Scalable PbS Quantum Dot Solar Cell Production by Blade Coating from Stable Inks

Area of Science:

• Materials Science
• Nanotechnology
• Renewable Energy

Background:

• Phase transfer ligand exchange methods have improved lead sulfide (PbS) quantum dot (QD) solar cells but inks often lack colloidal stability, hindering production.
• Current QD solar cell fabrication relies heavily on spin-coating, a wasteful method unsuitable for large-scale manufacturing.

Purpose of the Study:

• To develop a strategy for scalable solar cell fabrication using highly stable PbS QD inks.
• To address the limitations of colloidal instability and deposition methods in PbS QD solar cell production.

Main Methods:

• Dispersing PbS QDs capped with CH3NH3PbI3 in 2,6-difluoropyridine (DFP) to create stable inks.
• Utilizing blade-coating deposition for fabricating PbS QD solar cell layers.
• Evaluating the colloidal stability and photovoltaic performance of the developed inks and solar cells.

Main Results:

• Achieved colloidally stable PbS QD inks lasting over 3 months, even with large-diameter QDs.
• Demonstrated blade-coating deposition of DFP-based inks yielding PbS QD solar cells with up to 8.7% power conversion efficiency.
• Obtained a photovoltaic efficiency of 5.8% using inks stored for over 120 days, confirming ink shelf-life stability.

Conclusions:

• DFP enables the creation of highly stable PbS QD inks suitable for scalable solar cell fabrication.
• Blade-coating deposition with DFP-based inks offers a viable, efficient alternative to spin-coating for QD solar cells.
• The developed inks exhibit excellent shelf-life stability, crucial for commercial solar cell production.