Heterostructured Nanocrystal Synthesis with Large Lattice Mismatch by Sacrificial Agent Assisted Method

Heterostructured nanocrystals (HNCs) integrating dissimilar materials offer unprecedented functionalities for optoelectronics and bioimaging, yet their synthesis remains constrained by severe lattice mismatch (>5%) between crystallographically incompatible phases. To overcome this challenge, a sacrificial agent-assisted method is introduced to fabricate high-quality HNCs from materials with incompatible crystal structures and extreme lattice mismatches. Using ZnO nanocrystals as a sacrificial oxygen source, the method demonstrates the epitaxial growth of NaYF₄/YOF HNCs-combining hexagonal phase NaYF₄ and cubic phase YOF with a bulk lattice mismatch of 36%. This strategy suppresses shell self-nucleation and enables facet-selective heteroepitaxy by maintaining an ultra-low monomer concentration. Atomic-resolution characterization reveals a coherent interface between NaYF₄ {100} and YOF {311} planes, reducing the interfacial mismatch to 7.6%. This method operates efficiently across a wide temperature range (300-320 °C) with >92% yield, while morphology is tunable via Na⁺ additives. This approach facilitates the design of advanced metal fluoride/oxide HNCs for photonics, sensing, and catalysis, offering new opportunities for applications where lattice mismatch has previously limited heterostructure development.