Upconversion Perovskite Nanocrystal Heterostructures with Enhanced Luminescence and Stability by Lattice Matching

Area of Science:

• Materials Science
• Nanotechnology
• Biophotonics

Background:

• Lead halide perovskite quantum dots (PQDs) offer excellent optoelectronic properties but suffer from poor stability and low multiphoton absorption efficiency, limiting their biological applications.
• Combining PQDs with upconversion nanoparticles (UCNPs) creates NIR-excitable, upconverting, and tunable emission materials, but challenges exist in fabricating stable heterostructures with maintained optical properties due to differing crystal structures.

Purpose of the Study:

• To synthesize novel heterostructured UCNP-PQD nanocrystals for enhanced biological applications.
• To improve the stability and optical properties of UCNP-PQD composites by optimizing lattice matching.

Main Methods:

• Synthesis of heterostructured NaYF4 UCNP-CsPbBr1-2X PQD nanocrystals.
• Fabrication of improved CsPbBr3-NaGdF4:Yb,Tm nanocrystals by incorporating Gadolinium (Gd) to enhance lattice matching.
• Characterization of luminescence, stability, and Förster resonance energy transfer (FRET) efficiency.

Main Results:

• Achieved efficient Förster resonance energy transfer (FRET) from UCNPs to PQDs within the heterostructured nanocrystals under NIR excitation.
• Synthesized Gd-modified UCNP-PQD nanocrystals exhibiting significantly enhanced luminescence and stability under various conditions (high temperature, polar solvents, UV light).
• Demonstrated superior performance of the Gd-modified heterostructures compared to non-modified UCNP-PQD nanocrystals and pure PQDs.

Conclusions:

• The developed heterostructured UCNP-PQD nanocrystals offer a promising platform for advanced bioimaging due to their enhanced optical properties and stability.
• Optimizing lattice matching through compositional engineering (e.g., using Gd) is crucial for creating high-performance UCNP-PQD heterostructures.
• These findings pave the way for improved NIR-excitable and stable nanomaterials for diverse biomedical applications.