InCl 3 ‐Assisted Surface Defects Restoring to Enhance Lead‐Free Cs 2 ZrCl 6 Nanocrystals for X‐Ray Imaging and Blue LED Applications

As one type of recent emerging lead-free perovskites, Cs₂ZrCl₆ nanocrystals are widely concerned, benefiting from the eminent designability, high X-ray cutoff efficiency, and favorable stability. Improving the luminescence performance of Cs₂ZrCl₆ nanocrystals has great importance to cater for practical applications. In view of the surface defects frequently formed by the liquid phase method, the particle morphology and surface quality of this material are expected to be regulated if certain intervention is made in the synthesis process. In the work, differing from normal cell lattice modulation based on the ion doping, the grain size and surface morphology of Cs₂ZrCl₆ nanocrystals are optimized via adding a certain amount of InCl₃ to the synthetic solution. The surface defects are restored to inhibit the defect-induced non-radiative transition, resulting in the improvement of the luminescence properties. Moreover, a flexible Cs₂ZrCl₆@polydimethylsiloxane film with excellent heat, water, and bending resistance and a light-emitting diode (LED) device are fabricated, exhibiting excellent application potential for X-ray imaging and blue LED.