Ionic Liquid Modified Polymer Intermediate Layer for Improved Charge Extraction toward Efficient and Stable...

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Monolithic perovskite/silicon tandem solar cells offer high performance but face stability challenges.
• The perovskite/electron transporting layer interface is critical for efficiency and stability, often limited by poor adhesion.
• Current passivation methods using metal fluorides have limitations.

Purpose of the Study:

• To introduce a novel hybrid intermediate layer to improve the stability and efficiency of perovskite/silicon tandem solar cells.
• To address the poor adhesion and charge accumulation issues at the perovskite/C60 interface.
• To enhance the industrial viability of perovskite-based solar devices.

Main Methods:

• A hybrid intermediate layer comprising PMMA (polymethyl methacrylate) functionalized with ionic liquid (IL) was introduced at the perovskite/C60 interface.
• The hydrophobic nature of PMMA was utilized for interfacial stabilization.
• Ionic liquid was incorporated to mitigate charge accumulation between PMMA and perovskite.

Main Results:

• Optimal wide-bandgap perovskite solar cells achieved a power conversion efficiency (PCE) of 20.62%.
• Monolithic perovskite/silicon tandem cells demonstrated an optimized PCE of up to 27.51%.
• The developed cells maintained 90% of their initial efficiency after 1200 hours of continuous illumination, indicating superior stability.

Conclusions:

• The proposed PMMA-IL hybrid intermediate layer significantly enhances the interfacial stability of perovskite/silicon tandem solar cells.
• This approach effectively improves both device efficiency and long-term operational stability.
• The findings represent a significant step towards the commercialization of highly stable and efficient perovskite/silicon tandem solar technology.