Atomistic Insights into Halide Double Perovskite Nanocrystals obtained by Multistep Synthesis and Efficient...

Area of Science:

• Materials Science
• Inorganic Chemistry
• Nanotechnology

Background:

• Lead-free halide double perovskites (HDPs) are promising alternatives to toxic lead-based perovskites.
• Cs2B+InCl6 family HDPs offer tunable bandgaps and improved stability.
• Challenges remain in controlled synthesis and understanding structure-property relationships.

Purpose of the Study:

• To present a versatile, multistep, solution-based synthetic strategy for HDP nanocrystals.
• To enable precise control over HDP synthesis and facilitate bandgap engineering.
• To investigate the structural and chemical bonding evolution in specific HDP compositions.

Main Methods:

• Multistep, solution-based synthesis separating precursor dissolution and reaction.
• High-throughput flow chemistry adaptation (multifluidic platforms, automated labs).
• Atomic-scale experimental and theoretical characterization (e.g., X-ray diffraction, spectroscopy, DFT calculations).

Main Results:

• Stable Cs2(Na,Ag)InCl6 and Cs2(Na,K)InCl6 HDP nanocrystals were successfully synthesized.
• Insights into chemical bonding changes upon Na+/Ag+ substitution were obtained.
• Limited K+ miscibility in Cs2(Na,K)InCl6 was linked to distorted K+ coordination.

Conclusions:

• The developed synthetic strategy provides enhanced control and adaptability for HDP production.
• Fundamental structural insights inform the interpretation of HDP optical properties.
• This work lays the groundwork for further bandgap engineering and application of HDPs.