Tailored colloidal size and crystallization kinetics for high-efficiency carbon-based perovskite solar cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite solar cells (PSCs) offer high potential but face commercialization hurdles.
• Non-uniform crystallization and defects in perovskite films impede performance.
• Disordered colloidal aggregation and rapid crystallization are key challenges.

Purpose of the Study:

• To develop a novel crystallization approach for perovskite films.
• To enhance the uniformity and reduce defects in perovskite layers.
• To improve the efficiency and stability of carbon-based CsPbBr₃ PSCs.

Main Methods:

• Incorporation of methylenediammonium chloride (MDACl₂) and rubidium chloride (RbCl) into PbBr₂ precursor solutions.
• Utilizing the acidic environment from MDACl₂ decomposition to control colloid size and stability.
• Employing Rb⁺ ions as crystal growth inhibitors to manage crystallization rates.

Main Results:

• Achieved smaller, more uniform colloid sizes due to MDACl₂.
• Enhanced colloid stability through complex formation between MDACl₂ decomposition products and Pb²⁺.
• Produced PbBr₂ films with uniform pores, enabling large-grain, low-defect perovskite formation.
• Carbon-based CsPbBr₃ PSCs reached a record 11.36% power conversion efficiency (PCE).
• Demonstrated excellent operational stability, retaining over 96.4% PCE after 488 hours of continuous illumination.

Conclusions:

• The novel crystallization method significantly improves perovskite film quality.
• This approach leads to record efficiencies and enhanced stability in CsPbBr₃ PSCs.
• The findings pave the way for commercializing high-performance perovskite solar technology.