Highly Photostable Zn-Treated Halide Perovskite Nanocrystals for Efficient Single Photon Generation

Achieving pure single-photon emission is essential for a range of quantum technologies, from quantum computing to quantum key distribution to quantum metrology. Among solid-state quantum emitters, colloidal lead halide perovskite (LHP) nanocrystals (NCs) have attracted considerable interest due to their structural and optical properties, which make them attractive candidates for single-photon sources (SPSs). However, their practical utilization has been hampered by environment-induced instabilities. In this study, we fabricate and characterize in a systematic manner Zn-treated CsPbBr₃ colloidal NCs obtained through Zn²⁺ ion doping at the Pb-site, demonstrating improved stability under dilution and illumination. The doped NCs exhibit high single-photon purity, reduced blinking on a submillisecond time scale, and stability of the bright state even at excitation powers well above saturation. Our findings highlight the potential of this synthesis approach to optimize the performance of LHP-based SPSs, opening up interesting prospects for their integration into nanophotonic systems for quantum technology applications.