Interfacial Engineering via Polishing and Dipolar Synergy Toward Efficient Inverted CsPbI₃ Perovskite Solar Cells.

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Cesium lead triiodide perovskite (CsPbI3) shows promise for high-efficiency perovskite solar cells (PSCs).
• Device performance is limited by lead-poor surfaces and interfacial energy level mismatch.
• Existing challenges hinder PSCs from reaching their theoretical efficiency limits.

Purpose of the Study:

• To improve the efficiency and stability of CsPbI3-based PSCs.
• To address the lead-poor surface and energy level mismatch issues in CsPbI3 solar cells.
• To develop a synergistic surface treatment for CsPbI3 perovskite layers.

Main Methods:

• A synergistic strategy combining surface polishing and interfacial dipolar modulation was employed.
• 1,4-butanediamine (BDA) was used as a polishing agent.
• Pentafluorobenzoic acid (5-FBA) was utilized as a dipolar agent to modify the perovskite interface.

Main Results:

• Inverted CsPbI3-based PSCs achieved a peak power conversion efficiency (PCE) of 20.71%.
• The modified devices demonstrated a significantly improved fill factor (FF) of 83.92%.
• Devices treated with BDA+5-FBA retained over 99% of their initial efficiency after 1200 hours of storage.

Conclusions:

• The synergistic surface treatment effectively enhances CsPbI3 perovskite solar cell performance.
• The BDA+5-FBA modification strategy offers a promising route for developing efficient and stable PSCs.
• This approach overcomes key limitations in CsPbI3-based photovoltaic devices.