Quantum-confinement and defect-engineered N,S-carbon nanosheet-ruthenium quantum dot heterostructures for highly...

Area of Science:

• Materials Science
• Nanotechnology
• Renewable Energy

Background:

• Efficient electron transport layers (ETLs) are crucial for high-performance organic solar cells (OSCs).
• Interfacial charge dynamics and defect-mediated recombination significantly impact OSC performance.
• Developing advanced ETLs is key to overcoming current limitations in OSC technology.

Purpose of the Study:

• To engineer a hybrid ETL material for improved charge transport and stability in OSCs.
• To investigate the effects of quantum confinement and defect engineering on ETL properties.
• To enhance the power conversion efficiency (PCE) of inverted OSCs using the novel ETL.

Main Methods:

• Synthesis of a hybrid ETL using porous nitrogen/sulfur co-doped carbon nanosheets decorated with ruthenium quantum dots (NSCNSs/RuQDs) via a one-pot solvothermal method.
• Characterization using structural and spectroscopic techniques to analyze electronic structure, optical absorption, and defect passivation.
• Integration of the NSCNSs/RuQDs as a bilayer ETL in PTB7-Th:PC71BM-based OSCs and performance evaluation.

Main Results:

• The NSCNSs/RuQDs hybrid material exhibited quantum-confinement-driven bandgap modulation and reduced defect-associated recombination.
• Time-resolved photoluminescence showed an extended carrier lifetime (5.44 ns) compared to pristine NSCNSs (1.73 ns).
• Optimized OSCs with the bilayer ETL achieved a PCE of 10.77%, with improved short-circuit current density, open-circuit voltage, and fill factor.

Conclusions:

• The integration of quantum-confined ruthenium quantum dots with heteroatom-engineered carbon frameworks offers a promising strategy for advanced ETLs.
• The developed hybrid ETL effectively passivates defects, enhances charge extraction, and boosts OSC performance.
• This approach holds potential for next-generation optoelectronic and energy-conversion devices.