A Nonionic Alcohol Soluble Polymer Cathode Interlayer Enables Efficient Organic and Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Organic Electronics

Background:

• Interfacial materials are crucial for solar cell performance and stability.
• Developing stable cathode interface layers (CILs) compatible with roll-to-roll printing is essential.
• Orthogonal solvent processing over photoactive layers requires specific CIL properties.

Purpose of the Study:

• To develop a universal and efficient CIL for organic and perovskite photovoltaics.
• To create a CIL with good thermal stability and processability in alcohol/water.
• To investigate the impact of the new CIL on solar cell performance and stability.

Main Methods:

• Synthesis of an n-type conjugated polymer based on naphthalene diimide and oligo(ethylene glycol).
• Characterization of the polymer's electron transport properties and electrical conductivity.
• Fabrication and testing of organic solar cells (OSCs) and perovskite solar cells using the new CIL.

Main Results:

• The new CIL exhibits electron transport properties with conductivity of 2.3 × 10⁻⁶ S cm⁻¹.
• Achieved 16% PCE in OSCs (PM6-Y6) and 17.6% PCE in perovskite solar cells.
• Reduced trap-assisted carrier recombination and increased built-in potential by 80 mV.
• Demonstrated improved photostability with no burn-in losses.

Conclusions:

• The developed conjugated polymer serves as an effective universal CIL for both organic and perovskite solar cells.
• The new CIL enhances photovoltaic parameters and device stability.
• This CIL is suitable for scalable, roll-to-roll compatible solar cell manufacturing.