Solution-Processed Transparent Conducting Electrodes for Flexible Organic Solar Cells with 16.61% Efficiency

Area of Science:

• Materials Science
• Organic Electronics
• Renewable Energy

Background:

• Nonfullerene organic solar cells (OSCs) show promise for commercialization with efficiencies over 17%.
• Solution-processed flexible OSCs are crucial for widespread adoption but require optimized manufacturing.
• Transparent conducting polymer anodes are key components in flexible OSCs.

Purpose of the Study:

• To develop high-performance, solution-processed flexible organic solar cells (OSCs).
• To enhance carrier extraction and device stability through anode modification.
• To investigate the impact of trifluoromethanesulfonic acid doping on PEDOT:PSS anodes.

Main Methods:

• Solution processing of flexible organic solar cells (OSCs).
• Doping of PEDOT:PSS anodes with low-concentration, low-temperature trifluoromethanesulfonic acid (CF3SO3H).
• Characterization of anode properties (sheet resistance, work function, wettability, stability) and device performance (efficiency, flexibility, thermal stability).

Main Results:

• Doped PEDOT:PSS anodes achieved a sheet resistance of 35 Ω sq⁻¹, a work function of ~5.0 eV, improved wettability, and high electrical stability.
• Minimized energy level mismatch led to enhanced carrier extraction.
• Solution-processed flexible OSCs achieved a record efficiency of 16.41% (16.61% max).
• Devices demonstrated excellent flexibility (1000 bending cycles at 1.5 mm radius) and thermal stability (85°C).

Conclusions:

• Trifluoromethanesulfonic acid doping is an effective strategy for fabricating high-performance flexible organic solar cell anodes.
• The developed flexible OSCs exhibit promising efficiency, flexibility, and thermal stability for commercial applications.
• Solution processing enables scalable manufacturing of advanced organic photovoltaic devices.