Synergistic Cosensitization and Redox-Triggered Interfacial Engineering for Efficient and Durable Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Dye-sensitized solar cells (DSCs) face challenges in achieving both high power conversion efficiency (PCE) and long-term stability.
• Current strategies often struggle to balance performance with durability.

Purpose of the Study:

• To develop a synergistic strategy combining cosensitization and redox-active interfacial engineering to improve DSC performance and durability.
• To investigate the role of specific sensitizers and electrolyte additives in enhancing device characteristics.

Main Methods:

• Utilized cosensitization with a narrow-energy-gap sensitizer (H4) and a blue-light-absorbing dye (H15).
• Introduced a hypervalent iodine(III) compound (1-acetoxy-1,2-benziodoxol-3(1H)-one, IBA) into a cobalt-based electrolyte.
• Analyzed the effects of IBA and its redox byproduct (2-iodobenzoic acid, IA) on interfacial charge dynamics and recombination.

Main Results:

• Cosensitization compensated for spectral response and reduced charge recombination.
• The IBA additive facilitated electron donor oxidation and enhanced intramolecular charge transfer.
• The redox byproduct IA effectively suppressed interfacial recombination and passivated the interface.
• Achieved a PCE of 12.84% for the cosensitized DSC with excellent operational stability (1000 h indoor light).
• A control device demonstrated a high efficiency of 25.81% under indoor light (4500 lx).

Conclusions:

• The synergistic combination of cosensitization and IBA-mediated interfacial engineering significantly enhances DSC performance and stability.
• This approach offers a promising pathway for developing durable and efficient solar energy conversion devices for indoor applications.