Ternary All-Polymer Solar Cells With 8.5% Power Conversion Efficiency and Excellent Thermal Stability

Area of Science:

• Materials Science
• Renewable Energy
• Polymer Chemistry

Background:

• All-polymer solar cells (all-PSCs) are gaining attention for their potential in renewable energy.
• Efficient photon utilization in polymer:polymer blend films remains a significant challenge.
• Previous work developed NOE10, a polymer acceptor achieving 8.1% power conversion efficiency (PCE) with PBDT-TAZ.

Purpose of the Study:

• To enhance photon utilization and photovoltaic performance in all-PSCs.
• To investigate a ternary all-PSC strategy using a narrow bandgap polymer.
• To improve the power conversion efficiency (PCE) and stability of all-PSCs.

Main Methods:

• Developed a ternary all-polymer solar cell (all-PSC) system.
• Incorporated a narrow bandgap polymer (PTB7-Th) into a PBDT-TAZ:NOE10 binary system.
• Analyzed photovoltaic performance, charge generation, and charge transport.

Main Results:

• Achieved 8.5% power conversion efficiency (PCE) in ternary all-PSCs across a broad polymer ratio.
• Demonstrated enhanced photon absorption, charge generation, and balanced charge transport compared to binary systems.
• Maintained excellent thermal stability, retaining 98% of initial PCE after 300 hours of aging at 65°C.

Conclusions:

• The incorporation of a narrow bandgap polymer is an effective strategy for ternary all-PSCs.
• Ternary all-PSCs offer improved efficiency and stability over binary systems.
• This approach advances the development of high-performance and durable all-polymer solar cells.