Non-Corrosive Conjugated Polyelectrolyte as Anode Interlayer for Efficient and Stable Organic Solar Cells: Over 20%...

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Organic solar cells (OSCs) achieve high power conversion efficiencies (PCEs) but rely on corrosive acid-doped anode interlayers (AILs).
• The industrialization of OSCs is hindered by the corrosion issues associated with current AILs, limiting their long-term stability and viability.
• Existing non-corrosive AILs often underperform compared to traditional acid-doped options like PEDOT:PSS.

Purpose of the Study:

• To design and synthesize novel pH-neutral conjugated polyelectrolytes (CPEs) for use as non-corrosive AILs in OSCs.
• To investigate the impact of CPE conformation on charge transport properties and device performance.
• To achieve high PCEs and enhanced stability in OSCs using these new non-corrosive AILs.

Main Methods:

• Synthesis of two pH-neutral conjugated polyelectrolytes (CPEs) with distinct conformations (linear and zigzag).
• Fabrication of OSC devices utilizing the synthesized CPEs as anode interlayers.
• Characterization of the morphological, electronic, and photovoltaic properties of the CPE-based AILs and devices.

Main Results:

• The linear CPE, IDT-F, exhibited a dominant face-on orientation, facilitating efficient charge transport pathways.
• IDT-F-based AIL demonstrated superior hole-transporting capability compared to PEDOT:PSS.
• OSCs employing the IDT-F-based AIL achieved a record PCE of 20.06% with a fill factor of 82.2%, alongside excellent device stability due to chemical inertness.

Conclusions:

• pH-neutral CPEs can serve as high-performance, non-corrosive AILs for OSCs.
• The linear conformation of IDT-F promotes efficient charge transport and high photovoltaic performance.
• These findings pave the way for the industrialization of stable and efficient OSCs by addressing critical corrosion issues.