Modulating Crystallization and Defect Passivation by Butyrolactone Molecule for Perovskite Solar Cells

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• High-quality photo-absorbing layers are essential for efficient polycrystalline solar cells.
• Controlling crystallization and elemental distribution in perovskite solar cells (PSCs) via solution processing is challenging.
• Defects and nonradiative recombination limit the performance of PSCs.

Purpose of the Study:

• To introduce a multifunctional molecule, α-amino-γ-butyrolactone (ABL), as a modulator for PSCs.
• To enhance perovskite film quality by improving crystallization and passivating defects.
• To boost the photovoltaic performance and stability of PSCs.

Main Methods:

• Utilizing α-amino-γ-butyrolactone (ABL) as an additive in the perovskite precursor solution.
• Investigating the role of ABL's Lewis base groups in facilitating nucleation and controlling crystallization.
• Analyzing the passivation of Pb²⁺ dangling bonds by ABL to reduce recombination losses.

Main Results:

• ABL addition led to enhanced perovskite crystallinity and defect passivation.
• The passivation of Pb²⁺ dangling bonds reduced recombination and improved carrier dynamics.
• Perovskite solar cells with ABL achieved a conversion efficiency increase from 18.30% to 20.36%.
• Improved long-term environmental stability was observed in ABL-modified PSCs.

Conclusions:

• α-amino-γ-butyrolactone (ABL) is an effective multifunctional modulator for improving PSC performance and stability.
• ABL simultaneously enhances crystallization and passivates critical defects in perovskite films.
• This study provides insights for designing novel additives for perovskite precursor colloids and engineering solar cell components.