Sr derived synthesis of CsPbX3 nanocrystals for extraordinary stable luminescence

• Highly stable and bright CsPbCl 3 NCs were studied by combining Sr doping at Pb sites via surface passivation. • Sr 2+ reduced lattice defects and enlarged the bandgap to induce a blue-shifted photoluminescence (PL) peak. • Sr:CsPbCl 3 NCs exhibit a PL peak of 405 nm with a remarkable PL quantum yield of 90.7%. • These NCs reveal high stability in ambient conditions, UV light irradiation, and in polar solvents. Low photoluminescence quantum yields (PLQYs) and poor stability limited the application of violet-emitting CsPbCl 3 nanocrystals (NCs). In this paper,highly stable and bright CsPbCl 3 NCs were studied by combining Sr doping at Pb sites with surface passivation using n-octylphosphonic acid (OPA). A novel hot-injection route was developed by employing acetate precursors and chlorotrimethylsilane. Comprehensive characterization revealed that Sr 2+ possessed similar ionic radius with Pb 2+ to effectively reduce lattice defects and enlarge the band gap, thereby inducing a blue-shifted PL peak. Simultaneously, the OPA ligand, leveraging the strong coordination ability of its phosphonic group, binds firmly to surface metal ions, effectively passivating surface defects and forming a hydrophobic barrier. Sr:CsPbCl 3 NCs created using optimized conditions exhibit a PL peak of 405 nm with a remarkable PLQY of 90.7%. The effect of Sr doping on the fluorescence decay kinetics of Sr:CsPbX 3 NCs was discussed. Furthermore, these NCs demonstrate outstanding stability under ambient atmospheric conditions, continuous UV light irradiation, and in polar solvents. This synergistic strategy, integrating internal lattice reinforcement and external surface shielding, was successfully extended to Sr:CsPbBr 3 and Sr:CsPbI 3 NCs, demonstrating its general applicability. Finally, high-quality red, green, and violet-emitting films were fabricated, highlighting the great potential for display applications.