Carbon Counter-Electrode-Based Quantum-Dot-Sensitized Solar Cells with Certified Efficiency Exceeding 11

Area of Science:

• Materials Science
• Renewable Energy
• Electrochemistry

Background:

• Quantum-dot-sensitized solar cells (QDSCs) face efficiency limitations due to low photovoltage and fill factor.
• These limitations stem from the high redox potential of polysulfide electrolytes and the poor catalytic activity of counter electrodes (CEs).

Purpose of the Study:

• To overcome the efficiency limitations in QDSCs by developing a novel counter electrode.
• To enhance photovoltage and fill factor through improved CE design and electrolyte interaction.

Main Methods:

• Fabrication of a novel counter electrode using titanium mesh supported mesoporous carbon (MC/Ti).
• Characterization of the MC/Ti CE's catalytic activity, conductivity, and structural properties.
• Integration of the MC/Ti CE into CdSe0.65Te0.35 QDSCs and performance evaluation.

Main Results:

• The MC/Ti CE demonstrated robust catalytic capacity and superior three-dimensional electrical conductivity compared to conventional CEs.
• The MC/Ti CE effectively down-shifted the redox potential of the polysulfide electrolyte, promoting higher photovoltage.
• CdSe0.65Te0.35 QDSCs utilizing MC/Ti CEs achieved a certified record power conversion efficiency (PCE) of 11.16%, a 24% improvement.

Conclusions:

• The developed MC/Ti counter electrode effectively addresses key limitations in QDSC performance.
• This advancement offers a promising pathway for further enhancing the efficiency of quantum-dot-sensitized solar cells.