Efficient and Stable Perovskite Solar Cells Using Bathocuproine Bilateral-Modified Perovskite Layers

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Surface modification is crucial for improving perovskite solar cell (PSC) performance and stability.
• Interface engineering between perovskite layers and charge transport layers (HTL/ETL) is a common strategy.
• Coordination of modifying materials with perovskite interfaces enhances crystallinity and passivation.

Purpose of the Study:

• To investigate the effect of n-type bathocuproine (BCP) modification on PSC interfaces.
• To evaluate the impact of unilateral and bilateral BCP modification on PSC crystallinity, interface properties, and performance.
• To assess the enhanced stability of PSCs modified with BCP.

Main Methods:

• Modification of perovskite/HTL and/or perovskite/ETL interfaces using bathocuproine (BCP).
• Characterization of perovskite crystallinity and interface contact properties.
• Performance testing of PSCs under different BCP modification strategies (unilateral vs. bilateral).
• Stability assessment of the modified PSCs.

Main Results:

• Unilateral BCP modification improved perovskite crystallinity and interface contact, increasing PCE.
• Bilateral BCP modification further enhanced crystallinity, reduced defects, and improved contact properties.
• PSCs with bilateral BCP modification achieved a higher open-circuit voltage (1.14 V) and fill factor (77.1%).
• Bilateral BCP modification resulted in a significant increase in PCE to 20.6% compared to 17.5% for unmodified PSCs.
• Improved crystal quality and hydrophobic interfaces led to greatly enhanced PSC stability.

Conclusions:

• N-type BCP effectively modifies both perovskite/HTL and perovskite/ETL interfaces, improving PSCs beyond its semiconductor role.
• BCP modification passivates interfaces, enhances contact and hydrophobicity, promotes perovskite crystallinity, and reduces carrier recombination.
• Bilateral BCP modification offers a superior strategy for significantly boosting both the power conversion efficiency and operational stability of perovskite solar cells.