Thieno[3,2-b]thiophene-based conjugated polyfluorene copolymer for efficient polymer solar cell

Area of Science:

• Organic electronics
• Polymer chemistry
• Materials science

Background:

• Polyfluorene derivatives are promising materials for organic electronics.
• Efficient charge transport and broad absorption are key for high-performance organic solar cells.

Purpose of the Study:

• To synthesize and characterize a novel polyfluorene derivative incorporating octyl-substituted thieno[3,2,-b]thiophene and 2,1,3-benzothiadiazole units.
• To evaluate the performance of the synthesized polymer in organic solar cells.

Main Methods:

• Chemical synthesis of the polyfluorene derivative.
• Characterization of the polymer's optical and electrochemical properties.
• Fabrication and testing of organic solar cells using the polymer as the active layer with phenyl-C61-butyric acid methyl ester (PCBM) and phenyl-C71-butyric acid methyl ester (PC71BM) as electron acceptors.

Main Results:

• The synthesized polyfluorene derivative exhibited favorable characteristics for photovoltaic applications.
• Organic solar cells utilizing the polymer achieved power conversion efficiencies (PCEs) of 1.63% with PCBM.
• A higher PCE of 2.31% was obtained when using PC71BM as the electron acceptor.

Conclusions:

• The novel polyfluorene derivative demonstrates potential for use in efficient organic solar cells.
• The choice of fullerene derivative significantly impacts the device performance.
• Further optimization of the polymer structure and device architecture could lead to enhanced efficiencies.