Vertical Interfacial Engineering in Two-Step-Processed Perovskite Films Enabled by Dual-Interface Modification for...

Area of Science:

• Materials Science
• Renewable Energy
• Semiconductor Physics

Background:

• Two-step-processed (TSP) inverted p-i-n perovskite solar cells (PSCs) are promising for tandem applications but face efficiency limitations.
• Residual PbI2 clusters in TSP perovskite films create interfacial energy mismatches, hindering performance.

Purpose of the Study:

• To address efficiency limitations in TSP p-i-n PSCs by engineering the vertical interfaces.
• To investigate the impact of dual-interface modification on perovskite film quality and device performance.

Main Methods:

• Vertical interfacial engineering using tin trifluoromethanesulfonate (Sn(OTF)2) at the NiOx/perovskite interface.
• Dual-interface modification with 4-Fluorophenylethylamine chloride (F-PEA) at the perovskite/C60 interface.
• Characterization of film properties, interfacial energetics, and device performance.

Main Results:

• Sn(OTF)2 enhanced NiOx conductivity, suppressed ion migration, and formed a Pb-Sn mixed perovskite interlayer.
• F-PEA post-treatment passivated surface defects and improved energy-level alignment by forming a 2D perovskite capping layer.
• Optimized TSP p-i-n PSCs achieved a power conversion efficiency (PCE) of 25.6% with enhanced operational stability.

Conclusions:

• Dual-interface modification effectively overcomes limitations caused by residual PbI2 clusters in TSP p-i-n PSCs.
• The study provides design principles for achieving higher efficiencies in perovskite solar cells.
• This work paves the way for developing efficient and stable perovskite solar cells for future energy applications.