Energetics Modulation for Efficient and Stable n-i-p Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) show promise but suffer from performance degradation under light and voltage bias.
• Mobile ions within the perovskite film are a primary cause of this degradation, leading to ion migration and chemical breakdown.

Purpose of the Study:

• To develop an energetics modulation strategy to improve the operational stability of n-i-p perovskite solar cells.
• To inhibit ion generation and migration, thereby reducing self-accelerating chemical degradation in FAPbI3-based perovskites.

Main Methods:

• Introduction of an electron-withdrawing pyridinecarboxaldehyde oxime (PO) ligand into FAPbI3-based perovskites.
• Modulation of perovskite energetics to increase ionization potential and inhibit mobile ion formation.
• Facilitation of charge transport through improved reactions between PbI2 and organic salts.

Main Results:

• Optimized n-i-p PSCs achieved a high power conversion efficiency of 26.13%.
• The devices maintained over 88% of their initial efficiency after 1000 hours of maximum power point (MPP) tracking under 1 sun illumination.
• The PO ligand effectively suppressed ion generation and migration, crucial for long-term stability.

Conclusions:

• Energetics modulation is a key strategy for inhibiting intrinsic perovskite degradation.
• The developed PO ligand offers a pathway to enhance the commercial viability of perovskite solar cells.
• This approach complements device encapsulation by addressing fundamental material stability issues.