KCl-Mediated Defect Passivation in Vapor-Deposited Perovskites

Area of Science:

• Materials Science
• Renewable Energy
• Solid-State Physics

Background:

• Perovskite solar cells (PSCs) show comparable efficiencies to silicon solar panels.
• Key limitations for PSCs include defect-related nonradiative recombination, reproducibility issues, and scalability challenges associated with wet deposition methods.

Purpose of the Study:

• To investigate defect passivation in perovskite layers using potassium salt (KCl) during vapor deposition.
• To understand the impact of KCl on perovskite properties and photoluminescence.

Main Methods:

• Perovskite vapor deposition with KCl addition.
• Real-time photoluminescence (PL) intensity measurements.
• Grazing-incidence wide/small-angle X-ray scattering (GI-WAXS/SAXS) for structural analysis.

Main Results:

• KCl addition led to effective defect passivation, evidenced by a significant and immediate increase in real-time PL intensity.
• The passivation efficiency correlated with the ionic nature and flux density of the potassium salt.
• No significant changes in the perovskite's crystallographic structure or texture were observed.

Conclusions:

• Potassium salt is a viable additive for defect passivation in vapor-deposited perovskite layers.
• This strategy offers a promising route to enhance PSC performance and address scalability concerns.
• The findings have broad implications for various perovskite compositions and device architectures.