Metal-Complex-Functionalized Terpolymer Donors Enabling Efficient Solar Cells via Enhanced Dielectric Constant and...

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• The dielectric constant (εr) is crucial for exciton dynamics in polymer solar cells (PSCs), impacting performance.
• Low εr in conventional polymer donors causes high Coulombic interactions and energy loss (Eloss).

Purpose of the Study:

• To address low dielectric constants in polymer donors for improved PSC performance.
• To develop a dielectric engineering strategy for high-efficiency polymer donors.

Main Methods:

• Incorporated zinc porphyrin units into the D18 polymer donor matrix to create terpolymers (D18-Px).
• Investigated the effect of zinc-porphyrin incorporation on εr, molecular aggregation, and film morphology.
• Evaluated the performance of D18-P5:L8-BO blends in PSC devices.

Main Results:

• Terpolymers exhibited significantly enhanced εr and improved molecular aggregation.
• D18-P5:L8-BO blend films showed better miscibility, charge extraction, and transport.
• Achieved minimized non-radiative energy loss to 0.212 eV.
• Attained a record power conversion efficiency (PCE) of 20.27% for metalated complex-based PSCs.

Conclusions:

• Dielectric engineering via zinc porphyrin incorporation is an effective strategy for high-performance polymer donors.
• Increasing εr and minimizing non-radiative losses are key to boosting PSC efficiency.
• This approach offers a facile route to developing advanced polymer donors for efficient PSCs.