Organic Interlayer for Enhanced Buried Interfaces in Wide-Bandgap Perovskite Solar Cells

Area of Science:

• Materials Science
• Photovoltaics
• Organic Electronics

Background:

• Wide-bandgap perovskite solar cells (PSCs) are crucial for high-efficiency tandem devices.
• Non-radiative recombination at interfaces limits the performance of wide-bandgap PSCs.
• Interlayers in p-i-n architectures are key for charge transport and film quality.

Purpose of the Study:

• To design and implement a novel organic interlayer for wide-bandgap PSCs.
• To address interfacial defects and reduce non-radiative recombination.
• To enhance charge extraction and improve overall device performance and stability.

Main Methods:

• Development of a donor-acceptor quinoxaline-based organic interlayer (QxNN).
• Integration of the interlayer at the NiOx/wide-bandgap perovskite interface in a p-i-n PSC architecture.
• Characterization of device performance, including power conversion efficiency (PCE) and long-term stability.

Main Results:

• The QxNN interlayer effectively passivates interfacial defects in wide-bandgap PSCs.
• Significant reduction in non-radiative recombination and improved perovskite film quality observed.
• Power conversion efficiency (PCE) increased from 17.5% to 20.0%, with stable performance over 500 hours.

Conclusions:

• The novel quinoxaline-based organic interlayer is highly effective in enhancing wide-bandgap PSC performance.
• The interlayer's high dipole moment boosts the built-in potential, improving charge extraction.
• This strategy offers a promising pathway for developing highly efficient and stable perovskite solar cells.