Interfacial Passivation Engineering for Highly Efficient Perovskite Solar Cells with a Fill Factor over 83

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Charge carrier nonradiative recombination (NRR) due to interface defects and energy level misalignment hinders perovskite solar cell (PSC) performance.
• Interfacial modification is crucial for suppressing NRR and improving PSC efficiency.

Purpose of the Study:

• To develop novel interfacial materials for PSCs to mitigate NRR and enhance device performance.
• To investigate the impact of phthalimide and benzothiadiazole-dicarboxylicimide based materials on PSC efficiency and stability.

Main Methods:

• Synthesis and characterization of two interfacial materials: PhI-TPA and BTZI-TPA.
• Fabrication and testing of PSCs with and without the developed interfacial layers.
• Analysis of charge carrier dynamics, energy level alignment, and interface interactions.

Main Results:

• BTZI-TPA exhibits higher hole mobility, improved energy level alignment, and stronger interaction with perovskite surface defects compared to PhI-TPA.
• The BTZI-TPA interfacial layer effectively suppresses NRR and carrier accumulation, leading to enhanced open-circuit voltage and fill factor.
• PSCs utilizing BTZI-TPA achieved a peak efficiency of 24.06% with a fill factor of 83.10%, outperforming reference cells (21.47%) and demonstrating scalability (21.45% at 1.00 cm²).

Conclusions:

• The study highlights the potential of imide and thiadiazole functionalities in designing effective interfacial layers for PSCs.
• BTZI-TPA serves as a promising material for enhancing PSC performance through defect passivation and optimized charge transport.
• The developed interfacial strategy offers a pathway towards more efficient and stable perovskite solar cells.