Xinyu Shen, Henry J Snaith
The practical application of perovskite nanocrystals has been hindered by their intrinsic instability, arising from the coupled effects of soft ionic lattices, ion migration, and surface reactions. A hierarchical shell strategy now addresses these intertwined degradation pathways through lattice-interface "interlocking", achieving T90 values exceeding 27,000 h under continuous blue-light exposure. Notably, the resulting hierarchical shell-perovskite nanocrystals enable reliable colour-conversion display prototypes.