Directed Anion Diffusion Induces Defect Passivation in 0D/3D Perovskite Single-Crystal Heterostructures

Area of Science:

• Materials Science
• Solid-State Chemistry
• Optoelectronics

Background:

• 0D/3D perovskite heterostructures are vital for optoelectronic devices.
• Challenges exist in synthesizing these structures with controlled interfaces and understanding defect passivation due to their soft ionic nature.

Purpose of the Study:

• To develop a method for synthesizing pure-phase 0D/3D single-crystal perovskite heterostructures with well-defined interfaces.
• To elucidate the defect passivation mechanisms within these heterostructures.
• To investigate the stability and properties of the synthesized 0D/3D heterostructures.

Main Methods:

• One-step vapor-phase epitaxial growth.
• In situ measurements.
• Theoretical calculations.

Main Results:

• Successfully synthesized pure-phase 0D/3D single-crystal heterostructures with well-defined interfaces.
• Identified bromide anion diffusion from the 0D to the 3D phase as the primary defect passivation mechanism.
• Observed enhanced physical and optical stability in 0D/3D heterostructures compared to pure 3D perovskites.
• Demonstrated a significant reduction in bulk defect density (by an order of magnitude) in 0D/3D heterostructures.

Conclusions:

• The study provides a novel method for fabricating high-quality 0D/3D perovskite heterostructures.
• Bromide anion diffusion is confirmed as an effective self-passivation mechanism in these systems.
• The findings offer critical insights for designing next-generation, high-performance perovskite-based optoelectronic devices.