Bottom-Up Defect Modification Through Oily-Allicin Modified Buried Interface Achieving Highly Efficient and Stable...

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) face challenges with buried interface defects, leading to ion migration and reduced efficiency.
• The unexposed bottom interface and grain boundaries in PSCs are critical yet underexplored areas for stability improvements.

Purpose of the Study:

• To develop an effective strategy for passivating defects at the buried interface of PSCs.
• To enhance the operational stability and power conversion efficiency (PCE) of perovskite solar cells.

Main Methods:

• A solid-liquid strategy was employed, introducing oily allicin as an additive at the buried interface.
• Allicin was used to passivate shallow (V_I, V_O) and deep (V_Pb, Pb_I) traps within the perovskite material.
• The additive's ability to fill pinholes and encapsulate perovskite grains was investigated to suppress ion migration.

Main Results:

• The modified PSCs achieved a high power conversion efficiency (PCE) of 25.07% with a fill factor (FF) of 84.03%.
• Devices maintained 94.51% of their initial PCE after 1000 hours of light soaking under 1-sun illumination.
• Allicin effectively suppressed ion migration and passivated interface defects, significantly improving device stability.

Conclusions:

• Introducing oily allicin at the buried interface is a viable method for enhancing PSC performance and stability.
• This eco-friendly approach offers a promising pathway for developing high-performance and durable perovskite solar cells.
• The study highlights the importance of buried interface engineering for advancing photovoltaic technology.