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Low Pressure Vapor-assisted Solution Process for Tunable Band Gap Pinhole-free Methylammonium Lead Halide Perovskite Films
Published on: September 8, 2017
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Enhanced Emission in Core@Shell Heterostructure of 3D Halide Double Perovskites.
Rachna Singh1, Ajeet Singh1, Gauri Sharma2,3
1Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
Angewandte Chemie (International Ed. in English)
|September 19, 2025
Summary
Researchers developed a new method to enhance the optical properties of lead-free inorganic metal halide double perovskites (HDPs). This technique creates core@shell nanocrystals, significantly boosting photoluminescence quantum yield (PLQY) for improved performance.
Area of Science:
- Materials Science
- Nanotechnology
- Solid State Chemistry
Background:
- Inorganic metal halide double perovskites (HDPs) offer a non-toxic alternative to lead-based perovskites.
- Current HDPs require improved optical properties for wider applications.
- Core@shell heterostructures are effective for tuning material optical properties.
Purpose of the Study:
- To explore the fabrication of core@shell heterostructures for lead-free HDP nanocrystals (NCs).
- To investigate a facile colloidal technique for growing shells on HDP NCs.
- To enhance the optical properties of Cs2AgBiCl6 NCs.
Main Methods:
- Developed a colloidal technique to grow Cs2NaInCl6 shells on Cs2AgBiCl6 cubic NCs.
- Investigated carrier dynamics using time-resolved photoluminescence (TRPL) and transient absorption (TA).
- Analyzed optical measurements to identify new emissive states.
Main Results:
- Achieved a ten-fold enhancement in photoluminescence quantum yield (PLQY) immediately after shell growth.
- Observed a continuous increase in PLQY over time.
- Identified new emissive states at the core-shell interface, attributed to alloy formation.
- Characterized carrier dynamics, revealing insights into energy transfer and relaxation processes.
Conclusions:
- Demonstrated a facile method for creating core@shell HDP NCs.
- Successfully tuned the optical properties of lead-free HDPs via heterostructure formation.
- The developed technique offers a promising pathway for advancing lead-free perovskite optoelectronics.
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