieved up to a 43% increase in overall DSSC efficiency by adding the second porphyrin/BODIPY layer relative to the first porphyrin layer.

Conclusions:

• The developed functionalization concept enables precise control over dye layer assembly on TiO2 nanoparticles.
• The combination of covalent and non-covalent interactions leads to improved dye layer stability and performance.
• The integration of porphyrin and BODIPY dyes significantly boosts the efficiency of dye-sensitized solar cells.
• This approach offers a promising pathway for designing next-generation high-efficiency solar cells.