Ligand‐Free CsPbBr 3 Perovskite Quantum Dots in Silica‐Aerogel Composites with Enhanced Stability for w‐LED and Display by Substituting Pb 2+ with Pr 3+ or Gd 3+ Ions

Colloidal all-inorganic lead halide perovskite nanocrystals (LHP NCs) feature with tunable high-efficiency photoluminescence from blue to red for optoelectronic applications but suffer from instability under water moisture, UV light illumination, high-temperature shock, as well as oxygen erosion. Previous work to improve LHP NCs stability was mainly focused on either glass bulk sealed LHP quantum dots (QDs) with low quantum efficiency, or mesoporous silica matrixes confined LHP QDs with organic ligands still existing. Here, a facile, noncolloidal, ligand-free LHP QDs growth with physical confinement is proposed by integrating the growth of perovskite QDs with the fabrication process of hydrophobic silica-aerogel powders (SAPs). As a result, the as-synthesized mono- and mixed-cesium-lead-halide QDs @ SAPs composites show tunable photoluminescence from purple to deep red. Besides, the Pr3+ ions doped CsPbBr3 QDs @ SAPs composites exhibit moderate quantum efficiency, excellent stability under UV illumination, water moisture as well as temperature variation. Furthermore, performances of white LED device encapsulated Pr3+ doped composite with blue GaN chip and commercial red (Sr, Ca)AlSiN3:Eu2+ phosphor are evaluated. This work demonstrates a facile and general strategy for synthesizing high-stable all-inorganic cesium-lead-halide QDs for applications in white LED and display devices.