Vapor-phase Annealing toward Homogeneous Bottom-Up Crystallization in Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Chemical Engineering

Background:

• High-quality perovskite films are crucial for efficient and stable solar devices.
• Inhomogeneous crystallization and interfacial defects hinder perovskite film performance.

Purpose of the Study:

• To introduce a vapor-phase annealing (VPA) strategy for regulating perovskite crystallization kinetics and film morphology.
• To address challenges in achieving uniform crystallization and reducing defects in perovskite films.

Main Methods:

• Vapor-phase annealing (VPA) was employed to create a uniform thermal-humidity field.
• VPA was compared to conventional hot-plate annealing to analyze crystallization differences.
• Additive-free inverted perovskite solar cells were fabricated using VPA-treated films.

Main Results:

• VPA promoted a bottom-up crystallization tendency, contrasting with the top-down mode of hot-plate annealing.
• This led to more homogeneous nucleation, reduced interfacial voids, and complete precursor conversion.
• Perovskite films exhibited improved optoelectronic properties, with solar cells achieving a 22.15% power conversion efficiency (PCE).

Conclusions:

• VPA effectively mitigates crystallization inhomogeneity and interfacial defects in perovskite films.
• The strategy enables high-performance, stable perovskite solar cells.
• VPA offers a scalable approach for advancing perovskite photovoltaic technology.