Iron-Sensitized Solar Cells (FeSSCs)

Area of Science:

• Materials Science
• Renewable Energy
• Photochemistry

Background:

• Dye-sensitized solar cells (DSSCs) are promising alternatives to silicon cells, excelling in transparency and low-light conditions.
• Ruthenium complexes are benchmark sensitizers in DSSCs due to favorable photophysical properties, but their cost and scarcity necessitate sustainable alternatives.
• Iron (Fe) is an earth-abundant metal with potential for DSSC applications, but Fe(II) complexes typically suffer from short-lived excited states.

Purpose of the Study:

• To develop and characterize novel iron-based sensitizers for dye-sensitized solar cells (DSSCs).
• To overcome the limitations of short excited-state lifetimes in iron complexes for improved solar energy conversion.
• To explore the design of homoleptic and heteroleptic iron complexes and optimize electrolyte composition for iron-sensitized solar cells (FeSSCs).

Main Methods:

• Synthesis and characterization of iron(II) complexes featuring pyridyl-N-heterocyclic carbene (pyridylNHC) ligands to enhance excited-state lifetimes.
• Fabrication and testing of iron-sensitized solar cells (FeSSCs) using designed iron complexes as sensitizers.
• Optimization of sensitizer design (homoleptic to heteroleptic complexes with varying anchoring groups) and electrolyte composition.

Main Results:

• PyridylNHC ligands significantly improved the photophysical properties of iron(II) complexes, extending excited-state lifetimes to tens of picoseconds.
• The developed iron-sensitized solar cells (FeSSCs) achieved a record power conversion efficiency (PCE) of 2% and a photocurrent of 9 mA/cm².
• Cosensitization strategies further enhanced the performance of the iron-sensitized solar cells (FeSSCs).

Conclusions:

• Iron complexes, particularly those incorporating pyridylNHC ligands, are viable and promising sensitizers for dye-sensitized solar cells (DSSCs).
• The developed iron-sensitized solar cells (FeSSCs) demonstrate a significant advancement in sustainable solar energy conversion technology.
• This research opens a fruitful avenue for the development of efficient and earth-abundant metal-based solar cells.