Realizing Reduced Imperfections via Quantum Dots Interdiffusion in High Efficiency Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Nanotechnology

Background:

• Ionic defects at surfaces and grain boundaries (GBs) in organic-inorganic halide perovskite (OIHP) films hinder solar cell performance.
• Effective passivation of these diverse defects remains a significant challenge in OIHP solar cell development.

Purpose of the Study:

• To introduce a novel solid-state interdiffusion strategy using multi-cation hybrid halide perovskite quantum dots (QDs) for ionic defect healing.
• To investigate the influence of Cs+ distribution within QDs on defect passivation and photovoltaic performance.

Main Methods:

• A solid-state interdiffusion process was employed using multi-cation hybrid halide perovskite QDs.
• Cs+-containing QDs (Cs0.05(MA0.17FA0.83)0.95PbBr3, QDs-Cs5) were specifically utilized to treat OIHP films.
• Photovoltaic performance and stability under continuous illumination were evaluated.

Main Results:

• The solid-state interdiffusion process effectively reduced shallow ionic defects in OIHP films.
• Treatment with QDs-Cs5 significantly enhanced all photovoltaic performance characteristics.
• Power conversion efficiency (PCE) exceeding 21% was achieved.
• Over 90% of the initial PCE was retained after 550 hours of continuous illumination, demonstrating improved stability.

Conclusions:

• Multi-cation hybrid halide perovskite QDs are effective for passivating ionic defects in OIHP solar cells.
• The Cs+ content in QDs plays a crucial role in enhancing passivation efficacy and device performance.
• This QD-based strategy offers a promising route to high-efficiency and stable OIHP solar cells.